refactor: migrate db and config packages to use struct-based API

Removed global variables in favor of instance variables. This makes the code more maintainable and making it easier to write unit tests without relying on global state.

Marked the old functions with global state as obsolete, redirecting them to use a new API based on struct in order to rewrite the code using these functions gradually.

internal/config/paths.go

@@ -20,12 +20,6 @@ package config
 
 import (
 	"context"
-	"os"
-	"path/filepath"
-	"sync"
-
-	"github.com/pelletier/go-toml/v2"
-	"plemya-x.ru/alr/pkg/loggerctx"
 )
 
 // Paths contains various paths used by ALR
@@ -38,71 +32,13 @@ type Paths struct {
 	DBPath     string
 }
 
-var (
-	pathsMtx sync.Mutex
-	paths    *Paths
-)
-
 // GetPaths returns a Paths struct.
 // The first time it's called, it'll generate the struct
 // using information from the system.
 // Subsequent calls will return the same value.
+//
+// Depreacted: use struct API
 func GetPaths(ctx context.Context) *Paths {
-	pathsMtx.Lock()
-	defer pathsMtx.Unlock()
-
-	log := loggerctx.From(ctx)
-	if paths == nil {
-		paths = &Paths{}
-
-		cfgDir, err := os.UserConfigDir()
-		if err != nil {
-			log.Fatal("Unable to detect user config directory").Err(err).Send()
-		}
-
-		paths.ConfigDir = filepath.Join(cfgDir, "alr")
-
-		err = os.MkdirAll(paths.ConfigDir, 0o755)
-		if err != nil {
-			log.Fatal("Unable to create ALR config directory").Err(err).Send()
-		}
-
-		paths.ConfigPath = filepath.Join(paths.ConfigDir, "alr.toml")
-
-		if _, err := os.Stat(paths.ConfigPath); err != nil {
-			cfgFl, err := os.Create(paths.ConfigPath)
-			if err != nil {
-				log.Fatal("Unable to create ALR config file").Err(err).Send()
-			}
-
-			err = toml.NewEncoder(cfgFl).Encode(&defaultConfig)
-			if err != nil {
-				log.Fatal("Error encoding default configuration").Err(err).Send()
-			}
-
-			cfgFl.Close()
-		}
-
-		cacheDir, err := os.UserCacheDir()
-		if err != nil {
-			log.Fatal("Unable to detect cache directory").Err(err).Send()
-		}
-
-		paths.CacheDir = filepath.Join(cacheDir, "alr")
-		paths.RepoDir = filepath.Join(paths.CacheDir, "repo")
-		paths.PkgsDir = filepath.Join(paths.CacheDir, "pkgs")
-
-		err = os.MkdirAll(paths.RepoDir, 0o755)
-		if err != nil {
-			log.Fatal("Unable to create repo cache directory").Err(err).Send()
-		}
-
-		err = os.MkdirAll(paths.PkgsDir, 0o755)
-		if err != nil {
-			log.Fatal("Unable to create package cache directory").Err(err).Send()
-		}
-
-		paths.DBPath = filepath.Join(paths.CacheDir, "db")
-	}
-	return paths
+	alrConfig := GetInstance(ctx)
+	return alrConfig.GetPaths(ctx)
 }