package middleware

import (
	"net/http"

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

// CORSMiddleware 跨域中间件
func CORSMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		origin := c.Request.Header.Get("Origin")
		if origin == "" {
			c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
		} else {
			c.Writer.Header().Set("Access-Control-Allow-Origin", origin)
		}
		c.Header("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
		c.Header("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type")
		c.Header("Access-Control-Expose-Headers", "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers")
		c.Header("Access-Control-Max-Age", "172800")
		c.Header("Access-Control-Allow-Credentials", "true")

		if c.Request.Method == http.MethodOptions {
			c.AbortWithStatus(http.StatusOK)
			return
		}
		c.Next()
	}
}