// +build mage

package main

import (
	"context"
	"fmt"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"

	"github.com/jtolds/qod"
	"github.com/kr/fs"
	"github.com/pkg/errors"
	"layeh.com/asar"
)

func output(cmd string, args ...string) (string, error) {
	c := exec.Command(cmd, args...)
	c.Env = os.Environ()
	c.Stderr = os.Stderr
	b, err := c.Output()
	if err != nil {
		return "", errors.Wrapf(err, `failed to run %v %q`, cmd, args)
	}
	return string(b), nil
}

func gitTag() (string, error) {
	s, err := output("git", "describe", "--tags")
	if err != nil {
		ee, ok := errors.Cause(err).(*exec.ExitError)
		if ok && ee.Exited() {
			// probably no git tag
			return "dev", nil
		}
		return "", err
	}

	return strings.TrimSuffix(s, "\n"), nil
}

func shouldWork(ctx context.Context, env []string, dir string, cmdName string, args ...string) {
	loc, err := exec.LookPath(cmdName)
	qod.ANE(err)

	cmd := exec.CommandContext(ctx, loc, args...)
	cmd.Dir = dir
	cmd.Env = append(env, os.Environ()...)

	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	log.Printf("starting process, env: %v, pwd: %s, cmd: %s, args: %v", env, dir, loc, args)
	err = cmd.Run()
	qod.ANE(err)
}

func goBuild(ctx context.Context, env []string, dir string, pkgname string) {
	shouldWork(ctx, env, dir, "go", "build", "-v", pkgBase+pkgname)
}

func goInstall(ctx context.Context, env []string, pkgname string) {
	shouldWork(ctx, nil, wd, "go", "install", pkgBase+pkgname)
}

func goBuildPlugin(ctx context.Context, dir, pkgname, fname string) {
	if runtime.GOOS != "linux" {
		qod.Printlnf("plugins don't work on non-linux machines yet :(")
		return
	}

	shouldWork(ctx, nil, dir, "go", "build", "-v", "-buildmode=plugin", "-o="+fname, pkgBase+pkgname)
	qod.Printlnf("built %s for %s", fname, runtime.GOOS)
}

func asarPack(dir string) (*asar.Entry, error) {
	b := &asar.Builder{}

	w := fs.Walk(dir)
	for w.Step() {
		if err := w.Err(); err != nil {
			fmt.Printf("walk error: %v\n", err)
			continue
		}

		p := w.Path()
		st := w.Stat()

		if st.IsDir() {
			w.SkipDir()
		}

		fin, err := os.Open(p)
		if err != nil {
			return nil, err
		}
		defer fin.Close()

		b.Add(filepath.Base(p), fin, st.Size(), asar.FlagNone)
	}

	return b.Root(), nil
}