package middleware

import (
	"strings"
	"tyapi-server/internal/config"

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

// CORSMiddleware CORS中间件
type CORSMiddleware struct {
	config *config.Config
}

// NewCORSMiddleware 创建CORS中间件
func NewCORSMiddleware(cfg *config.Config) *CORSMiddleware {
	return &CORSMiddleware{
		config: cfg,
	}
}

// GetName 返回中间件名称
func (m *CORSMiddleware) GetName() string {
	return "cors"
}

// GetPriority 返回中间件优先级
func (m *CORSMiddleware) GetPriority() int {
	return 100 // 高优先级，最先执行
}

// Handle 返回中间件处理函数
func (m *CORSMiddleware) Handle() gin.HandlerFunc {
	if !m.config.Development.EnableCors {
		// 如果没有启用CORS，返回空处理函数
		return func(c *gin.Context) {
			c.Next()
		}
	}

	config := cors.Config{
		AllowAllOrigins: false,
		AllowOrigins:    m.getAllowedOrigins(),
		AllowMethods:    m.getAllowedMethods(),
		AllowHeaders:    m.getAllowedHeaders(),
		ExposeHeaders: []string{
			"Content-Length",
			"Content-Type",
			"X-Request-ID",
			"X-Response-Time",
		},
		AllowCredentials: true,
		MaxAge:           86400, // 24小时
	}

	return cors.New(config)
}

// IsGlobal 是否为全局中间件
func (m *CORSMiddleware) IsGlobal() bool {
	return true
}

// getAllowedOrigins 获取允许的来源
func (m *CORSMiddleware) getAllowedOrigins() []string {
	if m.config.Development.CorsOrigins == "" {
		return []string{"http://localhost:3000", "http://localhost:8080"}
	}

	// 解析配置中的origins字符串，按逗号分隔
	origins := strings.Split(m.config.Development.CorsOrigins, ",")
	// 去除空格
	for i, origin := range origins {
		origins[i] = strings.TrimSpace(origin)
	}
	return origins
}

// getAllowedMethods 获取允许的方法
func (m *CORSMiddleware) getAllowedMethods() []string {
	if m.config.Development.CorsMethods == "" {
		return []string{
			"GET", "POST", "PUT", "PATCH", "DELETE", "HEAD", "OPTIONS",
		}
	}

	// 解析配置中的methods字符串，按逗号分隔
	methods := strings.Split(m.config.Development.CorsMethods, ",")
	// 去除空格
	for i, method := range methods {
		methods[i] = strings.TrimSpace(method)
	}
	return methods
}

// getAllowedHeaders 获取允许的头部
func (m *CORSMiddleware) getAllowedHeaders() []string {
	if m.config.Development.CorsHeaders == "" {
		return []string{
			"Origin",
			"Content-Type",
			"Content-Length",
			"Accept",
			"Accept-Encoding",
			"Accept-Language",
			"Authorization",
			"X-Requested-With",
			"X-Request-ID",
			"Access-Id",
		}
	}

	// 解析配置中的headers字符串，按逗号分隔
	headers := strings.Split(m.config.Development.CorsHeaders, ",")
	// 去除空格
	for i, header := range headers {
		headers[i] = strings.TrimSpace(header)
	}
	return headers
}