// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// This is a tool for packaging binary releases.
// It supports FreeBSD, Linux, and OS X.
package main

import (
	"bytes"
	"encoding/base64"
	"errors"
	"flag"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"mime/multipart"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

var (
	tag  = flag.String("tag", "weekly", "mercurial tag to check out")
	repo = flag.String("repo", "https://code.google.com/p/go", "repo URL")

	username, password string // for Google Code upload
)

const (
	packageMaker = "/Applications/Utilities/PackageMaker.app/Contents/MacOS/PackageMaker"
	uploadURL    = "https://go.googlecode.com/files"
)

var cleanFiles = []string{
	".hg",
	".hgtags",
	".hgignore",
	"VERSION.cache",
}

func main() {
	flag.Usage = func() {
		fmt.Fprintf(os.Stderr, "usage: %s [flags] targets...\n", os.Args[0])
		flag.PrintDefaults()
		os.Exit(2)
	}
	flag.Parse()
	if flag.NArg() == 0 {
		flag.Usage()
	}
	readCredentials()
	for _, targ := range flag.Args() {
		p := strings.SplitN(targ, "-", 2)
		if len(p) != 2 {
			log.Println("Ignoring unrecognized target:", targ)
			continue
		}
		b := Build{OS: p[0], Arch: p[1]}
		if err := b.Do(); err != nil {
			log.Printf("%s: %v", targ, err)
		}
	}
}

type Build struct {
	OS   string
	Arch string
	root string
}

func (b *Build) Do() error {
	work, err := ioutil.TempDir("", "bindist")
	if err != nil {
		return err
	}
	defer os.RemoveAll(work)
	b.root = filepath.Join(work, "go")

	// Clone Go distribution and update to tag.
	_, err = b.run(work, "hg", "clone", "-q", *repo, b.root)
	if err != nil {
		return err
	}
	_, err = b.run(b.root, "hg", "update", *tag)
	if err != nil {
		return err
	}

	// Build.
	_, err = b.run(filepath.Join(work, "go/src"), "bash", "make.bash")
	if err != nil {
		return err
	}

	// Get version string.
	version, err := b.run("", filepath.Join(b.root, "bin/go"), "version")
	if err != nil {
		return err
	}
	v := bytes.SplitN(version, []byte(" "), 4)
	version = bytes.Join(v[2:], []byte(" "))

	// Write VERSION file.
	err = ioutil.WriteFile(filepath.Join(b.root, "VERSION"), version, 0644)
	if err != nil {
		return err
	}

	// Clean goroot.
	for _, name := range cleanFiles {
		err = os.RemoveAll(filepath.Join(b.root, name))
		if err != nil {
			return err
		}
	}

	// Create packages.
	targ := fmt.Sprintf("go.%s.%s-%s", v[2], b.OS, b.Arch)
	switch b.OS {
	case "linux", "freebsd":
		// build tarball
		targ += ".tar.gz"
		_, err = b.run("", "tar", "czf", targ, "-C", work, "go")
	case "darwin":
		// arrange work so it's laid out as the dest filesystem
		etc := filepath.Join(b.root, "misc/dist/darwin/etc")
		_, err = b.run(work, "cp", "-r", etc, ".")
		if err != nil {
			return err
		}
		localDir := filepath.Join(work, "usr/local")
		err = os.MkdirAll(localDir, 0744)
		if err != nil {
			return err
		}
		_, err = b.run(work, "mv", "go", localDir)
		if err != nil {
			return err
		}
		// build package
		pm := packageMaker
		if !exists(pm) {
			pm = "/Developer" + pm
			if !exists(pm) {
				return errors.New("couldn't find PackageMaker")
			}
		}
		targ += ".pkg"
		scripts := filepath.Join(work, "usr/local/go/misc/dist/darwin/scripts")
		_, err = b.run("", pm, "-v",
			"-r", work,
			"-o", targ,
			"--scripts", scripts,
			"--id", "com.googlecode.go",
			"--title", "Go",
			"--version", "1.0",
			"--target", "10.5")
	}
	if err == nil && password != "" {
		err = b.upload(string(v[2]), targ)
	}
	return err
}

func (b *Build) run(dir, name string, args ...string) ([]byte, error) {
	buf := new(bytes.Buffer)
	cmd := exec.Command(name, args...)
	cmd.Stdout = buf
	cmd.Stderr = buf
	cmd.Dir = dir
	cmd.Env = b.env()
	if err := cmd.Run(); err != nil {
		fmt.Fprintf(os.Stderr, "%s", buf.Bytes())
		return nil, fmt.Errorf("%s %s: %v", name, strings.Join(args, " "), err)
	}
	return buf.Bytes(), nil
}

var cleanEnv = []string{
	"GOARCH",
	"GOBIN",
	"GOHOSTARCH",
	"GOHOSTOS",
	"GOOS",
	"GOROOT",
	"GOROOT_FINAL",
}

func (b *Build) env() []string {
	env := os.Environ()
	for i := 0; i < len(env); i++ {
		for _, c := range cleanEnv {
			if strings.HasPrefix(env[i], c+"=") {
				env = append(env[:i], env[i+1:]...)
			}
		}
	}
	env = append(env,
		"GOARCH="+b.Arch,
		"GOHOSTARCH="+b.Arch,
		"GOHOSTOS="+b.OS,
		"GOOS="+b.OS,
		"GOROOT="+b.root,
		"GOROOT_FINAL=/usr/local/go",
	)
	return env
}

func (b *Build) upload(version string, filename string) error {
	// Prepare upload metadata.
	labels := []string{"Arch-" + b.Arch}
	os_, arch := b.OS, b.Arch
	switch b.Arch {
	case "386":
		arch = "32-bit"
	case "amd64":
		arch = "64-bit"
	}
	switch b.OS {
	case "linux":
		os_ = "Linux"
		labels = append(labels, "Type-Archive", "OpSys-Linux")
	case "freebsd":
		os_ = "FreeBSD"
		labels = append(labels, "Type-Archive", "OpSys-FreeBSD")
	case "darwin":
		os_ = "Mac OS X"
		labels = append(labels, "Type-Installer", "OpSys-OSX")
	}
	summary := fmt.Sprintf("Go %s %s (%s)", version, os_, arch)

	// Open file to upload.
	f, err := os.Open(filename)
	if err != nil {
		return err
	}
	defer f.Close()

	// Prepare multipart payload.
	body := new(bytes.Buffer)
	w := multipart.NewWriter(body)
	if err := w.WriteField("summary", summary); err != nil {
		return err
	}
	for _, l := range labels {
		if err := w.WriteField("label", l); err != nil {
			return err
		}
	}
	fw, err := w.CreateFormFile("filename", filename)
	if err != nil {
		return err
	}
	if _, err = io.Copy(fw, f); err != nil {
		return err
	}
	if err := w.Close(); err != nil {
		return err
	}

	// Send the file to Google Code.
	req, err := http.NewRequest("POST", uploadURL, body)
	if err != nil {
		return err
	}
	token := fmt.Sprintf("%s:%s", username, password)
	token = base64.StdEncoding.EncodeToString([]byte(token))
	req.Header.Set("Authorization", "Basic "+token)
	req.Header.Set("Content-type", w.FormDataContentType())

	resp, err := http.DefaultTransport.RoundTrip(req)
	if err != nil {
		return err
	}
	if resp.StatusCode/100 != 2 {
		fmt.Fprintln(os.Stderr, "upload failed")
		defer resp.Body.Close()
		io.Copy(os.Stderr, resp.Body)
		return fmt.Errorf("upload: %s", resp.Status)
	}
	return nil
}

func exists(path string) bool {
	_, err := os.Stat(path)
	return err == nil
}

func readCredentials() {
	name := filepath.Join(os.Getenv("HOME"), ".gobuildkey")
	c, err := ioutil.ReadFile(name)
	if err != nil {
		log.Println("readCredentials:", err)
		return
	}
	v := bytes.Split(c, []byte("\n"))
	if len(v) >= 3 {
		username, password = string(v[1]), string(v[2])
	}
}