package handler

import (
	"bytes"
	"carrotskin/internal/container"
	"carrotskin/internal/model"
	"carrotskin/internal/service"
	"carrotskin/pkg/utils"
	"io"
	"net/http"
	"regexp"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

// 常量定义
const (
	ErrInternalServer = "服务器内部错误"
	// 错误类型
	ErrInvalidEmailFormat = "邮箱格式不正确"
	ErrInvalidPassword    = "密码必须至少包含8个字符，只能包含字母、数字和特殊字符"
	ErrWrongPassword      = "密码错误"
	ErrUserNotMatch       = "用户不匹配"

	// 错误消息
	ErrInvalidRequest      = "请求格式无效"
	ErrJoinServerFailed    = "加入服务器失败"
	ErrServerIDRequired    = "服务器ID不能为空"
	ErrUsernameRequired    = "用户名不能为空"
	ErrSessionVerifyFailed = "会话验证失败"
	ErrProfileNotFound     = "未找到用户配置文件"
	ErrInvalidParams       = "无效的请求参数"
	ErrEmptyUserID         = "用户ID为空"
	ErrUnauthorized        = "无权操作此配置文件"
	ErrGetProfileService   = "获取配置文件服务失败"

	// 成功信息
	SuccessProfileCreated = "创建成功"
	MsgRegisterSuccess    = "注册成功"

	// 错误消息
	ErrGetProfile         = "获取配置文件失败"
	ErrGetTextureService  = "获取材质服务失败"
	ErrInvalidContentType = "无效的请求内容类型"
	ErrParseMultipartForm = "解析多部分表单失败"
	ErrGetFileFromForm    = "从表单获取文件失败"
	ErrInvalidFileType    = "无效的文件类型，仅支持PNG图片"
	ErrSaveTexture        = "保存材质失败"
	ErrSetTexture         = "设置材质失败"
	ErrGetTexture         = "获取材质失败"

	// 内存限制
	MaxMultipartMemory = 32 << 20 // 32 MB

	// 材质类型
	TextureTypeSkin = "SKIN"
	TextureTypeCape = "CAPE"

	// 内容类型
	ContentTypePNG       = "image/png"
	ContentTypeMultipart = "multipart/form-data"

	// 表单参数
	FormKeyModel = "model"
	FormKeyFile  = "file"

	// 元数据键
	MetaKeyModel = "model"
)

// 正则表达式
var (
	// 邮箱正则表达式
	emailRegex = regexp.MustCompile(`^[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}$`)

	// 密码强度正则表达式（最少8位，只允许字母、数字和特定特殊字符）
	passwordRegex = regexp.MustCompile(`^[a-zA-Z0-9!@#$%^&*]{8,}$`)
)

// 请求结构体
type (
	// AuthenticateRequest 认证请求
	AuthenticateRequest struct {
		Agent       map[string]interface{} `json:"agent"`
		ClientToken string                 `json:"clientToken"`
		Identifier  string                 `json:"username" binding:"required"`
		Password    string                 `json:"password" binding:"required"`
		RequestUser bool                   `json:"requestUser"`
	}

	// ValidTokenRequest 验证令牌请求
	ValidTokenRequest struct {
		AccessToken string `json:"accessToken" binding:"required"`
		ClientToken string `json:"clientToken"`
	}

	// RefreshRequest 刷新令牌请求
	RefreshRequest struct {
		AccessToken     string                 `json:"accessToken" binding:"required"`
		ClientToken     string                 `json:"clientToken"`
		RequestUser     bool                   `json:"requestUser"`
		SelectedProfile map[string]interface{} `json:"selectedProfile"`
	}

	// SignOutRequest 登出请求
	SignOutRequest struct {
		Email    string `json:"username" binding:"required"`
		Password string `json:"password" binding:"required"`
	}

	// JoinServerRequest 加入服务器请求
	JoinServerRequest struct {
		ServerID        string `json:"serverId" binding:"required"`
		AccessToken     string `json:"accessToken" binding:"required"`
		SelectedProfile string `json:"selectedProfile" binding:"required"`
	}
)

// 响应结构体
type (
	// AuthenticateResponse 认证响应
	AuthenticateResponse struct {
		AccessToken       string                   `json:"accessToken"`
		ClientToken       string                   `json:"clientToken"`
		SelectedProfile   map[string]interface{}   `json:"selectedProfile,omitempty"`
		AvailableProfiles []map[string]interface{} `json:"availableProfiles"`
		User              map[string]interface{}   `json:"user,omitempty"`
	}

	// RefreshResponse 刷新令牌响应
	RefreshResponse struct {
		AccessToken     string                 `json:"accessToken"`
		ClientToken     string                 `json:"clientToken"`
		SelectedProfile map[string]interface{} `json:"selectedProfile,omitempty"`
		User            map[string]interface{} `json:"user,omitempty"`
	}
)

// APIResponse API响应
type APIResponse struct {
	Status int         `json:"status"`
	Data   interface{} `json:"data"`
	Error  interface{} `json:"error"`
}

// standardResponse 生成标准响应
func standardResponse(c *gin.Context, status int, data interface{}, err interface{}) {
	c.JSON(status, APIResponse{
		Status: status,
		Data:   data,
		Error:  err,
	})
}

// YggdrasilHandler Yggdrasil API处理器
type YggdrasilHandler struct {
	container *container.Container
	logger    *zap.Logger
}

// NewYggdrasilHandler 创建YggdrasilHandler实例
func NewYggdrasilHandler(c *container.Container) *YggdrasilHandler {
	return &YggdrasilHandler{
		container: c,
		logger:    c.Logger,
	}
}

// Authenticate 用户认证
func (h *YggdrasilHandler) Authenticate(c *gin.Context) {
	rawData, err := io.ReadAll(c.Request.Body)
	if err != nil {
		h.logger.Error("读取请求体失败", zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": "读取请求体失败"})
		return
	}
	c.Request.Body = io.NopCloser(bytes.NewBuffer(rawData))

	var request AuthenticateRequest
	if err = c.ShouldBindJSON(&request); err != nil {
		h.logger.Error("解析认证请求失败", zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var userId int64
	var profile *model.Profile
	var UUID string

	if emailRegex.MatchString(request.Identifier) {
		userId, err = service.GetUserIDByEmail(h.container.DB, request.Identifier)
	} else {
		profile, err = service.GetProfileByProfileName(h.container.DB, request.Identifier)
		if err != nil {
			h.logger.Error("用户名不存在", zap.String("identifier", request.Identifier), zap.Error(err))
			c.JSON(http.StatusForbidden, gin.H{"error": err.Error()})
			return
		}
		userId = profile.UserID
		UUID = profile.UUID
	}

	if err != nil {
		h.logger.Warn("认证失败: 用户不存在", zap.String("identifier", request.Identifier), zap.Error(err))
		c.JSON(http.StatusForbidden, gin.H{"error": "用户不存在"})
		return
	}

	if err := service.VerifyPassword(h.container.DB, request.Password, userId); err != nil {
		h.logger.Warn("认证失败: 密码错误", zap.Error(err))
		c.JSON(http.StatusForbidden, gin.H{"error": ErrWrongPassword})
		return
	}

	selectedProfile, availableProfiles, accessToken, clientToken, err := h.container.TokenService.Create(userId, UUID, request.ClientToken)
	if err != nil {
		h.logger.Error("生成令牌失败", zap.Error(err), zap.Int64("userId", userId))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	user, err := h.container.UserService.GetByID(userId)
	if err != nil {
		h.logger.Error("获取用户信息失败", zap.Error(err), zap.Int64("userId", userId))
	}

	availableProfilesData := make([]map[string]interface{}, 0, len(availableProfiles))
	for _, p := range availableProfiles {
		availableProfilesData = append(availableProfilesData, service.SerializeProfile(h.container.DB, h.logger, h.container.Redis, *p))
	}

	response := AuthenticateResponse{
		AccessToken:       accessToken,
		ClientToken:       clientToken,
		AvailableProfiles: availableProfilesData,
	}

	if selectedProfile != nil {
		response.SelectedProfile = service.SerializeProfile(h.container.DB, h.logger, h.container.Redis, *selectedProfile)
	}

	if request.RequestUser && user != nil {
		response.User = service.SerializeUser(h.logger, user, UUID)
	}

	h.logger.Info("用户认证成功", zap.Int64("userId", userId))
	c.JSON(http.StatusOK, response)
}

// ValidToken 验证令牌
func (h *YggdrasilHandler) ValidToken(c *gin.Context) {
	var request ValidTokenRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		h.logger.Error("解析验证令牌请求失败", zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if h.container.TokenService.Validate(request.AccessToken, request.ClientToken) {
		h.logger.Info("令牌验证成功", zap.String("accessToken", request.AccessToken))
		c.JSON(http.StatusNoContent, gin.H{"valid": true})
	} else {
		h.logger.Warn("令牌验证失败", zap.String("accessToken", request.AccessToken))
		c.JSON(http.StatusForbidden, gin.H{"valid": false})
	}
}

// RefreshToken 刷新令牌
func (h *YggdrasilHandler) RefreshToken(c *gin.Context) {
	var request RefreshRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		h.logger.Error("解析刷新令牌请求失败", zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	UUID, err := h.container.TokenService.GetUUIDByAccessToken(request.AccessToken)
	if err != nil {
		h.logger.Warn("刷新令牌失败: 无效的访问令牌", zap.String("token", request.AccessToken), zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	userID, _ := h.container.TokenService.GetUserIDByAccessToken(request.AccessToken)
	UUID = utils.FormatUUID(UUID)

	profile, err := h.container.ProfileService.GetByUUID(UUID)
	if err != nil {
		h.logger.Error("刷新令牌失败: 无法获取用户信息", zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var profileData map[string]interface{}
	var userData map[string]interface{}
	var profileID string

	if request.SelectedProfile != nil {
		profileIDValue, ok := request.SelectedProfile["id"]
		if !ok {
			h.logger.Error("刷新令牌失败: 缺少配置文件ID", zap.Int64("userId", userID))
			c.JSON(http.StatusBadRequest, gin.H{"error": "缺少配置文件ID"})
			return
		}

		profileID, ok = profileIDValue.(string)
		if !ok {
			h.logger.Error("刷新令牌失败: 配置文件ID类型错误", zap.Int64("userId", userID))
			c.JSON(http.StatusBadRequest, gin.H{"error": "配置文件ID必须是字符串"})
			return
		}

		profileID = utils.FormatUUID(profileID)

		if profile.UserID != userID {
			h.logger.Warn("刷新令牌失败: 用户不匹配",
				zap.Int64("userId", userID),
				zap.Int64("profileUserId", profile.UserID),
			)
			c.JSON(http.StatusBadRequest, gin.H{"error": ErrUserNotMatch})
			return
		}

		profileData = service.SerializeProfile(h.container.DB, h.logger, h.container.Redis, *profile)
	}

	user, _ := h.container.UserService.GetByID(userID)
	if request.RequestUser && user != nil {
		userData = service.SerializeUser(h.logger, user, UUID)
	}

	newAccessToken, newClientToken, err := h.container.TokenService.Refresh(
		request.AccessToken,
		request.ClientToken,
		profileID,
	)
	if err != nil {
		h.logger.Error("刷新令牌失败", zap.Error(err), zap.Int64("userId", userID))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	h.logger.Info("刷新令牌成功", zap.Int64("userId", userID))
	c.JSON(http.StatusOK, RefreshResponse{
		AccessToken:     newAccessToken,
		ClientToken:     newClientToken,
		SelectedProfile: profileData,
		User:            userData,
	})
}

// InvalidToken 使令牌失效
func (h *YggdrasilHandler) InvalidToken(c *gin.Context) {
	var request ValidTokenRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		h.logger.Error("解析使令牌失效请求失败", zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	h.container.TokenService.Invalidate(request.AccessToken)
	h.logger.Info("令牌已失效", zap.String("token", request.AccessToken))
	c.JSON(http.StatusNoContent, gin.H{})
}

// SignOut 用户登出
func (h *YggdrasilHandler) SignOut(c *gin.Context) {
	var request SignOutRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		h.logger.Error("解析登出请求失败", zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if !emailRegex.MatchString(request.Email) {
		h.logger.Warn("登出失败: 邮箱格式不正确", zap.String("email", request.Email))
		c.JSON(http.StatusBadRequest, gin.H{"error": ErrInvalidEmailFormat})
		return
	}

	user, err := h.container.UserService.GetByEmail(request.Email)
	if err != nil || user == nil {
		h.logger.Warn("登出失败: 用户不存在", zap.String("email", request.Email), zap.Error(err))
		c.JSON(http.StatusBadRequest, gin.H{"error": "用户不存在"})
		return
	}

	if err := service.VerifyPassword(h.container.DB, request.Password, user.ID); err != nil {
		h.logger.Warn("登出失败: 密码错误", zap.Int64("userId", user.ID))
		c.JSON(http.StatusBadRequest, gin.H{"error": ErrWrongPassword})
		return
	}

	h.container.TokenService.InvalidateUserTokens(user.ID)
	h.logger.Info("用户登出成功", zap.Int64("userId", user.ID))
	c.JSON(http.StatusNoContent, gin.H{"valid": true})
}

// GetProfileByUUID 根据UUID获取档案
func (h *YggdrasilHandler) GetProfileByUUID(c *gin.Context) {
	uuid := utils.FormatUUID(c.Param("uuid"))
	h.logger.Info("获取配置文件请求", zap.String("uuid", uuid))

	profile, err := h.container.ProfileService.GetByUUID(uuid)
	if err != nil {
		h.logger.Error("获取配置文件失败", zap.Error(err), zap.String("uuid", uuid))
		standardResponse(c, http.StatusInternalServerError, nil, err.Error())
		return
	}

	h.logger.Info("成功获取配置文件", zap.String("uuid", uuid), zap.String("name", profile.Name))
	c.JSON(http.StatusOK, service.SerializeProfile(h.container.DB, h.logger, h.container.Redis, *profile))
}

// JoinServer 加入服务器
func (h *YggdrasilHandler) JoinServer(c *gin.Context) {
	var request JoinServerRequest
	clientIP := c.ClientIP()

	if err := c.ShouldBindJSON(&request); err != nil {
		h.logger.Error("解析加入服务器请求失败", zap.Error(err), zap.String("ip", clientIP))
		standardResponse(c, http.StatusBadRequest, nil, ErrInvalidRequest)
		return
	}

	h.logger.Info("收到加入服务器请求",
		zap.String("serverId", request.ServerID),
		zap.String("userUUID", request.SelectedProfile),
		zap.String("ip", clientIP),
	)

	if err := service.JoinServer(h.container.DB, h.logger, h.container.Redis, request.ServerID, request.AccessToken, request.SelectedProfile, clientIP); err != nil {
		h.logger.Error("加入服务器失败",
			zap.Error(err),
			zap.String("serverId", request.ServerID),
			zap.String("userUUID", request.SelectedProfile),
			zap.String("ip", clientIP),
		)
		standardResponse(c, http.StatusInternalServerError, nil, ErrJoinServerFailed)
		return
	}

	h.logger.Info("加入服务器成功",
		zap.String("serverId", request.ServerID),
		zap.String("userUUID", request.SelectedProfile),
		zap.String("ip", clientIP),
	)
	c.Status(http.StatusNoContent)
}

// HasJoinedServer 验证玩家是否已加入服务器
func (h *YggdrasilHandler) HasJoinedServer(c *gin.Context) {
	clientIP, _ := c.GetQuery("ip")

	serverID, exists := c.GetQuery("serverId")
	if !exists || serverID == "" {
		h.logger.Warn("缺少服务器ID参数", zap.String("ip", clientIP))
		standardResponse(c, http.StatusNoContent, nil, ErrServerIDRequired)
		return
	}

	username, exists := c.GetQuery("username")
	if !exists || username == "" {
		h.logger.Warn("缺少用户名参数", zap.String("serverId", serverID), zap.String("ip", clientIP))
		standardResponse(c, http.StatusNoContent, nil, ErrUsernameRequired)
		return
	}

	h.logger.Info("收到会话验证请求",
		zap.String("serverId", serverID),
		zap.String("username", username),
		zap.String("ip", clientIP),
	)

	if err := service.HasJoinedServer(h.logger, h.container.Redis, serverID, username, clientIP); err != nil {
		h.logger.Warn("会话验证失败",
			zap.Error(err),
			zap.String("serverId", serverID),
			zap.String("username", username),
			zap.String("ip", clientIP),
		)
		standardResponse(c, http.StatusNoContent, nil, ErrSessionVerifyFailed)
		return
	}

	profile, err := h.container.ProfileService.GetByUUID(username)
	if err != nil {
		h.logger.Error("获取用户配置文件失败", zap.Error(err), zap.String("username", username))
		standardResponse(c, http.StatusNoContent, nil, ErrProfileNotFound)
		return
	}

	h.logger.Info("会话验证成功",
		zap.String("serverId", serverID),
		zap.String("username", username),
		zap.String("uuid", profile.UUID),
	)
	c.JSON(200, service.SerializeProfile(h.container.DB, h.logger, h.container.Redis, *profile))
}

// GetProfilesByName 批量获取配置文件
func (h *YggdrasilHandler) GetProfilesByName(c *gin.Context) {
	var names []string

	if err := c.ShouldBindJSON(&names); err != nil {
		h.logger.Error("解析名称数组请求失败", zap.Error(err))
		standardResponse(c, http.StatusBadRequest, nil, ErrInvalidParams)
		return
	}

	h.logger.Info("接收到批量获取配置文件请求", zap.Int("count", len(names)))

	profiles, err := h.container.ProfileService.GetByNames(names)
	if err != nil {
		h.logger.Error("获取配置文件失败", zap.Error(err))
	}

	h.logger.Info("成功获取配置文件", zap.Int("requested", len(names)), zap.Int("returned", len(profiles)))
	c.JSON(http.StatusOK, profiles)
}

// GetMetaData 获取Yggdrasil元数据
func (h *YggdrasilHandler) GetMetaData(c *gin.Context) {
	meta := gin.H{
		"implementationName":    "CellAuth",
		"implementationVersion": "0.0.1",
		"serverName":            "LittleLan's Yggdrasil Server Implementation.",
		"links": gin.H{
			"homepage": "https://skin.littlelan.cn",
			"register": "https://skin.littlelan.cn/auth",
		},
		"feature.non_email_login":    true,
		"feature.enable_profile_key": true,
	}

	skinDomains := []string{".hitwh.games", ".littlelan.cn"}
	signature, err := service.GetPublicKeyFromRedisFunc(h.logger, h.container.Redis)
	if err != nil {
		h.logger.Error("获取公钥失败", zap.Error(err))
		standardResponse(c, http.StatusInternalServerError, nil, ErrInternalServer)
		return
	}

	h.logger.Info("提供元数据")
	c.JSON(http.StatusOK, gin.H{
		"meta":               meta,
		"skinDomains":        skinDomains,
		"signaturePublickey": signature,
	})
}

// GetPlayerCertificates 获取玩家证书
func (h *YggdrasilHandler) GetPlayerCertificates(c *gin.Context) {
	authHeader := c.GetHeader("Authorization")
	if authHeader == "" {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Authorization header not provided"})
		c.Abort()
		return
	}

	bearerPrefix := "Bearer "
	if len(authHeader) < len(bearerPrefix) || authHeader[:len(bearerPrefix)] != bearerPrefix {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid Authorization format"})
		c.Abort()
		return
	}

	tokenID := authHeader[len(bearerPrefix):]
	if tokenID == "" {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid Authorization format"})
		c.Abort()
		return
	}

	uuid, err := h.container.TokenService.GetUUIDByAccessToken(tokenID)
	if uuid == "" {
		h.logger.Error("获取玩家UUID失败", zap.Error(err))
		standardResponse(c, http.StatusInternalServerError, nil, ErrInternalServer)
		return
	}

	uuid = utils.FormatUUID(uuid)

	certificate, err := service.GeneratePlayerCertificate(h.container.DB, h.logger, h.container.Redis, uuid)
	if err != nil {
		h.logger.Error("生成玩家证书失败", zap.Error(err))
		standardResponse(c, http.StatusInternalServerError, nil, ErrInternalServer)
		return
	}

	h.logger.Info("成功生成玩家证书")
	c.JSON(http.StatusOK, certificate)
}