package config

import (
	"encoding/json"
	"log"
	"os"
	"path/filepath"
)

// Config holds persistent application settings.
type Config struct {
	Theme          string `json:"theme"`
	PreferredAccel string `json:"preferredAccel"`
	OutputDir      string `json:"outputDir"`
	NamingRule     string `json:"namingRule"`
	FFmpegPath     string `json:"ffmpegPath"`
	FFprobePath    string `json:"ffprobePath"`

	dir string `json:"-"` // config directory path
}

var current *Config

// Load reads config from AppData, creating defaults if needed.
func Load() *Config {
	dir := appDataDir()
	_ = os.MkdirAll(dir, 0755)

	cfg := &Config{
		Theme:      "light",
		NamingRule: "{name}_{codec}",
		dir:        dir,
	}

	path := filepath.Join(dir, "config.json")
	data, err := os.ReadFile(path)
	if err != nil {
		log.Printf("[config] read %s: %v (creating new)", path, err)
		cfg.Save()
		log.Printf("[config] created new config at %s", path)
		return cfg
	}

	if err := json.Unmarshal(data, cfg); err != nil {
		log.Printf("[config] corrupted config, resetting: %v", err)
		cfg = &Config{Theme: "light", NamingRule: "{name}_{codec}", dir: dir}
		cfg.Save()
		return cfg
	}

	cfg.dir = dir
	log.Printf("[config] loaded from %s: theme=%s accel=%s", path, cfg.Theme, cfg.PreferredAccel)
	current = cfg
	return cfg
}

// Save writes the current config to disk.
func (c *Config) Save() {
	path := filepath.Join(c.dir, "config.json")
	data, err := json.MarshalIndent(c, "", "  ")
	if err != nil {
		log.Printf("[config] marshal error: %v", err)
		return
	}
	if err := os.WriteFile(path, data, 0644); err != nil {
		log.Printf("[config] write error: %v", err)
		return
	}
	log.Printf("[config] saved: accel=%s out=%s", c.PreferredAccel, c.OutputDir)
}

// BinDir returns the directory where extracted ffmpeg binaries live.
func (c *Config) BinDir() string {
	d := filepath.Join(c.dir, "bin")
	os.MkdirAll(d, 0755)
	return d
}

// Get returns the current global config, loading if needed.
func Get() *Config {
	if current == nil {
		return Load()
	}
	return current
}