/*
 * Copyright (C) 2014 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. 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 INC. 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.
 */

WebInspector.TimelineRecordBar = function(records, renderMode)
{
    WebInspector.Object.call(this);

    this._element = document.createElement("div");
    this._element.classList.add(WebInspector.TimelineRecordBar.StyleClassName);

    this.renderMode = renderMode;
    this.records = records;
};

WebInspector.Object.addConstructorFunctions(WebInspector.TimelineRecordBar);

WebInspector.TimelineRecordBar.StyleClassName = "timeline-record-bar";
WebInspector.TimelineRecordBar.BarSegmentStyleClassName = "segment";
WebInspector.TimelineRecordBar.InactiveStyleClassName = "inactive";
WebInspector.TimelineRecordBar.UnfinishedStyleClassName = "unfinished";
WebInspector.TimelineRecordBar.HasInactiveSegmentStyleClassName = "has-inactive-segment";
WebInspector.TimelineRecordBar.MinimumWidthPixels = 4;
WebInspector.TimelineRecordBar.MinimumMarginPixels = 1;

WebInspector.TimelineRecordBar.RenderMode = {
    Normal: "timeline-record-bar-normal-render-mode",
    InactiveOnly: "timeline-record-bar-inactive-only-render-mode",
    ActiveOnly: "timeline-record-bar-active-only-render-mode"
};

WebInspector.TimelineRecordBar.createCombinedBars = function(records, secondsPerPixel, graphDataSource, createBarCallback)
{
    if (!records.length)
        return;

    var startTime = graphDataSource.startTime;
    var currentTime = graphDataSource.currentTime;
    var endTime = graphDataSource.endTime;

    var visibleRecords = [];
    var usesActiveStartTime = false;
    var lastRecordType = null;

    // FIXME: Do a binary search for records that fall inside start and current time.

    for (var record of records) {
        if (isNaN(record.startTime))
            continue;

        // If this bar is completely before the bounds of the graph, skip this record.
        if (record.endTime < startTime)
            continue;

        // If this record is completely after the current time or end time, break out now.
        // Records are sorted, so all records after this will be beyond the current or end time too.
        if (record.startTime > currentTime || record.startTime > endTime)
            break;

        if (record.usesActiveStartTime)
            usesActiveStartTime = true;

        // If one record uses active time the rest are assumed to use it.
        console.assert(record.usesActiveStartTime === usesActiveStartTime);

        // Only a single record type is supported right now.
        console.assert(!lastRecordType || record.type === lastRecordType);

        visibleRecords.push(record);

        lastRecordType = record.type;
    }

    if (!visibleRecords.length)
        return;

    if (visibleRecords.length === 1) {
        createBarCallback(visibleRecords, WebInspector.TimelineRecordBar.RenderMode.Normal);
        return;
    }

    function compareByActiveStartTime(a, b)
    {
        return a.activeStartTime - b.activeStartTime;
    }

    var minimumDuration = secondsPerPixel * WebInspector.TimelineRecordBar.MinimumWidthPixels;
    var minimumMargin = secondsPerPixel * WebInspector.TimelineRecordBar.MinimumMarginPixels;

    if (usesActiveStartTime) {
        var inactiveStartTime = NaN;
        var inactiveEndTime = NaN;
        var inactiveRecords = [];

        for (var record of visibleRecords) {
            // Check if the previous record is far enough away to create the inactive bar.
            if (!isNaN(inactiveStartTime) && inactiveStartTime + Math.max(inactiveEndTime - inactiveStartTime, minimumDuration) + minimumMargin <= record.startTime) {
                createBarCallback(inactiveRecords, WebInspector.TimelineRecordBar.RenderMode.InactiveOnly);
                inactiveRecords = [];
                inactiveStartTime = NaN;
                inactiveEndTime = NaN;
            }

            // If this is a new bar, peg the start time.
            if (isNaN(inactiveStartTime))
                inactiveStartTime = record.startTime;

            // Update the end time to be the maximum we encounter. inactiveEndTime might be NaN, so "|| 0" to prevent Math.max from returning NaN.
            inactiveEndTime = Math.max(inactiveEndTime || 0, record.activeStartTime);

            inactiveRecords.push(record);
        }

        // Create the inactive bar for the last record if needed.
        if (!isNaN(inactiveStartTime))
            createBarCallback(inactiveRecords, WebInspector.TimelineRecordBar.RenderMode.InactiveOnly);

        visibleRecords.sort(compareByActiveStartTime);
    }

    lastRecordType = null;

    var activeStartTime = NaN;
    var activeEndTime = NaN;
    var activeRecords = [];

    var startTimeProperty = usesActiveStartTime ? "activeStartTime" : "startTime";

    for (var record of visibleRecords) {
        // Check if the previous record is far enough away to create the active bar. We also create it now if the current record has no active state time.
        if (!isNaN(activeStartTime) && (activeStartTime + Math.max(activeEndTime - activeStartTime, minimumDuration) + minimumMargin <= record[startTimeProperty]
            || (isNaN(record[startTimeProperty]) && !isNaN(activeEndTime)))) {
            createBarCallback(activeRecords, WebInspector.TimelineRecordBar.RenderMode.ActiveOnly);
            activeRecords = [];
            activeStartTime = NaN;
            activeEndTime = NaN;
        }

        if (isNaN(record[startTimeProperty]))
            continue;

        // If this is a new bar, peg the start time.
        if (isNaN(activeStartTime))
            activeStartTime = record[startTimeProperty];

        // Update the end time to be the maximum we encounter. activeEndTime might be NaN, so "|| 0" to prevent Math.max from returning NaN.
        if (!isNaN(record.endTime))
            activeEndTime = Math.max(activeEndTime || 0, record.endTime);

        activeRecords.push(record);
    }

    // Create the active bar for the last record if needed.
    if (!isNaN(activeStartTime))
        createBarCallback(activeRecords, WebInspector.TimelineRecordBar.RenderMode.ActiveOnly);
};

WebInspector.TimelineRecordBar.prototype = {
    constructor: WebInspector.TimelineRecordBar,
    __proto__: WebInspector.Object.prototype,

    // Public

    get element()
    {
        return this._element;
    },

    get renderMode()
    {
        return this._renderMode;
    },

    set renderMode(renderMode)
    {
        this._renderMode = renderMode || WebInspector.TimelineRecordBar.RenderMode.Normal;
    },

    get records()
    {
        return this._records;
    },

    set records(records)
    {
        if (this._records && this._records.length)
            this._element.classList.remove(this._records[0].type);

        records = records || [];

        if (!(records instanceof Array))
            records = [records];

        this._records = records;

        // Assume all records are the same type.
        if (this._records.length)
            this._element.classList.add(this._records[0].type);
    },

    refresh: function(graphDataSource)
    {
        if (!this._records || !this._records.length)
            return false;

        var firstRecord = this._records[0];
        var barStartTime = firstRecord.startTime;

        // If this bar has no time info, return early.
        if (isNaN(barStartTime))
            return false;

        var graphStartTime = graphDataSource.startTime;
        var graphEndTime = graphDataSource.endTime;
        var graphCurrentTime = graphDataSource.currentTime;

        var barEndTime = this._records.reduce(function(previousValue, currentValue) { return Math.max(previousValue, currentValue.endTime); }, 0);

        // If this bar is completely after the current time, return early.
        if (barStartTime > graphCurrentTime)
            return false;

        // If this bar is completely before or after the bounds of the graph, return early.
        if (barEndTime < graphStartTime || barStartTime > graphEndTime)
            return false;

        var barUnfinished = isNaN(barEndTime) || barEndTime >= graphCurrentTime;
        if (barUnfinished)
            barEndTime = graphCurrentTime;

        var graphDuration = graphEndTime - graphStartTime;

        this._element.classList.toggle(WebInspector.TimelineRecordBar.UnfinishedStyleClassName, barUnfinished);

        var newBarLeftPosition = (barStartTime - graphStartTime) / graphDuration;
        this._updateElementPosition(this._element, newBarLeftPosition, "left");

        var newBarWidth = ((barEndTime - graphStartTime) / graphDuration) - newBarLeftPosition;
        this._updateElementPosition(this._element, newBarWidth, "width");

        if (!this._activeBarElement && this._renderMode !== WebInspector.TimelineRecordBar.RenderMode.InactiveOnly) {
            this._activeBarElement = document.createElement("div");
            this._activeBarElement.classList.add(WebInspector.TimelineRecordBar.BarSegmentStyleClassName);
        }

        if (!firstRecord.usesActiveStartTime) {
            this._element.classList.remove(WebInspector.TimelineRecordBar.HasInactiveSegmentStyleClassName);

            if (this._inactiveBarElement)
                this._inactiveBarElement.remove();

            if (this._renderMode === WebInspector.TimelineRecordBar.RenderMode.InactiveOnly) {
                if (this._activeBarElement)
                    this._activeBarElement.remove();

                return false;
            }

            // If this TimelineRecordBar is reused and had an inactive bar previously, clean it up.
            this._activeBarElement.style.removeProperty("left");
            this._activeBarElement.style.removeProperty("width");

            if (!this._activeBarElement.parentNode)
                this._element.appendChild(this._activeBarElement);

            return true;
        }

        this._element.classList.add(WebInspector.TimelineRecordBar.HasInactiveSegmentStyleClassName);

        // Find the earliest active start time for active only rendering, and the latest for the other modes.
        // This matches the values that TimelineRecordBar.createCombinedBars uses when combining.
        if (this._renderMode === WebInspector.TimelineRecordBar.RenderMode.ActiveOnly)
            var barActiveStartTime = this._records.reduce(function(previousValue, currentValue) { return Math.min(previousValue, currentValue.activeStartTime); }, Infinity);
        else
            var barActiveStartTime = this._records.reduce(function(previousValue, currentValue) { return Math.max(previousValue, currentValue.activeStartTime); }, 0);

        var barDuration = barEndTime - barStartTime;

        var inactiveUnfinished = isNaN(barActiveStartTime) || barActiveStartTime >= graphCurrentTime;
        this._element.classList.toggle(WebInspector.TimelineRecordBar.UnfinishedStyleClassName, inactiveUnfinished);

        if (inactiveUnfinished)
            barActiveStartTime = graphCurrentTime;

        var middlePercentage = (barActiveStartTime - barStartTime) / barDuration;

        if (this._renderMode !== WebInspector.TimelineRecordBar.RenderMode.ActiveOnly) {
            if (!this._inactiveBarElement) {
                this._inactiveBarElement = document.createElement("div");
                this._inactiveBarElement.classList.add(WebInspector.TimelineRecordBar.BarSegmentStyleClassName);
                this._inactiveBarElement.classList.add(WebInspector.TimelineRecordBar.InactiveStyleClassName);
            }

            this._updateElementPosition(this._inactiveBarElement, 1 - middlePercentage, "right");
            this._updateElementPosition(this._inactiveBarElement, middlePercentage, "width");

            if (!this._inactiveBarElement.parentNode)
                this._element.insertBefore(this._inactiveBarElement, this._element.firstChild);
        }

        if (!inactiveUnfinished && this._renderMode !== WebInspector.TimelineRecordBar.RenderMode.InactiveOnly) {
            this._updateElementPosition(this._activeBarElement, middlePercentage, "left");
            this._updateElementPosition(this._activeBarElement, 1 - middlePercentage, "width");

            if (!this._activeBarElement.parentNode)
                this._element.appendChild(this._activeBarElement);
        } else if (this._activeBarElement)
            this._activeBarElement.remove();

        return true;
    },

    // Private

    _updateElementPosition: function(element, newPosition, property)
    {
        newPosition *= 100;
        newPosition = newPosition.toFixed(2);

        var currentPosition = parseFloat(element.style[property]).toFixed(2);
        if (currentPosition !== newPosition)
            element.style[property] = newPosition + "%";
    }
};