package main

import (
	"encoding/json"
	"fmt"
	"html/template"
	"io/ioutil"
	"os"
	"path/filepath"

	"github.com/docopt/docopt-go"
)

func buildHtml(templatefile string, additionaldirs []string) error {
	data, err := ioutil.ReadAll(os.Stdin)
	if err != nil {
		return err
	}

	var d interface{}
	err = json.Unmarshal(data, &d)
	if err != nil {
		return err
	}

	templatename := filepath.Base(templatefile)
	t, err := template.ParseFiles(templatefile)
	if err != nil {
		return err
	}
	for _, d := range additionaldirs {
		_, err = t.ParseGlob(d + "/*")
		if err != nil {
			return err
		}
	}

	return t.ExecuteTemplate(os.Stdout, templatename, d)
}

func main() {
	usage := fmt.Sprintf(`Builds html from json data

Usage:
  %[1]s --template=<template> [--include=<dir>]...
`, filepath.Base(os.Args[0]))

	arguments, err := docopt.Parse(usage, nil, true, "0.1.0", false)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}

	err = buildHtml(arguments["--template"].(string),
		arguments["--include"].([]string))
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(2)
	}
	os.Exit(0)
}