window.onload = function() {
	if (hasSearchWord('utf')) {
		document.getElementById('charset_utf_8').checked = true;
		document.getElementById('encoding_none').checked = true;
	} else if (hasSearchWord('xml') || hasSearchWord('html')) {
		document.getElementById('encoding_xml').checked = true;
	} else if (hasSearchWord('base')) {
		document.getElementById('encoding_base64').checked = true;
	} else if (hasSearchWord('url')) {
		document.getElementById('encoding_url').checked = true;
	}
	if (hasSearchWord('decode') && !hasSearchWord('encode')) {
		document.getElementById('action_decode').checked = true;
	}
	update();
}

var exampleRaw = 'Joe\'s Caf\xe9 & Bar \u266b';
function update() {
    var encodingName = false;
    var charsetName = false;

    var radiosEncoding = document.getElementsByName('encoding');
    for (var i = 0; i < radiosEncoding.length; i++) {
        if (radiosEncoding[i].checked) {
            encodingName = radiosEncoding[i].value;
        }
    }

    var radiosCharset = document.getElementsByName('charset');
    for (var i = 0; i < radiosCharset.length; i++) {
        if (radiosCharset[i].checked) {
            charsetName = radiosCharset[i].value;
        }
    }

    var encoding = encodings[encodingName];
    var charset = charsets[charsetName];

    var radioNone = document.getElementById('charset_none');
    radioNone.disabled = !encoding.supportsNone;
    radioNone.parentNode.className = radioNone.disabled ? 'disabled' : '';
    if (charset.name == 'none' && radioNone.disabled) {
        var radioUsAscii = document.getElementById('charset_us_ascii');
        radioUsAscii.checked = true;
        charsetName = 'us_ascii';
        charset = charsets[charsetName];
    }

    var input = document.getElementById('input').value;
    var output;

    var encode = document.getElementById('action_encode').checked;

    var spanExampleInput = document.getElementById('exampleInput');
    var spanExampleOutput = document.getElementById('exampleOutput');
    var exampleEncoded = encoding.encode(exampleRaw, charset);
    if (encode) {
        output = encoding.encode(input, charset);
        spanExampleInput.firstChild.data = exampleRaw;
        spanExampleOutput.firstChild.data = exampleEncoded;
    } else {
        output = encoding.decode(input, charset);
        spanExampleInput.firstChild.data = exampleEncoded;
        spanExampleOutput.firstChild.data = exampleRaw;
    }

    document.getElementById('output').value = output;
}

var charsets = {
    none : {
        name : 'none',
        containsChar : function(c) {
            return false;
        }
    },
    us_ascii : {
        name : 'US-ASCII',
        containsChar : function(c) {
            return c.charCodeAt(0) < 128;
        }
    },
    iso_8859_1 : {
        name : 'ISO-8859-1',
        containsChar : function(c) {
            return c.charCodeAt(0) < 256;
        }
    },
    utf_8 : {
        name : 'UTF-8',
        containsChar : function(c) {
            return true;
        }
    }
}

var encodings = {
    base64 : {
        printable : 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
        supportsNone : false,
        encode : function(input, charset) {
            if (charset.name == 'UTF-8') {
                var bytes = string2utf8bytearray(input);
                var s = new Array(bytes.length);
                for (var i = 0; i < bytes.length; i++) {
                    s[i] = String.fromCharCode(bytes[i]);
                }
                input = s.join('');
            } else {
                input = input.replace(/[^\x00-\xFF]/, '?');
            }
            var output = [];
            if (typeof btoa == 'function') {
                var s = btoa(input);
                for (var p = 0; p < s.length; p += 76) {
                    output.push(s.substr(p, 76) + '\n');
                }
                return output.join('');
            }
            var iterations = Math.ceil(input.length * 4 / 3);
            input += '\0';
            var j = 8, b = input.charCodeAt(0), p = 0;
            for (var i = 0; i < iterations; i++) {
                if (j < 6) {
                    b = (input.charCodeAt(p) << 8) + input.charCodeAt(p + 1);
                    p++;
                    j += 2;
                } else {
                    j -= 6;
                }
                output.push(this.printable.substr((b >> j) & 0x3F, 1));
                if (i % 76 == 75) {
                    output.push('\n');
                }
            }
            output.push('=='.substr((1 + input.length) % 3));
            return output.join('');
        },
        decode : function(input, charset) {
            if (typeof atob == 'function') {
                return atob(input.replace(/\s/g, ''));
            }
            var output = '';
            input = input.replace(/(\s|={1,2}$)/g, '');
            var iterations = Math.floor(input.length * 3 / 4);
            input += '\0';
            var j = 2, d = '', p = 0;
            for (var i = 0; i < iterations; i++) {
                b = (this.printable.indexOf(input.charAt(p)) << j) + 
                    (this.printable.indexOf(input.charAt(p + 1)) >> (6 - j));
                output += String.fromCharCode(b & 0xFF);
                j = j % 6 + 2;
                p += (j == 2 ? 2 : 1);
            }
            return output;
        }
    },
    xml : {
        supportsNone : true,
        encode : function(input, charset) {
            var output = '';
            for (var i = 0; i < input.length; i++) {
                var j = '<>"&\''.indexOf(input.charAt(i));
                if (j != -1) {
                    output += '&' + ['lt', 'gt', 'quot', 'amp', '#39'][j] + ';';
                } else if (!charset.containsChar(input.charAt(i))) {
                    output += '&#' + input.charCodeAt(i) + ';';
                } else {
                    output += input.charAt(i);
                }
            }
            return output;
        },
        decode : function(input, charset) {
            var getText = function(element) {
                var s = '';
                for (var node = element.firstChild; node; node = node.nextSibling) {
                    if (node.nodeType == 1) {
                        s += getText(node);
                    } else if (node.nodeType == 3) {
                        s += node.data;
                    }
                }
                return s;
            }
            var div = document.createElement('DIV');
            div.innerHTML = input;
            return getText(div);
        }
    },
    url : {
        supportsNone : true,
        encode : function(input, charset) {
            return charset.name == 'UTF-8' ? encodeURIComponent(input) : escape(input).replace(/\+/g, '%2B');
        },
        decode : function(input, charset) {
            return unescape(input.replace(/\+/g, ' '));
        }
    },
    js : {
        supportsNone : true,
        encode : function(input, charset) {
            var output = '';
            for (var i = 0; i < input.length; i++) {
                var j = '\b\t\n\v\f\r"\'\\'.indexOf(input.charAt(i));
                if (j != -1) {
                    output += '\\' + 'btnvfr"\'\\'.substr(j, 1);
                } else if (input.substr(i, 2) == '</') {
                    output += '<\\/';
                    i++;
                } else if (!charset.containsChar(input.charAt(i))) {
                    if (input.charCodeAt(i) > 255) {
                        output += '\\u' + ('000' + input.charCodeAt(i).toString(16)).right(4);
                    } else {
                        output += '\\x' + ('0' + input.charCodeAt(i).toString(16)).right(2);
                    }
                } else {
                    output += input.charAt(i);
                }
            }
            return output;
        },
        decode : function(input, charset) {
            try {
                return !/([^\\]'|\r|\n)/.test(input)? eval("'" + input + "'") : false;
            } catch(e) {
                return false;
            }
        }
    },
    none : {
        supportsNone : false,
        encode : function(input, charset) {
            var output = [];
            if (charset.name == 'UTF-8') {
                var bytes = string2utf8bytearray(input);
                for (var i = 0; i < bytes.length; i++) {
                    output.push(String.fromCharCode(bytes[i]));
                }   
                return output.join('');
            } else {
                return input.replace(/[^\x00-\xFF]/, '?');
            }
        },
        decode : function(input, charset) {
            var output = [];
            for (var i = 0; i < input.length; i++) {
                var c = input.charCodeAt(i);
                if (c <= 0x7F) {
                    output.push(input.substr(i, 1));
                } else if (0xC0 <= c && c <= 0xDF) {
                    var c2 = input.charCodeAt(++i);
                    if (0x80 <= c2 && c2 <= 0xBF) {
                        var o = ((c & 0x1F) << 6) + (c2 & 0x3F);
                        output.push(String.fromCharCode(o));
                    } else {
                        return 'invalid input';
                    }
                } else if (0xE0 <= c && c <= 0xEF) {
                    var c2 = input.charCodeAt(++i);
                    var c3 = input.charCodeAt(++i);
                    if (0x80 <= c2 && c2 <= 0xBF &&
                        0x80 <= c3 && c3 <= 0xBF) {
                        var o = ((c & 0xF) << 12) + ((c2 & 0x3F) << 6) + (c3 & 0x3F);
                        output.push(String.fromCharCode(o));
                    } else {
                        return 'invalid input';
                    }
                    
                } else if (0xE0 <= c && c <= 0xEF) {
                    var c2 = input.charCodeAt(++i);
                    var c3 = input.charCodeAt(++i);
                    var c4 = input.charCodeAt(++i);
                    if (0x80 <= c2 && c2 <= 0xBF &&
                        0x80 <= c3 && c3 <= 0xBF &&
                        0x80 <= c4 && c4 <= 0xBF) {
                        var o = ((c & 7) << 18) + ((c2 & 0x3F) << 12) + ((c2 & 0x3F) << 6) + (c4 & 0x3F);
                        output.push(String.fromCharCode(o));
                    } else {
                        return 'invalid input';
                    }
                    
                } else {
                    return 'invalid input';
                }
            }
            return output.join('');
        }
    }
}

function string2utf8bytearray(s) {
    // We need to allocate at least one byte per character.
    var output = new Array(s.length);
    for (var i = 0, j = 0; i < s.length; i++) {
        var c = s.charCodeAt(i);
        if (c < 0x7F) {
            output[j++] = c;
        } else if (c < 0x7FF) {
            output[j++] = 0xC0 + (c >> 6);
            output[j++] = 0x80 + (c & 0x3F);
        } else if (c < 0xFFFF) {
            output[j++] = 0xE0 + (c >> 12);
            output[j++] = 0x80 + ((c >> 6) & 0x3F);
            output[j++] = 0x80 + (c & 0x3F);
        } else if (c < 0x10FFFF) {
            output[j++] = 0xF0 + (c >> 18);
            output[j++] = 0x80 + ((c >> 6) & 0x3F);
            output[j++] = 0x80 + ((c >> 12) & 0x3F);;
            output[j++] = 0x80 + (c & 0x3F);
        }
    }
    return output;
}