// -*- java -*-
/*
Copyright (c) 2005 Tony Garnock-Jones <tonyg@kcbbs.gen.nz>
Copyright (c) 2005 LShift Ltd. <query@lshift.net>

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

///////////////////////////////////////////////////////////////////////////
// console.js - a generic, reusable DHTML javascript console.
//
// To add a console to your page, for debugging or interactive
// development, create an empty div with an ID, and call the Console
// constructor with the ID of the div:
//
// var myConsole = new Console("the-div-id");
//
// If you would like focus to be given to the console input textarea,
// call the refocusInput() method.
///////////////////////////////////////////////////////////////////////////

function Console(containerId) {
    this.counter = 0;
    this.containerId = containerId;
    this.inputId = containerId + "_expression";
    this.outputId = containerId + "_output";
    this.buildView();
}

Console.prototype.escapeHTML = function (s) {
    var n = document.createElement("div");
    n.appendChild(document.createTextNode(s));
    return n.innerHTML;
}

Console.prototype.unescapeHTML = function (s) {
    var n = document.createElement("div");
    n.innerHTML = s;
    return n.firstChild.textContent;
}

Console.prototype.prependOutputDiv = function (styletext, content) {
    var d = document.createElement("div");
    d.style.cssText = styletext;
    d.innerHTML = content;

    var o = document.getElementById(this.outputId);
    o.insertBefore(d, o.firstChild);
}

Console.prototype.prependIO = function (styletext, input, output) {
    var id = this.containerId + 'expr' + this.counter;
    this.counter++;

    var editButtonId = id + '_editButton';
    var bodyHtml = '<div style="color: grey; font-style: italic">' +
    '<input style="float: right" id="'+editButtonId+'" value="Edit expression" type="submit">' +
    '<span id="'+id+'">' + this.escapeHTML(input.toString()) + '</span>' +
    '</div>';

    if (output != undefined) {
	this.prependOutputDiv(styletext, bodyHtml +
			      "<div style='border-top: 1px dashed grey'>" +
                              this.escapeHTML(output.toString()) +
			      "</div>");
    } else {
	this.prependOutputDiv(styletext, bodyHtml);
    }

    var thisConsole = this;
    document.getElementById(editButtonId).onclick = function () { thisConsole.loadInput(id); };
}

Console.prototype.recordOutput = function (input, output) {
    this.prependIO("border: 1px solid black; margin-top: 0.5em", input, output);
}

Console.prototype.recordError = function (input, e) {
    var style = "border: 2px solid red; background: #ffeeee; margin-top: 0.5em";
    if ((typeof e == typeof {}) && ('message' in e)) {
	this.prependIO(style, input, e.message + " (" + e.name + ")");
    } else {
	this.prependIO(style, input, e.toString());
    }
}

Console.prototype.refocusInput = function () {
    var codearea = document.getElementById(this.inputId);
    codearea.select();
    codearea.focus();
}

Console.prototype.loadInput = function (id) {
    document.getElementById(this.inputId).value =
        this.unescapeHTML(document.getElementById(id).innerHTML);
    this.refocusInput();
}

Console.prototype.processInput = function () {
    var codearea = document.getElementById(this.inputId);
    var code = codearea.value.replace(/^\s*|\s*$/g,'');
    if (code) {
	var result;
	var haveError = false;
	try {
	    result = eval(code);
	} catch (e) {
	    haveError = true;
	    result = e;
	}
	if (haveError) {
	    this.recordError(code, result);
	} else {
	    this.recordOutput(code, result);
	}
    }
    this.refocusInput();
}

Console.prototype.clearOutput = function () {
    document.getElementById(this.outputId).innerHTML = "";
    this.refocusInput();
}

Console.prototype.buildView = function () {
    var evalButtonId = this.containerId + "_evalButton";
    var clearButtonId = this.containerId + "_clearButton";

    var h = '<div style="margin-bottom: 0.5em">' +
    '<textarea id="'+this.inputId+'" rows="6" cols="70"></textarea><br>' +
    '<p>(Shortcut key: press ALT+P (on Windows or Linux) or CTRL+P (on Macintosh) to evaluate.</p>' +
    '<input id="'+evalButtonId+'" accesskey="p" type="submit" value="Evaluate">' +
    '<input id="'+clearButtonId+'" type="submit" value="Clear">' +
    '</div>' +
    '<div id="'+this.outputId+'"></div>';

    document.getElementById(this.containerId).innerHTML = h;

    var thisConsole = this;
    document.getElementById(evalButtonId).onclick = function () { thisConsole.processInput() };
    document.getElementById(clearButtonId).onclick = function () { thisConsole.clearOutput() };
}

Console.prototype.hide = function () {
    document.getElementById(this.containerId).style.display = "none";
}

Console.prototype.show = function () {
    document.getElementById(this.containerId).style.display = "block";
}