package config

import (
	"fmt"
	"os"
	"strings"

	"github.com/spf13/viper"
)

type Config struct {
	Workers      int  `toml:"workers" mapstructure:"workers"`
	Retry        int  `toml:"retry" mapstructure:"retry"`
	NoCleanCache bool `toml:"no_clean_cache" mapstructure:"no_clean_cache" json:"no_clean_cache"`
	Threads      int  `toml:"threads" mapstructure:"threads" json:"threads"`

	Users []userConfig `toml:"users" mapstructure:"users" json:"users"`

	Temp     tempConfig      `toml:"temp" mapstructure:"temp"`
	Log      logConfig       `toml:"log" mapstructure:"log"`
	DB       dbConfig        `toml:"db" mapstructure:"db"`
	Telegram telegramConfig  `toml:"telegram" mapstructure:"telegram"`
	Storages []StorageConfig `toml:"-" mapstructure:"-" json:"storages"`
	// Deprecated
	DeprecatedStorage deprecatedStorageConfig `toml:"storage" mapstructure:"storage"`
}

type tempConfig struct {
	BasePath string `toml:"base_path" mapstructure:"base_path" json:"base_path"`
	CacheTTL int64  `toml:"cache_ttl" mapstructure:"cache_ttl" json:"cache_ttl"`
}

type logConfig struct {
	Level       string `toml:"level" mapstructure:"level"`
	File        string `toml:"file" mapstructure:"file"`
	BackupCount uint   `toml:"backup_count" mapstructure:"backup_count" json:"backup_count"`
}

type dbConfig struct {
	Path string `toml:"path" mapstructure:"path"`
}

type telegramConfig struct {
	Token   string      `toml:"token" mapstructure:"token"`
	AppID   int         `toml:"app_id" mapstructure:"app_id" json:"app_id"`
	AppHash string      `toml:"app_hash" mapstructure:"app_hash" json:"app_hash"`
	Proxy   proxyConfig `toml:"proxy" mapstructure:"proxy"`

	// Deprecated
	Admins []int64 `toml:"admins" mapstructure:"admins"`
}

type proxyConfig struct {
	Enable bool   `toml:"enable" mapstructure:"enable"`
	URL    string `toml:"url" mapstructure:"url"`
}

var Cfg *Config

func Init() error {
	viper.SetConfigName("config")
	viper.AddConfigPath(".")
	viper.AddConfigPath("/etc/saveany/")
	viper.SetConfigType("toml")
	viper.SetEnvPrefix("SAVEANY")
	viper.AutomaticEnv()
	replacer := strings.NewReplacer(".", "_")
	viper.SetEnvKeyReplacer(replacer)

	viper.SetDefault("workers", 3)
	viper.SetDefault("retry", 3)
	viper.SetDefault("threads", 4)

	viper.SetDefault("telegram.app_id", 1025907)
	viper.SetDefault("telegram.app_hash", "452b0359b988148995f22ff0f4229750")

	viper.SetDefault("temp.base_path", "cache/")
	viper.SetDefault("temp.cache_ttl", 3600)

	viper.SetDefault("log.level", "INFO")
	viper.SetDefault("log.file", "logs/saveany.log")
	viper.SetDefault("log.backup_count", 7)

	viper.SetDefault("db.path", "data/saveany.db")

	if err := viper.SafeWriteConfigAs("config.toml"); err != nil {
		if _, ok := err.(viper.ConfigFileAlreadyExistsError); !ok {
			return fmt.Errorf("error saving default config: %w", err)
		}
	}

	if err := viper.ReadInConfig(); err != nil {
		fmt.Println("Error reading config file, ", err)
		os.Exit(1)
	}

	Cfg = &Config{}

	if err := viper.Unmarshal(Cfg); err != nil {
		fmt.Println("Error unmarshalling config file, ", err)
		os.Exit(1)
	}

	if Cfg.Telegram.Admins != nil {
		fmt.Println("警告: 你正在使用旧版 Telegram 管理员配置, 该配置下的用户将可用所有存储.\ntelegram.admins 未来版本将会被废弃, 请参考新的配置文件模板, 使用 users 配置替代.")
		for _, admin := range Cfg.Telegram.Admins {
			found := false
			for _, user := range Cfg.Users {
				if user.ID == admin {
					found = true
					break
				}
			}
			if found {
				continue
			}
			Cfg.Users = append(Cfg.Users, userConfig{
				ID:        admin,
				Storages:  []string{},
				Blacklist: true,
			})
		}
	}

	storagesConfig, err := LoadStorageConfigs(viper.GetViper())
	if err != nil {
		return fmt.Errorf("error loading storage configs: %w", err)
	}
	Cfg.Storages = storagesConfig

	if Cfg.DeprecatedStorage != (deprecatedStorageConfig{}) {
		fmt.Println("\n警告: 你正在使用旧版存储配置, 未来版本将会被废弃.\n请参考新的配置文件模板.")
		transformDeprecatedStorageConfig()
	}

	storageNames := make(map[string]struct{})
	for _, storage := range Cfg.Storages {
		if _, ok := storageNames[storage.GetName()]; ok {
			return fmt.Errorf("重复的存储名: %s", storage.GetName())
		}
		storageNames[storage.GetName()] = struct{}{}
	}

	fmt.Printf("已加载 %d 个存储:\n", len(Cfg.Storages))
	for _, storage := range Cfg.Storages {
		fmt.Printf("  - %s (%s)\n", storage.GetName(), storage.GetType())
	}

	if Cfg.Workers < 1 || Cfg.Retry < 1 {
		return fmt.Errorf("workers 和 retry 必须大于 0, 当前值: workers=%d, retry=%d", Cfg.Workers, Cfg.Retry)
	}

	return nil
}

func Set(key string, value any) {
	viper.Set(key, value)
}

func ReloadConfig() error {
	if err := viper.WriteConfig(); err != nil {
		return err
	}
	if err := viper.ReadInConfig(); err != nil {
		return err
	}
	if error := viper.Unmarshal(Cfg); error != nil {
		return error
	}
	return nil
}