refactor: better project structure (#35)

This project is starting to grow, and I've seen flaws in the initial
project structure design
I think I'll restructure the entire project directory for better
scalability and also cleaner

internal/config/config.go

@@ -0,0 +1,205 @@
+package config
+
+import (
+	"encoding"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"github.com/BurntSushi/toml"
+)
+
+type Duration time.Duration
+
+var (
+	_ encoding.TextUnmarshaler = (*Duration)(nil)
+	_ encoding.TextMarshaler   = (*Duration)(nil)
+)
+
+func (d *Duration) UnmarshalText(text []byte) error {
+	dur, err := time.ParseDuration(string(text))
+	if err != nil {
+		return err
+	}
+	*d = Duration(dur)
+	return nil
+}
+
+func (d Duration) MarshalText() ([]byte, error) {
+	return []byte(time.Duration(d).String()), nil
+}
+
+type CoreConfig struct {
+	Version int    `toml:"version"`
+	Shell   string `toml:"shell"`
+	Mode    string `toml:"mode"`
+	Debug   bool   `toml:"debug"`
+}
+
+type UIConfig struct {
+	Style          string `toml:"style"`
+	GhostText      bool   `toml:"ghost-text"`
+	MaxSuggestions int    `toml:"max-suggestions"`
+	MaxHeight      int    `toml:"max-height"`
+	NerdFonts      bool   `toml:"nerd-fonts"`
+}
+
+type GitConfig struct {
+	FilterActiveBranch  bool `toml:"filter-active-branch"`
+	DeduplicateBranches bool `toml:"deduplicate-branches"`
+}
+
+type UpdaterConfig struct {
+	CheckOnStartup bool     `toml:"check-on-startup"`
+	Channel        string   `toml:"channel"`
+	CheckInterval  Duration `toml:"check-interval"`
+}
+
+type SuggestOnEmptyConfig struct {
+	Enabled       bool `toml:"enabled"`
+	DebounceMS    int  `toml:"debounce_ms"`
+	MinIntervalMS int  `toml:"min_interval_ms"`
+}
+
+type ProviderConfig struct {
+	InheritedFrom    string         `toml:"inherited_from"`
+	Endpoint         string         `toml:"endpoint"`
+	APIKey           string         `toml:"api_key"`
+	APIKeyEnv        string         `toml:"api_key_env"`
+	Model            string         `toml:"model"`
+	TimeoutMS        int            `toml:"timeout_ms"`
+	ExtraRequestBody map[string]any `toml:"extra_request_body"`
+}
+
+type AIConfig struct {
+	Enabled        bool                      `toml:"enabled"`
+	Provider       string                    `toml:"provider"`
+	DebounceMS     int                       `toml:"debounce_ms"`
+	MinIntervalMS  int                       `toml:"min_interval_ms"`
+	Providers      map[string]ProviderConfig `toml:"providers"`
+	SuggestOnEmpty SuggestOnEmptyConfig      `toml:"suggest_on_empty"`
+}
+
+func (c *AIConfig) GetActiveProvider() (ProviderConfig, bool) {
+	if c.Providers == nil {
+		return ProviderConfig{}, false
+	}
+	p, ok := c.Providers[c.Provider]
+	return p, ok
+}
+
+func (p *ProviderConfig) GetAPIKey() string {
+	if p.APIKey != "" {
+		return p.APIKey
+	}
+	if p.APIKeyEnv != "" {
+		return os.Getenv(p.APIKeyEnv)
+	}
+	return ""
+}
+
+type Config struct {
+	Core    CoreConfig    `toml:"core"`
+	UI      UIConfig      `toml:"ui"`
+	Git     GitConfig     `toml:"git"`
+	Updater UpdaterConfig `toml:"updater"`
+	AI      AIConfig      `toml:"ai"`
+}
+
+var (
+	activeConfig *Config
+	once         sync.Once
+)
+
+func Get() *Config {
+	once.Do(func() {
+		if activeConfig == nil {
+			activeConfig = DefaultConfig()
+		}
+	})
+	return activeConfig
+}
+
+func Init(cfg *Config) {
+	activeConfig = cfg
+	once.Do(func() {})
+}
+
+func Load() (*Config, error) {
+	cfg := DefaultConfig()
+
+	path, err := ConfigPath()
+	if err == nil {
+		if _, statErr := os.Stat(path); statErr == nil {
+			data, readErr := os.ReadFile(path)
+			if readErr != nil {
+				return cfg, fmt.Errorf("config: read %s: %w", path, readErr)
+			}
+			if _, decodeErr := toml.Decode(string(data), cfg); decodeErr != nil {
+				return cfg, fmt.Errorf("config: parse %s: %w", path, decodeErr)
+			}
+		}
+	}
+
+	applyEnv(cfg)
+
+	if err := validate(cfg); err != nil {
+		return cfg, fmt.Errorf("config: invalid value: %w", err)
+	}
+
+	return cfg, nil
+}
+
+func Save(cfg *Config) error {
+	path, err := ConfigPath()
+	if err != nil {
+		return err
+	}
+
+	err = os.MkdirAll(filepath.Dir(path), 0755)
+	if err != nil {
+		return err
+	}
+
+	file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	enc := toml.NewEncoder(file)
+	if err := enc.Encode(cfg); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func validate(cfg *Config) error {
+	validModes := map[string]bool{"last": true, "spec": true, "history": true}
+	if cfg.Core.Mode != "" && !validModes[cfg.Core.Mode] {
+		return fmt.Errorf("core.mode: invalid value %q (want: last|spec|history)", cfg.Core.Mode)
+	}
+
+	validShells := map[string]bool{"": true, "bash": true, "zsh": true, "fish": true}
+	if !validShells[cfg.Core.Shell] {
+		return fmt.Errorf("core.shell: invalid value %q (want: bash|zsh|fish)", cfg.Core.Shell)
+	}
+
+	validChannels := map[string]bool{"stable": true, "nightly": true}
+	if !validChannels[cfg.Updater.Channel] {
+		return fmt.Errorf("updater.channel: invalid value %q (want: stable|nightly)", cfg.Updater.Channel)
+	}
+
+	if cfg.UI.MaxSuggestions < 1 || cfg.UI.MaxSuggestions > 500 {
+		return fmt.Errorf("ui.max-suggestions: must be between 1 and 500")
+	}
+
+	if cfg.UI.MaxHeight < 3 || cfg.UI.MaxHeight > 50 {
+		return fmt.Errorf("ui.max-height: must be between 3 and 50")
+	}
+
+	return nil
+}