// Package middleware Gin 中间件：会话鉴权、admin 校验。
package middleware

import (
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/openteam/server/internal/app"
	"github.com/openteam/server/internal/pkg/resp"
	"github.com/openteam/server/internal/store"
)

const CtxSessionUser = "session_user"

// SessionAuth 会话鉴权：Authorization: Bearer <access token>。
func SessionAuth(a *app.App) gin.HandlerFunc {
	return func(c *gin.Context) {
		auth := c.GetHeader("Authorization")
		if len(auth) < 8 || auth[:7] != "Bearer " {
			resp.Fail(c, http.StatusUnauthorized, "missing or invalid access token")
			c.Abort()
			return
		}
		claims, err := a.JWT.Parse(auth[7:])
		if err != nil || claims.Subject != "access" {
			resp.Fail(c, http.StatusUnauthorized, "invalid or expired access token")
			c.Abort()
			return
		}
		var u store.User
		if err := a.DB.First(&u, claims.UserID).Error; err != nil {
			resp.Fail(c, http.StatusUnauthorized, "user not found")
			c.Abort()
			return
		}
		if u.Status != store.UserStatusActive {
			resp.Fail(c, http.StatusForbidden, "user account disabled")
			c.Abort()
			return
		}
		c.Set(CtxSessionUser, &u)
		c.Next()
	}
}

// AdminOnly 仅管理员。
func AdminOnly(c *gin.Context) {
	u, ok := c.Get(CtxSessionUser)
	if !ok {
		resp.Fail(c, http.StatusUnauthorized, "authentication required")
		c.Abort()
		return
	}
	if u.(*store.User).Role != store.RoleAdmin {
		resp.Fail(c, http.StatusForbidden, "admin permission required")
		c.Abort()
		return
	}
	c.Next()
}

// CORS 开发期放开；生产按配置白名单（PLANNING §8）。
func CORS() gin.HandlerFunc {
	return func(c *gin.Context) {
		origin := c.GetHeader("Origin")
		if origin != "" {
			c.Header("Access-Control-Allow-Origin", origin)
			c.Header("Vary", "Origin")
			c.Header("Access-Control-Allow-Credentials", "true")
			c.Header("Access-Control-Allow-Headers", "Authorization, Content-Type, X-Requested-With")
			c.Header("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE, OPTIONS")
		}
		if c.Request.Method == http.MethodOptions {
			c.AbortWithStatus(http.StatusNoContent)
			return
		}
		c.Next()
	}
}