package response

import (
	"encoding/json"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
)

// Response 统一响应格式
type Response struct {
	Code    int         `json:"code"`
	Message string      `json:"message"`
	Data    interface{} `json:"data,omitempty"`
}

// writeJSON 统一输出 JSON，并关闭 HTML 转义（避免将 & 转成 \u0026，导致预签名 URL 失效）
func writeJSON(c *gin.Context, httpCode int, payload interface{}) {
	c.Status(httpCode)
	c.Header("Content-Type", "application/json; charset=utf-8")
	enc := json.NewEncoder(c.Writer)
	enc.SetEscapeHTML(false)
	_ = enc.Encode(payload)
}

// Success 成功响应（200）
func Success(c *gin.Context, data interface{}) {
	writeJSON(c, http.StatusOK, Response{
		Code:    200,
		Message: "ok",
		Data:    data,
	})
}

// SuccessWithMessage 成功响应（自定义消息）
func SuccessWithMessage(c *gin.Context, message string, data interface{}) {
	writeJSON(c, http.StatusOK, Response{
		Code:    200,
		Message: message,
		Data:    data,
	})
}

// Error 错误响应
func Error(c *gin.Context, httpCode int, message string) {
	writeJSON(c, httpCode, Response{
		Code:    httpCode,
		Message: message,
	})
}

// ErrorWithCode 错误响应（自定义业务错误码）
func ErrorWithCode(c *gin.Context, code int, message string) {
	// 根据业务错误码映射到HTTP状态码
	httpCode := http.StatusBadRequest
	switch code {
	case 401:
		httpCode = http.StatusUnauthorized
	case 403:
		httpCode = http.StatusForbidden
	case 404:
		httpCode = http.StatusNotFound
	case 409:
		httpCode = http.StatusConflict
	case 500:
		httpCode = http.StatusInternalServerError
	}

	writeJSON(c, httpCode, Response{
		Code:    code,
		Message: message,
	})
}

// BadRequest 400 错误请求
func BadRequest(c *gin.Context, message string) {
	if message == "" {
		message = "请求参数错误"
	}
	Error(c, http.StatusBadRequest, message)
}

// Unauthorized 401 未授权
func Unauthorized(c *gin.Context, message string) {
	if message == "" {
		message = "未授权，请先登录"
	}
	Error(c, http.StatusUnauthorized, message)
}

// Forbidden 403 禁止访问
func Forbidden(c *gin.Context, message string) {
	if message == "" {
		message = "权限不足，禁止访问"
	}
	Error(c, http.StatusForbidden, message)
}

// NotFound 404 未找到
func NotFound(c *gin.Context, message string) {
	if message == "" {
		message = "资源不存在"
	}
	Error(c, http.StatusNotFound, message)
}

// InternalError 500 服务器内部错误
func InternalError(c *gin.Context, message string) {
	if message == "" {
		message = "服务器内部错误"
	}
	Error(c, http.StatusInternalServerError, message)
}

// CleanErrorMessage 清理错误消息，转换为中文友好提示
func CleanErrorMessage(err error) string {
	if err == nil {
		return ""
	}

	msg := err.Error()

	// 移除 gRPC 错误前缀
	if idx := strings.Index(msg, "code_"); idx >= 0 {
		if colonIdx := strings.Index(msg[idx:], ": "); colonIdx >= 0 {
			msg = msg[idx+colonIdx+2:]
		}
	}

	// 中英文错误映射
	errorMap := map[string]string{
		"user not found":                           "用户不存在",
		"user already exists":                      "该手机号已被注册",
		"invalid password":                         "密码错误",
		"invalid mobile format":                    "手机号格式不正确",
		"password too short":                       "密码长度不足，至少需要6位",
		"star not found":                           "明星不存在",
		"fan profile not found":                    "粉丝档案不存在",
		"invalid token":                            "Token无效",
		"token expired":                            "Token已过期",
		"user is inactive":                         "用户已被禁用",
		"maximum number of identities reached":     "已达到最大身份数量限制（最多2个）",
		"invalid star_id":                          "明星ID无效",
		"invalid user_id":                          "用户ID无效",
		"invalid nickname":                         "昵称格式不正确",
		"nickname too long":                        "昵称过长，最多20个字符",
		"nickname too short":                       "昵称过短，至少需要2个字符",
		"user info not found in Dubbo attachments": "请先登录",
		"missing or invalid authorization token":   "Token缺失或无效",
	}

	msgLower := strings.ToLower(msg)
	for eng, chn := range errorMap {
		if strings.Contains(msgLower, eng) {
			return chn
		}
	}

	// 如果没有匹配，返回原始消息
	return msg
}

// HandleError 统一处理错误并返回
func HandleError(c *gin.Context, err error) {
	if err == nil {
		InternalError(c, "未知错误")
		return
	}

	msg := CleanErrorMessage(err)
	msgLower := strings.ToLower(msg)

	// 根据错误类型返回对应的 HTTP 状态码
	switch {
	case strings.Contains(msgLower, "not found") || strings.Contains(msgLower, "不存在"):
		NotFound(c, msg)
	case strings.Contains(msgLower, "unauthorized") ||
		strings.Contains(msgLower, "token") ||
		strings.Contains(msgLower, "请先登录"):
		Unauthorized(c, msg)
	case strings.Contains(msgLower, "invalid") ||
		strings.Contains(msgLower, "格式不正确") ||
		strings.Contains(msgLower, "过长") ||
		strings.Contains(msgLower, "过短"):
		BadRequest(c, msg)
	case strings.Contains(msgLower, "already exists") ||
		strings.Contains(msgLower, "已被注册"):
		Error(c, http.StatusConflict, msg)
	case strings.Contains(msgLower, "forbidden") ||
		strings.Contains(msgLower, "permission denied") ||
		strings.Contains(msgLower, "权限不足"):
		Forbidden(c, msg)
	default:
		InternalError(c, msg)
	}
}