// 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.
//
//
// Modifications copyright (C) 2020 Finogeeks Co., Ltd

package httputil

import (
	"context"
	"io/ioutil"
	"net/http"

	"github.com/finogeeks/ligase/common/jsonerror"
	util "github.com/finogeeks/ligase/skunkworks/gomatrixutil"
	log "github.com/finogeeks/ligase/skunkworks/log"
	jsoniter "github.com/json-iterator/go"
)

var json = jsoniter.ConfigCompatibleWithStandardLibrary

// UnmarshalJSONRequest into the given interface pointer. Returns an error JSON response if
// there was a problem unmarshalling. Calling this function consumes the request body.
func UnmarshalJSONRequest(req *http.Request, iface interface{}) *util.JSONResponse {
	content, _ := ioutil.ReadAll(req.Body)
	if len(content) == 0 {
		return nil
	}

	if err := json.Unmarshal(content, iface); err != nil {
		// TODO: We may want to suppress the Error() return in production? It's useful when
		// debugging because an error will be produced for both invalid/malformed JSON AND
		// valid JSON with incorrect types for values.
		return &util.JSONResponse{
			Code: http.StatusBadRequest,
			JSON: jsonerror.BadJSON("The request body could not be decoded into valid JSON. " + err.Error()),
		}
	}
	return nil
}

// LogThenError logs the given error then returns a matrix-compliant 500 internal server error response.
// This should be used to log fatal errors which require investigation. It should not be used
// to log client validation errors, etc.
func LogThenError(req *http.Request, err error) util.JSONResponse {
	fields := util.GetLogFields(req.Context())
	fields = append(fields, log.KeysAndValues{"error", err}...)
	log.Errorw("request failed", fields)
	return jsonerror.InternalServerError()
}

// LogThenErrorCtx logs the given error then returns a matrix-compliant 500 internal server error response.
// This should be used to log fatal errors which require investigation. It should not be used
// to log client validation errors, etc.
func LogThenErrorCtx(ctx context.Context, err error) (int, *jsonerror.MatrixError) {
	fields := util.GetLogFields(ctx)
	fields = append(fields, log.KeysAndValues{"error", err}...)
	log.Errorw("request failed", fields)
	return http.StatusInternalServerError, jsonerror.Unknown("Internal Server Error")
}