import { Directive, ElementRef, OnInit, Input, Renderer2, Output, EventEmitter, OnChanges } from '@angular/core';
import { TransportInputValueService } from '../services/transport-input.data.service';
import { TransportObjectDataService } from '../services/transport-object.data.service';
 
@Directive({
  selector: '[colorContrast]'
})
 
 
export class ColorContrastDirective implements OnInit, OnChanges {
 
  @Input() userInputValue: string;
  @Input() extractedHexValue: string;
  @Input() basicColorContrast: boolean = false;
  anyHexPattern: any = /#([A-Fa-f0-9]{0,6})/;
  invalidHex: boolean;
  ratio: number;
  @Input() bgColorFromComponent: string;
  @Input() custom: boolean = false;
  formattedRatio: string;
  @Output() colorContrastDetector = new EventEmitter();
  @Output() colorSwitchDetector = new EventEmitter();
  @Input() blackWhiteSwitch: boolean = false;
  aaNormalText: string;
  aaLargeText: string;
  aaaNormalText: string;
  aaaLargeText: string;
  basicColorContrastObject: any = {};
  blackWhiteColorObject: any = {};
  blackRatio: number;
  whiteRatio: number;
  blackPassAANormal: string;
  blackPassAALarge: string;
  whitePassAANormal: string;
  whitePassAALarge: string;
  blackColor = '#000000';
  whiteColor = '#FFFFFF';
 
 
  constructor(private _el: ElementRef, private renderer: Renderer2, private transportInputData: TransportInputValueService, private transportObjectData: TransportObjectDataService) { 
 
  }
 
 
  ngOnInit() {
  }
 
 
 
  ngOnChanges() {
    if (this.basicColorContrast) {
      if (this.anyHexPattern.test(this.userInputValue)) {
        this.basicColorContrastRatioCalculation();
        this.getColorContrastInfo();
        this.setSharedObject(this.makeOpacityObject())
        console.table(this.getColorContrastInfo())
      }
    }
 
    if (this.blackWhiteSwitch) {
      this.ratioCalculationForColorSwitchTest(this.blackColor, this.whiteColor)
      this.getBlackWhiteSwitchInfo();
    }
 
  }
 
 
  /* Math for getting color contrast ratio*/
 
  //Get the luminance of each color hex value
  luminance(r, g, b) {
    let [lumR, lumG, lumB] = [r, g, b].map(component => {
      let proportion = component / 255;
 
      return proportion <= 0.03928
        ? proportion / 12.92
        : Math.pow((proportion + 0.055) / 1.055, 2.4);
    });
 
    return 0.2126 * lumR + 0.7152 * lumG + 0.0722 * lumB;
  }
 
 
 
  contrastRatio(luminance1, luminance2) {
    let lighterLum = Math.max(luminance1, luminance2);
    let darkerLum = Math.min(luminance1, luminance2);
    return (lighterLum + 0.05) / (darkerLum + 0.05);
  }
 
 
  //Returns the ratio of the two colors
  checkContrast(color1, color2) {
    let [luminance1, luminance2] = [color1, color2].map(color => {
      /* Remove the leading hash sign if it exists */
      color = color.startsWith("#") ? color.slice(1) : color;
 
 
      //If hex value is 3 digits, then the value is calculated by doubling each digit
      //I.E. #F6C equal to FF + 66 + CC 
      if (color.length === 3) {
        color = color.split('').map(function (hex) {
          return hex + hex;
        }).join('');
      }
      let r = parseInt(color.slice(0, 2), 16);
      let g = parseInt(color.slice(2, 4), 16);
      let b = parseInt(color.slice(4, 6), 16);
      return this.luminance(r, g, b);
    });
    return this.contrastRatio(luminance1, luminance2);
  }
 
  //Round and format ratio
  formatRatio(ratio) {
    let ratioAsFloat = ratio.toFixed(2);
    return `${ratioAsFloat}:1`
  }
 
 
  //Detects any 3 or 6 digit value beginning with a "#" and returns that value 
  detectHexValue(originalInputValue) {
    let trackHex = originalInputValue.match(this.anyHexPattern)[0];
    return trackHex
  }
 
  //Returns whether the there are 5 digits in a hex value 
  fiveDigitHexValue(originalInputValue) {
    let hexWithoutHash = originalInputValue.match(this.anyHexPattern)[1];
    return hexWithoutHash.length === 5 ? true : false;
  }
 
  //Automatically Adds a maxlength of 7 to an input if the first character of an input is a '#'.
  addMaxlength() {
    let hash = '#';
    if (this.userInputValue.indexOf(hash) === 0) {
      this._el.nativeElement.setAttribute('maxlength', '7');
    }
  }
 
  /*Basic Color Contrast Ratio Calculation
  Will run two colors through the color contrast calulation to produce a ratio.
  this function returns an object that includes the input value, extracted hex value, whether the input value is invalid, formatted ratio, background color,
  and whether the ratio passes AA Normal or Large. The object is what is emitted to your component*/
  basicColorContrastRatioCalculation() {
    this.addMaxlength();
    this.extractedHexValue = this.detectHexValue(this.userInputValue);
    this.ratio = this.checkContrast(this.extractedHexValue, this.bgColorFromComponent);
    this.formattedRatio = this.formatRatio(this.ratio);
 
 
    /*Uncomment this if you want to include WCAG Level AAA*/
    //this.aaaNormalText = ratio > 7 ? 'PASS': 'FAIL';
    //this.aaaLargeText = ratio > 4.5 ? 'PASS': 'FAIL';
 
    const object = {
      basicColorContrast: this.basicColorContrast,
      inputValue: this.userInputValue, //user entered value
      extractedHexValue: this.extractedHexValue, //takes the input value and only extract the hex value
      invalidHex: this.fiveDigitHexValue(this.userInputValue) || this.formattedRatio == 'NaN:1', //Detects if the input value is 5 digits OR not a number
      formattedRatio: this.formattedRatio, // Produces the ratio in a formatted fashion (i.e. "21.00:1")
      backgroundColor: this.bgColorFromComponent, //Background Color From the Component 
      aaNormalText: this.ratio > 4.5 ? 'PASS' : 'FAIL', //Computes the ratio of two colors against the Level AA normal text standard of 4.5
      aaLargeText: this.ratio > 3 ? 'PASS' : 'FAIL', //Computes the ratio of two colors against the Level AA large text standard of 4.5
 
    }
 
 
    return this.basicColorContrastObject = object;
  }
 
 
  /* Event Emitter that will take the object on line 135 and send it to the component where the directive is called*/
  getColorContrastInfo() {
    this.colorContrastDetector.emit(this.basicColorContrastObject)
  }
 
  /* This function runs both black and white against the hex value in the input field. It is designed
  to default to black. This means that black will be tested first for PASS or FAIL. If it passes, black will be the selected color regardless if
  it also passes for white. White will only be selected if black fails.
  This function returns an object that will be emitted via the Event Emitter*/
  ratioCalculationForColorSwitchTest(blackColor, whiteColor) {
    this.addMaxlength();
    this.blackRatio = this.checkContrast(this.userInputValue, blackColor);
    this.whiteRatio = this.checkContrast(this.userInputValue, whiteColor);
    this.blackPassAANormal = (this.blackRatio > 4.5) ? 'PASS' : 'FAIL';
    this.whitePassAANormal = (this.whiteRatio > 4.5) ? 'PASS' : 'FAIL';
    this.blackPassAALarge = (this.blackRatio > 3) ? 'PASS' : 'FAIL';
    this.whitePassAALarge = (this.whiteRatio > 3) ? 'PASS' : 'FAIL';
 
    const object = {
      blackWhiteSwitch: this.blackWhiteSwitch,
      inputValue: this.userInputValue, //user entered value
      extractedHexValue: this.detectHexValue(this.userInputValue), //extracted hex value from user entered text
      formattedRatio: (this.blackPassAANormal === 'PASS') ? this.formatRatio(this.blackRatio) : (this.whitePassAANormal === 'PASS') ? this.formatRatio(this.whiteRatio) : this.formatRatio(this.blackRatio), // Produces the ratio in a formatted fashion (i.e. "21.00:1")
      aaNormalText: (this.blackPassAANormal === 'PASS') ? this.blackPassAANormal : (this.whitePassAANormal === 'PASS') ? this.whitePassAANormal : this.blackPassAANormal,
      aaLargeText: (this.blackPassAALarge === 'PASS') ? this.blackPassAALarge : (this.whitePassAALarge === 'PASS') ? this.whitePassAALarge : this.blackPassAALarge,
      ratioAgainstBlack: this.formatRatio(this.blackRatio),  //runs the ratio between the user entered value and the color black
      ratioAgainstWhite: this.formatRatio(this.whiteRatio), //runs the ratio between the user entered value and the color white
      aaNormalTextForBlack: this.blackPassAANormal, //reports if the ratio against black has passed or not
      aaNormalTextForWhite: this.whitePassAANormal, //reports if the ratio against white has failed or not
      passForBlackAndWhite: (this.blackPassAANormal === 'PASS' && this.whitePassAANormal === 'PASS') ? true : false, //reports if the user entered value passes both black and white
      contrastingTextColor: (this.blackPassAANormal === 'PASS') ? this.blackColor : (this.whitePassAANormal === 'PASS') ? this.whiteColor : this.blackColor, //reports the contrasting text color for the user entered value, assumes that black is the default, so the only way white appears is if black fails
 
    }
    return this.blackWhiteColorObject = object
 
  }
 
 
  /* Event Emitter that will take the object on line 165 and send it to the component where the directive is called*/
  getBlackWhiteSwitchInfo() {
    this.colorSwitchDetector.emit(this.blackWhiteColorObject);
  }
 
  //Creates a smaller object for the <app-color-input> opacity inputs
  makeOpacityObject() {
    const object = {
      extractedHexValue: this.basicColorContrastRatioCalculation().extractedHexValue, //takes the input value and only extract the hex value
      invalidHex: this.basicColorContrastRatioCalculation().invalidHex, //Detects if the input value is 5 digits OR not a number
    }
 
    return object
  }
 
  //Sends object to transport object service
  setSharedObject(object) {
      this.transportObjectData.storePassedObject(object);
  }
 
 
 
 
}