package main

import (
	"bufio"
	"log"
	"os"
	"strings"
)

const (
	indent = "    "
)

func main() {
	if len(os.Args) < 2 {
		log.Fatal("Required argument(s): filename(s)")
	}

	for _, filename := range os.Args[1:] {
		processFile(filename)
	}

}

func processFile(filename string) {
	file, err := os.Open(filename)
	if err != nil {
		log.Fatalf("Could not read file %v: %v\n", filename, err)
	}

	scanner := bufio.NewScanner(file)
	var lines []string

	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}

	file.Close()

	file, err = os.Create(filename)
	defer file.Close()
	if err != nil {
		log.Fatalf("Could not write to file %v: %v\n", filename, err)
	}

	indentCount := 0
	inMultiLineComment := false

	for ln, line := range lines {

		singleCommentPos := strings.Index(line, "//")
		multiLineCommentStartPos := strings.Index(line, "/*")
		multiLineCommentEndPos := strings.Index(line, "*/")

		openPos := strings.Index(line, "{")
		closePos := strings.Index(line, "}")

		if !inMultiLineComment && closePos > -1 && (openPos == -1 || openPos > closePos) && (singleCommentPos == -1 || closePos < singleCommentPos) &&
			(multiLineCommentStartPos == -1 || closePos < multiLineCommentStartPos) &&
			(multiLineCommentEndPos == -1 || closePos > multiLineCommentEndPos) {
			indentCount--
		}

		trimedLine := strings.Trim(line, " \t")
		if trimedLine == "" {
			file.Write([]byte("\n"))
		} else {
			if indentCount < 0 {
				log.Fatalf("indent Count negative in %v at line %v\n", filename, ln)
			}

			file.Write([]byte(strings.Repeat(indent, indentCount) + trimedLine + "\n"))
		}

		if !inMultiLineComment && openPos > -1 && (closePos == -1 || openPos > closePos) && (singleCommentPos == -1 || openPos < singleCommentPos) &&
			(multiLineCommentStartPos == -1 || openPos < multiLineCommentStartPos) &&
			(multiLineCommentEndPos == -1 || openPos > multiLineCommentEndPos) {
			indentCount++
		}

		if multiLineCommentStartPos > -1 {
			inMultiLineComment = true
		}

		if multiLineCommentEndPos > -1 {
			inMultiLineComment = false
		}

	}

}