//----------------------------------------------------------------------------
//  Copyright (C) 2008-2011  The IPython Development Team
//
//  Distributed under the terms of the BSD License.  The full license is in
//  the file COPYING, distributed as part of this software.
//----------------------------------------------------------------------------

//============================================================================
// CodeCell
//============================================================================
/**
 * An extendable module that provide base functionnality to create cell for notebook.
 * @module IPython
 * @namespace IPython
 * @submodule CodeCell
 */


/* local util for codemirror */
var posEq = function(a, b) {return a.line == b.line && a.ch == b.ch;};

/**
 *
 * function to delete until previous non blanking space character
 * or first multiple of 4 tabstop.
 * @private
 */
CodeMirror.commands.delSpaceToPrevTabStop = function(cm){
    var from = cm.getCursor(true), to = cm.getCursor(false), sel = !posEq(from, to);
    if (!posEq(from, to)) { cm.replaceRange("", from, to); return; }
    var cur = cm.getCursor(), line = cm.getLine(cur.line);
    var tabsize = cm.getOption('tabSize');
    var chToPrevTabStop = cur.ch-(Math.ceil(cur.ch/tabsize)-1)*tabsize;
    from = {ch:cur.ch-chToPrevTabStop,line:cur.line};
    var select = cm.getRange(from,cur);
    if( select.match(/^\ +$/) !== null){
        cm.replaceRange("",from,cur);
    } else {
        cm.deleteH(-1,"char");
    }
};


var IPython = (function (IPython) {
    "use strict";

    var utils = IPython.utils;
    var key   = IPython.utils.keycodes;

    /**
     * A Cell conceived to write code.
     *
     * The kernel doesn't have to be set at creation time, in that case
     * it will be null and set_kernel has to be called later.
     * @class CodeCell
     * @extends IPython.Cell
     *
     * @constructor
     * @param {Object|null} kernel
     * @param {object|undefined} [options]
     *      @param [options.cm_config] {object} config to pass to CodeMirror
     */
    var CodeCell = function (kernel, options) {
        this.kernel = kernel || null;
        this.code_mirror = null;
        this.input_prompt_number = null;
        this.collapsed = false;
        this.cell_type = "code";


        var cm_overwrite_options  = {
            onKeyEvent: $.proxy(this.handle_codemirror_keyevent,this)
        };

        options = this.mergeopt(CodeCell, options, {cm_config:cm_overwrite_options});

        IPython.Cell.apply(this,[options]);

        var that = this;
        this.element.focusout(
            function() { that.auto_highlight(); }
        );
    };

    CodeCell.options_default = {
        cm_config : {
            extraKeys: {
                "Tab" :  "indentMore",
                "Shift-Tab" : "indentLess",
                "Backspace" : "delSpaceToPrevTabStop",
                "Cmd-/" : "toggleComment",
                "Ctrl-/" : "toggleComment"
            },
            mode: 'ipython',
            theme: 'ipython',
            matchBrackets: true
        }
    };


    CodeCell.prototype = new IPython.Cell();

    /**
     * @method auto_highlight
     */
    CodeCell.prototype.auto_highlight = function () {
        this._auto_highlight(IPython.config.cell_magic_highlight);
    };

    /** @method create_element */
    CodeCell.prototype.create_element = function () {
        IPython.Cell.prototype.create_element.apply(this, arguments);

        var cell =  $('<div></div>').addClass('cell border-box-sizing code_cell');
        cell.attr('tabindex','2');

        this.celltoolbar = new IPython.CellToolbar(this);

        var input = $('<div></div>').addClass('input');
        var vbox = $('<div/>').addClass('vbox box-flex1');
        input.append($('<div/>').addClass('prompt input_prompt'));
        vbox.append(this.celltoolbar.element);
        var input_area = $('<div/>').addClass('input_area');
        this.code_mirror = CodeMirror(input_area.get(0), this.cm_config);
        $(this.code_mirror.getInputField()).attr("spellcheck", "false");
        vbox.append(input_area);
        input.append(vbox);
        var output = $('<div></div>');
        cell.append(input).append(output);
        this.element = cell;
        this.output_area = new IPython.OutputArea(output, true);

        // construct a completer only if class exist
        // otherwise no print view
        if (IPython.Completer !== undefined)
        {
            this.completer = new IPython.Completer(this);
        }
    };

    /**
     *  This method gets called in CodeMirror's onKeyDown/onKeyPress
     *  handlers and is used to provide custom key handling. Its return
     *  value is used to determine if CodeMirror should ignore the event:
     *  true = ignore, false = don't ignore.
     *  @method handle_codemirror_keyevent
     */
    CodeCell.prototype.handle_codemirror_keyevent = function (editor, event) {

        var that = this;
        // whatever key is pressed, first, cancel the tooltip request before
        // they are sent, and remove tooltip if any, except for tab again
        if (event.type === 'keydown' && event.which != key.TAB ) {
            IPython.tooltip.remove_and_cancel_tooltip();
        }

        var cur = editor.getCursor();
        if (event.keyCode === key.ENTER){
            this.auto_highlight();
        }

        if (event.keyCode === key.ENTER && (event.shiftKey || event.ctrlKey)) {
            // Always ignore shift-enter in CodeMirror as we handle it.
            return true;
        } else if (event.which === 40 && event.type === 'keypress' && IPython.tooltip.time_before_tooltip >= 0) {
            // triger on keypress (!) otherwise inconsistent event.which depending on plateform
            // browser and keyboard layout !
            // Pressing '(' , request tooltip, don't forget to reappend it
            // The second argument says to hide the tooltip if the docstring
            // is actually empty
            IPython.tooltip.pending(that, true);
        } else if (event.which === key.UPARROW && event.type === 'keydown') {
            // If we are not at the top, let CM handle the up arrow and
            // prevent the global keydown handler from handling it.
            if (!that.at_top()) {
                event.stop();
                return false;
            } else {
                return true;
            }
        } else if (event.which === key.ESC) {
            return IPython.tooltip.remove_and_cancel_tooltip(true);
        } else if (event.which === key.DOWNARROW && event.type === 'keydown') {
            // If we are not at the bottom, let CM handle the down arrow and
            // prevent the global keydown handler from handling it.
            if (!that.at_bottom()) {
                event.stop();
                return false;
            } else {
                return true;
            }
        } else if (event.keyCode === key.TAB && event.type == 'keydown' && event.shiftKey) {
                if (editor.somethingSelected()){
                    var anchor = editor.getCursor("anchor");
                    var head = editor.getCursor("head");
                    if( anchor.line != head.line){
                        return false;
                    }
                }
                IPython.tooltip.request(that);
                event.stop();
                return true;
        } else if (event.keyCode === key.TAB && event.type == 'keydown') {
            // Tab completion.
            //Do not trim here because of tooltip
            if (editor.somethingSelected()) { return false; }
            var pre_cursor = editor.getRange({line:cur.line,ch:0},cur);
            if (pre_cursor.trim() === "") {
                // Don't autocomplete if the part of the line before the cursor
                // is empty.  In this case, let CodeMirror handle indentation.
                return false;
            } else {
                event.stop();
                this.completer.startCompletion();
                return true;
            }
        } else {
            // keypress/keyup also trigger on TAB press, and we don't want to
            // use those to disable tab completion.
            return false;
        }
        return false;
    };


    // Kernel related calls.

    CodeCell.prototype.set_kernel = function (kernel) {
        this.kernel = kernel;
    };

    /**
     * Execute current code cell to the kernel
     * @method execute
     */
    CodeCell.prototype.execute = function () {
        this.output_area.clear_output();
        this.set_input_prompt('*');
        this.element.addClass("running");
        if (this.last_msg_id) {
            this.kernel.clear_callbacks_for_msg(this.last_msg_id);
        }
        var callbacks = this.get_callbacks();
        
        this.last_msg_id = this.kernel.execute(this.get_text(), callbacks, {silent: false, store_history: true});
    };
    
    /**
     * Construct the default callbacks for
     * @method get_callbacks
     */
    CodeCell.prototype.get_callbacks = function () {
        return {
            shell : {
                reply : $.proxy(this._handle_execute_reply, this),
                payload : {
                    set_next_input : $.proxy(this._handle_set_next_input, this),
                    page : $.proxy(this._open_with_pager, this)
                }
            },
            iopub : {
                output : $.proxy(this.output_area.handle_output, this.output_area),
                clear_output : $.proxy(this.output_area.handle_clear_output, this.output_area),
            },
            input : $.proxy(this._handle_input_request, this)
        };
    };
    
    CodeCell.prototype._open_with_pager = function (payload) {
        $([IPython.events]).trigger('open_with_text.Pager', payload);
    };

    /**
     * @method _handle_execute_reply
     * @private
     */
    CodeCell.prototype._handle_execute_reply = function (msg) {
        this.set_input_prompt(msg.content.execution_count);
        this.element.removeClass("running");
        $([IPython.events]).trigger('set_dirty.Notebook', {value: true});
    };

    /**
     * @method _handle_set_next_input
     * @private
     */
    CodeCell.prototype._handle_set_next_input = function (payload) {
        var data = {'cell': this, 'text': payload.text};
        $([IPython.events]).trigger('set_next_input.Notebook', data);
    };

    /**
     * @method _handle_input_request
     * @private
     */
    CodeCell.prototype._handle_input_request = function (msg) {
        this.output_area.append_raw_input(msg);
    };


    // Basic cell manipulation.

    CodeCell.prototype.select = function () {
        IPython.Cell.prototype.select.apply(this);
        this.code_mirror.refresh();
        this.code_mirror.focus();
        this.auto_highlight();
        // We used to need an additional refresh() after the focus, but
        // it appears that this has been fixed in CM. This bug would show
        // up on FF when a newly loaded markdown cell was edited.
    };


    CodeCell.prototype.select_all = function () {
        var start = {line: 0, ch: 0};
        var nlines = this.code_mirror.lineCount();
        var last_line = this.code_mirror.getLine(nlines-1);
        var end = {line: nlines-1, ch: last_line.length};
        this.code_mirror.setSelection(start, end);
    };


    CodeCell.prototype.collapse = function () {
        this.collapsed = true;
        this.output_area.collapse();
    };


    CodeCell.prototype.expand = function () {
        this.collapsed = false;
        this.output_area.expand();
    };


    CodeCell.prototype.toggle_output = function () {
        this.collapsed = Boolean(1 - this.collapsed);
        this.output_area.toggle_output();
    };


    CodeCell.prototype.toggle_output_scroll = function () {
    this.output_area.toggle_scroll();
    };


    CodeCell.input_prompt_classical = function (prompt_value, lines_number) {
        var ns = prompt_value || "&nbsp;";
        return 'In&nbsp;[' + ns + ']:';
    };

    CodeCell.input_prompt_continuation = function (prompt_value, lines_number) {
        var html = [CodeCell.input_prompt_classical(prompt_value, lines_number)];
        for(var i=1; i < lines_number; i++) {
            html.push(['...:']);
        }
        return html.join('<br/>');
    };

    CodeCell.input_prompt_function = CodeCell.input_prompt_classical;


    CodeCell.prototype.set_input_prompt = function (number) {
        var nline = 1;
        if (this.code_mirror !== undefined) {
           nline = this.code_mirror.lineCount();
        }
        this.input_prompt_number = number;
        var prompt_html = CodeCell.input_prompt_function(this.input_prompt_number, nline);
        this.element.find('div.input_prompt').html(prompt_html);
    };


    CodeCell.prototype.clear_input = function () {
        this.code_mirror.setValue('');
    };


    CodeCell.prototype.get_text = function () {
        return this.code_mirror.getValue();
    };


    CodeCell.prototype.set_text = function (code) {
        return this.code_mirror.setValue(code);
    };


    CodeCell.prototype.at_top = function () {
        var cursor = this.code_mirror.getCursor();
        if (cursor.line === 0 && cursor.ch === 0) {
            return true;
        } else {
            return false;
        }
    };


    CodeCell.prototype.at_bottom = function () {
        var cursor = this.code_mirror.getCursor();
        if (cursor.line === (this.code_mirror.lineCount()-1) && cursor.ch === this.code_mirror.getLine(cursor.line).length) {
            return true;
        } else {
            return false;
        }
    };


    CodeCell.prototype.clear_output = function (wait) {
        this.output_area.clear_output(wait);
    };


    // JSON serialization

    CodeCell.prototype.fromJSON = function (data) {
        IPython.Cell.prototype.fromJSON.apply(this, arguments);
        if (data.cell_type === 'code') {
            if (data.input !== undefined) {
                this.set_text(data.input);
                // make this value the starting point, so that we can only undo
                // to this state, instead of a blank cell
                this.code_mirror.clearHistory();
                this.auto_highlight();
            }
            if (data.prompt_number !== undefined) {
                this.set_input_prompt(data.prompt_number);
            } else {
                this.set_input_prompt();
            }
            this.output_area.fromJSON(data.outputs);
            if (data.collapsed !== undefined) {
                if (data.collapsed) {
                    this.collapse();
                } else {
                    this.expand();
                }
            }
        }
    };


    CodeCell.prototype.toJSON = function () {
        var data = IPython.Cell.prototype.toJSON.apply(this);
        data.input = this.get_text();
        data.cell_type = 'code';
        if (this.input_prompt_number) {
            data.prompt_number = this.input_prompt_number;
        }
        var outputs = this.output_area.toJSON();
        data.outputs = outputs;
        data.language = 'python';
        data.collapsed = this.collapsed;
        return data;
    };


    IPython.CodeCell = CodeCell;

    return IPython;
}(IPython));