// Copyright 2020 The Matrix.org Foundation C.I.C.
//
// 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 msc2836 'Threading' implements https://github.com/matrix-org/matrix-doc/pull/2836
package msc2836

import (
	"encoding/json"
	"fmt"
	"net/http"

	"github.com/matrix-org/dendrite/clientapi/jsonerror"
	"github.com/matrix-org/dendrite/internal/httputil"
	"github.com/matrix-org/dendrite/internal/setup"
	userapi "github.com/matrix-org/dendrite/userapi/api"
	"github.com/matrix-org/util"
)

type eventRelationshipRequest struct {
	EventID         string `json:"event_id"`
	MaxDepth        int    `json:"max_depth"`
	MaxBreadth      int    `json:"max_breadth"`
	Limit           int    `json:"limit"`
	DepthFirst      bool   `json:"depth_first"`
	RecentFirst     bool   `json:"recent_first"`
	IncludeParent   bool   `json:"include_parent"`
	IncludeChildren bool   `json:"include_children"`
	Direction       string `json:"direction"`
	Batch           string `json:"batch"`
}

// Enable this MSC
func Enable(base *setup.BaseDendrite, monolith *setup.Monolith) error {
	_, err := NewDatabase(&base.Cfg.MSCs.Database)
	if err != nil {
		return fmt.Errorf("Cannot enable MSC2836: %w", err)
	}

	base.PublicClientAPIMux.Handle("/unstable/event_relationships",
		httputil.MakeAuthAPI("eventRelationships", monolith.UserAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
			var relation eventRelationshipRequest
			if err := json.NewDecoder(req.Body).Decode(&relation); err != nil {
				util.GetLogger(req.Context()).WithError(err).Error("failed to decode HTTP request as JSON")
				return util.JSONResponse{
					Code: 400,
					JSON: jsonerror.BadJSON(fmt.Sprintf("invalid json: %s", err)),
				}
			}
			return util.JSONResponse{
				Code: 200,
				JSON: struct{}{},
			}
		}),
	).Methods(http.MethodPost, http.MethodOptions)
	return nil
}