// Copyright 2022 Ariadne Conill
//
// 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 (
	"errors"
	"fmt"
	"os"
	"path/filepath"

	"github.com/docker/cli/cli/config"
	"github.com/docker/cli/cli/config/types"
	"github.com/google/go-containerregistry/pkg/authn"
	"github.com/google/go-containerregistry/pkg/name"
	"github.com/joho/godotenv"
	"github.com/urfave/cli"
)

const version = "unknown"

func main() {
	if env := os.Getenv("PLUGIN_ENV_FILE"); env != "" {
		godotenv.Load(env)
	}

	app := cli.NewApp()
	app.Name = "crane-login plugin"
	app.Usage = "crane-login"
	app.Action = run
	app.Version = version
	app.Flags = []cli.Flag{
		cli.StringFlag{
			Name:   "registry",
			Usage:  "docker registry for login",
			EnvVar: "PLUGIN_REGISTRY",
		},
		cli.StringFlag{
			Name:   "username",
			Usage:  "username for login",
			EnvVar: "PLUGIN_USERNAME",
		},
		cli.StringFlag{
			Name:   "password",
			Usage:  "password for login",
			EnvVar: "PLUGIN_PASSWORD",
		},
	}

	if err := app.Run(os.Args); err != nil {
		fmt.Fprintf(os.Stderr, "ERROR: %v\n", err)
		os.Exit(1)
	}
}

func run(c *cli.Context) error {
	user := c.String("username")
	if user == "" {
		return errors.New("username required")
	}

	pass := c.String("password")
	if pass == "" {
		return errors.New("password required")
	}

	reg, err := name.NewRegistry(c.String("registry"))
	if err != nil {
		return err
	}

	workspaceConfig := filepath.Join(os.Getenv("CI_WORKSPACE"), ".docker.json")
	cf, err := config.Load(workspaceConfig)
	if err != nil {
		return err
	}

	regName := reg.Name()
	creds := cf.GetCredentialsStore(regName)

	if regName == name.DefaultRegistry {
		regName = authn.DefaultAuthKey
	}

	if err := creds.Store(types.AuthConfig{
		ServerAddress: regName,
		Username:      user,
		Password:      pass,
	}); err != nil {
		return err
	}

	if err := cf.Save(); err != nil {
		return err
	}

	fmt.Printf("Logged in via %s.\n", cf.Filename)

	return nil
}