package service

import (
	"encoding/json"
	"errors"
	"photowall/internal/model"
	"strconv"
	"sync"

	"gorm.io/gorm"
)

type ConfigService struct {
	db    *gorm.DB
	cache map[string]string
	mu    sync.RWMutex
}

func NewConfigService(db *gorm.DB) *ConfigService {
	return &ConfigService{
		db:    db,
		cache: make(map[string]string),
	}
}

// defaultConfigs 所有可配置项及说明
var defaultConfigs = []model.SystemConfig{
	// ===== 基础配置 =====
	{Key: "site_name", Value: "PhotoWall 毕业照墙", Label: "站点名称", Description: "显示在浏览器标题和登录页的站点名称", Category: "basic", Placeholder: "PhotoWall 毕业照墙", Sort: 1},
	{Key: "jwt_secret", Value: "photowall-dev-secret-change-in-prod", Label: "JWT 密钥", Description: "用于签发和验证登录Token，生产环境务必修改为随机字符串", Category: "basic", Placeholder: "随机字符串至少32位", Sort: 2},
	{Key: "jwt_expire_hours", Value: "3", Label: "登录有效期(小时)", Description: "用户登录后Token的有效时长，超时需重新登录", Category: "basic", Placeholder: "3", Sort: 3},
	{Key: "audit_grace_days", Value: "30", Label: "审核补齐期限(天)", Description: "班级被打回后，超过该天数未补齐则自动删除", Category: "basic", Placeholder: "30", Sort: 4},

	// ===== 极验行为验证 =====
	{Key: "geetest_id", Value: "662e68b7ce24be211fa97a53975c5d96", Label: "极验 ID", Description: "极验行为验证的Captcha ID，用于防机器人和暴力破解", Category: "geetest", Placeholder: "如：64a####################", DocLink: "https://www.geetest.com 注册后在应用管理获取", Sort: 1},
	{Key: "geetest_key", Value: "2789075bc2b25a04c0f7c5420bfa3d6f", Label: "极验 Key", Description: "极验行为验证的私钥，与ID配对使用", Category: "geetest", Placeholder: "如：64a####################", DocLink: "https://www.geetest.com 注册后在应用管理获取", Sort: 2},

	// ===== 短信验证码 =====
	{Key: "sms_provider", Value: "aliyun", Label: "短信服务商", Description: "选择短信服务商，目前支持阿里云和腾讯云", Category: "sms", Placeholder: "aliyun 或 tencent", DocLink: "阿里云: https://dysms.console.aliyun.com | 腾讯云: https://console.cloud.tencent.com/sms", Sort: 1},
	{Key: "sms_access_key", Value: "", Label: "短信 AccessKey", Description: "短信服务商的访问密钥ID", Category: "sms", Placeholder: "如：LTAI5t################", DocLink: "阿里云: https://ram.console.aliyun.com | 腾讯云: https://console.cloud.tencent.com/cam", Sort: 2},
	{Key: "sms_secret_key", Value: "", Label: "短信 SecretKey", Description: "短信服务商的访问密钥密码", Category: "sms", Placeholder: "如：########################", DocLink: "与AccessKey在同一页面获取", Sort: 3},
	{Key: "sms_sign_name", Value: "", Label: "短信签名", Description: "短信签名，需在短信服务商审核通过，如：PhotoWall", Category: "sms", Placeholder: "如：PhotoWall", DocLink: "在短信服务商控制台的国内消息-签名管理中申请", Sort: 4},
	{Key: "sms_template_code", Value: "", Label: "短信模板CODE", Description: "短信模板编码，需在短信服务商审核通过，模板内容需包含验证码变量", Category: "sms", Placeholder: "如：SMS_123456789", DocLink: "在短信服务商控制台的国内消息-模板管理中申请", Sort: 5},

	// ===== 微信扫码登录 =====
	{Key: "wechat_app_id", Value: "", Label: "微信 AppID", Description: "微信开放平台应用的AppID，用于扫码登录", Category: "wechat", Placeholder: "如：wx################", DocLink: "https://open.weixin.qq.com 注册开发者账号并创建网站应用", Sort: 1},
	{Key: "wechat_app_secret", Value: "", Label: "微信 AppSecret", Description: "微信开放平台应用的密钥，与AppID配对", Category: "wechat", Placeholder: "如：########################", DocLink: "在微信开放平台应用详情中查看", Sort: 2},
	{Key: "wechat_redirect_uri", Value: "", Label: "微信回调地址", Description: "微信授权后的回调URL，需与开放平台配置一致，需HTTPS", Category: "wechat", Placeholder: "如：https://yourdomain.com/api/auth/wechat/callback", DocLink: "在微信开放平台应用的网站应用-授权回调域中配置", Sort: 3},

	// ===== 存储配置 =====
	{Key: "upload_dir", Value: "uploads", Label: "上传目录", Description: "图片文件存储的相对路径", Category: "storage", Placeholder: "uploads", Sort: 1},
	{Key: "max_file_size_mb", Value: "10", Label: "单文件大小上限(MB)", Description: "上传图片的最大大小限制", Category: "storage", Placeholder: "10", Sort: 2},
}

// InitDefaults 初始化默认配置（不存在则创建，已存在但为空且默认有初始值则补齐）
func (s *ConfigService) InitDefaults() error {
	for _, c := range defaultConfigs {
		var existing model.SystemConfig
		err := s.db.Where("`key` = ?", c.Key).First(&existing).Error
		if errors.Is(err, gorm.ErrRecordNotFound) {
			if err := s.db.Create(&c).Error; err != nil {
				return err
			}
		} else if err == nil && existing.Value == "" && c.Value != "" {
			s.db.Model(&existing).Update("value", c.Value)
		}
	}

	// 预热内存缓存
	var list []model.SystemConfig
	if err := s.db.Find(&list).Error; err == nil {
		s.mu.Lock()
		for _, item := range list {
			s.cache[item.Key] = item.Value
		}
		s.mu.Unlock()
	}
	return nil
}

// GetAll 获取所有配置（按分类和排序）
func (s *ConfigService) GetAll() ([]model.SystemConfig, error) {
	var list []model.SystemConfig
	err := s.db.Order("category, sort").Find(&list).Error
	return list, err
}

// GetByCategory 按分类获取配置
func (s *ConfigService) GetByCategory(category string) ([]model.SystemConfig, error) {
	var list []model.SystemConfig
	err := s.db.Where("category = ?", category).Order("sort").Find(&list).Error
	return list, err
}

// UpdateConfigReq 更新配置请求（支持 map 与 key-value 列表格式）
type UpdateConfigReq struct {
	Configs map[string]string `json:"configs"`
}

func (r *UpdateConfigReq) UnmarshalJSON(data []byte) error {
	// 格式1: {"configs": {"k1": "v1", "k2": "v2"}}
	var auxMap struct {
		Configs map[string]string `json:"configs"`
	}
	if err := json.Unmarshal(data, &auxMap); err == nil && auxMap.Configs != nil {
		r.Configs = auxMap.Configs
		return nil
	}

	// 格式2: {"configs": [{"key": "k1", "value": "v1"}]}
	var auxList struct {
		Configs []struct {
			Key   string `json:"key"`
			Value string `json:"value"`
		} `json:"configs"`
	}
	if err := json.Unmarshal(data, &auxList); err == nil && auxList.Configs != nil {
		r.Configs = make(map[string]string, len(auxList.Configs))
		for _, item := range auxList.Configs {
			r.Configs[item.Key] = item.Value
		}
		return nil
	}

	// 格式3: 直接传入 map: {"k1": "v1"}
	var directMap map[string]string
	if err := json.Unmarshal(data, &directMap); err == nil {
		r.Configs = directMap
		return nil
	}

	return errors.New("invalid configs format")
}

// Update 批量更新配置
func (s *ConfigService) Update(req *UpdateConfigReq) error {
	err := s.db.Transaction(func(tx *gorm.DB) error {
		for key, value := range req.Configs {
			if err := tx.Model(&model.SystemConfig{}).Where("`key` = ?", key).Update("value", value).Error; err != nil {
				return err
			}
		}
		return nil
	})
	if err == nil {
		s.mu.Lock()
		for key, value := range req.Configs {
			s.cache[key] = value
		}
		s.mu.Unlock()
	}
	return err
}

// GetValue 获取单个配置值（优先走内存缓存）
func (s *ConfigService) GetValue(key string) string {
	s.mu.RLock()
	val, ok := s.cache[key]
	s.mu.RUnlock()
	if ok {
		return val
	}

	var c model.SystemConfig
	if err := s.db.Where("`key` = ?", key).First(&c).Error; err != nil {
		return ""
	}

	s.mu.Lock()
	s.cache[key] = c.Value
	s.mu.Unlock()

	return c.Value
}

// GetInt 获取整数配置值，解析失败或不存在则返回 def
func (s *ConfigService) GetInt(key string, def int) int {
	val := s.GetValue(key)
	if val == "" {
		return def
	}
	if n, err := strconv.Atoi(val); err == nil {
		return n
	}
	return def
}

// GetGeetestConfig 获取极验验证配置
func (s *ConfigService) GetGeetestConfig() (id, key string) {
	return s.GetValue("geetest_id"), s.GetValue("geetest_key")
}

// GetSmsConfig 获取短信配置
func (s *ConfigService) GetSmsConfig() (provider, accessKey, secretKey, signName, templateCode string) {
	return s.GetValue("sms_provider"),
		s.GetValue("sms_access_key"),
		s.GetValue("sms_secret_key"),
		s.GetValue("sms_sign_name"),
		s.GetValue("sms_template_code")
}

// GetWechatConfig 获取微信登录配置
func (s *ConfigService) GetWechatConfig() (appID, appSecret, redirectURI string) {
	return s.GetValue("wechat_app_id"),
		s.GetValue("wechat_app_secret"),
		s.GetValue("wechat_redirect_uri")
}