// Copyright 2019 Drone IO, Inc.
//
// 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 render

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

	"github.com/drone/drone/handler/api/errors"
)

// indent the json-encoded API responses
var indent bool

func init() {
	indent, _ = strconv.ParseBool(
		os.Getenv("HTTP_JSON_INDENT"),
	)
}

var (
	// ErrInvalidToken is returned when the api request token is invalid.
	ErrInvalidToken = errors.New("Invalid or missing token")

	// ErrUnauthorized is returned when the user is not authorized.
	ErrUnauthorized = errors.New("Unauthorized")

	// ErrForbidden is returned when user access is forbidden.
	ErrForbidden = errors.New("Forbidden")

	// ErrNotFound is returned when a resource is not found.
	ErrNotFound = errors.New("Not Found")

	// ErrNotImplemented is returned when an endpoint is not implemented.
	ErrNotImplemented = errors.New("Not Implemented")
)

// ErrorCode writes the json-encoded error message to the response.
func ErrorCode(w http.ResponseWriter, err error, status int) {
	JSON(w, &errors.Error{Message: err.Error()}, status)
}

// InternalError writes the json-encoded error message to the response
// with a 500 internal server error.
func InternalError(w http.ResponseWriter, err error) {
	ErrorCode(w, err, 500)
}

// InternalErrorf writes the json-encoded error message to the response
// with a 500 internal server error.
func InternalErrorf(w http.ResponseWriter, format string, a ...interface{}) {
	ErrorCode(w, fmt.Errorf(format, a...), 500)
}

// NotImplemented writes the json-encoded error message to the
// response with a 501 not found status code.
func NotImplemented(w http.ResponseWriter, err error) {
	ErrorCode(w, err, 501)
}

// NotFound writes the json-encoded error message to the response
// with a 404 not found status code.
func NotFound(w http.ResponseWriter, err error) {
	ErrorCode(w, err, 404)
}

// NotFoundf writes the json-encoded error message to the response
// with a 404 not found status code.
func NotFoundf(w http.ResponseWriter, format string, a ...interface{}) {
	ErrorCode(w, fmt.Errorf(format, a...), 404)
}

// Unauthorized writes the json-encoded error message to the response
// with a 401 unauthorized status code.
func Unauthorized(w http.ResponseWriter, err error) {
	ErrorCode(w, err, 401)
}

// Forbidden writes the json-encoded error message to the response
// with a 403 forbidden status code.
func Forbidden(w http.ResponseWriter, err error) {
	ErrorCode(w, err, 403)
}

// BadRequest writes the json-encoded error message to the response
// with a 400 bad request status code.
func BadRequest(w http.ResponseWriter, err error) {
	ErrorCode(w, err, 400)
}

// BadRequestf writes the json-encoded error message to the response
// with a 400 bad request status code.
func BadRequestf(w http.ResponseWriter, format string, a ...interface{}) {
	ErrorCode(w, fmt.Errorf(format, a...), 400)
}

// JSON writes the json-encoded error message to the response
// with a 400 bad request status code.
func JSON(w http.ResponseWriter, v interface{}, status int) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	enc := json.NewEncoder(w)
	if indent {
		enc.SetIndent("", "  ")
	}
	enc.Encode(v)
}