package funkin.ui.debug.latency;

import flash.display.Graphics;
import flash.display.Shape;
import flash.display.Sprite;
import flash.text.TextField;
import flash.text.TextFormatAlign;
import flixel.math.FlxMath;
import flixel.system.debug.DebuggerUtil;
import flixel.system.debug.stats.Stats;
import flixel.util.FlxColor;
import flixel.util.FlxDestroyUtil;

/**
 * This is a helper function for the stats window to draw a graph with given values.
 * SHAMELESSLY STOLEN FROM FLIXEL
 * https://github.com/HaxeFlixel/flixel/blob/master/flixel/system/debug/stats/StatsGraph.hx
 */
#if FLX_DEBUG
class CoolStatsGraph extends Sprite
{
  static inline var AXIS_COLOR:FlxColor = 0xffffff;
  static inline var AXIS_ALPHA:Float = 0.5;
  static inline var HISTORY_MAX:Int = 500;

  public var minLabel:TextField;
  public var curLabel:TextField;
  public var maxLabel:TextField;
  public var avgLabel:TextField;

  public var minValue:Float = FlxMath.MAX_VALUE_FLOAT;
  public var maxValue:Float = FlxMath.MIN_VALUE_FLOAT;

  public var graphColor:FlxColor;

  public var history:Array<Float> = [];

  var _axis:Shape;
  var _width:Int;
  var _height:Int;
  var _unit:String;
  var _labelWidth:Int;
  var _label:String;

  public function new(X:Int, Y:Int, Width:Int, Height:Int, GraphColor:FlxColor, Unit:String, LabelWidth:Int = 45, ?Label:String)
  {
    super();
    x = X;
    y = Y;
    _width = Width - LabelWidth;
    _height = Height;
    graphColor = GraphColor;
    _unit = Unit;
    _labelWidth = LabelWidth;
    _label = (Label == null) ? "" : Label;

    _axis = new Shape();
    _axis.x = _labelWidth + 10;

    maxLabel = DebuggerUtil.createTextField(0, 0, Stats.LABEL_COLOR, Stats.TEXT_SIZE);
    curLabel = DebuggerUtil.createTextField(0, (_height / 2) - (Stats.TEXT_SIZE / 2), graphColor, Stats.TEXT_SIZE);
    minLabel = DebuggerUtil.createTextField(0, _height - Stats.TEXT_SIZE, Stats.LABEL_COLOR, Stats.TEXT_SIZE);

    avgLabel = DebuggerUtil.createTextField(_labelWidth + 20, (_height / 2) - (Stats.TEXT_SIZE / 2) - 10, Stats.LABEL_COLOR, Stats.TEXT_SIZE);
    avgLabel.width = _width;
    avgLabel.defaultTextFormat.align = TextFormatAlign.CENTER;
    avgLabel.alpha = 0.5;

    addChild(_axis);
    addChild(maxLabel);
    addChild(curLabel);
    addChild(minLabel);
    addChild(avgLabel);

    drawAxes();
  }

  /**
   * Redraws the axes of the graph.
   */
  function drawAxes():Void
  {
    var gfx = _axis.graphics;
    gfx.clear();
    gfx.lineStyle(1, AXIS_COLOR, AXIS_ALPHA);

    // y-Axis
    gfx.moveTo(0, 0);
    gfx.lineTo(0, _height);

    // x-Axis
    gfx.moveTo(0, _height);
    gfx.lineTo(_width, _height);
  }

  /**
   * Redraws the graph based on the values stored in the history.
   */
  function drawGraph():Void
  {
    var gfx:Graphics = graphics;
    gfx.clear();
    gfx.lineStyle(1, graphColor, 1);

    var inc:Float = _width / (HISTORY_MAX - 1);
    var range:Float = Math.max(maxValue - minValue, maxValue * 0.1);
    var graphX = _axis.x + 1;

    for (i in 0...history.length)
    {
      var value = (history[i] - minValue) / range;

      var pointY = (-value * _height - 1) + _height;
      if (i == 0) gfx.moveTo(graphX, _axis.y + pointY);
      gfx.lineTo(graphX + (i * inc), pointY);
    }
  }

  public function update(Value:Float):Void
  {
    history.unshift(Value);
    if (history.length > HISTORY_MAX) history.pop();

    // Update range
    maxValue = Math.max(maxValue, Value);
    minValue = Math.min(minValue, Value);

    minLabel.text = formatValue(minValue);
    curLabel.text = formatValue(Value);
    maxLabel.text = formatValue(maxValue);

    avgLabel.text = _label + "\nAvg: " + formatValue(average());

    drawGraph();
  }

  function formatValue(value:Float):String
  {
    return FlxMath.roundDecimal(value, Stats.DECIMALS) + " " + _unit;
  }

  public function average():Float
  {
    var sum:Float = 0;
    for (value in history)
      sum += value;
    return sum / history.length;
  }

  public function destroy():Void
  {
    _axis = FlxDestroyUtil.removeChild(this, _axis);
    minLabel = FlxDestroyUtil.removeChild(this, minLabel);
    curLabel = FlxDestroyUtil.removeChild(this, curLabel);
    maxLabel = FlxDestroyUtil.removeChild(this, maxLabel);
    avgLabel = FlxDestroyUtil.removeChild(this, avgLabel);
    history = null;
  }
}
#end