// Package config 配置管理模块
// 负责账号、设置、统计数据的持久化存储
package config

import (
	"crypto/rand"
	"encoding/json"
	"fmt"
	"os"
	"sync"
)

// GenerateMachineId 生成 UUID v4 格式的机器码
func GenerateMachineId() string {
	bytes := make([]byte, 16)
	rand.Read(bytes)
	bytes[6] = (bytes[6] & 0x0f) | 0x40 // 版本 4
	bytes[8] = (bytes[8] & 0x3f) | 0x80 // 变体
	return fmt.Sprintf("%08x-%04x-%04x-%04x-%012x",
		bytes[0:4], bytes[4:6], bytes[6:8], bytes[8:10], bytes[10:16])
}

// Account 账号信息
type Account struct {
	// 基本信息
	ID           string `json:"id"`
	Email        string `json:"email,omitempty"`
	UserId       string `json:"userId,omitempty"`
	Nickname     string `json:"nickname,omitempty"`
	
	// 认证信息
	AccessToken  string `json:"accessToken"`
	RefreshToken string `json:"refreshToken"`
	ClientID     string `json:"clientId,omitempty"`
	ClientSecret string `json:"clientSecret,omitempty"`
	AuthMethod   string `json:"authMethod"`          // idc | social
	Provider     string `json:"provider,omitempty"`
	Region       string `json:"region"`
	StartUrl     string `json:"startUrl,omitempty"`
	ExpiresAt    int64  `json:"expiresAt,omitempty"`
	MachineId    string `json:"machineId,omitempty"` // UUID 格式机器码
	
	// 状态
	Enabled bool `json:"enabled"`
	
	// 订阅信息
	SubscriptionType  string `json:"subscriptionType,omitempty"`  // FREE | PRO | PRO_PLUS | POWER
	SubscriptionTitle string `json:"subscriptionTitle,omitempty"`
	DaysRemaining     int    `json:"daysRemaining,omitempty"`
	
	// 使用量
	UsageCurrent  float64 `json:"usageCurrent,omitempty"`
	UsageLimit    float64 `json:"usageLimit,omitempty"`
	UsagePercent  float64 `json:"usagePercent,omitempty"`
	NextResetDate string  `json:"nextResetDate,omitempty"`
	LastRefresh   int64   `json:"lastRefresh,omitempty"`
	
	// 运行时统计
	RequestCount int     `json:"requestCount,omitempty"`
	ErrorCount   int     `json:"errorCount,omitempty"`
	LastUsed     int64   `json:"lastUsed,omitempty"`
	TotalTokens  int     `json:"totalTokens,omitempty"`
	TotalCredits float64 `json:"totalCredits,omitempty"`
}

// Config 全局配置
type Config struct {
	Password      string    `json:"password"`
	Port          int       `json:"port"`
	Host          string    `json:"host"`
	ApiKey        string    `json:"apiKey,omitempty"`
	RequireApiKey bool      `json:"requireApiKey"`
	Accounts      []Account `json:"accounts"`
	
	// 全局统计
	TotalRequests   int     `json:"totalRequests,omitempty"`
	SuccessRequests int     `json:"successRequests,omitempty"`
	FailedRequests  int     `json:"failedRequests,omitempty"`
	TotalTokens     int     `json:"totalTokens,omitempty"`
	TotalCredits    float64 `json:"totalCredits,omitempty"`
}

// AccountInfo 账户信息更新结构
type AccountInfo struct {
	Email             string
	UserId            string
	SubscriptionType  string
	SubscriptionTitle string
	DaysRemaining     int
	UsageCurrent      float64
	UsageLimit        float64
	UsagePercent      float64
	NextResetDate     string
	LastRefresh       int64
}

var (
	cfg     *Config
	cfgLock sync.RWMutex
	cfgPath string
)

// Init 初始化配置
func Init(path string) error {
	cfgPath = path
	return Load()
}

// Load 从文件加载配置
func Load() error {
	cfgLock.Lock()
	defer cfgLock.Unlock()

	data, err := os.ReadFile(cfgPath)
	if err != nil {
		if os.IsNotExist(err) {
			// 创建默认配置
			cfg = &Config{
				Password:      "changeme",
				Port:          8080,
				Host:          "127.0.0.1",
				RequireApiKey: false,
				Accounts:      []Account{},
			}
			return Save()
		}
		return err
	}

	var c Config
	if err := json.Unmarshal(data, &c); err != nil {
		return err
	}
	cfg = &c
	return nil
}

// Save 保存配置到文件
func Save() error {
	data, err := json.MarshalIndent(cfg, "", "  ")
	if err != nil {
		return err
	}
	return os.WriteFile(cfgPath, data, 0600)
}

// SetPassword 设置密码（用于环境变量覆盖）
func SetPassword(password string) {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	cfg.Password = password
}

func Get() *Config {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	return cfg
}

func GetPassword() string {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	return cfg.Password
}

func GetPort() int {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	if cfg.Port == 0 {
		return 8080
	}
	return cfg.Port
}

func GetHost() string {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	if cfg.Host == "" {
		return "127.0.0.1"
	}
	return cfg.Host
}

func GetAccounts() []Account {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	accounts := make([]Account, len(cfg.Accounts))
	copy(accounts, cfg.Accounts)
	return accounts
}

func GetEnabledAccounts() []Account {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	var accounts []Account
	for _, a := range cfg.Accounts {
		if a.Enabled {
			accounts = append(accounts, a)
		}
	}
	return accounts
}

func AddAccount(account Account) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	cfg.Accounts = append(cfg.Accounts, account)
	return Save()
}

func UpdateAccount(id string, account Account) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	for i, a := range cfg.Accounts {
		if a.ID == id {
			cfg.Accounts[i] = account
			return Save()
		}
	}
	return nil
}

func DeleteAccount(id string) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	for i, a := range cfg.Accounts {
		if a.ID == id {
			cfg.Accounts = append(cfg.Accounts[:i], cfg.Accounts[i+1:]...)
			return Save()
		}
	}
	return nil
}

func UpdateAccountToken(id, accessToken, refreshToken string, expiresAt int64) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	for i, a := range cfg.Accounts {
		if a.ID == id {
			cfg.Accounts[i].AccessToken = accessToken
			if refreshToken != "" {
				cfg.Accounts[i].RefreshToken = refreshToken
			}
			cfg.Accounts[i].ExpiresAt = expiresAt
			return Save()
		}
	}
	return nil
}

func GetApiKey() string {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	return cfg.ApiKey
}

func IsApiKeyRequired() bool {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	return cfg.RequireApiKey
}

func UpdateSettings(apiKey string, requireApiKey bool, password string) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	cfg.ApiKey = apiKey
	cfg.RequireApiKey = requireApiKey
	if password != "" {
		cfg.Password = password
	}
	return Save()
}

func UpdateStats(totalReq, successReq, failedReq, totalTokens int, totalCredits float64) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	cfg.TotalRequests = totalReq
	cfg.SuccessRequests = successReq
	cfg.FailedRequests = failedReq
	cfg.TotalTokens = totalTokens
	cfg.TotalCredits = totalCredits
	return Save()
}

func GetStats() (int, int, int, int, float64) {
	cfgLock.RLock()
	defer cfgLock.RUnlock()
	return cfg.TotalRequests, cfg.SuccessRequests, cfg.FailedRequests, cfg.TotalTokens, cfg.TotalCredits
}

func UpdateAccountStats(id string, requestCount, errorCount, totalTokens int, totalCredits float64, lastUsed int64) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	for i, a := range cfg.Accounts {
		if a.ID == id {
			cfg.Accounts[i].RequestCount = requestCount
			cfg.Accounts[i].ErrorCount = errorCount
			cfg.Accounts[i].TotalTokens = totalTokens
			cfg.Accounts[i].TotalCredits = totalCredits
			cfg.Accounts[i].LastUsed = lastUsed
			return Save()
		}
	}
	return nil
}

// UpdateAccountInfo 更新账户的订阅和使用量信息
func UpdateAccountInfo(id string, info AccountInfo) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()
	for i, a := range cfg.Accounts {
		if a.ID == id {
			if info.Email != "" {
				cfg.Accounts[i].Email = info.Email
			}
			if info.UserId != "" {
				cfg.Accounts[i].UserId = info.UserId
			}
			cfg.Accounts[i].SubscriptionType = info.SubscriptionType
			cfg.Accounts[i].SubscriptionTitle = info.SubscriptionTitle
			cfg.Accounts[i].DaysRemaining = info.DaysRemaining
			cfg.Accounts[i].UsageCurrent = info.UsageCurrent
			cfg.Accounts[i].UsageLimit = info.UsageLimit
			cfg.Accounts[i].UsagePercent = info.UsagePercent
			cfg.Accounts[i].NextResetDate = info.NextResetDate
			cfg.Accounts[i].LastRefresh = info.LastRefresh
			return Save()
		}
	}
	return nil
}