// Copyright 2019 Google Inc. All rights reserved.
//
// 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 main

import (
	"encoding/json"
	"flag"
	"io/ioutil"
	"log"
	"net/url"
	"os"
	"time"

	linter "github.com/google/gerrit-linter"
	"github.com/google/gerrit-linter/gerrit"
)

func main() {
	gerritURL := flag.String("gerrit", "", "URL to gerrit host")
	register := flag.Bool("register", false, "Register with the host")
	update := flag.Bool("update", false, "Update an existing checker on the host")
	list := flag.Bool("list", false, "List pending checks")
	agent := flag.String("agent", "fmtserver", "user-agent for the fmtserver.")
	gcpServiceAccount := flag.String("gcp_service_account", "", "A GCP service account ID to run this as")
	authFile := flag.String("auth_file", "", "file containing user:password")
	repo := flag.String("repo", "", "the repository (project) name to apply the checker to.")
	language := flag.String("language", "", "the language that the checker should apply to.")
	flag.Parse()
	if *gerritURL == "" {
		log.Fatal("must set --gerrit")
	}

	u, err := url.Parse(*gerritURL)
	if err != nil {
		log.Fatalf("url.Parse: %v", err)
	}

	if (*authFile == "" && *gcpServiceAccount == "") || (*authFile != "" && *gcpServiceAccount != "") {
		log.Fatal("must set one of --auth_file or --gcp_service_account")
	}

	g := gerrit.New(*u)

	g.UserAgent = *agent

	if *authFile != "" {
		content, err := ioutil.ReadFile(*authFile)
		if err != nil {
			log.Fatal(err)
		}
		g.Authenticator = gerrit.NewBasicAuth(string(content))
	}
	if *gcpServiceAccount != "" {
		g.Authenticator, err = NewGCPServiceAccount(*gcpServiceAccount)
		if err != nil {
			log.Fatal(err)
		}
	}

	// Do a GET first to complete any cookie dance, because POST
	// aren't redirected properly. Also, this avoids spamming logs with
	// failure messages.
	if _, err := g.GetPath("a/accounts/self"); err != nil {
		log.Fatalf("accounts/self: %v", err)
	}

	gc, err := NewGerritChecker(g, 5*time.Second)
	if err != nil {
		log.Fatal(err)
	}

	if *list {
		if out, err := gc.ListCheckers(); err != nil {
			log.Fatalf("List: %v", err)
		} else {
			for _, ch := range out {
				json, _ := json.Marshal(ch)
				os.Stdout.Write(json)
				os.Stdout.Write([]byte{'\n'})
			}
		}

		os.Exit(0)
	}

	if *register || *update {
		if *repo == "" {
			log.Fatalf("need to set --repo")
		}

		if *language == "" {
			log.Fatalf("must set --language.")
		}

		if !linter.IsSupported(*language) {
			log.Fatalf("language is not supported. Choices are %s", linter.SupportedLanguages())
		}

		ch, err := gc.PostChecker(*repo, *language, *update)
		if err != nil {
			log.Fatalf("CreateChecker: %v", err)
		}
		log.Printf("CreateChecker result: %v", ch)
		os.Exit(0)
	}

	gc.Serve()
}