package main

import (
	"bytes"
	"flag"
	"html/template"
	"io/ioutil"
	"os"
)

type IndexData struct {
	Assets      string
	Development bool
	Build       string
	Metadata    Metadata
}

type Metadata struct {
	Title string
}

var data = IndexData{
	Development: true,
}
var tmpl string
var out string

func main() {
	flag.StringVar(&tmpl, "t", "", "template file")
	flag.StringVar(&out, "o", "", "output file")
	flag.StringVar(&data.Assets, "a", "", ".Assets")
	flag.StringVar(&data.Build, "b", "", ".Build")
	flag.StringVar(&data.Metadata.Title, "mt", "", ".Metadata.Title")
	flag.Parse()

	f, err := os.Open(tmpl)
	if err != nil {
		panic(err)
	}
	buf, err := ioutil.ReadAll(f)
	if err != nil {
		panic(err)
	}

	t := template.Must(
		template.New("index").Parse(string(buf)),
	)

	indexBuf := new(bytes.Buffer)
	err = t.Execute(indexBuf, data)
	if err != nil {
		panic(err)
	}

	of, err := os.OpenFile(out, os.O_WRONLY|os.O_CREATE, 0644)
	if err != nil {
		panic(err)
	}
	_, err = of.Write(indexBuf.Bytes())
	if err != nil {
		panic(err)
	}
}