package http

import (
	"math"
	"net/http"
	"time"

	"tyapi-server/internal/shared/interfaces"

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

// ResponseBuilder 响应构建器实现
type ResponseBuilder struct{}

// NewResponseBuilder 创建响应构建器
func NewResponseBuilder() interfaces.ResponseBuilder {
	return &ResponseBuilder{}
}

// Success 成功响应
func (r *ResponseBuilder) Success(c *gin.Context, data interface{}, message ...string) {
	msg := "操作成功"
	if len(message) > 0 && message[0] != "" {
		msg = message[0]
	}

	response := interfaces.APIResponse{
		Success:   true,
		Message:   msg,
		Data:      data,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusOK, response)
}

// Created 创建成功响应
func (r *ResponseBuilder) Created(c *gin.Context, data interface{}, message ...string) {
	msg := "创建成功"
	if len(message) > 0 && message[0] != "" {
		msg = message[0]
	}

	response := interfaces.APIResponse{
		Success:   true,
		Message:   msg,
		Data:      data,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusCreated, response)
}

// Error 错误响应
func (r *ResponseBuilder) Error(c *gin.Context, err error) {
	// 根据错误类型确定状态码
	statusCode := http.StatusInternalServerError
	message := "服务器内部错误"
	errorDetail := err.Error()

	// 这里可以根据不同的错误类型设置不同的状态码
	// 例如：ValidationError -> 400, NotFoundError -> 404, etc.

	response := interfaces.APIResponse{
		Success:   false,
		Message:   message,
		Errors:    errorDetail,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(statusCode, response)
}

// BadRequest 400错误响应
func (r *ResponseBuilder) BadRequest(c *gin.Context, message string, errors ...interface{}) {
	response := interfaces.APIResponse{
		Success:   false,
		Message:   message,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	if len(errors) > 0 {
		response.Errors = errors[0]
	}

	c.JSON(http.StatusBadRequest, response)
}

// Unauthorized 401错误响应
func (r *ResponseBuilder) Unauthorized(c *gin.Context, message ...string) {
	msg := "用户未登录或认证已过期"
	if len(message) > 0 && message[0] != "" {
		msg = message[0]
	}

	response := interfaces.APIResponse{
		Success:   false,
		Message:   msg,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusUnauthorized, response)
}

// Forbidden 403错误响应
func (r *ResponseBuilder) Forbidden(c *gin.Context, message ...string) {
	msg := "权限不足，无法访问此资源"
	if len(message) > 0 && message[0] != "" {
		msg = message[0]
	}

	response := interfaces.APIResponse{
		Success:   false,
		Message:   msg,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusForbidden, response)
}

// NotFound 404错误响应
func (r *ResponseBuilder) NotFound(c *gin.Context, message ...string) {
	msg := "请求的资源不存在"
	if len(message) > 0 && message[0] != "" {
		msg = message[0]
	}

	response := interfaces.APIResponse{
		Success:   false,
		Message:   msg,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusNotFound, response)
}

// Conflict 409错误响应
func (r *ResponseBuilder) Conflict(c *gin.Context, message string) {
	response := interfaces.APIResponse{
		Success:   false,
		Message:   message,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusConflict, response)
}

// InternalError 500错误响应
func (r *ResponseBuilder) InternalError(c *gin.Context, message ...string) {
	msg := "服务器内部错误"
	if len(message) > 0 && message[0] != "" {
		msg = message[0]
	}

	response := interfaces.APIResponse{
		Success:   false,
		Message:   msg,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusInternalServerError, response)
}

// Paginated 分页响应
func (r *ResponseBuilder) Paginated(c *gin.Context, data interface{}, pagination interfaces.PaginationMeta) {
	response := interfaces.APIResponse{
		Success:    true,
		Message:    "查询成功",
		Data:       data,
		Pagination: &pagination,
		RequestID:  r.getRequestID(c),
		Timestamp:  time.Now().Unix(),
	}

	c.JSON(http.StatusOK, response)
}

// getRequestID 从上下文获取请求ID
func (r *ResponseBuilder) getRequestID(c *gin.Context) string {
	if requestID, exists := c.Get("request_id"); exists {
		if id, ok := requestID.(string); ok {
			return id
		}
	}
	return ""
}

// BuildPagination 构建分页元数据
func BuildPagination(page, pageSize int, total int64) interfaces.PaginationMeta {
	totalPages := int(math.Ceil(float64(total) / float64(pageSize)))

	if totalPages < 1 {
		totalPages = 1
	}

	return interfaces.PaginationMeta{
		Page:       page,
		PageSize:   pageSize,
		Total:      total,
		TotalPages: totalPages,
		HasNext:    page < totalPages,
		HasPrev:    page > 1,
	}
}

// CustomResponse 自定义响应
func (r *ResponseBuilder) CustomResponse(c *gin.Context, statusCode int, data interface{}) {
	var message string
	switch statusCode {
	case http.StatusOK:
		message = "请求成功"
	case http.StatusCreated:
		message = "创建成功"
	case http.StatusNoContent:
		message = "无内容"
	case http.StatusBadRequest:
		message = "请求参数错误"
	case http.StatusUnauthorized:
		message = "认证失败"
	case http.StatusForbidden:
		message = "权限不足"
	case http.StatusNotFound:
		message = "资源不存在"
	case http.StatusConflict:
		message = "资源冲突"
	case http.StatusTooManyRequests:
		message = "请求过于频繁"
	case http.StatusInternalServerError:
		message = "服务器内部错误"
	default:
		message = "未知状态"
	}

	response := interfaces.APIResponse{
		Success:   statusCode >= 200 && statusCode < 300,
		Message:   message,
		Data:      data,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(statusCode, response)
}

// ValidationError 验证错误响应
func (r *ResponseBuilder) ValidationError(c *gin.Context, errors interface{}) {
	response := interfaces.APIResponse{
		Success:   false,
		Message:   "请求参数验证失败",
		Errors:    errors,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
	}

	c.JSON(http.StatusUnprocessableEntity, response)
}

// TooManyRequests 限流错误响应
func (r *ResponseBuilder) TooManyRequests(c *gin.Context, message ...string) {
	msg := "请求过于频繁，请稍后再试"
	if len(message) > 0 && message[0] != "" {
		msg = message[0]
	}

	response := interfaces.APIResponse{
		Success:   false,
		Message:   msg,
		RequestID: r.getRequestID(c),
		Timestamp: time.Now().Unix(),
		Meta: map[string]interface{}{
			"retry_after": "60s",
		},
	}

	c.JSON(http.StatusTooManyRequests, response)
}