package middleware

import (
	"context"
	"encoding/json"
	"errors"
	"net/http"
	"strconv"
	"strings"

	"go.uber.org/zap"
	"penahub.gitlab.yandexcloud.net/backend/penahub_common/jwt_adapter"
	"penahub.gitlab.yandexcloud.net/backend/templategen/amo"
	"penahub.gitlab.yandexcloud.net/backend/templategen/dal"
	"penahub.gitlab.yandexcloud.net/backend/templategen/dal/model"
)

type Middleware struct {
	dal          *dal.MongoDAL
	amo          *amo.ClientApp
	logger       *zap.Logger
	AmoAccessMap map[string]string // key - endpoint; value - access (visibility, creation, delete)
}

func InitMiddleware(dal *dal.MongoDAL, amo *amo.ClientApp, logger *zap.Logger,
	amoAccessMap map[string]string) *Middleware {
	return &Middleware{dal: dal, amo: amo, logger: logger, AmoAccessMap: amoAccessMap}
}

func (mw *Middleware) MiddlewareCors(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == "OPTIONS" {
			w.WriteHeader(http.StatusOK)
		} else {
			next.ServeHTTP(w, r)
		}
	})
}

func (mw *Middleware) Logger(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if strings.Contains(r.URL.String(), "/assets/") {
			next.ServeHTTP(w, r)
			return
		}
		userId := getJwtUser(r)

		amoData := getAmoByJwt(r)
		if amoData != nil {
			userId = amoData.UserID
		}

		mw.logger.Info("HttpRequest",
			zap.String("URL", r.URL.String()),
			zap.String("UserID", userId),
		)
		next.ServeHTTP(w, r)
	})
}

func (mw *Middleware) MiddlewareJwt(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if strings.Contains(r.URL.String(), "/assets/") {
			next.ServeHTTP(w, r)
			return
		}

		ctx := r.Context()
		if amoData := getAmoByJwt(r); amoData != nil {
			ctx = context.WithValue(ctx, "UserID", amoData.UserID)
		}

		// Check token in cookies
		c := r.Header.Get(jwt_adapter.DefaultHeaderKey)

		jwt, err := jwt_adapter.Decode(c)
		if err == nil {
			ctx = context.WithValue(ctx, "PenaUserID", jwt.GetUserID())
		}

		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

func (mw *Middleware) MiddlewareHeaders(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization, X-Requested-With, X-Auth-Token")
		w.Header().Set("Access-Control-Allow-Credentials", "true")
		w.Header().Set("Access-Control-Expose-Headers", "*")
		w.Header().Set("Access-Control-Allow-Methods", "POST, PUT, GET, OPTIONS, DELETE")
		//w.Header().Add()
		next.ServeHTTP(w, r)
	})
}

func (mw *Middleware) MiddlewareAmoJwt(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if strings.Contains(r.URL.String(), "/assets/") {
			next.ServeHTTP(w, r)
			return
		}

		authMap := map[string]interface{}{
			//"/amo": nil,
		}

		required := false
		_, ok := authMap[r.URL.String()]
		if ok {
			required = true
		}

		token, err := mw.amo.DecodeJwt(r)
		if err != nil {
			if required {
				mw.reportError(w, err, http.StatusUnauthorized)
			} else {
				// mw.logger.Error("ErrAmoJwtAccess", zap.Error(err))
				next.ServeHTTP(w, r)
			}
			return
		}

		data, err := mw.dal.Amo.GetByAccountID(r.Context(), strconv.FormatInt(token.AccountId, 10))
		if err != nil {
			mw.reportError(w, err, http.StatusInternalServerError)
			return
		}

		if data == nil {
			mw.reportError(w, errors.New("amo account not found"), http.StatusUnauthorized)
			return
		}

		// check access rules
		isAcessGranted := token.IsAdmin

		// Если права не указаны для эндпоинта, то доступно любому юзеру
		rule, ok := mw.AmoAccessMap[r.URL.String()]
		if ok {
			// Если не админ, то проверяем права пользователя
			if rule == "visibility" && !isAcessGranted {
				for _, userId := range data.AccessRules.Visibility {
					if userId == token.UserId {
						isAcessGranted = true
						break
					}
				}
			}

			if rule == "creation" && !isAcessGranted {
				for _, userId := range data.AccessRules.Creation {
					if userId == token.UserId {
						isAcessGranted = true
						break
					}
				}
			}

			if rule == "delete" && !isAcessGranted {
				for _, userId := range data.AccessRules.Delete {
					if userId == token.UserId {
						isAcessGranted = true
						break
					}
				}
			}
		} else {
			isAcessGranted = true
		}

		// Если прав нет, прерываемся
		if !isAcessGranted {
			mw.reportError(w, errors.New("amoUser forbidden"), http.StatusForbidden) // mb: http.StatusForbidden
			return
		}

		ctx := context.WithValue(r.Context(), "amoData", data)
		ctx = context.WithValue(ctx, "amoIsAdmin", token.IsAdmin)
		ctx = context.WithValue(ctx, "amoUserID", token.UserId)
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

func (mw *Middleware) MiddlewareAmoPlug(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if strings.Contains(r.URL.String(), "/assets/") {
			next.ServeHTTP(w, r)
			return
		}

		ctx := r.Context()

		if r.Header.Get("TestAuth") == "75bc853ae763ffc36cad97069682fed1" {
			data, err := mw.dal.Amo.GetByAccountID(r.Context(), "30228997")

			if err != nil {
				mw.reportError(w, err, http.StatusInternalServerError)
				return
			}

			if data == nil {
				mw.reportError(w, errors.New("amo account not found"), http.StatusUnauthorized)
				return
			}

			ctx = context.WithValue(ctx, "amoData", data)
		}

		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

func getJwtUser(r *http.Request) string {
	user, ok := r.Context().Value("UserID").(string)
	if ok {
		return user
	}

	return ""
}

func getAmoByJwt(r *http.Request) *model.Amo {
	amoData, ok := r.Context().Value("amoData").(*model.Amo)
	if ok {
		return amoData
	}

	return nil
}

func (mw *Middleware) reportError(w http.ResponseWriter, err error, status int) error {
	mw.logger.Error("ErrorMiddleware", zap.Error(err))
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
	w.WriteHeader(status)
	return json.NewEncoder(w).Encode(err)
}