package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"strings"
	"time"

	"github.com/drone/drone-plugin-go/plugin"
)

type Docker struct {
	Storage  string `json:"storage_driver"`
	Registry string `json:"registry"`
	Username string `json:"username"`
	Password string `json:"password"`
	Email    string `json:"email"`
	Repo     string `json:"repo"`
	Tag      string `json:"tag"`
	File     string `json:"file"`
}

func main() {
	clone := plugin.Clone{}
	vargs := Docker{}

	plugin.Param("clone", &clone)
	plugin.Param("vargs", &vargs)
	if err := plugin.Parse(); err != nil {
		println(err.Error())
		os.Exit(1)
	}

	// Set the storage driver
	if len(vargs.Storage) == 0 {
		vargs.Storage = "aufs"
	}

	stop := func() {
		cmd := exec.Command("start-stop-daemon", "--stop", "--pidfile", "/var/run/docker.pid")
		cmd.Stdout = os.Stdout
		cmd.Stderr = os.Stderr
		trace(cmd)
		cmd.Run()
	}
	defer stop()

	// Starts the Docker daemon
	go func() {
		cmd := exec.Command("/bin/bash", "/bin/wrapdocker")
		cmd.Stdout = ioutil.Discard
		cmd.Stderr = ioutil.Discard
		cmd.Run()

		cmd = exec.Command("docker", "-d", "-s", vargs.Storage)
		cmd.Stdout = ioutil.Discard
		cmd.Stderr = ioutil.Discard
		trace(cmd)
		cmd.Run()
	}()

	// Sleep for a few seconds
	time.Sleep(5 * time.Second)

	// Set the Registry value
	if len(vargs.Registry) == 0 {
		vargs.Registry = "https://index.docker.io/v1/"
	}
	// Set the Dockerfile path
	if len(vargs.File) == 0 {
		vargs.File = "."
	}
	// Set the Tag value
	switch vargs.Tag {
	case "$DRONE_BRANCH":
		vargs.Tag = clone.Branch
	case "$DRONE_COMMIT":
		vargs.Tag = clone.Sha
	case "":
		vargs.Tag = "latest"
	}
	vargs.Repo = fmt.Sprintf("%s:%s", vargs.Repo, vargs.Tag)

	// Login to Docker
	cmd := exec.Command("docker", "login", "-u", vargs.Username, "-p", vargs.Password, "-e", vargs.Email, "index.docker.io")
	cmd.Dir = clone.Dir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	err := cmd.Run()
	if err != nil {
		stop()
		os.Exit(1)
	}

	// Build the container
	cmd = exec.Command("docker", "build", "--pull=true", "--rm=true", "-t", vargs.Repo, vargs.File)
	cmd.Dir = clone.Dir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	trace(cmd)
	err = cmd.Run()
	if err != nil {
		stop()
		os.Exit(1)
	}

	// Push the container
	cmd = exec.Command("docker", "push", vargs.Repo)
	cmd.Dir = clone.Dir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	trace(cmd)
	err = cmd.Run()
	if err != nil {
		stop()
		os.Exit(1)
	}
}

// Trace writes each command to standard error (preceded by a ‘$ ’) before it
// is executed. Used for debugging your build.
func trace(cmd *exec.Cmd) {
	fmt.Println("$", strings.Join(cmd.Args, " "))
}