Initialize config if it does not exist, set database relative to config dir

internal/config/config.go

@@ -0,0 +1,87 @@
+/*
+Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
+
+Scotty is free software: you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later version.
+
+Scotty is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+Scotty. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package config
+
+import (
+	"os"
+	"path"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+	"go.uploadedlobster.com/scotty/internal/version"
+)
+
+const (
+	defaultDatabase  = "scotty.sqlite3"
+	defaultOAuthHost = "127.0.0.1:2369"
+)
+
+func DefaultConfigDir() string {
+	configDir, err := os.UserConfigDir()
+	cobra.CheckErr(err)
+	return path.Join(configDir, version.AppName)
+}
+
+// initConfig reads in config file and ENV variables if set.
+func InitConfig(cfgFile string) error {
+	configDir := DefaultConfigDir()
+	if cfgFile != "" {
+		// Use given config file
+		viper.SetConfigFile(cfgFile)
+	} else {
+		viper.AddConfigPath(configDir)
+		viper.SetConfigType("toml")
+		viper.SetConfigName(version.AppName)
+		viper.SetConfigPermissions(0640)
+	}
+
+	setDefaults()
+
+	// Create global config if it does not exist
+	if viper.ConfigFileUsed() == "" && cfgFile == "" {
+		if err := os.MkdirAll(configDir, 0750); err == nil {
+			viper.SafeWriteConfig()
+		}
+	}
+
+	// read in environment variables that match
+	viper.AutomaticEnv()
+
+	// If a config file is found, read it in.
+	return viper.ReadInConfig()
+}
+
+func DatabasePath() string {
+	path := viper.GetString("database")
+	if filepath.IsAbs(path) {
+		return path
+	}
+
+	return filepath.Join(getConfigDir(), path)
+}
+
+func setDefaults() {
+	viper.SetDefault("database", defaultDatabase)
+	viper.SetDefault("oauth-host", defaultOAuthHost)
+
+	// Always configure the dump backend as a default service
+	viper.SetDefault("service.dump.backend", "dump")
+}
+
+func getConfigDir() string {
+	return filepath.Dir(viper.ConfigFileUsed())
+}