package main

import (
	"bytes"
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"

	"gopkg.in/src-d/enry.v1"
)

func main() {
	flag.Usage = usage
	breakdownFlag := flag.Bool("breakdown", false, "")
	jsonFlag := flag.Bool("json", false, "")
	flag.Parse()

	root, err := filepath.Abs(flag.Arg(0))
	if err != nil {
		log.Fatal(err)
	}

	errors := false
	out := make(map[string][]string, 0)
	err = filepath.Walk(root, func(path string, f os.FileInfo, err error) error {
		if err != nil {
			errors = true
			log.Println(err)
			return filepath.SkipDir
		}

		relativePath, err := filepath.Rel(root, path)
		if err != nil {
			errors = true
			log.Println(err)
			return nil
		}

		if relativePath == "." {
			return nil
		}

		if f.IsDir() {
			relativePath = relativePath + "/"
		}

		if enry.IsVendor(relativePath) || enry.IsDotFile(relativePath) ||
			enry.IsDocumentation(relativePath) || enry.IsConfiguration(relativePath) {
			if f.IsDir() {
				return filepath.SkipDir
			}

			return nil
		}

		if f.IsDir() {
			return nil
		}

		content, err := ioutil.ReadFile(path)
		if err != nil {
			errors = true
			log.Println(err)
			return nil
		}

		language := enry.GetLanguage(filepath.Base(path), content)
		if language == enry.OtherLanguage {
			return nil
		}

		out[language] = append(out[language], relativePath)
		return nil
	})

	if err != nil {
		log.Fatal(err)
	}

	var buff bytes.Buffer
	switch {
	case *jsonFlag && !*breakdownFlag:
		printJson(out, &buff)
	case *jsonFlag && *breakdownFlag:
		printBreakDown(out, &buff)
	case *breakdownFlag:
		printPercents(out, &buff)
		buff.WriteByte('\n')
		printBreakDown(out, &buff)
	default:
		printPercents(out, &buff)
	}

	fmt.Print(buff.String())
}

func usage() {
	fmt.Fprintf(
		os.Stderr, "enry, A simple (and faster) implementation of github/linguist \nusage: %s <path>\n       %s [-json] [-breakdown] <path>\n       %s [-json] [-breakdown]\n",
		os.Args[0], os.Args[0], os.Args[0],
	)
}

func printBreakDown(out map[string][]string, buff *bytes.Buffer) {
	for name, language := range out {
		writeStringLn(name, buff)
		for _, file := range language {
			writeStringLn(file, buff)
		}

		writeStringLn("", buff)
	}
}

func printJson(out map[string][]string, buff *bytes.Buffer) {
	data, _ := json.Marshal(out)
	buff.Write(data)
	buff.WriteByte('\n')
}

func printPercents(out map[string][]string, buff *bytes.Buffer) {
	fileCount := make(map[string]int, len(out))
	total := 0
	for name, language := range out {
		fileCount[name] = len(language)
		total += len(language)
	}

	for name, count := range fileCount {
		percent := float32(count) / float32(total) * 100
		buff.WriteString(fmt.Sprintf("%.2f%%	%s\n", percent, name))
	}
}

func writeStringLn(s string, buff *bytes.Buffer) {
	buff.WriteString(s)
	buff.WriteByte('\n')
}