// Copyright 2017 Vector Creations Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package routing

import (
	"net/http"

	"github.com/gorilla/mux"
	eduserverAPI "github.com/matrix-org/dendrite/eduserver/api"
	federationSenderAPI "github.com/matrix-org/dendrite/federationsender/api"
	"github.com/matrix-org/dendrite/internal/config"
	"github.com/matrix-org/dendrite/internal/httputil"
	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
	userapi "github.com/matrix-org/dendrite/userapi/api"
	"github.com/matrix-org/gomatrixserverlib"
	"github.com/matrix-org/util"
)

const (
	pathPrefixV2Keys       = "/key/v2"
	pathPrefixV1Federation = "/federation/v1"
	pathPrefixV2Federation = "/federation/v2"
)

// Setup registers HTTP handlers with the given ServeMux.
// The provided publicAPIMux MUST have `UseEncodedPath()` enabled or else routes will incorrectly
// path unescape twice (once from the router, once from MakeFedAPI). We need to have this enabled
// so we can decode paths like foo/bar%2Fbaz as [foo, bar/baz] - by default it will decode to [foo, bar, baz]
//
// Due to Setup being used to call many other functions, a gocyclo nolint is
// applied:
// nolint: gocyclo
func Setup(
	publicAPIMux *mux.Router,
	cfg *config.Dendrite,
	rsAPI roomserverAPI.RoomserverInternalAPI,
	eduAPI eduserverAPI.EDUServerInputAPI,
	fsAPI federationSenderAPI.FederationSenderInternalAPI,
	keys gomatrixserverlib.JSONVerifier,
	federation *gomatrixserverlib.FederationClient,
	userAPI userapi.UserInternalAPI,
) {
	v2keysmux := publicAPIMux.PathPrefix(pathPrefixV2Keys).Subrouter()
	v1fedmux := publicAPIMux.PathPrefix(pathPrefixV1Federation).Subrouter()
	v2fedmux := publicAPIMux.PathPrefix(pathPrefixV2Federation).Subrouter()

	wakeup := &httputil.FederationWakeups{
		FsAPI: fsAPI,
	}

	localKeys := httputil.MakeExternalAPI("localkeys", func(req *http.Request) util.JSONResponse {
		return LocalKeys(cfg)
	})

	// Ignore the {keyID} argument as we only have a single server key so we always
	// return that key.
	// Even if we had more than one server key, we would probably still ignore the
	// {keyID} argument and always return a response containing all of the keys.
	v2keysmux.Handle("/server/{keyID}", localKeys).Methods(http.MethodGet)
	v2keysmux.Handle("/server/", localKeys).Methods(http.MethodGet)
	v2keysmux.Handle("/server", localKeys).Methods(http.MethodGet)

	v1fedmux.Handle("/send/{txnID}", httputil.MakeFedAPI(
		"federation_send", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return Send(
				httpReq, request, gomatrixserverlib.TransactionID(vars["txnID"]),
				cfg, rsAPI, eduAPI, keys, federation,
			)
		},
	)).Methods(http.MethodPut, http.MethodOptions)

	v2fedmux.Handle("/invite/{roomID}/{eventID}", httputil.MakeFedAPI(
		"federation_invite", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return Invite(
				httpReq, request, vars["roomID"], vars["eventID"],
				cfg, rsAPI, keys,
			)
		},
	)).Methods(http.MethodPut, http.MethodOptions)

	v1fedmux.Handle("/3pid/onbind", httputil.MakeExternalAPI("3pid_onbind",
		func(req *http.Request) util.JSONResponse {
			return CreateInvitesFrom3PIDInvites(req, rsAPI, cfg, federation, userAPI)
		},
	)).Methods(http.MethodPost, http.MethodOptions)

	v1fedmux.Handle("/exchange_third_party_invite/{roomID}", httputil.MakeFedAPI(
		"exchange_third_party_invite", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return ExchangeThirdPartyInvite(
				httpReq, request, vars["roomID"], rsAPI, cfg, federation,
			)
		},
	)).Methods(http.MethodPut, http.MethodOptions)

	v1fedmux.Handle("/event/{eventID}", httputil.MakeFedAPI(
		"federation_get_event", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return GetEvent(
				httpReq.Context(), request, rsAPI, vars["eventID"], cfg.Matrix.ServerName,
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/state/{roomID}", httputil.MakeFedAPI(
		"federation_get_state", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return GetState(
				httpReq.Context(), request, rsAPI, vars["roomID"],
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/state_ids/{roomID}", httputil.MakeFedAPI(
		"federation_get_state_ids", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return GetStateIDs(
				httpReq.Context(), request, rsAPI, vars["roomID"],
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/event_auth/{roomID}/{eventID}", httputil.MakeFedAPI(
		"federation_get_event_auth", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return GetEventAuth(
				httpReq.Context(), request, rsAPI, vars["roomID"], vars["eventID"],
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/query/directory", httputil.MakeFedAPI(
		"federation_query_room_alias", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return RoomAliasToID(
				httpReq, federation, cfg, rsAPI, fsAPI,
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/query/profile", httputil.MakeFedAPI(
		"federation_query_profile", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return GetProfile(
				httpReq, userAPI, cfg,
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/user/devices/{userID}", httputil.MakeFedAPI(
		"federation_user_devices", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return GetUserDevices(
				httpReq, userAPI, vars["userID"],
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/make_join/{roomID}/{eventID}", httputil.MakeFedAPI(
		"federation_make_join", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			roomID := vars["roomID"]
			eventID := vars["eventID"]
			queryVars := httpReq.URL.Query()
			remoteVersions := []gomatrixserverlib.RoomVersion{}
			if vers, ok := queryVars["ver"]; ok {
				// The remote side supplied a ?=ver so use that to build up the list
				// of supported room versions
				for _, v := range vers {
					remoteVersions = append(remoteVersions, gomatrixserverlib.RoomVersion(v))
				}
			} else {
				// The remote side didn't supply a ?ver= so just assume that they only
				// support room version 1, as per the spec
				// https://matrix.org/docs/spec/server_server/r0.1.3#get-matrix-federation-v1-make-join-roomid-userid
				remoteVersions = append(remoteVersions, gomatrixserverlib.RoomVersionV1)
			}
			return MakeJoin(
				httpReq, request, cfg, rsAPI, roomID, eventID, remoteVersions,
			)
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/send_join/{roomID}/{eventID}", httputil.MakeFedAPI(
		"federation_send_join", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			roomID := vars["roomID"]
			eventID := vars["eventID"]
			res := SendJoin(
				httpReq, request, cfg, rsAPI, keys, roomID, eventID,
			)
			return util.JSONResponse{
				Headers: res.Headers,
				Code:    res.Code,
				JSON: []interface{}{
					res.Code, res.JSON,
				},
			}
		},
	)).Methods(http.MethodPut)

	v2fedmux.Handle("/send_join/{roomID}/{eventID}", httputil.MakeFedAPI(
		"federation_send_join", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			roomID := vars["roomID"]
			eventID := vars["eventID"]
			return SendJoin(
				httpReq, request, cfg, rsAPI, keys, roomID, eventID,
			)
		},
	)).Methods(http.MethodPut)

	v1fedmux.Handle("/make_leave/{roomID}/{eventID}", httputil.MakeFedAPI(
		"federation_make_leave", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			roomID := vars["roomID"]
			eventID := vars["eventID"]
			return MakeLeave(
				httpReq, request, cfg, rsAPI, roomID, eventID,
			)
		},
	)).Methods(http.MethodGet)

	v2fedmux.Handle("/send_leave/{roomID}/{eventID}", httputil.MakeFedAPI(
		"federation_send_leave", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			roomID := vars["roomID"]
			eventID := vars["eventID"]
			return SendLeave(
				httpReq, request, cfg, rsAPI, keys, roomID, eventID,
			)
		},
	)).Methods(http.MethodPut)

	v1fedmux.Handle("/version", httputil.MakeExternalAPI(
		"federation_version",
		func(httpReq *http.Request) util.JSONResponse {
			return Version()
		},
	)).Methods(http.MethodGet)

	v1fedmux.Handle("/get_missing_events/{roomID}", httputil.MakeFedAPI(
		"federation_get_missing_events", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return GetMissingEvents(httpReq, request, rsAPI, vars["roomID"])
		},
	)).Methods(http.MethodPost)

	v1fedmux.Handle("/backfill/{roomID}", httputil.MakeFedAPI(
		"federation_backfill", cfg.Matrix.ServerName, keys, wakeup,
		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
			return Backfill(httpReq, request, rsAPI, vars["roomID"], cfg)
		},
	)).Methods(http.MethodGet)
}