config: add log-file and log-level settings

Allow configuring persistent logging to file with a log level. When
redirecting the output of aerc to a file these two settings are ignored
and all messages are printed to stdout.

Suggested-by: Moritz Poldrack <moritz@poldrack.dev>
Suggested-by: Tim Culverhouse <tim@timculverhouse.com>
Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Tim Culverhouse <tim@timculverhouse.com>

4 files changed, 57 insertions, 14 deletions

diff --git a/config/aerc.conf b/config/aerc.conf
index 557cea8e..adfa1e12 100644
--- a/config/aerc.conf
+++ b/config/aerc.conf
@@ -24,6 +24,21 @@ pgp-provider=internal
 # Default: false
 unsafe-accounts-conf=false
 
+# Output log messages to specified file. A path starting with ~/ is expanded to
+# the user home dir. When redirecting aerc's output to a file using > shell
+# redirection, this setting is ignored and log messages are printed to stdout.
+#
+# Default: ""
+#log-file=
+
+# Only log messages above the specified level to log-file. Supported levels
+# are: debug, info, warn and error. When redirecting aerc's output to a file
+# using > shell redirection, this setting is ignored and the log level is
+# forced to debug.
+#
+# Default: info
+#log-level=info
+
 [ui]
 #
 # Describes the format for each row in a mailbox view. This field is compatible
diff --git a/config/binds.go b/config/binds.go
index 63fc335a..4b32e6da 100644
--- a/config/binds.go
+++ b/config/binds.go
@@ -72,7 +72,7 @@ func (config *AercConfig) parseBinds(root string) error {
 
 	filename := path.Join(root, "binds.conf")
 	if _, err := os.Stat(filename); errors.Is(err, os.ErrNotExist) {
-		logging.Debugf("%s not found, installing the system default", filename)
+		fmt.Printf("%s not found, installing the system default", filename)
 		if err := installTemplate(root, "binds.conf"); err != nil {
 			return err
 		}
diff --git a/config/config.go b/config/config.go
index 049b305f..c4794cc1 100644
--- a/config/config.go
+++ b/config/config.go
@@ -2,6 +2,7 @@ package config
 
 import (
 	"errors"
+	"fmt"
 	"log"
 	"os"
 	"path"
@@ -11,8 +12,6 @@ import (
 	"github.com/go-ini/ini"
 	"github.com/kyoh86/xdg"
 	"github.com/mitchellh/go-homedir"
-
-	"git.sr.ht/~rjarry/aerc/logging"
 )
 
 type AercConfig struct {
@@ -119,14 +118,12 @@ func LoadConfigFromFile(root *string, accts []string) (*AercConfig, error) {
 
 	// if it doesn't exist copy over the template, then load
 	if _, err := os.Stat(filename); errors.Is(err, os.ErrNotExist) {
-		logging.Debugf("%s not found, installing the system default", filename)
+		fmt.Printf("%s not found, installing the system default", filename)
 		if err := installTemplate(*root, "aerc.conf"); err != nil {
 			return nil, err
 		}
 	}
 
-	logging.Infof("Parsing configuration from %s", filename)
-
 	file, err := ini.LoadSources(ini.LoadOptions{
 		KeyValueDelimiters: "=",
 	}, filename)
@@ -147,6 +144,9 @@ func LoadConfigFromFile(root *string, accts []string) (*AercConfig, error) {
 		Openers:         make(map[string][]string),
 	}
 
+	if err := config.parseGeneral(file); err != nil {
+		return nil, err
+	}
 	if err := config.parseFilters(file); err != nil {
 		return nil, err
 	}
@@ -168,9 +168,6 @@ func LoadConfigFromFile(root *string, accts []string) (*AercConfig, error) {
 	if err := config.parseUi(file); err != nil {
 		return nil, err
 	}
-	if err := config.parseGeneral(file); err != nil {
-		return nil, err
-	}
 	if err := config.parseTemplates(file); err != nil {
 		return nil, err
 	}
diff --git a/config/general.go b/config/general.go
index 7f8ed2ef..2a462a3e 100644
--- a/config/general.go
+++ b/config/general.go
@@ -2,38 +2,69 @@ package config
 
 import (
 	"fmt"
+	"os"
 
 	"git.sr.ht/~rjarry/aerc/logging"
 	"github.com/go-ini/ini"
+	"github.com/mattn/go-isatty"
+	"github.com/mitchellh/go-homedir"
 )
 
 type GeneralConfig struct {
-	DefaultSavePath    string `ini:"default-save-path"`
-	PgpProvider        string `ini:"pgp-provider"`
-	UnsafeAccountsConf bool   `ini:"unsafe-accounts-conf"`
+	DefaultSavePath    string           `ini:"default-save-path"`
+	PgpProvider        string           `ini:"pgp-provider"`
+	UnsafeAccountsConf bool             `ini:"unsafe-accounts-conf"`
+	LogFile            string           `ini:"log-file"`
+	LogLevel           logging.LogLevel `ini:"-"`
 }
 
 func defaultGeneralConfig() GeneralConfig {
 	return GeneralConfig{
 		PgpProvider:        "internal",
 		UnsafeAccountsConf: false,
+		LogLevel:           logging.INFO,
 	}
 }
 
 func (config *AercConfig) parseGeneral(file *ini.File) error {
+	var level *ini.Key
+	var logFile *os.File
+
 	gen, err := file.GetSection("general")
 	if err != nil {
 		goto end
 	}
-
 	if err := gen.MapTo(&config.General); err != nil {
 		return err
 	}
+	level, err = gen.GetKey("log-level")
+	if err == nil {
+		l, err := logging.ParseLevel(level.String())
+		if err != nil {
+			return err
+		}
+		config.General.LogLevel = l
+	}
 	if err := config.General.validatePgpProvider(); err != nil {
 		return err
 	}
-
 end:
+	if !isatty.IsTerminal(os.Stdout.Fd()) {
+		logFile = os.Stdout
+		// redirected to file, force DEBUG level
+		config.General.LogLevel = logging.DEBUG
+	} else if config.General.LogFile != "" {
+		path, err := homedir.Expand(config.General.LogFile)
+		if err != nil {
+			return fmt.Errorf("log-file: %w", err)
+		}
+		logFile, err = os.OpenFile(path,
+			os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o600)
+		if err != nil {
+			return fmt.Errorf("log-file: %w", err)
+		}
+	}
+	logging.Init(logFile, config.General.LogLevel)
 	logging.Debugf("aerc.conf: [general] %#v", config.General)
 	return nil
 }