/*
 * Copyright (C) 2008 Apple Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @constructor
 */
WebInspector.TextPrompt = function(element, completions, stopCharacters, omitHistory)
{
    this.element = element;
    this.element.addStyleClass("text-prompt");
    this.completions = completions;
    this.completionStopCharacters = stopCharacters;
    if (!omitHistory) {
        this.history = [];
        this.historyOffset = 0;
    }
    this._boundOnKeyDown = this._onKeyDown.bind(this);
    this.element.addEventListener("keydown", this._boundOnKeyDown, true);
}

WebInspector.TextPrompt.prototype = {
    get text()
    {
        return this.element.textContent;
    },

    set text(x)
    {
        if (!x) {
            // Append a break element instead of setting textContent to make sure the selection is inside the prompt.
            this.element.removeChildren();
            this.element.appendChild(document.createElement("br"));
        } else
            this.element.textContent = x;

        this.moveCaretToEndOfPrompt();
    },

    removeFromElement: function()
    {
        this.clearAutoComplete(true);
        this.element.removeEventListener("keydown", this._boundOnKeyDown, true);
    },

    _onKeyDown: function(event)
    {
        function defaultAction()
        {
            this.clearAutoComplete();
            this.autoCompleteSoon();
        }

        if (event.handled)
            return;

        var handled = false;

        switch (event.keyIdentifier) {
            case "Up":
                this.upKeyPressed(event);
                break;
            case "Down":
                this.downKeyPressed(event);
                break;
            case "U+0009": // Tab
                this.tabKeyPressed(event);
                break;
            case "Right":
            case "End":
                if (!this.acceptAutoComplete())
                    this.autoCompleteSoon();
                break;
            case "Alt":
            case "Meta":
            case "Shift":
            case "Control":
                break;
            case "U+0050": // Ctrl+P = Previous
                if (this.history && WebInspector.isMac() && event.ctrlKey && !event.metaKey && !event.altKey && !event.shiftKey) {
                    handled = true;
                    this._moveBackInHistory();
                    break;
                }
                defaultAction.call(this);
                break;
            case "U+004E": // Ctrl+N = Next
                if (this.history && WebInspector.isMac() && event.ctrlKey && !event.metaKey && !event.altKey && !event.shiftKey) {
                    handled = true;
                    this._moveForwardInHistory();
                    break;
                }
                defaultAction.call(this);
                break;
            default:
                defaultAction.call(this);
                break;
        }

        handled |= event.handled;
        if (handled) {
            event.handled = true;
            event.preventDefault();
            event.stopPropagation();
        }
    },

    acceptAutoComplete: function()
    {
        if (!this.autoCompleteElement || !this.autoCompleteElement.parentNode)
            return false;

        var text = this.autoCompleteElement.textContent;
        var textNode = document.createTextNode(text);
        this.autoCompleteElement.parentNode.replaceChild(textNode, this.autoCompleteElement);
        delete this.autoCompleteElement;

        var finalSelectionRange = document.createRange();
        finalSelectionRange.setStart(textNode, text.length);
        finalSelectionRange.setEnd(textNode, text.length);

        var selection = window.getSelection();
        selection.removeAllRanges();
        selection.addRange(finalSelectionRange);

        return true;
    },

    clearAutoComplete: function(includeTimeout)
    {
        if (includeTimeout && "_completeTimeout" in this) {
            clearTimeout(this._completeTimeout);
            delete this._completeTimeout;
        }

        if (!this.autoCompleteElement)
            return;

        if (this.autoCompleteElement.parentNode)
            this.autoCompleteElement.parentNode.removeChild(this.autoCompleteElement);
        delete this.autoCompleteElement;

        if (!this._userEnteredRange || !this._userEnteredText)
            return;

        this._userEnteredRange.deleteContents();
        this.element.pruneEmptyTextNodes();

        var userTextNode = document.createTextNode(this._userEnteredText);
        this._userEnteredRange.insertNode(userTextNode);

        var selectionRange = document.createRange();
        selectionRange.setStart(userTextNode, this._userEnteredText.length);
        selectionRange.setEnd(userTextNode, this._userEnteredText.length);

        var selection = window.getSelection();
        selection.removeAllRanges();
        selection.addRange(selectionRange);

        delete this._userEnteredRange;
        delete this._userEnteredText;
    },

    autoCompleteSoon: function()
    {
        if (!("_completeTimeout" in this))
            this._completeTimeout = setTimeout(this.complete.bind(this, true), 250);
    },

    complete: function(auto, reverse)
    {
        this.clearAutoComplete(true);
        var selection = window.getSelection();
        if (!selection.rangeCount)
            return;

        var selectionRange = selection.getRangeAt(0);
        var isEmptyInput = selectionRange.commonAncestorContainer === this.element; // this.element has no child Text nodes.

        // Do not attempt to auto-complete an empty input in the auto mode (only on demand).
        if (auto && isEmptyInput)
            return;
        if (!auto && !isEmptyInput && !selectionRange.commonAncestorContainer.isDescendant(this.element))
            return;
        if (auto && !this.isCaretAtEndOfPrompt())
            return;
        var wordPrefixRange = selectionRange.startContainer.rangeOfWord(selectionRange.startOffset, this.completionStopCharacters, this.element, "backward");
        this.completions(wordPrefixRange, auto, this._completionsReady.bind(this, selection, auto, wordPrefixRange, reverse));
    },

    _completionsReady: function(selection, auto, originalWordPrefixRange, reverse, completions)
    {
        if (!completions || !completions.length)
            return;

        var selectionRange = selection.getRangeAt(0);

        var fullWordRange = document.createRange();
        fullWordRange.setStart(originalWordPrefixRange.startContainer, originalWordPrefixRange.startOffset);
        fullWordRange.setEnd(selectionRange.endContainer, selectionRange.endOffset);

        if (originalWordPrefixRange.toString() + selectionRange.toString() != fullWordRange.toString())
            return;

        var wordPrefixLength = originalWordPrefixRange.toString().length;

        if (auto)
            var completionText = completions[0];
        else {
            if (completions.length === 1) {
                var completionText = completions[0];
                wordPrefixLength = completionText.length;
            } else {
                var commonPrefix = completions[0];
                for (var i = 0; i < completions.length; ++i) {
                    var completion = completions[i];
                    var lastIndex = Math.min(commonPrefix.length, completion.length);
                    for (var j = wordPrefixLength; j < lastIndex; ++j) {
                        if (commonPrefix[j] !== completion[j]) {
                            commonPrefix = commonPrefix.substr(0, j);
                            break;
                        }
                    }
                }
                wordPrefixLength = commonPrefix.length;

                if (selection.isCollapsed)
                    var completionText = completions[0];
                else {
                    var currentText = fullWordRange.toString();

                    var foundIndex = null;
                    for (var i = 0; i < completions.length; ++i) {
                        if (completions[i] === currentText)
                            foundIndex = i;
                    }

                    var nextIndex = foundIndex + (reverse ? -1 : 1);
                    if (foundIndex === null || nextIndex >= completions.length)
                        var completionText = completions[0];
                    else if (nextIndex < 0)
                        var completionText = completions[completions.length - 1];
                    else
                        var completionText = completions[nextIndex];
                }
            }
        }

        this._userEnteredRange = fullWordRange;
        this._userEnteredText = fullWordRange.toString();

        fullWordRange.deleteContents();
        this.element.pruneEmptyTextNodes();

        var finalSelectionRange = document.createRange();

        if (auto) {
            var prefixText = completionText.substring(0, wordPrefixLength);
            var suffixText = completionText.substring(wordPrefixLength);

            var prefixTextNode = document.createTextNode(prefixText);
            fullWordRange.insertNode(prefixTextNode);

            this.autoCompleteElement = document.createElement("span");
            this.autoCompleteElement.className = "auto-complete-text";
            this.autoCompleteElement.textContent = suffixText;

            prefixTextNode.parentNode.insertBefore(this.autoCompleteElement, prefixTextNode.nextSibling);

            finalSelectionRange.setStart(prefixTextNode, wordPrefixLength);
            finalSelectionRange.setEnd(prefixTextNode, wordPrefixLength);
        } else {
            var completionTextNode = document.createTextNode(completionText);
            fullWordRange.insertNode(completionTextNode);

            if (completions.length > 1)
                finalSelectionRange.setStart(completionTextNode, wordPrefixLength);
            else
                finalSelectionRange.setStart(completionTextNode, completionText.length);

            finalSelectionRange.setEnd(completionTextNode, completionText.length);
        }

        selection.removeAllRanges();
        selection.addRange(finalSelectionRange);
    },

    isCaretInsidePrompt: function()
    {
        return this.element.isInsertionCaretInside();
    },

    isCaretAtEndOfPrompt: function()
    {
        var selection = window.getSelection();
        if (!selection.rangeCount || !selection.isCollapsed)
            return false;

        var selectionRange = selection.getRangeAt(0);
        var node = selectionRange.startContainer;
        if (node !== this.element && !node.isDescendant(this.element))
            return false;

        if (node.nodeType === Node.TEXT_NODE && selectionRange.startOffset < node.nodeValue.length)
            return false;

        var foundNextText = false;
        while (node) {
            if (node.nodeType === Node.TEXT_NODE && node.nodeValue.length) {
                if (foundNextText)
                    return false;
                foundNextText = true;
            }

            node = node.traverseNextNode(this.element);
        }

        return true;
    },

    isCaretOnFirstLine: function()
    {
        var selection = window.getSelection();
        var focusNode = selection.focusNode;
        if (!focusNode || focusNode.nodeType !== Node.TEXT_NODE || focusNode.parentNode !== this.element)
            return true;

        if (focusNode.textContent.substring(0, selection.focusOffset).indexOf("\n") !== -1)
            return false;
        focusNode = focusNode.previousSibling;

        while (focusNode) {
            if (focusNode.nodeType !== Node.TEXT_NODE)
                return true;
            if (focusNode.textContent.indexOf("\n") !== -1)
                return false;
            focusNode = focusNode.previousSibling;
        }

        return true;
    },

    isCaretOnLastLine: function()
    {
        var selection = window.getSelection();
        var focusNode = selection.focusNode;
        if (!focusNode || focusNode.nodeType !== Node.TEXT_NODE || focusNode.parentNode !== this.element)
            return true;

        if (focusNode.textContent.substring(selection.focusOffset).indexOf("\n") !== -1)
            return false;
        focusNode = focusNode.nextSibling;

        while (focusNode) {
            if (focusNode.nodeType !== Node.TEXT_NODE)
                return true;
            if (focusNode.textContent.indexOf("\n") !== -1)
                return false;
            focusNode = focusNode.nextSibling;
        }

        return true;
    },

    moveCaretToEndOfPrompt: function()
    {
        var selection = window.getSelection();
        var selectionRange = document.createRange();

        var offset = this.element.childNodes.length;
        selectionRange.setStart(this.element, offset);
        selectionRange.setEnd(this.element, offset);

        selection.removeAllRanges();
        selection.addRange(selectionRange);
    },

    tabKeyPressed: function(event)
    {
        event.handled = true;
        this.complete(false, event.shiftKey);
    },

    upKeyPressed: function(event)
    {
        if (!this.isCaretOnFirstLine())
            return;

        event.handled = true;
        this._moveBackInHistory();
    },

    downKeyPressed: function(event)
    {
        if (!this.isCaretOnLastLine())
            return;

        event.handled = true;
        this._moveForwardInHistory();
    },

    _moveBackInHistory: function()
    {
        if (!this.history || this.historyOffset == this.history.length)
            return;

        this.clearAutoComplete(true);

        if (this.historyOffset === 0)
            this.tempSavedCommand = this.text;

        ++this.historyOffset;
        this.text = this.history[this.history.length - this.historyOffset];

        this.element.scrollIntoView(true);
        var firstNewlineIndex = this.text.indexOf("\n");
        if (firstNewlineIndex === -1)
            this.moveCaretToEndOfPrompt();
        else {
            var selection = window.getSelection();
            var selectionRange = document.createRange();

            selectionRange.setStart(this.element.firstChild, firstNewlineIndex);
            selectionRange.setEnd(this.element.firstChild, firstNewlineIndex);

            selection.removeAllRanges();
            selection.addRange(selectionRange);
        }
    },

    _moveForwardInHistory: function()
    {
        if (!this.history || this.historyOffset === 0)
            return;

        this.clearAutoComplete(true);

        --this.historyOffset;

        if (this.historyOffset === 0) {
            this.text = this.tempSavedCommand;
            delete this.tempSavedCommand;
            return;
        }

        this.text = this.history[this.history.length - this.historyOffset];
        this.element.scrollIntoView();
    }
}
