const vec = p5.Vector;

class Leg {
  constructor() {
    this.base = new vec(0, 0);
    this.end = new vec(0, 0);
    this.interPos = new vec(0, 0);
    this.ikJoint = new IKJoint(8, 8);
    this.repositionDist = 50;
    this.moveSpeed = 0.4;
  }

  moveTo(startX, startY, endX, endY) {
    // mover final de pierna cuando quede esta fuera del rango
  }

  getPoints() {
    return this.ikJoint.points;
  }
}

class IKJoint {
  constructor(numSegments, pointDist) {
    this.origin = new vec(0, 0);
    this.points = [];
    for (let i = 0; i < numSegments + 1; i++) {
      this.points.push(new ConstraintPoint(0, 0, pointDist, 0.5));
    }
    this.pointDist = pointDist;
    this.iterations = 20;
  }

  moveStart(targetX, targetY) {
    // empezar a mover desde el punto 0
  }

  moveEnd(targetX, targetY) {
    // empezar a mover desde el punto final
  }

  moveTo(origX, origY, targetX, targetY) {
    // alternar movimientos
    for (let i = 0; i < this.iterations; i++) {
      this.moveEnd(targetX, targetY);
      this.moveStart(origX, origY);
    }
  }
}

class ConstraintPoint {
  constructor(x, y, size, angleConstraint = 0.2) {
    this.size = size;
    this.pos = new vec(x, y);
    this.forward = new vec(0, 0);
    this.angleConstraint = angleConstraint;
  }

  getRel(angleOffset, dist) {
    // devolver vector relativo al punto con un angulo y distancia, completar
    return this.pos;
  }

  follow(targetX, targetY, parentForward = null) {
    // mover punto dentro de los constraints, completar
    let target = new vec(targetX, targetY);

    if (parentForward) {
      // si tenemos punto anterior, limitar angulos, completar
    }

    // asignar sigiente forward, completar
    this.forward = null;

    this.pos = target;
  }
}

function drawPoints(points, sizes, turnSegments = 10) {
  beginShape();
  // dibujar vertice, completar

  let numPoints = points.length;
  let head = points[0];
  let tail = points[numPoints - 1];
  // debug
  push()
  noFill();
  for (let i = 0; i < numPoints;i++) {
    circle(head.pos.x, head.pos.y, sizes[i] * 2);
  }
  pop()

  endShape(CLOSE);

}

function drawGills(basePoint, sign) {
  push();
  // dibujar forma de branquias, completar

  pop();
}

let numPoints = 0;
const bodySizes = [60, 55, 50, 40, 45, 47, 50, 47, 45, 42, 39, 35, 30, 25, 22, 17, 13];
const legSizes = Array.from({ length: 20 }, () => 15);
const bodyPoints = [];
const leg1 = new Leg();
const leg2 = new Leg();
const leg3 = new Leg();
const leg4 = new Leg();
let mouseInter = new vec(0, 0);
let baseColor;
let gillColor;
let lastBlinkTime = 0;
let nextBlinkDelay = 3000;
let blinkDuration = 150;

function setup() {
  createCanvas(displayWidth, displayHeight);
  numPoints = bodySizes.length;
  for (let i = 0; i < numPoints; i++) {
    let pt = new ConstraintPoint(400, 400, 20);
    bodyPoints.push(pt);
  }
  baseColor = color(249, 182, 249)
  gillColor = color(243, 158, 189)
}

function draw() {
  background(150);

  mouseInter.lerp(new vec(mouseX, mouseY), 0.01);
  let time = millis();

  // fisica
  bodyPoints[0].follow(mouseInter.x, mouseInter.y);

  for (let i = 1; i < numPoints; i++) {
    let prevPoint = bodyPoints[i - 1];
    bodyPoints[i].follow(prevPoint.pos.x, prevPoint.pos.y, prevPoint.forward);

    let tailStart = Math.floor(numPoints / 2);
  }
  let legEndDist = 70;
  let baseJointL1 = bodyPoints[2];
  let baseL1 = baseJointL1.getRel(-HALF_PI, 30);
  let endL1 = baseJointL1.getRel(-HALF_PI, legEndDist);
  let baseR1 = baseJointL1.getRel(HALF_PI, 30);
  let endR1 = baseJointL1.getRel(HALF_PI, legEndDist);

  let baseJointL2 = bodyPoints[6];
  let baseL2 = baseJointL2.getRel(-HALF_PI, 30);
  let endL2 = baseJointL2.getRel(-HALF_PI, legEndDist);
  let baseR2 = baseJointL2.getRel(HALF_PI, 30);
  let endR2 = baseJointL2.getRel(HALF_PI, legEndDist);

  leg1.moveTo(baseL1.x, baseL1.y, endL1.x, endL1.y);
  leg2.moveTo(baseR1.x, baseR1.y, endR1.x, endR1.y);
  leg3.moveTo(baseL2.x, baseL2.y, endL2.x, endL2.y);
  leg4.moveTo(baseR2.x, baseR2.y, endR2.x, endR2.y);

  // dibujar
  fill(baseColor);
  stroke(0);
  strokeWeight(2);

  drawPoints(leg1.getPoints(), legSizes);
  drawPoints(leg2.getPoints(), legSizes);
  drawPoints(leg3.getPoints(), legSizes);
  drawPoints(leg4.getPoints(), legSizes);

  let currentBodySizes = [...bodySizes];

  // animacion de respirar, completar

  drawPoints(bodyPoints, currentBodySizes);

  // dibujar aleta, completar
  let p1 = bodyPoints[4].pos;
  let p2 = bodyPoints[6].pos;
  let p3 = bodyPoints[8].pos;
  let p4 = bodyPoints[10].pos;

  drawGills(bodyPoints[2], 1);
  drawGills(bodyPoints[2], -1);

  let eye1 = bodyPoints[0].getRel(HALF_PI / 2, 45);
  let eye2 = bodyPoints[0].getRel(-HALF_PI / 2, 45);

  push();
  fill(0);
  noStroke();
  circle(eye1.x, eye1.y, 12);
  circle(eye2.x, eye2.y, 12);
  pop();
}