#!/usr/bin/env node
'use strict';

/* globals Set */
/*!
 * Script to update version number references in the project.
 * Copyright 2015 Twitter, Inc.
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
 */
var fs          = require('fs');
var path        = require('path');
var sh          = require('shelljs');
sh.config.fatal = true;
var sed         = sh.sed;

// Blame TC39... https://github.com/benjamingr/RegExp.escape/issues/37
RegExp.quote            = function (string) {
    return string.replace(/[-\\^$*+?.()|[\]{}]/g, '\\$&');
};
RegExp.quoteReplacement = function (string) {
    return string.replace(/[$]/g, '$$');
};

var DRY_RUN = false;

function walkAsync(directory, excludedDirectories, fileCallback, errback) {
    if (excludedDirectories.has(path.parse(directory).base)) {
        return;
    }
    fs.readdir(directory, function (err, names) {
        if (err) {
            errback(err);
            return;
        }
        names.forEach(function (name) {
            var filepath = path.join(directory, name);
            fs.lstat(filepath, function (err, stats) {
                if (err) {
                    process.nextTick(errback, err);
                    return;
                }
                if (stats.isSymbolicLink()) {
                    return;
                }
                else if (stats.isDirectory()) {
                    process.nextTick(walkAsync, filepath, excludedDirectories, fileCallback, errback);
                }
                else if (stats.isFile()) {
                    process.nextTick(fileCallback, filepath);
                }
            });
        });
    });
}

function replaceRecursively(directory, excludedDirectories, allowedExtensions, original, replacement) {
    original       = new RegExp(RegExp.quote(original), 'g');
    replacement    = RegExp.quoteReplacement(replacement);
    var updateFile = !DRY_RUN ? function (filepath) {
        if (allowedExtensions.has(path.parse(filepath).ext)) {
            sed('-i', original, replacement, filepath);
        }
    } : function (filepath) {
        if (allowedExtensions.has(path.parse(filepath).ext)) {
            console.log('FILE: ' + filepath);
        }
        else {
            console.log('EXCLUDED:' + filepath);
        }
    };
    walkAsync(directory, excludedDirectories, updateFile, function (err) {
        console.error('ERROR while traversing directory!:');
        console.error(err);
        process.exit(1);
    });
}

function main(args) {
    if (args.length !== 2) {
        console.error('USAGE: change-version old_version new_version');
        console.error('Got arguments:', args);
        process.exit(1);
    }
    var oldVersion          = args[0];
    var newVersion          = args[1];
    var EXCLUDED_DIRS       = new Set([
        '.git',
        'node_modules',
        'vendor'
    ]);
    var INCLUDED_EXTENSIONS = new Set([
        // This extension whitelist is how we avoid modifying binary files
        '',
        '.css',
        '.html',
        '.js',
        '.json',
        '.less',
        '.md',
        '.nuspec',
        '.ps1',
        '.scss',
        '.txt',
        '.yml'
    ]);
    replaceRecursively('.', EXCLUDED_DIRS, INCLUDED_EXTENSIONS, oldVersion, newVersion);
}

main(process.argv.slice(2));