package middleware

import (
	"context"
	"net/http"
	"server/internal/db"
	"server/internal/db/sqlc"
	"server/internal/pkg/cache"
	"server/internal/pkg/cache/cachekey"
	"server/internal/pkg/errs"
	"server/internal/pkg/httputil"
	"strings"

	"github.com/go-chi/chi/v5"
)

const (
	IsAdminKey contextKey = "is_admin"
)

type AuthMiddleware struct {
	store *db.Store
	cache *cache.Caches
}

func NewAuthMiddleware(store *db.Store, cache *cache.Caches) *AuthMiddleware {
	return &AuthMiddleware{
		cache: cache,
		store: store,
	}
}

func (m *AuthMiddleware) Middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ctx := r.Context()
		var err error

		claims, ok := GetClaims(ctx)
		if !ok || claims.UserID == 0 {
			httputil.Fail(w, errs.ErrUnauthorized)
			return
		}

		// 判断是否有管理员权限 目前只判断uid是否为1
		isAdmin := userIsAdmin(claims.UserID)

		if isAdmin {
			ctx = context.WithValue(ctx, IsAdminKey, isAdmin)
			next.ServeHTTP(w, r.WithContext(ctx))
			return
		}

		// 不是管理员 判断api权限
		hasPermission, err := userHasApiPermission(ctx, r, m.store, claims.UserID, m.cache)
		if err != nil {
			httputil.Fail(w, err)
			return
		}

		if !hasPermission {
			httputil.Fail(w, errs.ErrPermissionDenied)
			return
		}

		next.ServeHTTP(w, r)
	})
}

func userIsAdmin(uid int32) bool {
	if uid == 1 {
		return true
	}

	return false
}

func userHasApiPermission(ctx context.Context, r *http.Request, store *db.Store, uid int32, c *cache.Caches) (bool, error) {
	var (
		apis []sqlc.GetSysUserApisRow
		err  error
	)

	// 先从缓存中获取api数据
	k := cachekey.UserApiPermissions(uid)
	apis, err = cache.GetOrSetJSON[[]sqlc.GetSysUserApisRow](ctx, c, k, 0, func() ([]sqlc.GetSysUserApisRow, error) {
		return store.GetSysUserApis(ctx, uid)
	})

	if err != nil {
		return false, err
	}

	requestPath := chi.RouteContext(r.Context()).RoutePattern()
	requestPath = strings.TrimPrefix(requestPath, "/api")
	requestMethod := r.Method

	for _, api := range apis {
		if api.Path == requestPath && api.Method == requestMethod {
			return true, nil
		}
	}

	return false, nil
}