package utils

import (
	"net/http"
	"github.com/gin-gonic/gin"
)

// APIResponse 统一API响应格式
type APIResponse struct {
	Code    int         `json:"code"`
	Message string      `json:"message"`
	Data    interface{} `json:"data,omitempty"`
	Meta    *MetaInfo   `json:"meta,omitempty"`
}

// MetaInfo 分页信息
type MetaInfo struct {
	Page      int `json:"page"`
	PageSize  int `json:"page_size"`
	Total     int `json:"total"`
	TotalPage int `json:"total_page"`
}

// SuccessResponse 成功响应
func SuccessResponse(c *gin.Context, statusCode int, message string, data interface{}) {
	response := APIResponse{
		Code:    statusCode,
		Message: message,
		Data:    data,
	}
	c.JSON(statusCode, response)
}

// ErrorResponse 错误响应
func ErrorResponse(c *gin.Context, statusCode int, message string, details string) {
	response := APIResponse{
		Code:    statusCode,
		Message: message,
		Data:    map[string]interface{}{"details": details},
	}
	c.JSON(statusCode, response)
}

// PaginatedResponse 分页响应
func PaginatedResponse(c *gin.Context, statusCode int, message string, data interface{}, page, pageSize, total int) {
	totalPage := (total + pageSize - 1) / pageSize
	
	response := APIResponse{
		Code:    statusCode,
		Message: message,
		Data:    data,
		Meta: &MetaInfo{
			Page:      page,
			PageSize:  pageSize,
			Total:     total,
			TotalPage: totalPage,
		},
	}
	c.JSON(statusCode, response)
}

// GetPaginationParams 获取分页参数
func GetPaginationParams(c *gin.Context) (page, pageSize int) {
	page = 1
	pageSize = 10

	// 获取页码
	if p := c.Query("page"); p != "" {
		if parsedPage, err := parseInt(p); err == nil && parsedPage > 0 {
			page = parsedPage
		}
	}

	// 获取每页数量
	if ps := c.Query("page_size"); ps != "" {
		if parsedPageSize, err := parseInt(ps); err == nil && parsedPageSize > 0 && parsedPageSize <= 100 {
			pageSize = parsedPageSize
		}
	}

	return page, pageSize
}

// GetIDParam 获取ID参数
func GetIDParam(c *gin.Context) (uint, error) {
	idStr := c.Param("id")
	id, err := parseUint(idStr)
	if err != nil {
		return 0, err
	}
	return id, nil
}

// parseInt 解析整数
func parseInt(s string) (int, error) {
	var result int
	_, err := fmt.Sscanf(s, "%d", &result)
	return result, err
}

// parseUint 解析无符号整数
func parseUint(s string) (uint, error) {
	var result uint
	_, err := fmt.Sscanf(s, "%d", &result)
	return result, err
}