/* Mandy Wu's Website
 * common.js: The common JavaScript subroutines.
 */

/*  Copyright (c) 2007-2018 imacat.
 * 
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/* Author: imacat <imacat@mail.imacat.idv.tw>
 * First written: 2007-09-27
 */

// _: Gettext
function _(msg) {
    var i;
    for (i = 0; i < lc_messages.length; i++) {
        if (lc_messages[i][0] == msg) {
            return lc_messages[i][1];
        }
    }
    return msg;
}
// The messages
lc_messages = [];

// isEmail: Check if an email address is legal
function isEmail(a) {
    var i, c, re;
    if (typeof(RegExp) == "undefined") return true;
    re = new RegExp("^[\\w\\-]+(\\.[\\w\\-]+)*\\@([\\w\\-]+\\.)+[\\w\\-]+$");
    if (typeof(a) != "string") return false;
    a = a.toLowerCase();
    if (re.exec(a) == null) return false;
    return true;
}

// isDate: Check if a date is legal
function isDate(dateText) {
    var i, year, month, day, maxDay;
    if (dateText.length != 10) {
        return false;
    }
    // Check each character
    for (i = 0; i < dateText.length; i++) {
        // The dash sign
        if (i == 4 || i == 7) {
            if (dateText.charAt(i) != "-")
                return false;
        // The digits
        } else {
            if (dateText.charCodeAt(i) < 48 || dateText.charCodeAt(i) > 57)
                return false;
        }
    }
    // Check if the date is valid
    year = dateText.substr(0, 4) * 1;
    month = dateText.substr(5, 2) * 1;
    day  = dateText.substr(8, 2) * 1;
    // A reasonable month
    if (month < 1 || month > 12)
        return false;
    // Find the maximum day in this month
    switch (month) {
    case 1:
    case 3:
    case 5:
    case 7:
    case 8:
    case 10:
    case 12:
        maxDay = 31;
        break;
    case 4:
    case 6:
    case 9:
    case 11:
        maxDay = 30;
        break;
    case 2:
        maxDay = 28;
        if (year % 4 == 0)
            maxDay = 29;
        if (year % 100 == 0)
            maxDay = 28;
        if (year % 400 == 0)
            maxDay = 29;
        break;
    }
    // A reasonable day
    if (day < 1 || day > maxDay)
        return false;
    return true;
}

// trim: Trim the leading and tailing spaces
function trim(a) {
    var pos, start, len, spaces;
    start = 0;
    len = a.length;
    spaces = " \t\f\n\r";
    for (start = 0; start < a.length && spaces.indexOf(a.charAt(start)) >= 0; start++, len--);
    for (pos = a.length - 1; pos >= 0 && spaces.indexOf(a.charAt(pos)) >= 0; pos--, len--);
    return a.substr(start, len);
}
function trimText(a) {
    var pos, start, len, spaces, newlines;
    start = 0;
    len = a.length;
    spaces = " \t\f\n\r";
    newlines = "\n\r";
    for (start = 0; start < a.length && spaces.indexOf(a.charAt(start)) >= 0; start++, len--);
    for ( ; start-1 >= 0 && newlines.indexOf(a.charAt(start-1)) < 0; start--, len++);
    for (pos = a.length - 1; pos >= 0 && spaces.indexOf(a.charAt(pos)) >= 0; pos--, len--);
    return a.substr(start, len);
}

// Replace one phace with another in a string
function replace(source, oldStr, newStr) {
	var pos;
	pos = 0;
	while (true) {
		pos = source.indexOf(oldStr, pos);
		if (pos == -1) break;
		source = source.substr(0, pos) + newStr + source.substr(pos + oldStr.length)
		pos += newStr.length;
	}
	return source;
}