/*
 * Copyright (c) 2015 Alex Yatskov <alex@foosoft.net>
 * Author: Alex Yatskov <alex@foosoft.net>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"path/filepath"

	"github.com/naoina/toml"
	"gopkg.in/yaml.v2"
)

type config struct {
	Tasks  map[string]task
	Macros map[string]macro

	handled map[string]bool
	srcDir  string
	dstDir  string
	variant string
	flags   int
}

func newConfig(filename string) (*config, error) {
	bytes, err := ioutil.ReadFile(filename)
	if err != nil {
		return nil, err
	}

	conf := &config{handled: make(map[string]bool)}
	switch filepath.Ext(filename) {
	case ".json":
		if err := json.Unmarshal(bytes, &conf); err != nil {
			return nil, err
		}
	case ".toml", ".tml":
		if err := toml.Unmarshal(bytes, &conf); err != nil {
			return nil, err
		}
	case ".yaml", ".yml":
		if err := yaml.Unmarshal(bytes, &conf); err != nil {
			return nil, err
		}
	default:
		return nil, fmt.Errorf("unsupported configuration file format")
	}

	return conf, nil
}