package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/codegangsta/cli"
	_ "github.com/joho/godotenv/autoload"
)

// build number set at compile-time
var version string

// default docker registry
const defaultRegistry = "https://index.docker.io/v1/"

func main() {
	app := cli.NewApp()
	app.Name = "docker plugin"
	app.Usage = "docker plugin"
	app.Action = run
	app.Version = version
	app.Flags = []cli.Flag{

		cli.BoolFlag{
			Name:   "dry-run",
			Usage:  "dry run disables docker push",
			EnvVar: "PLUGIN_DRY_RUN",
		},

		cli.StringFlag{
			Name:   "commit.sha",
			Usage:  "git commit sha",
			EnvVar: "DRONE_COMMIT_SHA",
			Value:  "00000000",
		},

		// daemon parameters
		cli.StringFlag{
			Name:   "daemon.mirror",
			Usage:  "docker daemon registry mirror",
			EnvVar: "PLUGIN_MIRROR",
		},
		cli.StringFlag{
			Name:   "daemon.storage-driver",
			Usage:  "docker daemon storage driver",
			EnvVar: "PLUGIN_STORAGE_DRIVER",
		},
		cli.StringFlag{
			Name:   "daemon.storage-path",
			Usage:  "docker daemon storage path",
			Value:  "/var/lib/docker",
			EnvVar: "PLUGIN_STORAGE_PATH",
		},
		cli.StringFlag{
			Name:   "daemon.bip",
			Usage:  "docker daemon bride ip address",
			EnvVar: "PLUGIN_BIP",
		},
		cli.StringSliceFlag{
			Name:   "daemon.dns",
			Usage:  "docker daemon dns server",
			EnvVar: "PLUGIN_DNS",
		},
		cli.BoolFlag{
			Name:   "daemon.insecure",
			Usage:  "docker daemon allows insecure registries",
			EnvVar: "PLUGIN_INSECURE",
		},
		cli.BoolFlag{
			Name:   "daemon.debug",
			Usage:  "docker daemon executes in debug mode",
			EnvVar: "PLUGIN_DEBUG,DOCKER_LAUNCH_DEBUG",
		},
		cli.BoolFlag{
			Name:   "daemon.off",
			Usage:  "docker daemon executes in debug mode",
			EnvVar: "PLUGIN_DAEMON_OFF",
		},

		// build parameters

		cli.StringFlag{
			Name:   "dockerfile",
			Usage:  "build dockerfile",
			Value:  "Dockerfile",
			EnvVar: "PLUGIN_DOCKERFILE",
		},
		cli.StringFlag{
			Name:   "context",
			Usage:  "build context",
			Value:  ".",
			EnvVar: "PLUGIN_CONTEXT",
		},
		cli.StringSliceFlag{
			Name:   "tags",
			Usage:  "build tags",
			Value:  &cli.StringSlice{"latest"},
			EnvVar: "PLUGIN_TAG,PLUGIN_TAGS",
		},
		cli.StringSliceFlag{
			Name:   "args",
			Usage:  "build args",
			EnvVar: "PLUGIN_BUILD_ARGS",
		},
		cli.StringFlag{
			Name:   "repo",
			Usage:  "docker repository",
			EnvVar: "PLUGIN_REPO",
		},

		// secret variables
		cli.StringFlag{
			Name:   "docker.registry",
			Usage:  "docker username",
			Value:  defaultRegistry,
			EnvVar: "DOCKER_REGISTRY,PLUGIN_REGISTRY",
		},
		cli.StringFlag{
			Name:   "docker.username",
			Usage:  "docker username",
			EnvVar: "DOCKER_USERNAME,PLUGIN_USERNAME",
		},
		cli.StringFlag{
			Name:   "docker.password",
			Usage:  "docker password",
			EnvVar: "DOCKER_PASSWORD,PLUGIN_PASSWORD",
		},
		cli.StringFlag{
			Name:   "docker.email",
			Usage:  "docker email",
			EnvVar: "DOCKER_EMAIL,PLUGIN_EMAIL",
		},
	}

	app.Run(os.Args)
}

func run(c *cli.Context) {
	plugin := Plugin{
		Dryrun: c.Bool("dry-run"),
		Login: Login{
			Registry: c.String("docker.registry"),
			Username: c.String("docker.username"),
			Password: c.String("docker.password"),
			Email:    c.String("docker.email"),
		},
		Build: Build{
			Name:       c.String("commit.sha"),
			Dockerfile: c.String("dockerfile"),
			Context:    c.String("context"),
			Tags:       c.StringSlice("tags"),
			Args:       c.StringSlice("args"),
			Repo:       c.String("repo"),
		},
		Daemon: Daemon{
			Registry:      c.String("docker.registry"),
			Mirror:        c.String("daemon.mirror"),
			StorageDriver: c.String("daemon.storage-driver"),
			StoragePath:   c.String("daemon.storage-path"),
			Insecure:      c.Bool("daemon.insecure"),
			Disabled:      c.Bool("daemon.off"),
			Debug:         c.Bool("daemon.debug"),
			Bip:           c.String("daemon.bip"),
			DNS:           c.StringSlice("daemon.dns"),
		},
	}

	// this code attempts to normalize the repository name by appending the fully
	// qualified registry name if otherwise omitted.
	if plugin.Login.Registry != defaultRegistry &&
		strings.HasPrefix(plugin.Build.Repo, defaultRegistry) {
		plugin.Build.Repo = plugin.Login.Registry + "/" + plugin.Build.Repo
	}

	if err := plugin.Exec(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	// TODO execute code remove dangling images
	// this is problematic because we are running docker in scratch which does
	// not have bash, so we need to hack something together
	// docker images --quiet --filter=dangling=true | xargs --no-run-if-empty docker rmi
}

/*
cmd = exec.Command("docker", "images", "-q", "-f", "dangling=true")
cmd = exec.Command("docker", append([]string{"rmi"}, images...)...)
*/