package api

import (
	"net/http"

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

func CORSMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		origin := c.GetHeader("Origin")
		if origin != "" {
			// In production, frontend is same-origin so browsers don't send Origin header.
			// In dev, Next.js on :3000 needs CORS to reach Go on :3721.
			// Allow all origins since this is a local-first application.
			c.Header("Access-Control-Allow-Origin", origin)
		}
		c.Header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
		c.Header("Access-Control-Allow-Headers", "Content-Type, Authorization, X-Relay-Token")
		c.Header("Access-Control-Allow-Credentials", "true")

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

		c.Next()
	}
}