package routing

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"time"

	"github.com/gorilla/mux"
	"github.com/matrix-org/dendrite/internal"
	"github.com/matrix-org/dendrite/internal/eventutil"
	"github.com/matrix-org/gomatrixserverlib"
	"github.com/matrix-org/gomatrixserverlib/spec"
	"github.com/matrix-org/util"
	"github.com/nats-io/nats.go"
	"github.com/sirupsen/logrus"

	"github.com/matrix-org/dendrite/internal/httputil"
	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
	"github.com/matrix-org/dendrite/setup/config"
	"github.com/matrix-org/dendrite/setup/jetstream"
	"github.com/matrix-org/dendrite/userapi/api"
)

func AdminEvacuateRoom(req *http.Request, rsAPI roomserverAPI.ClientRoomserverAPI) util.JSONResponse {
	vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
	if err != nil {
		return util.ErrorResponse(err)
	}

	affected, err := rsAPI.PerformAdminEvacuateRoom(req.Context(), vars["roomID"])
	switch err {
	case nil:
	case eventutil.ErrRoomNoExists:
		return util.JSONResponse{
			Code: http.StatusNotFound,
			JSON: spec.NotFound(err.Error()),
		}
	default:
		logrus.WithError(err).WithField("roomID", vars["roomID"]).Error("Failed to evacuate room")
		return util.ErrorResponse(err)
	}
	return util.JSONResponse{
		Code: 200,
		JSON: map[string]interface{}{
			"affected": affected,
		},
	}
}

func AdminEvacuateUser(req *http.Request, rsAPI roomserverAPI.ClientRoomserverAPI) util.JSONResponse {
	vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
	if err != nil {
		return util.ErrorResponse(err)
	}

	affected, err := rsAPI.PerformAdminEvacuateUser(req.Context(), vars["userID"])
	if err != nil {
		logrus.WithError(err).WithField("userID", vars["userID"]).Error("Failed to evacuate user")
		return util.MessageResponse(http.StatusBadRequest, err.Error())
	}

	return util.JSONResponse{
		Code: 200,
		JSON: map[string]interface{}{
			"affected": affected,
		},
	}
}

func AdminPurgeRoom(req *http.Request, rsAPI roomserverAPI.ClientRoomserverAPI) util.JSONResponse {
	vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
	if err != nil {
		return util.ErrorResponse(err)
	}

	if err = rsAPI.PerformAdminPurgeRoom(context.Background(), vars["roomID"]); err != nil {
		return util.ErrorResponse(err)
	}

	return util.JSONResponse{
		Code: 200,
		JSON: struct{}{},
	}
}

func AdminResetPassword(req *http.Request, cfg *config.ClientAPI, device *api.Device, userAPI api.ClientUserAPI) util.JSONResponse {
	if req.Body == nil {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.Unknown("Missing request body"),
		}
	}
	vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
	if err != nil {
		return util.ErrorResponse(err)
	}
	var localpart string
	userID := vars["userID"]
	localpart, serverName, err := cfg.Matrix.SplitLocalID('@', userID)
	if err != nil {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.InvalidParam(err.Error()),
		}
	}
	accAvailableResp := &api.QueryAccountAvailabilityResponse{}
	if err = userAPI.QueryAccountAvailability(req.Context(), &api.QueryAccountAvailabilityRequest{
		Localpart:  localpart,
		ServerName: serverName,
	}, accAvailableResp); err != nil {
		return util.JSONResponse{
			Code: http.StatusInternalServerError,
			JSON: spec.InternalServerError(),
		}
	}
	if accAvailableResp.Available {
		return util.JSONResponse{
			Code: http.StatusNotFound,
			JSON: spec.Unknown("User does not exist"),
		}
	}
	request := struct {
		Password string `json:"password"`
	}{}
	if err = json.NewDecoder(req.Body).Decode(&request); err != nil {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.Unknown("Failed to decode request body: " + err.Error()),
		}
	}
	if request.Password == "" {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.MissingParam("Expecting non-empty password."),
		}
	}

	if err = internal.ValidatePassword(request.Password); err != nil {
		return *internal.PasswordResponse(err)
	}

	updateReq := &api.PerformPasswordUpdateRequest{
		Localpart:     localpart,
		ServerName:    serverName,
		Password:      request.Password,
		LogoutDevices: true,
	}
	updateRes := &api.PerformPasswordUpdateResponse{}
	if err := userAPI.PerformPasswordUpdate(req.Context(), updateReq, updateRes); err != nil {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.Unknown("Failed to perform password update: " + err.Error()),
		}
	}
	return util.JSONResponse{
		Code: http.StatusOK,
		JSON: struct {
			Updated bool `json:"password_updated"`
		}{
			Updated: updateRes.PasswordUpdated,
		},
	}
}

func AdminReindex(req *http.Request, cfg *config.ClientAPI, device *api.Device, natsClient *nats.Conn) util.JSONResponse {
	_, err := natsClient.RequestMsg(nats.NewMsg(cfg.Matrix.JetStream.Prefixed(jetstream.InputFulltextReindex)), time.Second*10)
	if err != nil {
		logrus.WithError(err).Error("failed to publish nats message")
		return spec.InternalServerError()
	}
	return util.JSONResponse{
		Code: http.StatusOK,
		JSON: struct{}{},
	}
}

func AdminMarkAsStale(req *http.Request, cfg *config.ClientAPI, keyAPI api.ClientKeyAPI) util.JSONResponse {
	vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
	if err != nil {
		return util.ErrorResponse(err)
	}
	userID := vars["userID"]

	_, domain, err := gomatrixserverlib.SplitID('@', userID)
	if err != nil {
		return util.MessageResponse(http.StatusBadRequest, err.Error())
	}
	if cfg.Matrix.IsLocalServerName(domain) {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.InvalidParam("Can not mark local device list as stale"),
		}
	}

	err = keyAPI.PerformMarkAsStaleIfNeeded(req.Context(), &api.PerformMarkAsStaleRequest{
		UserID: userID,
		Domain: domain,
	}, &struct{}{})
	if err != nil {
		return util.JSONResponse{
			Code: http.StatusInternalServerError,
			JSON: spec.Unknown(fmt.Sprintf("Failed to mark device list as stale: %s", err)),
		}
	}
	return util.JSONResponse{
		Code: http.StatusOK,
		JSON: struct{}{},
	}
}

func AdminDownloadState(req *http.Request, device *api.Device, rsAPI roomserverAPI.ClientRoomserverAPI) util.JSONResponse {
	vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
	if err != nil {
		return util.ErrorResponse(err)
	}
	roomID, ok := vars["roomID"]
	if !ok {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.MissingParam("Expecting room ID."),
		}
	}
	serverName, ok := vars["serverName"]
	if !ok {
		return util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: spec.MissingParam("Expecting remote server name."),
		}
	}
	if err = rsAPI.PerformAdminDownloadState(req.Context(), roomID, device.UserID, spec.ServerName(serverName)); err != nil {
		if errors.Is(err, eventutil.ErrRoomNoExists) {
			return util.JSONResponse{
				Code: 200,
				JSON: spec.NotFound(eventutil.ErrRoomNoExists.Error()),
			}
		}
		logrus.WithError(err).WithFields(logrus.Fields{
			"userID":     device.UserID,
			"serverName": serverName,
			"roomID":     roomID,
		}).Error("failed to download state")
		return util.ErrorResponse(err)
	}
	return util.JSONResponse{
		Code: 200,
		JSON: struct{}{},
	}
}