query: add completions for notmuch search-terms

Add completions to :query for the notmuch search terms. Most search
terms that seemed valid for interactive use in aerc are listed as
options. Some of them (from, to, tag, path, and folder) get actual
completions. The function was designed, so later patches can reuse it to
add completions to :cf, :filter and :search for notmuch accounts.

References: https://todo.sr.ht/~rjarry/aerc/244
Changelog-added: Notmuch search term completions to `:query`.
Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
Tested-by: Julio B <julio.bacel@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>

2 files changed, 60 insertions, 2 deletions

diff --git a/commands/account/query.go b/commands/account/query.go
index fccdc756..65c3c3a8 100644
--- a/commands/account/query.go
+++ b/commands/account/query.go
@@ -3,6 +3,7 @@ package account
 import (
 	"errors"
 	"reflect"
+	"strings"
 	"time"
 
 	"git.sr.ht/~rjarry/aerc/app"
@@ -14,7 +15,7 @@ import (
 type Query struct {
 	Account string `opt:"-a" complete:"CompleteAccount"`
 	Name    string `opt:"-n"`
-	Query   string `opt:"..."`
+	Query   string `opt:"..." complete:"CompleteNotmuch"`
 }
 
 func init() {
@@ -65,3 +66,60 @@ func (q Query) Execute([]string) error {
 	acct.Directories().Open(name, q.Query, 0*time.Second, finalize)
 	return nil
 }
+
+func (*Query) CompleteNotmuch(arg string) []string {
+	return handleNotmuchComplete(arg)
+}
+
+var notmuch_search_terms = []string{
+	"from:",
+	"to:",
+	"tag:",
+	"date:",
+	"attachment:",
+	"mimetype:",
+	"subject:",
+	"body:",
+	"id:",
+	"thread:",
+	"folder:",
+	"path:",
+}
+
+func handleNotmuchComplete(arg string) []string {
+	prefixes := []string{"from:", "to:"}
+	for _, prefix := range prefixes {
+		if strings.HasPrefix(arg, prefix) {
+			arg = strings.TrimPrefix(arg, prefix)
+			return commands.FilterList(
+				commands.GetAddress(arg), arg,
+				func(v string) string { return prefix + v },
+			)
+		}
+	}
+
+	prefixes = []string{"tag:"}
+	for _, prefix := range prefixes {
+		if strings.HasPrefix(arg, prefix) {
+			arg = strings.TrimPrefix(arg, prefix)
+			return commands.FilterList(
+				commands.GetLabels(arg), arg,
+				func(v string) string { return prefix + v },
+			)
+		}
+	}
+
+	prefixes = []string{"path:", "folder:"}
+	dbPath := strings.TrimPrefix(app.SelectedAccount().AccountConfig().Source, "notmuch://")
+	for _, prefix := range prefixes {
+		if strings.HasPrefix(arg, prefix) {
+			arg = strings.TrimPrefix(arg, prefix)
+			return commands.FilterList(
+				commands.CompletePath(dbPath+arg, true), arg,
+				func(v string) string { return prefix + strings.TrimPrefix(v, dbPath) },
+			)
+		}
+	}
+
+	return commands.FilterList(notmuch_search_terms, arg, nil)
+}
diff --git a/commands/completion_helpers.go b/commands/completion_helpers.go
index 02c13526..7f046630 100644
--- a/commands/completion_helpers.go
+++ b/commands/completion_helpers.go
@@ -29,7 +29,7 @@ func GetAddress(search string) []string {
 		log.Warnf("could not complete header: %v", err)
 	})
 
-	if len(search) > config.Ui.CompletionMinChars && cmpl != nil {
+	if cmpl != nil {
 		addrList, _ := cmpl.ForHeader("to")(search)
 		for _, full := range addrList {
 			addr, err := mail.ParseAddress(full)