commands: use completion from go-opt

Implement command completion with complete struct field tags from the
get-opt library introduced earlier.

Changelog-changed: Improved command completion.
Signed-off-by: Robin Jarry <robin@jarry.cc>
Reviewed-by: Koni Marti <koni.marti@gmail.com>
Tested-by: Moritz Poldrack <moritz@poldrack.dev>
Tested-by: Inwit <inwit@sindominio.net>

81 files changed, 197 insertions, 968 deletions

diff --git a/commands/account/cf.go b/commands/account/cf.go
index 59203a89..d73d4978 100644
--- a/commands/account/cf.go
+++ b/commands/account/cf.go
@@ -11,7 +11,7 @@ import (
 var history map[string]string
 
 type ChangeFolder struct {
-	Folder string `opt:"..." metavar:"<folder>"`
+	Folder string `opt:"folder" complete:"CompleteFolder"`
 }
 
 func init() {
@@ -23,8 +23,8 @@ func (ChangeFolder) Aliases() []string {
 	return []string{"cf"}
 }
 
-func (ChangeFolder) Complete(args []string) []string {
-	return commands.GetFolders(args)
+func (*ChangeFolder) CompleteFolder(arg string) []string {
+	return commands.GetFolders(arg)
 }
 
 func (c ChangeFolder) Execute(args []string) error {
diff --git a/commands/account/check-mail.go b/commands/account/check-mail.go
index a8d80a66..d31b2648 100644
--- a/commands/account/check-mail.go
+++ b/commands/account/check-mail.go
@@ -16,10 +16,6 @@ func (CheckMail) Aliases() []string {
 	return []string{"check-mail"}
 }
 
-func (CheckMail) Complete(args []string) []string {
-	return nil
-}
-
 func (CheckMail) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/clear.go b/commands/account/clear.go
index fd209d07..dec6bcd2 100644
--- a/commands/account/clear.go
+++ b/commands/account/clear.go
@@ -19,10 +19,6 @@ func (Clear) Aliases() []string {
 	return []string{"clear"}
 }
 
-func (Clear) Complete(args []string) []string {
-	return nil
-}
-
 func (c Clear) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/compose.go b/commands/account/compose.go
index 81eb3de0..fe86a179 100644
--- a/commands/account/compose.go
+++ b/commands/account/compose.go
@@ -11,12 +11,13 @@ import (
 	"github.com/emersion/go-message/mail"
 
 	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
 	"git.sr.ht/~rjarry/aerc/config"
 )
 
 type Compose struct {
 	Headers  string `opt:"-H" action:"ParseHeader"`
-	Template string `opt:"-T"`
+	Template string `opt:"-T" complete:"CompleteTemplate"`
 	Edit     bool   `opt:"-e"`
 	NoEdit   bool   `opt:"-E"`
 	Body     string `opt:"..." required:"false"`
@@ -37,12 +38,12 @@ func (c *Compose) ParseHeader(arg string) error {
 	return nil
 }
 
-func (Compose) Aliases() []string {
-	return []string{"compose"}
+func (*Compose) CompleteTemplate(arg string) []string {
+	return commands.GetTemplates(arg)
 }
 
-func (Compose) Complete(args []string) []string {
-	return nil
+func (Compose) Aliases() []string {
+	return []string{"compose"}
 }
 
 func (c Compose) Execute(args []string) error {
diff --git a/commands/account/connection.go b/commands/account/connection.go
index b9cd887b..d633c1ce 100644
--- a/commands/account/connection.go
+++ b/commands/account/connection.go
@@ -18,10 +18,6 @@ func (Connection) Aliases() []string {
 	return []string{"connect", "disconnect"}
 }
 
-func (Connection) Complete(args []string) []string {
-	return nil
-}
-
 func (c Connection) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/expand-folder.go b/commands/account/expand-folder.go
index f26da70a..c264872a 100644
--- a/commands/account/expand-folder.go
+++ b/commands/account/expand-folder.go
@@ -16,10 +16,6 @@ func (ExpandCollapseFolder) Aliases() []string {
 	return []string{"expand-folder", "collapse-folder"}
 }
 
-func (ExpandCollapseFolder) Complete(args []string) []string {
-	return nil
-}
-
 func (ExpandCollapseFolder) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/export-mbox.go b/commands/account/export-mbox.go
index 00e03ca6..14d9290e 100644
--- a/commands/account/export-mbox.go
+++ b/commands/account/export-mbox.go
@@ -17,7 +17,7 @@ import (
 )
 
 type ExportMbox struct {
-	Filename string `opt:"filename"`
+	Filename string `opt:"filename" complete:"CompleteFilename"`
 }
 
 func init() {
@@ -28,8 +28,8 @@ func (ExportMbox) Aliases() []string {
 	return []string{"export-mbox"}
 }
 
-func (ExportMbox) Complete(args []string) []string {
-	return commands.CompletePath(filepath.Join(args...))
+func (*ExportMbox) CompleteFilename(arg string) []string {
+	return commands.CompletePath(arg)
 }
 
 func (e ExportMbox) Execute(args []string) error {
diff --git a/commands/account/import-mbox.go b/commands/account/import-mbox.go
index b3ad2a08..774dfa8f 100644
--- a/commands/account/import-mbox.go
+++ b/commands/account/import-mbox.go
@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"path/filepath"
 	"sync/atomic"
 	"time"
 
@@ -19,7 +18,7 @@ import (
 )
 
 type ImportMbox struct {
-	Filename string `opt:"filename"`
+	Filename string `opt:"filename" complete:"CompleteFilename"`
 }
 
 func init() {
@@ -30,8 +29,8 @@ func (ImportMbox) Aliases() []string {
 	return []string{"import-mbox"}
 }
 
-func (ImportMbox) Complete(args []string) []string {
-	return commands.CompletePath(filepath.Join(args...))
+func (*ImportMbox) CompleteFilename(arg string) []string {
+	return commands.CompletePath(arg)
 }
 
 func (i ImportMbox) Execute(args []string) error {
diff --git a/commands/account/mkdir.go b/commands/account/mkdir.go
index 9beeb01a..3e546ace 100644
--- a/commands/account/mkdir.go
+++ b/commands/account/mkdir.go
@@ -2,15 +2,15 @@ package account
 
 import (
 	"errors"
-	"strings"
 	"time"
 
 	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
 	"git.sr.ht/~rjarry/aerc/worker/types"
 )
 
 type MakeDir struct {
-	Folder string `opt:"..." metavar:"<folder>"`
+	Folder string `opt:"folder" complete:"CompleteFolder"`
 }
 
 func init() {
@@ -21,26 +21,15 @@ func (MakeDir) Aliases() []string {
 	return []string{"mkdir"}
 }
 
-func (MakeDir) Complete(args []string) []string {
-	if len(args) == 0 {
+func (*MakeDir) CompleteFolder(arg string) []string {
+	acct := app.SelectedAccount()
+	if acct == nil {
 		return nil
 	}
-	name := strings.Join(args, " ")
-
-	list := app.SelectedAccount().Directories().List()
-	inboxes := make([]string, len(list))
-	copy(inboxes, list)
-
-	// remove inboxes that don't match and append the path separator to all
-	// others
-	for i := len(inboxes) - 1; i >= 0; i-- {
-		if !strings.HasPrefix(inboxes[i], name) && name != "" {
-			inboxes = append(inboxes[:i], inboxes[i+1:]...)
-			continue
-		}
-		inboxes[i] += app.SelectedAccount().Worker().PathSeparator()
-	}
-	return inboxes
+	return commands.FilterList(
+		acct.Directories().List(), arg, "",
+		app.SelectedAccount().Worker().PathSeparator(),
+		app.SelectedAccountUiConfig().FuzzyComplete)
 }
 
 func (m MakeDir) Execute(args []string) error {
diff --git a/commands/account/next-folder.go b/commands/account/next-folder.go
index 1b5651c8..f44abdc1 100644
--- a/commands/account/next-folder.go
+++ b/commands/account/next-folder.go
@@ -18,10 +18,6 @@ func (NextPrevFolder) Aliases() []string {
 	return []string{"next-folder", "prev-folder"}
 }
 
-func (NextPrevFolder) Complete(args []string) []string {
-	return nil
-}
-
 func (np NextPrevFolder) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/next-result.go b/commands/account/next-result.go
index e841899f..d624e559 100644
--- a/commands/account/next-result.go
+++ b/commands/account/next-result.go
@@ -17,10 +17,6 @@ func (NextPrevResult) Aliases() []string {
 	return []string{"next-result", "prev-result"}
 }
 
-func (NextPrevResult) Complete(args []string) []string {
-	return nil
-}
-
 func (NextPrevResult) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/next.go b/commands/account/next.go
index 14679b1b..142f6151 100644
--- a/commands/account/next.go
+++ b/commands/account/next.go
@@ -35,10 +35,6 @@ func (NextPrevMsg) Aliases() []string {
 	return []string{"next", "next-message", "prev", "prev-message"}
 }
 
-func (NextPrevMsg) Complete(args []string) []string {
-	return nil
-}
-
 func (np NextPrevMsg) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/recover.go b/commands/account/recover.go
index dae3d807..cba6e0cb 100644
--- a/commands/account/recover.go
+++ b/commands/account/recover.go
@@ -16,7 +16,7 @@ type Recover struct {
 	Force  bool   `opt:"-f"`
 	Edit   bool   `opt:"-e"`
 	NoEdit bool   `opt:"-E"`
-	File   string `opt:"file"`
+	File   string `opt:"file" complete:"CompleteFile"`
 }
 
 func init() {
@@ -31,7 +31,7 @@ func (Recover) Options() string {
 	return "feE"
 }
 
-func (r Recover) Complete(args []string) []string {
+func (*Recover) CompleteFile(arg string) []string {
 	// file name of temp file is hard-coded in the NewComposer() function
 	files, err := filepath.Glob(
 		filepath.Join(os.TempDir(), "aerc-compose-*.eml"),
@@ -39,8 +39,7 @@ func (r Recover) Complete(args []string) []string {
 	if err != nil {
 		return nil
 	}
-	return commands.CompletionFromList(files,
-		commands.Operands(args, r.Options()))
+	return commands.CompletionFromList(files, arg)
 }
 
 func (r Recover) Execute(args []string) error {
diff --git a/commands/account/rmdir.go b/commands/account/rmdir.go
index 36bfc699..398f375f 100644
--- a/commands/account/rmdir.go
+++ b/commands/account/rmdir.go
@@ -20,10 +20,6 @@ func (RemoveDir) Aliases() []string {
 	return []string{"rmdir"}
 }
 
-func (RemoveDir) Complete(args []string) []string {
-	return nil
-}
-
 func (r RemoveDir) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/search.go b/commands/account/search.go
index bb5617c0..ca1b9684 100644
--- a/commands/account/search.go
+++ b/commands/account/search.go
@@ -23,12 +23,12 @@ type SearchFilter struct {
 	Body         bool                 `opt:"-b"`
 	All          bool                 `opt:"-a"`
 	Headers      textproto.MIMEHeader `opt:"-H" action:"ParseHeader" metavar:"<header>:<value>"`
-	WithFlags    models.Flags         `opt:"-x" action:"ParseFlag"`
-	WithoutFlags models.Flags         `opt:"-X" action:"ParseNotFlag"`
-	To           []string             `opt:"-t" action:"ParseTo"`
-	From         []string             `opt:"-f" action:"ParseFrom"`
-	Cc           []string             `opt:"-c" action:"ParseCc"`
-	StartDate    time.Time            `opt:"-d" action:"ParseDate"`
+	WithFlags    models.Flags         `opt:"-x" action:"ParseFlag" complete:"CompleteFlag"`
+	WithoutFlags models.Flags         `opt:"-X" action:"ParseNotFlag" complete:"CompleteFlag"`
+	To           []string             `opt:"-t" action:"ParseTo" complete:"CompleteAddress"`
+	From         []string             `opt:"-f" action:"ParseFrom" complete:"CompleteAddress"`
+	Cc           []string             `opt:"-c" action:"ParseCc" complete:"CompleteAddress"`
+	StartDate    time.Time            `opt:"-d" action:"ParseDate" complete:"CompleteDate"`
 	EndDate      time.Time
 	Terms        string `opt:"..." required:"false"`
 }
@@ -37,33 +37,20 @@ func init() {
 	register(SearchFilter{})
 }
 
-func (SearchFilter) Options() string {
-	return "rubax:X:t:H:f:c:d:"
-}
-
 func (SearchFilter) Aliases() []string {
 	return []string{"search", "filter"}
 }
 
-func (s SearchFilter) CompleteOption(
-	r rune,
-	search string,
-) []string {
-	var valid []string
-	switch r {
-	case 'x', 'X':
-		valid = commands.GetFlagList()
-	case 't', 'f', 'c':
-		valid = commands.GetAddress(search)
-	case 'd':
-		valid = commands.GetDateList()
-	default:
-	}
-	return commands.CompletionFromList(valid, []string{search})
+func (*SearchFilter) CompleteFlag(arg string) []string {
+	return commands.CompletionFromList(commands.GetFlagList(), arg)
 }
 
-func (SearchFilter) Complete(args []string) []string {
-	return nil
+func (*SearchFilter) CompleteAddress(arg string) []string {
+	return commands.CompletionFromList(commands.GetAddress(arg), arg)
+}
+
+func (*SearchFilter) CompleteDate(arg string) []string {
+	return commands.CompletionFromList(commands.GetDateList(), arg)
 }
 
 func (s *SearchFilter) ParseRead(arg string) error {
diff --git a/commands/account/select.go b/commands/account/select.go
index efd8f53b..884b4bce 100644
--- a/commands/account/select.go
+++ b/commands/account/select.go
@@ -18,10 +18,6 @@ func (SelectMessage) Aliases() []string {
 	return []string{"select", "select-message"}
 }
 
-func (SelectMessage) Complete(args []string) []string {
-	return nil
-}
-
 func (s SelectMessage) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/sort.go b/commands/account/sort.go
index 2adfbf19..ccccab25 100644
--- a/commands/account/sort.go
+++ b/commands/account/sort.go
@@ -2,7 +2,6 @@ package account
 
 import (
 	"errors"
-	"strings"
 
 	"git.sr.ht/~rjarry/aerc/app"
 	"git.sr.ht/~rjarry/aerc/commands"
@@ -13,6 +12,9 @@ import (
 
 type Sort struct {
 	Unused struct{} `opt:"-"`
+	// these fields are only used for completion
+	Reverse  bool     `opt:"-r"`
+	Criteria []string `opt:"criteria" complete:"CompleteCriteria"`
 }
 
 func init() {
@@ -23,46 +25,20 @@ func (Sort) Aliases() []string {
 	return []string{"sort"}
 }
 
-func (Sort) Complete(args []string) []string {
-	supportedCriteria := []string{
-		"arrival",
-		"cc",
-		"date",
-		"from",
-		"read",
-		"size",
-		"subject",
-		"to",
-		"flagged",
-	}
-	if len(args) == 0 {
-		return supportedCriteria
-	}
-	last := args[len(args)-1]
-	var completions []string
-	currentPrefix := strings.Join(args, " ") + " "
-	// if there is a completed criteria or option then suggest all again
-	for _, criteria := range append(supportedCriteria, "-r") {
-		if criteria == last {
-			for _, criteria := range supportedCriteria {
-				completions = append(completions, currentPrefix+criteria)
-			}
-			return completions
-		}
-	}
+var supportedCriteria = []string{
+	"arrival",
+	"cc",
+	"date",
+	"from",
+	"read",
+	"size",
+	"subject",
+	"to",
+	"flagged",
+}
 
-	currentPrefix = strings.Join(args[:len(args)-1], " ")
-	if len(args) > 1 {
-		currentPrefix += " "
-	}
-	// last was beginning an option
-	if last == "-" {
-		return []string{currentPrefix + "-r"}
-	}
-	// the last item is not complete
-	completions = commands.FilterList(supportedCriteria, last, currentPrefix,
-		app.SelectedAccountUiConfig().FuzzyComplete)
-	return completions
+func (*Sort) CompleteCriteria(arg string) []string {
+	return commands.CompletionFromList(supportedCriteria, arg)
 }
 
 func (Sort) Execute(args []string) error {
diff --git a/commands/account/split.go b/commands/account/split.go
index 4774297f..8690d99a 100644
--- a/commands/account/split.go
+++ b/commands/account/split.go
@@ -33,10 +33,6 @@ func (Split) Aliases() []string {
 	return []string{"split", "vsplit", "hsplit"}
 }
 
-func (Split) Complete(args []string) []string {
-	return nil
-}
-
 func (s Split) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/account/view.go b/commands/account/view.go
index 701a7738..0cdc175d 100644
--- a/commands/account/view.go
+++ b/commands/account/view.go
@@ -19,10 +19,6 @@ func (ViewMessage) Aliases() []string {
 	return []string{"view-message", "view"}
 }
 
-func (ViewMessage) Complete(args []string) []string {
-	return nil
-}
-
 func (v ViewMessage) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/cd.go b/commands/cd.go
index 6620e732..d2dc5310 100644
--- a/commands/cd.go
+++ b/commands/cd.go
@@ -12,7 +12,7 @@ import (
 var previousDir string
 
 type ChangeDirectory struct {
-	Target string `opt:"directory" default:"~"`
+	Target string `opt:"directory" default:"~" complete:"CompleteTarget"`
 }
 
 func init() {
@@ -23,9 +23,8 @@ func (ChangeDirectory) Aliases() []string {
 	return []string{"cd"}
 }
 
-func (ChangeDirectory) Complete(args []string) []string {
-	path := strings.Join(args, " ")
-	completions := CompletePath(path)
+func (*ChangeDirectory) CompleteTarget(arg string) []string {
+	completions := CompletePath(arg)
 
 	var dirs []string
 	for _, c := range completions {
diff --git a/commands/choose.go b/commands/choose.go
index 4e2007fd..19958dce 100644
--- a/commands/choose.go
+++ b/commands/choose.go
@@ -18,10 +18,6 @@ func (Choose) Aliases() []string {
 	return []string{"choose"}
 }
 
-func (Choose) Complete(args []string) []string {
-	return nil
-}
-
 func (Choose) Execute(args []string) error {
 	if len(args) < 5 || len(args)%4 != 1 {
 		return chooseUsage(args[0])
diff --git a/commands/commands.go b/commands/commands.go
index d76194af..9c193018 100644
--- a/commands/commands.go
+++ b/commands/commands.go
@@ -3,12 +3,13 @@ package commands
 import (
 	"bytes"
 	"errors"
+	"path"
 	"reflect"
+	"sort"
 	"strings"
 	"unicode"
 
 	"git.sr.ht/~rjarry/go-opt"
-	"github.com/google/shlex"
 
 	"git.sr.ht/~rjarry/aerc/app"
 	"git.sr.ht/~rjarry/aerc/config"
@@ -21,17 +22,6 @@ import (
 type Command interface {
 	Aliases() []string
 	Execute([]string) error
-	Complete([]string) []string
-}
-
-type OptionsProvider interface {
-	Command
-	Options() string
-}
-
-type OptionCompleter interface {
-	OptionsProvider
-	CompleteOption(rune, string) []string
 }
 
 type Commands map[string]Command
@@ -174,6 +164,7 @@ func GetTemplateCompletion(
 			templates.Terms(),
 			strings.TrimSpace(search),
 			"",
+			"",
 			app.SelectedAccountUiConfig().FuzzyComplete,
 		)
 		return options, prefix + padding, true
@@ -194,117 +185,62 @@ func GetTemplateCompletion(
 func GetCompletions(
 	cmd Command, args *opt.Args,
 ) (options []string, prefix string) {
-	// complete options
-	var spec string
-	if provider, ok := cmd.(OptionsProvider); ok {
-		spec = provider.Options()
-	}
-
-	parser, err := newParser(args.String(), spec, strings.HasSuffix(args.String(), " "))
-	if err != nil {
-		log.Debugf("completion parser failed: %v", err)
-		return
-	}
-
-	switch parser.kind {
-	case SHORT_OPTION:
-		for _, r := range strings.ReplaceAll(spec, ":", "") {
-			if strings.ContainsRune(parser.flag, r) {
-				continue
-			}
-			option := string(r)
-			if strings.Contains(spec, option+":") {
-				option += " "
-			}
-			options = append(options, option)
-		}
-		prefix = args.String()
-	case OPTION_ARGUMENT:
-		cmpl, ok := cmd.(OptionCompleter)
-		if !ok {
-			return
-		}
-		stem := args.String()
-		if parser.arg != "" {
-			stem = strings.TrimSuffix(stem, parser.arg)
-		}
-		pad := ""
-		if !strings.HasSuffix(stem, " ") {
-			pad += " "
-		}
-		s := parser.flag
-		r := rune(s[len(s)-1])
-		for _, option := range cmpl.CompleteOption(r, parser.arg) {
-			options = append(options, pad+escape(option)+" ")
-		}
-		prefix = stem
-	case OPERAND:
-		clone := args.Clone()
-		clone.Cut(clone.Count() - parser.optind)
-		args.Shift(1)
-		for _, option := range cmd.Complete(args.Args()) {
-			if strings.Contains(option, "  ") {
-				option = escape(option)
-			}
-			options = append(options, " "+option)
-		}
-		prefix = clone.String()
-	}
-
-	return
+	// copy zeroed struct
+	tmp := reflect.New(reflect.TypeOf(cmd)).Interface().(Command)
+	spec := opt.NewCmdSpec(args.Arg(0), tmp)
+	return spec.GetCompletions(args)
 }
 
-func GetFolders(args []string) []string {
+func GetFolders(arg string) []string {
 	acct := app.SelectedAccount()
 	if acct == nil {
 		return make([]string, 0)
 	}
-	if len(args) == 0 {
-		return acct.Directories().List()
-	}
-	return FilterList(acct.Directories().List(), args[0], "", acct.UiConfig().FuzzyComplete)
+	return CompletionFromList(acct.Directories().List(), arg)
 }
 
-// CompletionFromList provides a convenience wrapper for commands to use in the
-// Complete function. It simply matches the items provided in valid
-func CompletionFromList(valid []string, args []string) []string {
-	if len(args) == 0 {
-		return valid
+func GetTemplates(arg string) []string {
+	templates := make(map[string]bool)
+	for _, dir := range config.Templates.TemplateDirs {
+		for _, f := range listDir(dir, false) {
+			if !isDir(path.Join(dir, f)) {
+				templates[f] = true
+			}
+		}
+	}
+	names := make([]string, len(templates))
+	for n := range templates {
+		names = append(names, n)
 	}
-	return FilterList(valid, args[0], "", app.SelectedAccountUiConfig().FuzzyComplete)
+	sort.Strings(names)
+	return CompletionFromList(names, arg)
 }
 
-func GetLabels(args []string) []string {
+// CompletionFromList provides a convenience wrapper for commands to use in a
+// complete callback. It simply matches the items provided in valid
+func CompletionFromList(valid []string, arg string) []string {
+	return FilterList(valid, arg, "", "", app.SelectedAccountUiConfig().FuzzyComplete)
+}
+
+func GetLabels(arg string) []string {
 	acct := app.SelectedAccount()
 	if acct == nil {
 		return make([]string, 0)
 	}
-	if len(args) == 0 {
-		return acct.Labels()
-	}
-
-	// + and - are used to denote tag addition / removal and need to be striped
-	// only the last tag should be completed, so that multiple labels can be
-	// selected
-	last := args[len(args)-1]
-	others := strings.Join(args[:len(args)-1], " ")
 	var prefix string
-	switch last[0] {
-	case '+':
-		prefix = "+"
-	case '-':
-		prefix = "-"
-	default:
-		prefix = ""
-	}
-	trimmed := strings.TrimLeft(last, "+-")
-
-	var prev string
-	if len(others) > 0 {
-		prev = others + " "
+	if arg != "" {
+		// + and - are used to denote tag addition / removal and need to
+		// be striped only the last tag should be completed, so that
+		// multiple labels can be selected
+		switch arg[0] {
+		case '+':
+			prefix = "+"
+		case '-':
+			prefix = "-"
+		}
+		arg = strings.TrimLeft(arg, "+-")
 	}
-	out := FilterList(acct.Labels(), trimmed, prev+prefix, acct.UiConfig().FuzzyComplete)
-	return out
+	return FilterList(acct.Labels(), arg, prefix, " ", acct.UiConfig().FuzzyComplete)
 }
 
 // hasCaseSmartPrefix checks whether s starts with prefix, using a case
@@ -324,19 +260,3 @@ func hasUpper(s string) bool {
 	}
 	return false
 }
-
-// splitCmd splits the command into arguments
-func splitCmd(cmd string) ([]string, error) {
-	args, err := shlex.Split(cmd)
-	if err != nil {
-		return nil, err
-	}
-	return args, nil
-}
-
-func escape(s string) string {
-	if strings.Contains(s, " ") {
-		return strings.ReplaceAll(s, " ", "\\ ")
-	}
-	return s
-}
diff --git a/commands/compose/abort.go b/commands/compose/abort.go
index 4bacb9c3..cde43f46 100644
--- a/commands/compose/abort.go
+++ b/commands/compose/abort.go
@@ -14,10 +14,6 @@ func (Abort) Aliases() []string {
 	return []string{"abort"}
 }
 
-func (Abort) Complete(args []string) []string {
-	return nil
-}
-
 func (Abort) Execute(args []string) error {
 	composer, _ := app.SelectedTabContent().(*app.Composer)
 	app.RemoveTab(composer, true)
diff --git a/commands/compose/attach-key.go b/commands/compose/attach-key.go
index e81a6a5a..6ba5eae0 100644
--- a/commands/compose/attach-key.go
+++ b/commands/compose/attach-key.go
@@ -14,10 +14,6 @@ func (AttachKey) Aliases() []string {
 	return []string{"attach-key"}
 }
 
-func (AttachKey) Complete(args []string) []string {
-	return nil
-}
-
 func (AttachKey) Execute(args []string) error {
 	composer, _ := app.SelectedTabContent().(*app.Composer)
 	return composer.SetAttachKey(!composer.AttachKey())
diff --git a/commands/compose/attach.go b/commands/compose/attach.go
index 3acf28c2..49d63bb8 100644
--- a/commands/compose/attach.go
+++ b/commands/compose/attach.go
@@ -23,7 +23,8 @@ import (
 type Attach struct {
 	Menu bool   `opt:"-m"`
 	Name string `opt:"-r"`
-	Path string `opt:"..." metavar:"<path>" required:"false"`
+	Path string `opt:"path" required:"false" complete:"CompletePath"`
+	Args string `opt:"..." required:"false"`
 }
 
 func init() {
@@ -34,9 +35,8 @@ func (Attach) Aliases() []string {
 	return []string{"attach"}
 }
 
-func (Attach) Complete(args []string) []string {
-	path := strings.Join(args, " ")
-	return commands.CompletePath(path)
+func (*Attach) CompletePath(arg string) []string {
+	return commands.CompletePath(arg)
 }
 
 func (a Attach) Execute(args []string) error {
@@ -52,6 +52,9 @@ func (a Attach) Execute(args []string) error {
 		}
 		return a.readCommand()
 	default:
+		if a.Args != "" {
+			return errors.New("only a single path is supported")
+		}
 		return a.addPath(a.Path)
 	}
 }
@@ -186,7 +189,7 @@ func (a Attach) openMenu() error {
 }
 
 func (a Attach) readCommand() error {
-	cmd := exec.Command("sh", "-c", a.Path)
+	cmd := exec.Command("sh", "-c", a.Path+" "+a.Args)
 
 	data, err := cmd.Output()
 	if err != nil {
diff --git a/commands/compose/cc-bcc.go b/commands/compose/cc-bcc.go
index aeb6af97..dd5e9614 100644
--- a/commands/compose/cc-bcc.go
+++ b/commands/compose/cc-bcc.go
@@ -16,10 +16,6 @@ func (CC) Aliases() []string {
 	return []string{"cc", "bcc"}
 }
 
-func (CC) Complete(args []string) []string {
-	return nil
-}
-
 func (c CC) Execute(args []string) error {
 	composer, _ := app.SelectedTabContent().(*app.Composer)
 
diff --git a/commands/compose/detach.go b/commands/compose/detach.go
index a2996516..91cf2a58 100644
--- a/commands/compose/detach.go
+++ b/commands/compose/detach.go
@@ -4,10 +4,11 @@ import (
 	"fmt"
 
 	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
 )
 
 type Detach struct {
-	Path string `opt:"path" required:"false"`
+	Path string `opt:"path" required:"false" complete:"CompletePath"`
 }
 
 func init() {
@@ -18,9 +19,9 @@ func (Detach) Aliases() []string {
 	return []string{"detach"}
 }
 
-func (Detach) Complete(args []string) []string {
+func (*Detach) CompletePath(arg string) []string {
 	composer, _ := app.SelectedTabContent().(*app.Composer)
-	return composer.GetAttachments()
+	return commands.CompletionFromList(composer.GetAttachments(), arg)
 }
 
 func (d Detach) Execute(args []string) error {
diff --git a/commands/compose/edit.go b/commands/compose/edit.go
index 80f4e6f4..1929f45a 100644
--- a/commands/compose/edit.go
+++ b/commands/compose/edit.go
@@ -20,10 +20,6 @@ func (Edit) Aliases() []string {
 	return []string{"edit"}
 }
 
-func (Edit) Complete(args []string) []string {
-	return nil
-}
-
 func (e Edit) Execute(args []string) error {
 	composer, ok := app.SelectedTabContent().(*app.Composer)
 	if !ok {
diff --git a/commands/compose/encrypt.go b/commands/compose/encrypt.go
index 3121dff0..ee902f6e 100644
--- a/commands/compose/encrypt.go
+++ b/commands/compose/encrypt.go
@@ -14,10 +14,6 @@ func (Encrypt) Aliases() []string {
 	return []string{"encrypt"}
 }
 
-func (Encrypt) Complete(args []string) []string {
-	return nil
-}
-
 func (Encrypt) Execute(args []string) error {
 	composer, _ := app.SelectedTabContent().(*app.Composer)
 	composer.SetEncrypt(!composer.Encrypt())
diff --git a/commands/compose/header.go b/commands/compose/header.go
index aaa14e43..afc27e92 100644
--- a/commands/compose/header.go
+++ b/commands/compose/header.go
@@ -11,7 +11,7 @@ import (
 type Header struct {
 	Force  bool   `opt:"-f"`
 	Remove bool   `opt:"-d"`
-	Name   string `opt:"name"`
+	Name   string `opt:"name" complete:"CompleteHeaders"`
 	Value  string `opt:"..." required:"false"`
 }
 
@@ -37,8 +37,8 @@ func (Header) Options() string {
 	return "fd"
 }
 
-func (Header) Complete(args []string) []string {
-	return commands.CompletionFromList(headers, args)
+func (*Header) CompleteHeaders(arg string) []string {
+	return commands.CompletionFromList(headers, arg)
 }
 
 func (h Header) Execute(args []string) error {
diff --git a/commands/compose/multipart.go b/commands/compose/multipart.go
index 96941062..5b701342 100644
--- a/commands/compose/multipart.go
+++ b/commands/compose/multipart.go
@@ -11,7 +11,7 @@ import (
 
 type Multipart struct {
 	Remove bool   `opt:"-d"`
-	Mime   string `opt:"mime" metavar:"<mime/type>"`
+	Mime   string `opt:"mime" metavar:"<mime/type>" complete:"CompleteMime"`
 }
 
 func init() {
@@ -22,13 +22,12 @@ func (Multipart) Aliases() []string {
 	return []string{"multipart"}
 }
 
-func (Multipart) Complete(args []string) []string {
+func (*Multipart) CompleteMime(arg string) []string {
 	var completions []string
-	completions = append(completions, "-d")
 	for mime := range config.Converters {
 		completions = append(completions, mime)
 	}
-	return commands.CompletionFromList(completions, args)
+	return commands.CompletionFromList(completions, arg)
 }
 
 func (m Multipart) Execute(args []string) error {
diff --git a/commands/compose/next-field.go b/commands/compose/next-field.go
index 88fbb03d..396c1ce1 100644
--- a/commands/compose/next-field.go
+++ b/commands/compose/next-field.go
@@ -14,10 +14,6 @@ func (NextPrevField) Aliases() []string {
 	return []string{"next-field", "prev-field"}
 }
 
-func (NextPrevField) Complete(args []string) []string {
-	return nil
-}
-
 func (NextPrevField) Execute(args []string) error {
 	composer, _ := app.SelectedTabContent().(*app.Composer)
 	if args[0] == "prev-field" {
diff --git a/commands/compose/postpone.go b/commands/compose/postpone.go
index 767e759c..3ce9cc84 100644
--- a/commands/compose/postpone.go
+++ b/commands/compose/postpone.go
@@ -14,7 +14,7 @@ import (
 )
 
 type Postpone struct {
-	Folder string `opt:"-t"`
+	Folder string `opt:"-t" complete:"CompleteFolder"`
 }
 
 func init() {
@@ -25,20 +25,8 @@ func (Postpone) Aliases() []string {
 	return []string{"postpone"}
 }
 
-func (Postpone) Options() string {
-	return "t:"
-}
-
-func (Postpone) CompleteOption(r rune, arg string) []string {
-	var valid []string
-	if r == 't' {
-		valid = commands.GetFolders([]string{arg})
-	}
-	return commands.CompletionFromList(valid, []string{arg})
-}
-
-func (Postpone) Complete(args []string) []string {
-	return nil
+func (*Postpone) CompleteFolder(arg string) []string {
+	return commands.GetFolders(arg)
 }
 
 func (p Postpone) Execute(args []string) error {
diff --git a/commands/compose/send.go b/commands/compose/send.go
index e3672471..6f905628 100644
--- a/commands/compose/send.go
+++ b/commands/compose/send.go
@@ -28,8 +28,8 @@ import (
 )
 
 type Send struct {
-	Archive string `opt:"-a" action:"ParseArchive" metavar:"flat|year|month"`
-	CopyTo  string `opt:"-t"`
+	Archive string `opt:"-a" action:"ParseArchive" metavar:"flat|year|month" complete:"CompleteArchive"`
+	CopyTo  string `opt:"-t" complete:"CompleteFolders"`
 }
 
 func init() {
@@ -40,19 +40,12 @@ func (Send) Aliases() []string {
 	return []string{"send"}
 }
 
-func (Send) Options() string {
-	return "a:t:"
+func (*Send) CompleteArchive(arg string) []string {
+	return commands.CompletionFromList(msg.ARCHIVE_TYPES, arg)
 }
 
-func (s Send) CompleteOption(r rune, term string) []string {
-	if r == 't' {
-		return commands.GetFolders([]string{term})
-	}
-	return nil
-}
-
-func (Send) Complete(args []string) []string {
-	return nil
+func (*Send) CompleteFolders(arg string) []string {
+	return commands.GetFolders(arg)
 }
 
 func (s *Send) ParseArchive(arg string) error {
diff --git a/commands/compose/sign.go b/commands/compose/sign.go
index e30fca05..faeceed4 100644
--- a/commands/compose/sign.go
+++ b/commands/compose/sign.go
@@ -16,10 +16,6 @@ func (Sign) Aliases() []string {
 	return []string{"sign"}
 }
 
-func (Sign) Complete(args []string) []string {
-	return nil
-}
-
 func (Sign) Execute(args []string) error {
 	composer, _ := app.SelectedTabContent().(*app.Composer)
 
diff --git a/commands/compose/switch.go b/commands/compose/switch.go
index 0c027a41..637099b5 100644
--- a/commands/compose/switch.go
+++ b/commands/compose/switch.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 
 	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
 )
 
 type AccountSwitcher interface {
@@ -13,7 +14,7 @@ type AccountSwitcher interface {
 type SwitchAccount struct {
 	Next    bool   `opt:"-n"`
 	Prev    bool   `opt:"-p"`
-	Account string `opt:"..." metavar:"<account>" required:"false"`
+	Account string `opt:"account" required:"false" complete:"CompleteAccount"`
 }
 
 func init() {
@@ -24,8 +25,8 @@ func (SwitchAccount) Aliases() []string {
 	return []string{"switch-account"}
 }
 
-func (SwitchAccount) Complete(args []string) []string {
-	return app.AccountNames()
+func (*SwitchAccount) CompleteAccount(arg string) []string {
+	return commands.CompletionFromList(app.AccountNames(), arg)
 }
 
 func (s SwitchAccount) Execute(args []string) error {
diff --git a/commands/ct.go b/commands/ct.go
index 8a6bb063..2d057b4f 100644
--- a/commands/ct.go
+++ b/commands/ct.go
@@ -9,7 +9,7 @@ import (
 )
 
 type ChangeTab struct {
-	Tab string `opt:"tab"`
+	Tab string `opt:"tab" complete:"CompleteTab"`
 }
 
 func init() {
@@ -20,12 +20,8 @@ func (ChangeTab) Aliases() []string {
 	return []string{"ct", "change-tab"}
 }
 
-func (ChangeTab) Complete(args []string) []string {
-	if len(args) == 0 {
-		return app.TabNames()
-	}
-	joinedArgs := strings.Join(args, " ")
-	return FilterList(app.TabNames(), joinedArgs, "", app.SelectedAccountUiConfig().FuzzyComplete)
+func (*ChangeTab) CompleteTab(arg string) []string {
+	return CompletionFromList(app.TabNames(), arg)
 }
 
 func (c ChangeTab) Execute(args []string) error {
diff --git a/commands/eml.go b/commands/eml.go
index adacd05b..fe735243 100644
--- a/commands/eml.go
+++ b/commands/eml.go
@@ -5,14 +5,13 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"strings"
 
 	"git.sr.ht/~rjarry/aerc/app"
 	"git.sr.ht/~rjarry/aerc/lib"
 )
 
 type Eml struct {
-	Path string `opt:"path" required:"false"`
+	Path string `opt:"path" required:"false" complete:"CompletePath"`
 }
 
 func init() {
@@ -23,8 +22,8 @@ func (Eml) Aliases() []string {
 	return []string{"eml", "preview"}
 }
 
-func (Eml) Complete(args []string) []string {
-	return CompletePath(strings.Join(args, " "))
+func (*Eml) CompletePath(arg string) []string {
+	return CompletePath(arg)
 }
 
 func (e Eml) Execute(args []string) error {
diff --git a/commands/exec.go b/commands/exec.go
index 4c2f3d1b..2a3ed5f5 100644
--- a/commands/exec.go
+++ b/commands/exec.go
@@ -22,10 +22,6 @@ func (ExecCmd) Aliases() []string {
 	return []string{"exec"}
 }
 
-func (ExecCmd) Complete(args []string) []string {
-	return nil
-}
-
 func (e ExecCmd) Execute(args []string) error {
 	cmd := exec.Command(e.Args[0], e.Args[1:]...)
 	env := os.Environ()
diff --git a/commands/help.go b/commands/help.go
index b2bcdf7c..07332303 100644
--- a/commands/help.go
+++ b/commands/help.go
@@ -7,7 +7,7 @@ import (
 )
 
 type Help struct {
-	Topic string `opt:"topic" action:"ParseTopic" default:"aerc"`
+	Topic string `opt:"topic" action:"ParseTopic" default:"aerc" complete:"CompleteTopic"`
 }
 
 var pages = []string{
@@ -35,8 +35,8 @@ func (Help) Aliases() []string {
 	return []string{"help"}
 }
 
-func (Help) Complete(args []string) []string {
-	return CompletionFromList(pages, args)
+func (*Help) CompleteTopic(arg string) []string {
+	return CompletionFromList(pages, arg)
 }
 
 func (h *Help) ParseTopic(arg string) error {
diff --git a/commands/move-tab.go b/commands/move-tab.go
index 23580f2d..7ebe269c 100644
--- a/commands/move-tab.go
+++ b/commands/move-tab.go
@@ -32,10 +32,6 @@ func (MoveTab) Aliases() []string {
 	return []string{"move-tab"}
 }
 
-func (MoveTab) Complete(args []string) []string {
-	return nil
-}
-
 func (m MoveTab) Execute(args []string) error {
 	app.MoveTab(m.Index, m.Relative)
 	return nil
diff --git a/commands/msg/archive.go b/commands/msg/archive.go
index f4d6e3be..34cba8b8 100644
--- a/commands/msg/archive.go
+++ b/commands/msg/archive.go
@@ -21,7 +21,7 @@ const (
 var ARCHIVE_TYPES = []string{ARCHIVE_FLAT, ARCHIVE_YEAR, ARCHIVE_MONTH}
 
 type Archive struct {
-	Type string `opt:"type" action:"ParseArchiveType" metavar:"flat|year|month"`
+	Type string `opt:"type" action:"ParseArchiveType" metavar:"flat|year|month" complete:"CompleteType"`
 }
 
 func (a *Archive) ParseArchiveType(arg string) error {
@@ -42,9 +42,8 @@ func (Archive) Aliases() []string {
 	return []string{"archive"}
 }
 
-func (Archive) Complete(args []string) []string {
-	valid := []string{"flat", "year", "month"}
-	return commands.CompletionFromList(valid, args)
+func (*Archive) CompleteType(arg string) []string {
+	return commands.CompletionFromList(ARCHIVE_TYPES, arg)
 }
 
 func (a Archive) Execute(args []string) error {
diff --git a/commands/msg/copy.go b/commands/msg/copy.go
index 4109ef99..77c9ade1 100644
--- a/commands/msg/copy.go
+++ b/commands/msg/copy.go
@@ -10,7 +10,7 @@ import (
 
 type Copy struct {
 	CreateFolders bool   `opt:"-p"`
-	Folder        string `opt:"..." metavar:"<folder>"`
+	Folder        string `opt:"folder" complete:"CompleteFolder"`
 }
 
 func init() {
@@ -21,8 +21,8 @@ func (Copy) Aliases() []string {
 	return []string{"cp", "copy"}
 }
 
-func (Copy) Complete(args []string) []string {
-	return commands.GetFolders(args)
+func (*Copy) CompleteFolder(arg string) []string {
+	return commands.GetFolders(arg)
 }
 
 func (c Copy) Execute(args []string) error {
diff --git a/commands/msg/delete.go b/commands/msg/delete.go
index 49463abc..1a1a130c 100644
--- a/commands/msg/delete.go
+++ b/commands/msg/delete.go
@@ -21,10 +21,6 @@ func (Delete) Aliases() []string {
 	return []string{"delete", "delete-message"}
 }
 
-func (Delete) Complete(args []string) []string {
-	return nil
-}
-
 func (Delete) Execute(args []string) error {
 	h := newHelper()
 	store, err := h.store()
diff --git a/commands/msg/envelope.go b/commands/msg/envelope.go
index 6da82a1e..e104648d 100644
--- a/commands/msg/envelope.go
+++ b/commands/msg/envelope.go
@@ -25,10 +25,6 @@ func (Envelope) Aliases() []string {
 	return []string{"envelope"}
 }
 
-func (Envelope) Complete(args []string) []string {
-	return nil
-}
-
 func (e Envelope) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/msg/fold.go b/commands/msg/fold.go
index 0621c8c3..06e933d7 100644
--- a/commands/msg/fold.go
+++ b/commands/msg/fold.go
@@ -17,10 +17,6 @@ func (Fold) Aliases() []string {
 	return []string{"fold", "unfold"}
 }
 
-func (Fold) Complete(args []string) []string {
-	return nil
-}
-
 func (Fold) Execute(args []string) error {
 	h := newHelper()
 	store, err := h.store()
diff --git a/commands/msg/forward.go b/commands/msg/forward.go
index e6e386a9..4147e8c7 100644
--- a/commands/msg/forward.go
+++ b/commands/msg/forward.go
@@ -13,6 +13,7 @@ import (
 	"sync"
 
 	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
 	"git.sr.ht/~rjarry/aerc/config"
 	"git.sr.ht/~rjarry/aerc/lib"
 	"git.sr.ht/~rjarry/aerc/lib/format"
@@ -27,7 +28,7 @@ type forward struct {
 	AttachFull bool     `opt:"-F"`
 	Edit       bool     `opt:"-e"`
 	NoEdit     bool     `opt:"-E"`
-	Template   string   `opt:"-T"`
+	Template   string   `opt:"-T" complete:"CompleteTemplate"`
 	To         []string `opt:"..." required:"false"`
 }
 
@@ -39,8 +40,8 @@ func (forward) Aliases() []string {
 	return []string{"forward"}
 }
 
-func (forward) Complete(args []string) []string {
-	return nil
+func (*forward) CompleteTemplate(arg string) []string {
+	return commands.GetTemplates(arg)
 }
 
 func (f forward) Execute(args []string) error {
diff --git a/commands/msg/invite.go b/commands/msg/invite.go
index 5b8558b0..12bea93e 100644
--- a/commands/msg/invite.go
+++ b/commands/msg/invite.go
@@ -28,10 +28,6 @@ func (invite) Aliases() []string {
 	return []string{"accept", "accept-tentative", "decline"}
 }
 
-func (invite) Complete(args []string) []string {
-	return nil
-}
-
 func (i invite) Execute(args []string) error {
 	acct := app.SelectedAccount()
 	if acct == nil {
diff --git a/commands/msg/mark.go b/commands/msg/mark.go
index c2c21cf2..9547548f 100644
--- a/commands/msg/mark.go
+++ b/commands/msg/mark.go
@@ -20,10 +20,6 @@ func (Mark) Aliases() []string {
 	return []string{"mark", "unmark", "remark"}
 }
 
-func (Mark) Complete(args []string) []string {
-	return nil
-}
-
 func (m Mark) Execute(args []string) error {
 	h := newHelper()
 	OnSelectedMessage := func(fn func(uint32)) error {
diff --git a/commands/msg/modify-labels.go b/commands/msg/modify-labels.go
index 6fdbeac4..8cc72f2a 100644
--- a/commands/msg/modify-labels.go
+++ b/commands/msg/modify-labels.go
@@ -9,7 +9,7 @@ import (
 )
 
 type ModifyLabels struct {
-	Labels []string `opt:"..." metavar:"[+-]<label>"`
+	Labels []string `opt:"..." metavar:"[+-]<label>" complete:"CompleteLabels"`
 }
 
 func init() {
@@ -20,8 +20,8 @@ func (ModifyLabels) Aliases() []string {
 	return []string{"modify-labels", "tag"}
 }
 
-func (ModifyLabels) Complete(args []string) []string {
-	return commands.GetLabels(args)
+func (*ModifyLabels) CompleteLabels(arg string) []string {
+	return commands.GetLabels(arg)
 }
 
 func (m ModifyLabels) Execute(args []string) error {
diff --git a/commands/msg/move.go b/commands/msg/move.go
index 1dd68d35..06c7fc15 100644
--- a/commands/msg/move.go
+++ b/commands/msg/move.go
@@ -14,7 +14,7 @@ import (
 
 type Move struct {
 	CreateFolders bool   `opt:"-p"`
-	Folder        string `opt:"..." metavar:"<folder>"`
+	Folder        string `opt:"folder" complete:"CompleteFolder"`
 }
 
 func init() {
@@ -25,8 +25,8 @@ func (Move) Aliases() []string {
 	return []string{"mv", "move"}
 }
 
-func (Move) Complete(args []string) []string {
-	return commands.GetFolders(args)
+func (*Move) CompleteFolder(arg string) []string {
+	return commands.GetFolders(arg)
 }
 
 func (m Move) Execute(args []string) error {
diff --git a/commands/msg/pipe.go b/commands/msg/pipe.go
index b984752b..b32d7159 100644
--- a/commands/msg/pipe.go
+++ b/commands/msg/pipe.go
@@ -32,10 +32,6 @@ func (Pipe) Aliases() []string {
 	return []string{"pipe"}
 }
 
-func (Pipe) Complete(args []string) []string {
-	return nil
-}
-
 func (p Pipe) Execute(args []string) error {
 	if p.Full && p.Part {
 		return errors.New("-m and -p are mutually exclusive")
diff --git a/commands/msg/read.go b/commands/msg/read.go
index e55ed00e..72159a53 100644
--- a/commands/msg/read.go
+++ b/commands/msg/read.go
@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
 	"git.sr.ht/~rjarry/aerc/models"
 	"git.sr.ht/~rjarry/aerc/worker/types"
 )
@@ -13,7 +14,7 @@ import (
 type FlagMsg struct {
 	Toggle   bool         `opt:"-t"`
 	Answered bool         `opt:"-a" aliases:"flag,unflag"`
-	Flag     models.Flags `opt:"-x" aliases:"flag,unflag" action:"ParseFlag"`
+	Flag     models.Flags `opt:"-x" aliases:"flag,unflag" action:"ParseFlag" complete:"CompleteFlag"`
 	FlagName string
 }
 
@@ -25,10 +26,6 @@ func (FlagMsg) Aliases() []string {
 	return []string{"flag", "unflag", "read", "unread"}
 }
 
-func (FlagMsg) Complete(args []string) []string {
-	return nil
-}
-
 func (f *FlagMsg) ParseFlag(arg string) error {
 	switch strings.ToLower(arg) {
 	case "seen":
@@ -46,6 +43,12 @@ func (f *FlagMsg) ParseFlag(arg string) error {
 	return nil
 }
 
+var validFlags = []string{"seen", "answered", "flagged"}
+
+func (*FlagMsg) CompleteFlag(arg string) []string {
+	return commands.CompletionFromList(validFlags, arg)
+}
+
 // If this was called as 'flag' or 'unflag', without the toggle (-t)
 // option, then it will flag the corresponding messages with the given
 // flag.  If the toggle option was given, it will individually toggle
diff --git a/commands/msg/recall.go b/commands/msg/recall.go
index 3b78a763..cea02ddb 100644
--- a/commands/msg/recall.go
+++ b/commands/msg/recall.go
@@ -31,10 +31,6 @@ func (Recall) Aliases() []string {
 	return []string{"recall"}
 }
 
-func (Recall) Complete(args []string) []string {
-	return nil
-}
-
 func (r Recall) Execute(args []string) error {
 	editHeaders := (config.Compose.EditHeaders || r.Edit) && !r.NoEdit
 
diff --git a/commands/msg/reply.go b/commands/msg/reply.go
index 2ab9e9f8..ebf20317 100644
--- a/commands/msg/reply.go
+++ b/commands/msg/reply.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
 	"git.sr.ht/~rjarry/aerc/commands/account"
 	"git.sr.ht/~rjarry/aerc/config"
 	"git.sr.ht/~rjarry/aerc/lib"
@@ -26,7 +27,7 @@ type reply struct {
 	All      bool   `opt:"-a"`
 	Close    bool   `opt:"-c"`
 	Quote    bool   `opt:"-q"`
-	Template string `opt:"-T"`
+	Template string `opt:"-T" complete:"CompleteTemplate"`
 	Edit     bool   `opt:"-e"`
 	NoEdit   bool   `opt:"-E"`
 }
@@ -39,8 +40,8 @@ func (reply) Aliases() []string {
 	return []string{"reply"}
 }
 
-func (reply) Complete(args []string) []string {
-	return nil
+func (*reply) CompleteTemplate(arg string) []string {
+	return commands.GetTemplates(arg)
 }
 
 func (r reply) Execute(args []string) error {
diff --git a/commands/msg/toggle-thread-context.go b/commands/msg/toggle-thread-context.go
index 0ef6778f..4b87eaa8 100644
--- a/commands/msg/toggle-thread-context.go
+++ b/commands/msg/toggle-thread-context.go
@@ -14,10 +14,6 @@ func (ToggleThreadContext) Aliases() []string {
 	return []string{"toggle-thread-context"}
 }
 
-func (ToggleThreadContext) Complete(args []string) []string {
-	return nil
-}
-
 func (ToggleThreadContext) Execute(args []string) error {
 	h := newHelper()
 	store, err := h.store()
diff --git a/commands/msg/toggle-threads.go b/commands/msg/toggle-threads.go
index 88cc763f..d2933bba 100644
--- a/commands/msg/toggle-threads.go
+++ b/commands/msg/toggle-threads.go
@@ -15,10 +15,6 @@ func (ToggleThreads) Aliases() []string {
 	return []string{"toggle-threads"}
 }
 
-func (ToggleThreads) Complete(args []string) []string {
-	return nil
-}
-
 func (ToggleThreads) Execute(args []string) error {
 	h := newHelper()
 	acct, err := h.account()
diff --git a/commands/msg/unsubscribe.go b/commands/msg/unsubscribe.go
index 6fef16f5..c6a0b23f 100644
--- a/commands/msg/unsubscribe.go
+++ b/commands/msg/unsubscribe.go
@@ -31,11 +31,6 @@ func (Unsubscribe) Aliases() []string {
 	return []string{"unsubscribe"}
 }
 
-// Complete returns a list of completions
-func (Unsubscribe) Complete(args []string) []string {
-	return nil
-}
-
 // Execute runs the Unsubscribe command
 func (u Unsubscribe) Execute(args []string) error {
 	editHeaders := (config.Compose.EditHeaders || u.Edit) && !u.NoEdit
diff --git a/commands/msgview/close.go b/commands/msgview/close.go
index 32702da9..95960ef3 100644
--- a/commands/msgview/close.go
+++ b/commands/msgview/close.go
@@ -14,10 +14,6 @@ func (Close) Aliases() []string {
 	return []string{"close"}
 }
 
-func (Close) Complete(args []string) []string {
-	return nil
-}
-
 func (Close) Execute(args []string) error {
 	mv, _ := app.SelectedTabContent().(*app.MessageViewer)
 	app.RemoveTab(mv, true)
diff --git a/commands/msgview/next-part.go b/commands/msgview/next-part.go
index 9b1b1fcc..77eb008d 100644
--- a/commands/msgview/next-part.go
+++ b/commands/msgview/next-part.go
@@ -16,10 +16,6 @@ func (NextPrevPart) Aliases() []string {
 	return []string{"next-part", "prev-part"}
 }
 
-func (NextPrevPart) Complete(args []string) []string {
-	return nil
-}
-
 func (np NextPrevPart) Execute(args []string) error {
 	mv, _ := app.SelectedTabContent().(*app.MessageViewer)
 	for n := 0; n < np.Offset; n++ {
diff --git a/commands/msgview/next.go b/commands/msgview/next.go
index d8f046f8..c953cd5d 100644
--- a/commands/msgview/next.go
+++ b/commands/msgview/next.go
@@ -39,10 +39,6 @@ func (NextPrevMsg) Aliases() []string {
 	return []string{"next", "next-message", "prev", "prev-message"}
 }
 
-func (NextPrevMsg) Complete(args []string) []string {
-	return nil
-}
-
 func (np NextPrevMsg) Execute(args []string) error {
 	cmd := account.NextPrevMsg{Amount: np.Amount, Percent: np.Percent}
 	err := cmd.Execute(args)
diff --git a/commands/msgview/open-link.go b/commands/msgview/open-link.go
index 55aee08c..eceb4232 100644
--- a/commands/msgview/open-link.go
+++ b/commands/msgview/open-link.go
@@ -11,7 +11,7 @@ import (
 )
 
 type OpenLink struct {
-	Url *url.URL `opt:"url" action:"ParseUrl"`
+	Url *url.URL `opt:"url" action:"ParseUrl" complete:"CompleteUrl"`
 	Cmd string   `opt:"..." required:"false"`
 }
 
@@ -23,11 +23,11 @@ func (OpenLink) Aliases() []string {
 	return []string{"open-link"}
 }
 
-func (OpenLink) Complete(args []string) []string {
+func (*OpenLink) CompleteUrl(arg string) []string {
 	mv := app.SelectedTabContent().(*app.MessageViewer)
 	if mv != nil {
 		if p := mv.SelectedMessagePart(); p != nil {
-			return commands.CompletionFromList(p.Links, args)
+			return commands.CompletionFromList(p.Links, arg)
 		}
 	}
 	return nil
diff --git a/commands/msgview/open.go b/commands/msgview/open.go
index 0d6db5b0..a8443404 100644
--- a/commands/msgview/open.go
+++ b/commands/msgview/open.go
@@ -29,10 +29,6 @@ func (Open) Aliases() []string {
 	return []string{"open"}
 }
 
-func (Open) Complete(args []string) []string {
-	return nil
-}
-
 func (o Open) Execute(args []string) error {
 	mv := app.SelectedTabContent().(*app.MessageViewer)
 	if mv == nil {
diff --git a/commands/msgview/save.go b/commands/msgview/save.go
index ea7599d3..9f2b71fc 100644
--- a/commands/msgview/save.go
+++ b/commands/msgview/save.go
@@ -22,7 +22,7 @@ type Save struct {
 	CreateDirs     bool   `opt:"-p"`
 	Attachments    bool   `opt:"-a"`
 	AllAttachments bool   `opt:"-A"`
-	Path           string `opt:"..." required:"false" metavar:"<path>"`
+	Path           string `opt:"path" required:"false" complete:"CompletePath"`
 }
 
 func init() {
@@ -37,14 +37,12 @@ func (Save) Aliases() []string {
 	return []string{"save"}
 }
 
-func (s Save) Complete(args []string) []string {
-	trimmed := commands.Operands(args, s.Options())
-	path := strings.Join(trimmed, " ")
+func (*Save) CompletePath(arg string) []string {
 	defaultPath := config.General.DefaultSavePath
-	if defaultPath != "" && !isAbsPath(path) {
-		path = filepath.Join(defaultPath, path)
+	if defaultPath != "" && !isAbsPath(arg) {
+		arg = filepath.Join(defaultPath, arg)
 	}
-	return commands.CompletePath(xdg.ExpandHome(path))
+	return commands.CompletePath(xdg.ExpandHome(arg))
 }
 
 func (s Save) Execute(args []string) error {
diff --git a/commands/msgview/toggle-headers.go b/commands/msgview/toggle-headers.go
index c27307d3..37f5b22f 100644
--- a/commands/msgview/toggle-headers.go
+++ b/commands/msgview/toggle-headers.go
@@ -14,10 +14,6 @@ func (ToggleHeaders) Aliases() []string {
 	return []string{"toggle-headers"}
 }
 
-func (ToggleHeaders) Complete(args []string) []string {
-	return nil
-}
-
 func (ToggleHeaders) Execute(args []string) error {
 	mv, _ := app.SelectedTabContent().(*app.MessageViewer)
 	mv.ToggleHeaders()
diff --git a/commands/msgview/toggle-key-passthrough.go b/commands/msgview/toggle-key-passthrough.go
index 32735870..b4c5f2c7 100644
--- a/commands/msgview/toggle-key-passthrough.go
+++ b/commands/msgview/toggle-key-passthrough.go
@@ -15,10 +15,6 @@ func (ToggleKeyPassthrough) Aliases() []string {
 	return []string{"toggle-key-passthrough"}
 }
 
-func (ToggleKeyPassthrough) Complete(args []string) []string {
-	return nil
-}
-
 func (ToggleKeyPassthrough) Execute(args []string) error {
 	mv, _ := app.SelectedTabContent().(*app.MessageViewer)
 	keyPassthroughEnabled := mv.ToggleKeyPassthrough()
diff --git a/commands/new-account.go b/commands/new-account.go
index b30e0e34..1a14a821 100644
--- a/commands/new-account.go
+++ b/commands/new-account.go
@@ -16,10 +16,6 @@ func (NewAccount) Aliases() []string {
 	return []string{"new-account"}
 }
 
-func (NewAccount) Complete(args []string) []string {
-	return nil
-}
-
 func (n NewAccount) Execute(args []string) error {
 	wizard := app.NewAccountWizard()
 	wizard.ConfigureTemporaryAccount(n.Temp)
diff --git a/commands/next-tab.go b/commands/next-tab.go
index d8374191..f1f34d22 100644
--- a/commands/next-tab.go
+++ b/commands/next-tab.go
@@ -16,10 +16,6 @@ func (NextPrevTab) Aliases() []string {
 	return []string{"next-tab", "prev-tab"}
 }
 
-func (NextPrevTab) Complete(args []string) []string {
-	return nil
-}
-
 func (np NextPrevTab) Execute(args []string) error {
 	for n := 0; n < np.Offset; n++ {
 		if args[0] == "prev-tab" {
diff --git a/commands/parser.go b/commands/parser.go
deleted file mode 100644
index e8146506..00000000
--- a/commands/parser.go
+++ /dev/null
@@ -1,134 +0,0 @@
-package commands
-
-import (
-	"strings"
-)
-
-type completionType int
-
-const (
-	NONE completionType = iota
-	COMMAND
-	OPERAND
-	SHORT_OPTION
-	OPTION_ARGUMENT
-)
-
-type parser struct {
-	tokens []string
-	optind int
-	spec   string
-	space  bool
-	kind   completionType
-	flag   string
-	arg    string
-	err    error
-}
-
-func newParser(cmd, spec string, spaceTerminated bool) (*parser, error) {
-	args, err := splitCmd(cmd)
-	if err != nil {
-		return nil, err
-	}
-
-	p := &parser{
-		tokens: args,
-		optind: 0,
-		spec:   spec,
-		space:  spaceTerminated,
-		kind:   NONE,
-		flag:   "",
-		arg:    "",
-		err:    nil,
-	}
-
-	state := command
-	for state != nil {
-		state = state(p)
-	}
-
-	return p, p.err
-}
-
-func (p *parser) empty() bool {
-	return len(p.tokens) == 0
-}
-
-func (p *parser) peek() string {
-	return p.tokens[0]
-}
-
-func (p *parser) advance() string {
-	if p.empty() {
-		return ""
-	}
-	tok := p.tokens[0]
-	p.tokens = p.tokens[1:]
-	p.optind++
-	return tok
-}
-
-func (p *parser) set(t completionType) {
-	p.kind = t
-}
-
-func (p *parser) hasArgument() bool {
-	n := len(p.flag)
-	if n > 0 {
-		s := string(p.flag[n-1]) + ":"
-		return strings.Contains(p.spec, s)
-	}
-	return false
-}
-
-type stateFn func(*parser) stateFn
-
-func command(p *parser) stateFn {
-	p.set(COMMAND)
-	p.advance()
-	return peek(p)
-}
-
-func peek(p *parser) stateFn {
-	if p.empty() {
-		if p.space {
-			return operand
-		}
-		return nil
-	}
-	if p.spec == "" {
-		return operand
-	}
-	s := p.peek()
-	switch {
-	case s == "--":
-		p.advance()
-	case strings.HasPrefix(s, "-"):
-		return short_option
-	}
-	return operand
-}
-
-func short_option(p *parser) stateFn {
-	p.set(SHORT_OPTION)
-	tok := p.advance()
-	p.flag = tok[1:]
-	if p.hasArgument() {
-		return option_argument
-	}
-	return peek(p)
-}
-
-func option_argument(p *parser) stateFn {
-	p.set(OPTION_ARGUMENT)
-	p.arg = p.advance()
-	if p.empty() && len(p.arg) == 0 {
-		return nil
-	}
-	return peek(p)
-}
-
-func operand(p *parser) stateFn {
-	p.set(OPERAND)
-	return nil
-}
diff --git a/commands/parser_test.go b/commands/parser_test.go
deleted file mode 100644
index d6ccd385..00000000
--- a/commands/parser_test.go
+++ /dev/null
@@ -1,258 +0,0 @@
-package commands
-
-import (
-	"testing"
-)
-
-var parserTests = []struct {
-	name       string
-	cmd        string
-	wantType   completionType
-	wantFlag   string
-	wantArg    string
-	wantOptind int
-}{
-	{
-		name:       "empty command",
-		cmd:        "",
-		wantType:   COMMAND,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 0,
-	},
-	{
-		name:       "command only",
-		cmd:        "cmd",
-		wantType:   COMMAND,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 1,
-	},
-	{
-		name:       "with space",
-		cmd:        "cmd ",
-		wantType:   OPERAND,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 1,
-	},
-	{
-		name:       "with two spaces",
-		cmd:        "cmd  ",
-		wantType:   OPERAND,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 1,
-	},
-	{
-		name:       "with single option flag",
-		cmd:        "cmd -",
-		wantType:   SHORT_OPTION,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with single option flag two spaces",
-		cmd:        "cmd  -",
-		wantType:   SHORT_OPTION,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with single option flag completed",
-		cmd:        "cmd -a",
-		wantType:   SHORT_OPTION,
-		wantFlag:   "a",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with single option flag completed and space",
-		cmd:        "cmd -a ",
-		wantType:   OPERAND,
-		wantFlag:   "a",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with single option flag completed and two spaces",
-		cmd:        "cmd -a ",
-		wantType:   OPERAND,
-		wantFlag:   "a",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with two single option flag completed",
-		cmd:        "cmd -b -a",
-		wantType:   SHORT_OPTION,
-		wantFlag:   "a",
-		wantArg:    "",
-		wantOptind: 3,
-	},
-	{
-		name:       "with two single option flag combined",
-		cmd:        "cmd -ab",
-		wantType:   SHORT_OPTION,
-		wantFlag:   "ab",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with two single option flag and space",
-		cmd:        "cmd -ab ",
-		wantType:   OPERAND,
-		wantFlag:   "ab",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with mandatory option flag",
-		cmd:        "cmd -f",
-		wantType:   OPTION_ARGUMENT,
-		wantFlag:   "f",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with mandatory option flag and space",
-		cmd:        "cmd -f ",
-		wantType:   OPTION_ARGUMENT,
-		wantFlag:   "f",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with mandatory option flag and two spaces",
-		cmd:        "cmd -f  ",
-		wantType:   OPTION_ARGUMENT,
-		wantFlag:   "f",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with mandatory option flag and completed",
-		cmd:        "cmd -f a",
-		wantType:   OPTION_ARGUMENT,
-		wantFlag:   "f",
-		wantArg:    "a",
-		wantOptind: 3,
-	},
-	{
-		name:       "with mandatory option flag and completed quote",
-		cmd:        "cmd -f 'a b'",
-		wantType:   OPTION_ARGUMENT,
-		wantFlag:   "f",
-		wantArg:    "a b",
-		wantOptind: 3,
-	},
-	{
-		name:       "with mandatory option flag and operand",
-		cmd:        "cmd -f 'a b' hello",
-		wantType:   OPERAND,
-		wantFlag:   "f",
-		wantArg:    "a b",
-		wantOptind: 3,
-	},
-	{
-		name:       "with mandatory option flag and two spaces between",
-		cmd:        "cmd -f  a",
-		wantType:   OPTION_ARGUMENT,
-		wantFlag:   "f",
-		wantArg:    "a",
-		wantOptind: 3,
-	},
-	{
-		name:       "with mandatory option flag and more spaces",
-		cmd:        "cmd -f  a ",
-		wantType:   OPERAND,
-		wantFlag:   "f",
-		wantArg:    "a",
-		wantOptind: 3,
-	},
-	{
-		name:       "with template data",
-		cmd:        "cmd -a {{if .Size}}  hello {{else}} {{end}}",
-		wantType:   OPERAND,
-		wantFlag:   "a",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with operand",
-		cmd:        "cmd -ab /tmp/aerc-",
-		wantType:   OPERAND,
-		wantFlag:   "ab",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-	{
-		name:       "with operand indicator",
-		cmd:        "cmd -ab -- /tmp/aerc-",
-		wantType:   OPERAND,
-		wantFlag:   "ab",
-		wantArg:    "",
-		wantOptind: 3,
-	},
-	{
-		name:       "hyphen connected command",
-		cmd:        "cmd-dmc",
-		wantType:   COMMAND,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 1,
-	},
-	{
-		name:       "incomplete hyphen connected command",
-		cmd:        "cmd-",
-		wantType:   COMMAND,
-		wantFlag:   "",
-		wantArg:    "",
-		wantOptind: 1,
-	},
-	{
-		name:       "hyphen connected command with option",
-		cmd:        "cmd-dmc -a",
-		wantType:   SHORT_OPTION,
-		wantFlag:   "a",
-		wantArg:    "",
-		wantOptind: 2,
-	},
-}
-
-func TestCommands_Parser(t *testing.T) {
-	for i, test := range parserTests {
-		n := len(test.cmd)
-		spaceTerminated := n > 0 && test.cmd[n-1] == ' '
-		parser, err := newParser(test.cmd, "abf:", spaceTerminated)
-		if err != nil {
-			t.Errorf("parser error: %v", err)
-		}
-
-		if test.wantType != parser.kind {
-			t.Errorf("test %d '%s': completion type does not match: "+
-				"want %d, but got %d", i, test.cmd, test.wantType,
-				parser.kind)
-		}
-
-		if test.wantFlag != parser.flag {
-			t.Errorf("test %d '%s': flag does not match: "+
-				"want %s, but got %s", i, test.cmd, test.wantFlag,
-				parser.flag)
-		}
-
-		if test.wantArg != parser.arg {
-			t.Errorf("test %d '%s': arg does not match: "+
-				"want %s, but got %s", i, test.cmd, test.wantArg,
-				parser.arg)
-		}
-
-		if test.wantOptind != parser.optind {
-			t.Errorf("test %d '%s': optind does not match: "+
-				"want %d, but got %d", i, test.cmd, test.wantOptind,
-				parser.optind)
-		}
-	}
-}
diff --git a/commands/pin-tab.go b/commands/pin-tab.go
index 276442ce..d5013bf6 100644
--- a/commands/pin-tab.go
+++ b/commands/pin-tab.go
@@ -14,10 +14,6 @@ func (PinTab) Aliases() []string {
 	return []string{"pin-tab", "unpin-tab"}
 }
 
-func (PinTab) Complete(args []string) []string {
-	return nil
-}
-
 func (PinTab) Execute(args []string) error {
 	switch args[0] {
 	case "pin-tab":
diff --git a/commands/prompt.go b/commands/prompt.go
index dd259c30..d791f7a9 100644
--- a/commands/prompt.go
+++ b/commands/prompt.go
@@ -1,8 +1,6 @@
 package commands
 
 import (
-	"strings"
-
 	"git.sr.ht/~rjarry/go-opt"
 
 	"git.sr.ht/~rjarry/aerc/app"
@@ -10,7 +8,7 @@ import (
 
 type Prompt struct {
 	Text string   `opt:"text"`
-	Cmd  []string `opt:"..."`
+	Cmd  []string `opt:"..." complete:"CompleteCommand"`
 }
 
 func init() {
@@ -21,56 +19,8 @@ func (Prompt) Aliases() []string {
 	return []string{"prompt"}
 }
 
-func (Prompt) Complete(args []string) []string {
-	argc := len(args)
-	if argc == 0 {
-		return nil
-	}
-	hascommand := argc > 2
-	if argc == 1 {
-		args = append(args, "")
-	}
-
-	cmd := GlobalCommands.ByName(args[1])
-	var cs []string
-	if cmd != nil {
-		cs = cmd.Complete(args[2:])
-		hascommand = true
-	} else {
-		if hascommand {
-			return nil
-		}
-		cs = GlobalCommands.Names()
-	}
-	if cs == nil {
-		return nil
-	}
-
-	var b strings.Builder
-	// it seems '' quoting is enough
-	// to keep quoted arguments in one piece
-	b.WriteRune('\'')
-	b.WriteString(args[0])
-	b.WriteRune('\'')
-	b.WriteRune(' ')
-	if hascommand {
-		b.WriteString(args[1])
-		b.WriteRune(' ')
-	}
-
-	src := b.String()
-	b.Reset()
-
-	rs := make([]string, 0, len(cs))
-	for _, c := range cs {
-		b.WriteString(src)
-		b.WriteString(c)
-
-		rs = append(rs, b.String())
-		b.Reset()
-	}
-
-	return rs
+func (*Prompt) CompleteCommand(arg string) []string {
+	return CompletionFromList(GlobalCommands.Names(), arg)
 }
 
 func (p Prompt) Execute(args []string) error {
diff --git a/commands/pwd.go b/commands/pwd.go
index 426be78b..2b1961a1 100644
--- a/commands/pwd.go
+++ b/commands/pwd.go
@@ -17,10 +17,6 @@ func (PrintWorkDir) Aliases() []string {
 	return []string{"pwd"}
 }
 
-func (PrintWorkDir) Complete(args []string) []string {
-	return nil
-}
-
 func (PrintWorkDir) Execute(args []string) error {
 	pwd, err := os.Getwd()
 	if err != nil {
diff --git a/commands/quit.go b/commands/quit.go
index 3e0f2968..e96c9253 100644
--- a/commands/quit.go
+++ b/commands/quit.go
@@ -18,10 +18,6 @@ func (Quit) Aliases() []string {
 	return []string{"quit", "exit"}
 }
 
-func (Quit) Complete(args []string) []string {
-	return nil
-}
-
 type ErrorExit int
 
 func (err ErrorExit) Error() string {
diff --git a/commands/send-keys.go b/commands/send-keys.go
index 9541b88d..bb872a33 100644
--- a/commands/send-keys.go
+++ b/commands/send-keys.go
@@ -19,10 +19,6 @@ func (SendKeys) Aliases() []string {
 	return []string{"send-keys"}
 }
 
-func (SendKeys) Complete(args []string) []string {
-	return nil
-}
-
 func (s SendKeys) Execute(args []string) error {
 	tab, ok := app.SelectedTabContent().(app.HasTerminal)
 	if !ok {
diff --git a/commands/suspend.go b/commands/suspend.go
index 80d59028..a8996441 100644
--- a/commands/suspend.go
+++ b/commands/suspend.go
@@ -12,10 +12,6 @@ func (Suspend) Aliases() []string {
 	return []string{"suspend"}
 }
 
-func (Suspend) Complete(args []string) []string {
-	return nil
-}
-
 func (Suspend) Execute(args []string) error {
 	ui.QueueSuspend()
 	return nil
diff --git a/commands/term.go b/commands/term.go
index 225fee57..3f8f9875 100644
--- a/commands/term.go
+++ b/commands/term.go
@@ -21,10 +21,6 @@ func (Term) Aliases() []string {
 	return []string{"terminal", "term"}
 }
 
-func (Term) Complete(args []string) []string {
-	return nil
-}
-
 func (t Term) Execute(args []string) error {
 	if len(t.Cmd) == 0 {
 		shell, err := loginshell.Shell()
diff --git a/commands/terminal/close.go b/commands/terminal/close.go
index 913a3387..610a8463 100644
--- a/commands/terminal/close.go
+++ b/commands/terminal/close.go
@@ -14,10 +14,6 @@ func (Close) Aliases() []string {
 	return []string{"close"}
 }
 
-func (Close) Complete(args []string) []string {
-	return nil
-}
-
 func (Close) Execute(args []string) error {
 	term, _ := app.SelectedTabContent().(*app.Terminal)
 	term.Close()
diff --git a/commands/util.go b/commands/util.go
index e9a377a6..a9aa81b3 100644
--- a/commands/util.go
+++ b/commands/util.go
@@ -18,6 +18,7 @@ import (
 	"git.sr.ht/~rjarry/aerc/log"
 	"git.sr.ht/~rjarry/aerc/models"
 	"git.sr.ht/~rjarry/aerc/worker/types"
+	"git.sr.ht/~rjarry/go-opt"
 	"github.com/gdamore/tcell/v2"
 )
 
@@ -93,7 +94,7 @@ func CompletePath(path string) []string {
 		}
 
 		if !strings.HasPrefix(path, ".") && !strings.Contains(path, "/.") {
-			log.Debugf("removing hidden files from glob results")
+			log.Tracef("removing hidden files from glob results")
 			for i := len(matches) - 1; i >= 0; i-- {
 				if strings.HasPrefix(filepath.Base(matches[i]), ".") {
 					if i == len(matches)-1 {
@@ -107,11 +108,13 @@ func CompletePath(path string) []string {
 
 		for i, m := range matches {
 			if isDir(m) {
-				matches[i] = m + "/"
+				m += "/"
 			}
+			matches[i] = opt.QuoteArg((xdg.TildeHome(m)))
 		}
 
 		sort.Strings(matches)
+
 		return matches
 	}
 
@@ -122,11 +125,11 @@ func CompletePath(path string) []string {
 		if isDir(f) {
 			f += "/"
 		}
-
-		files[i] = f
+		files[i] = opt.QuoteArg((xdg.TildeHome(f)))
 	}
 
 	sort.Strings(files)
+
 	return files
 }
 
@@ -227,16 +230,16 @@ func MsgInfoFromUids(store *lib.MessageStore, uids []uint32, statusInfo func(str
 
 // FilterList takes a list of valid completions and filters it, either
 // by case smart prefix, or by fuzzy matching, prepending "prefix" to each completion
-func FilterList(valid []string, search, prefix string, isFuzzy bool) []string {
-	out := make([]string, 0)
+func FilterList(valid []string, search, prefix, suffix string, isFuzzy bool) []string {
+	out := make([]string, 0, len(valid))
 	if isFuzzy {
 		for _, v := range fuzzy.RankFindFold(search, valid) {
-			out = append(out, prefix+v.Target)
+			out = append(out, opt.QuoteArg(prefix+v.Target+suffix))
 		}
 	} else {
 		for _, v := range valid {
 			if hasCaseSmartPrefix(v, search) {
-				out = append(out, prefix+v)
+				out = append(out, opt.QuoteArg(prefix+v+suffix))
 			}
 		}
 	}
diff --git a/commands/z.go b/commands/z.go
index 5aee2a2c..2ea65e0c 100644
--- a/commands/z.go
+++ b/commands/z.go
@@ -8,7 +8,8 @@ import (
 )
 
 type Zoxide struct {
-	Target string `opt:"..." default:"~" metavar:"<folder> | <query>..."`
+	Target string   `opt:"folder" default:"~" complete:"CompleteFolder"`
+	Args   []string `opt:"..." required:"false" metavar:"<query>..."`
 }
 
 func ZoxideAdd(arg string) error {
@@ -36,8 +37,8 @@ func (Zoxide) Aliases() []string {
 	return []string{"z"}
 }
 
-func (Zoxide) Complete(args []string) []string {
-	return ChangeDirectory{}.Complete(args)
+func (*Zoxide) CompleteFolder(arg string) []string {
+	return GetFolders(arg)
 }
 
 // Execute calls zoxide add and query and delegates actually changing the
diff --git a/main.go b/main.go
index dc7d0267..75069e13 100644
--- a/main.go
+++ b/main.go
@@ -143,7 +143,7 @@ func getCompletions(cmdline string) ([]string, string) {
 		for _, set := range cmds {
 			for _, n := range set.Names() {
 				if strings.HasPrefix(n, cmdline) {
-					completions = append(completions, n)
+					completions = append(completions, n+" ")
 				}
 			}
 		}