import * as THREE from "./lib/three.module.js";

function dotproduct(a, b) {
  var ret = 0;
  for (let i = 0; i < a.length; i++) {
    ret += a[i] * b[i];
  }

  return ret;
}

// matrix (m*n), matrix(n*l), vl: vector length=n
// this matmul is row-wise multiplication. 'x' and result are row-vectors.
// ret^T = m * x^T
//
function matmul(m, x, vl) {
  //vl is vector length
  var ret = [];
  var res_l = m.length / vl;
  for (var vi = 0; vi < x.length / vl; vi++) {
    //vector index
    for (var r = 0; r < m.length / vl; r++) {
      //row of matrix
      ret[vi * res_l + r] = 0;
      for (var i = 0; i < vl; i++) {
        ret[vi * res_l + r] += m[r * vl + i] * x[vi * vl + i];
      }
    }
  }

  return ret;
}

function matmul2(m, x, vl) {
  //vl is vector length
  var ret = [];
  var rows = m.length / vl;
  var cols = x.length / vl;
  for (var r = 0; r < rows; r++) {
    for (var c = 0; c < cols; c++) {
      ret[r * cols + c] = 0;
      for (var i = 0; i < vl; i++) {
        ret[r * cols + c] += m[r * vl + i] * x[i * cols + c];
      }
    }
  }

  return ret;
}

// box(position, scale, rotation) to box corner corrdinates.
// return 8 points, represented as (x,y,z,1)
// note the vertices order cannot be changed, draw-box-on-image assumes
//  the first 4 vertex is the front plane, so it knows box direction.
function psr_to_xyz(p, s, r) {
  /*
    var trans_matrix=[
        Math.cos(r.z), -Math.sin(r.z), 0, p.x,
        Math.sin(r.z), Math.cos(r.z),  0, p.y,
        0,             0,              1, p.z,
        0,             0,              0, 1,
    ];
    */
  var trans_matrix = euler_angle_to_rotate_matrix(r, p);

  var x = s.x / 2;
  var y = s.y / 2;
  var z = s.z / 2;
  /*
    var local_coord = [
        -x, y, -z, 1,   x, y, -z, 1,  //front-left-bottom, front-right-bottom
        x, y, z, 1,    -x, y, z, 1,  //front-right-top,   front-left-top

        -x, -y, -z, 1,   x, -y, -z, 1,  
        x, -y, z, 1,   -x, -y, z, 1,        
        
    ];
    */

  var local_coord = [
    x,
    y,
    -z,
    1,
    x,
    -y,
    -z,
    1, //front-left-bottom, front-right-bottom
    x,
    -y,
    z,
    1,
    x,
    y,
    z,
    1, //front-right-top,   front-left-top

    -x,
    y,
    -z,
    1,
    -x,
    -y,
    -z,
    1, //rear-left-bottom, rear-right-bottom
    -x,
    -y,
    z,
    1,
    -x,
    y,
    z,
    1, //rear-right-top,   rear-left-top

    //middle plane
    // 0, y, -z, 1,   0, -y, -z, 1,  //rear-left-bottom, rear-right-bottom
    // 0, -y, z, 1,   0, y, z, 1,  //rear-right-top,   rear-left-top
  ];

  var world_coord = matmul(trans_matrix, local_coord, 4);
  var w = world_coord;
  return w;
}

function xyz_to_psr(vertices) {
  var ann = vertices;
  var ROW = 4;
  var pos = { x: 0, y: 0, z: 0 };
  for (var i = 0; i < 8; i++) {
    pos.x += ann[i * ROW];
    pos.y += ann[i * ROW + 1];
    pos.z += ann[i * ROW + 2];
  }
  pos.x /= 8;
  pos.y /= 8;
  pos.z /= 8;

  var scale = {
    x: Math.sqrt(
      (ann[0] - ann[ROW]) * (ann[0] - ann[ROW]) +
        (ann[1] - ann[ROW + 1]) * (ann[1] - ann[ROW + 1])
    ),
    y: Math.sqrt(
      (ann[0] - ann[ROW * 3]) * (ann[0] - ann[ROW * 3]) +
        (ann[1] - ann[ROW * 3 + 1]) * (ann[1] - ann[ROW * 3 + 1])
    ),
    z: ann[3 * ROW + 2] - ann[2],
  };

  /*
    1. atan2(y,x), not x,y
    2. point order in xy plane
        0   1
        3   2
    */

  var angle = Math.atan2(
    ann[1 * ROW + 1] + ann[5 * ROW + 1] - 2 * pos.y,
    ann[1 * ROW] + ann[5 * ROW] - 2 * pos.x
  );

  return {
    position: pos,
    scale: scale,
    rotation: { x: 0, y: 0, z: angle },
  };
  return w;
}

function vector4to3(v) {
  var ret = [];
  for (var i = 0; i < v.length; i++) {
    if ((i + 1) % 4 != 0) {
      ret.push(v[i]);
    }
  }

  return ret;
}

function vector_range(v) {
  if (v.length === 0) {
    return null;
  }

  var min, max;
  min = [...v[0]];
  max = [...v[0]];

  for (var i = 1; i < v.length; ++i) {
    for (var j = 0; j < min.length; ++j) {
      if (min[j] > v[i][j]) {
        min[j] = v[i][j];
      }

      if (max[j] < v[i][j]) {
        max[j] = v[i][j];
      }
    }
  }

  return {
    min: min,
    max: max,
  };
}

// v is array of vector, vl is vector length
function array_as_vector_range(v, vl) {
  var n = v.length / vl;

  var min, max;
  if (n === 0) {
    return null;
  } else {
    min = v.slice(0, vl);
    max = v.slice(0, vl);
  }

  for (var i = 1; i < n; ++i) {
    for (var j = 0; j < vl; ++j) {
      if (min[j] > v[i * vl + j]) {
        min[j] = v[i * vl + j];
      }

      if (max[j] < v[i * vl + j]) {
        max[j] = v[i * vl + j];
      }
    }
  }

  return {
    min: min,
    max: max,
  };
}

// v is 1-d array of vector, vl is vector length, p is index into v.
function array_as_vector_index_range(v, vl, p) {
  var n = p.length;

  var min, max;
  if (n === 0) {
    return null;
  } else {
    min = v.slice(p[0] * vl, (p[0] + 1) * vl);
    max = v.slice(p[0] * vl, (p[0] + 1) * vl);
  }

  for (var i = 1; i < n; ++i) {
    for (var j = 0; j < vl; ++j) {
      if (min[j] > v[p[i] * vl + j]) {
        min[j] = v[p[i] * vl + j];
      }

      if (max[j] < v[p[i] * vl + j]) {
        max[j] = v[p[i] * vl + j];
      }
    }
  }

  return {
    min: min,
    max: max,
  };
}

function vector3_nomalize(m) {
  var ret = [];
  for (var i = 0; i < m.length / 3; i++) {
    ret.push(m[i * 3 + 0] / m[i * 3 + 2]);
    ret.push(m[i * 3 + 1] / m[i * 3 + 2]);
  }

  return ret;
}

function mat(m, s, x, y) {
  return m[x * s + y];
}

// m; matrix, vl: column vector length
function transpose(m, cl = NaN) {
  var rl = m.length / cl;
  for (var i = 0; i < cl; i++) {
    for (var j = i + 1; j < rl; j++) {
      var t = m[i * rl + j];
      m[i * rl + j] = m[j * cl + i];
      m[j * cl + i] = t;
    }
  }

  return m;
}

function euler_angle_to_rotate_matrix(eu, tr, order = "ZYX") {
  var theta = [eu.x, eu.y, eu.z];
  // Calculate rotation about x axis
  var R_x = [
    1,
    0,
    0,
    0,
    Math.cos(theta[0]),
    -Math.sin(theta[0]),
    0,
    Math.sin(theta[0]),
    Math.cos(theta[0]),
  ];

  // Calculate rotation about y axis
  var R_y = [
    Math.cos(theta[1]),
    0,
    Math.sin(theta[1]),
    0,
    1,
    0,
    -Math.sin(theta[1]),
    0,
    Math.cos(theta[1]),
  ];

  // Calculate rotation about z axis
  var R_z = [
    Math.cos(theta[2]),
    -Math.sin(theta[2]),
    0,
    Math.sin(theta[2]),
    Math.cos(theta[2]),
    0,
    0,
    0,
    1,
  ];

  //console.log(R_x, R_y, R_z);

  // Combined rotation matrix
  //var R = matmul(matmul(R_z, R_y, 3), R_x,3);
  //var R = matmul2(R_x, matmul2(R_y, R_z, 3), 3);

  let matrices = {
    Z: R_z,
    Y: R_y,
    X: R_x,
  };

  let R = matmul2(
    matrices[order[2]],
    matmul2(matrices[order[1]], matrices[order[0]], 3),
    3
  );

  return [
    mat(R, 3, 0, 0),
    mat(R, 3, 0, 1),
    mat(R, 3, 0, 2),
    tr.x,
    mat(R, 3, 1, 0),
    mat(R, 3, 1, 1),
    mat(R, 3, 1, 2),
    tr.y,
    mat(R, 3, 2, 0),
    mat(R, 3, 2, 1),
    mat(R, 3, 2, 2),
    tr.z,
    0,
    0,
    0,
    1,
  ];
}

function euler_angle_to_rotate_matrix_3by3(eu, order = "ZYX") {
  var theta = [eu.x, eu.y, eu.z];
  // Calculate rotation about x axis
  var R_x = [
    1,
    0,
    0,
    0,
    Math.cos(theta[0]),
    -Math.sin(theta[0]),
    0,
    Math.sin(theta[0]),
    Math.cos(theta[0]),
  ];

  // Calculate rotation about y axis
  var R_y = [
    Math.cos(theta[1]),
    0,
    Math.sin(theta[1]),
    0,
    1,
    0,
    -Math.sin(theta[1]),
    0,
    Math.cos(theta[1]),
  ];

  // Calculate rotation about z axis
  var R_z = [
    Math.cos(theta[2]),
    -Math.sin(theta[2]),
    0,
    Math.sin(theta[2]),
    Math.cos(theta[2]),
    0,
    0,
    0,
    1,
  ];

  //console.log(R_x, R_y, R_z);

  // Combined rotation matrix
  //var R = matmul(matmul(R_z, R_y, 3), R_x,3);

  let matrices = {
    Z: R_z,
    Y: R_y,
    X: R_x,
  };

  let R = matmul2(
    matrices[order[2]],
    matmul2(matrices[order[1]], matrices[order[0]], 3),
    3
  );

  return [
    mat(R, 3, 0, 0),
    mat(R, 3, 0, 1),
    mat(R, 3, 0, 2),
    mat(R, 3, 1, 0),
    mat(R, 3, 1, 1),
    mat(R, 3, 1, 2),
    mat(R, 3, 2, 0),
    mat(R, 3, 2, 1),
    mat(R, 3, 2, 2),
  ];
}

function rotation_matrix_to_euler_angle(m, msize) {
  //m is 4* 4

  /*

    var sy = Math.sqrt(mat(m,4,0,0) * mat(m,4,0,0) +  mat(m,4,1,0) * mat(m,4, 1,0));
 

    var z = Math.atan2(mat(m,4,2,1) , mat(m,4,2,2));
    var y = Math.atan2(-mat(m,4,2,0), sy);
    var x = Math.atan2(mat(m,4,1,0), mat(m,4,0,0));


    return {
        x: x,
        y: y,
        z: z,
    };
    */
  var odd = false;
  var res = [0, 0, 0];
  var i = 0,
    j = 1,
    k = 2;

  if (!msize) {
    msize = 4;
  }

  function coeff(x, y) {
    return mat(m, msize, x, y);
  }

  function atan2(x, y) {
    return Math.atan2(x, y);
  }
  var sin = Math.sin;
  var cos = Math.cos;
  function Scalar(x) {
    return x;
  }

  res[0] = atan2(coeff(j, k), coeff(k, k));
  //var c2 = Vector2(coeff(i,i), coeff(i,j)).norm();
  var c2 = Math.sqrt(coeff(i, i) * coeff(i, i) + coeff(i, j) * coeff(i, j));
  if ((odd && res[0] < Scalar(0)) || (!odd && res[0] > Scalar(0))) {
    if (res[0] > Scalar(0)) {
      res[0] -= Scalar(Math.PI);
    } else {
      res[0] += Scalar(Math.PI);
    }
    res[1] = atan2(-coeff(i, k), -c2);
  } else res[1] = atan2(-coeff(i, k), c2);
  var s1 = sin(res[0]);
  var c1 = cos(res[0]);
  res[2] = atan2(
    s1 * coeff(k, i) - c1 * coeff(j, i),
    c1 * coeff(j, j) - s1 * coeff(k, j)
  );

  if (!odd)
    res = res.map(function (x) {
      return -x;
    });

  return {
    x: res[0],
    y: res[1],
    z: res[2],
  };
}

var linalg_std = {
  euler_angle_to_rotation_matrix: function (euler) {
    var theta = [euler.x, euler.y, euler.z];
    // Calculate rotation about x axis
    var R_x = new THREE.Matrix4();
    R_x.set(
      1,
      0,
      0,
      0,
      0,
      Math.cos(theta[0]),
      -Math.sin(theta[0]),
      0,
      0,
      Math.sin(theta[0]),
      Math.cos(theta[0]),
      0,
      0,
      0,
      0,
      1
    );

    // Calculate rotation about y axis
    var R_y = new THREE.Matrix4();
    R_y.set(
      Math.cos(theta[1]),
      0,
      Math.sin(theta[1]),
      0,
      0,
      1,
      0,
      0,
      -Math.sin(theta[1]),
      0,
      Math.cos(theta[1]),
      0,
      0,
      0,
      0,
      1
    );

    // Calculate rotation about z axis
    var R_z = new THREE.Matrix4();
    R_z.set(
      Math.cos(theta[2]),
      -Math.sin(theta[2]),
      0,
      0,
      Math.sin(theta[2]),
      Math.cos(theta[2]),
      0,
      0,
      0,
      0,
      1,
      0,
      0,
      0,
      0,
      1
    );

    R_z.multiply(R_y);
    R_z.multiply(R_x);

    return R_z;
  },

  euler_angle_from_rotation_matrix: function (m) {
    var euler = new THREE.Euler();
    euler.setFromRotationMatrix(m);
    return euler;
  },

  // {x:, y:, z:}
  euler_angle_composite: function (current, delta) {
    var current_matrix = this.euler_angle_to_rotation_matrix(current);
    var delta_matrix = this.euler_angle_to_rotation_matrix(delta);
    var composite_matrix = new THREE.Matrix4();
    composite_matrix.multiplyMatrices(delta_matrix, current_matrix);

    return this.euler_angle_from_rotation_matrix(composite_matrix);
  },
};

function normalizeAngle(a) {
  while (true) {
    if (a > Math.PI) a -= Math.PI * 2;
    else if (a < -Math.PI) a += Math.PI * 2;
    else return a;
  }
}

// box(position, scale, rotation) to box corner corrdinates.
// return 8 points, represented as (x,y,z,1)
// note the vertices order cannot be changed, draw-box-on-image assumes
//  the first 4 vertex is the front plane, so it knows box direction.
function psr_to_xyz_face_points(p, s, r, minGrid) {
  /*
    var trans_matrix=[
        Math.cos(r.z), -Math.sin(r.z), 0, p.x,
        Math.sin(r.z), Math.cos(r.z),  0, p.y,
        0,             0,              1, p.z,
        0,             0,              0, 1,
    ];
    */
  var trans_matrix = euler_angle_to_rotate_matrix(r, p);

  var x = s.x / 2;
  var y = s.y / 2;
  var z = s.z / 2;

  //    var local_coord = [
  //         [x, y, -z],   [x, -y, -z],  //front-left-bottom, front-right-bottom
  //         [x, -y, z],   [x, y, z],  //front-right-top,   front-left-top

  //         [-x, y, -z],   [-x, -y, -z],  //rear-left-bottom, rear-right-bottom
  //         [-x, -y, z],   [-x, y, z],  //rear-right-top,   rear-left-top
  //    ];

  let xs = [];
  for (let i = -x; i <= x; i += minGrid) {
    xs.push(i);
  }

  let ys = [];
  for (let i = -y; i <= y; i += minGrid) {
    ys.push(i);
  }

  let zs = [];
  for (let i = -z; i <= z; i += minGrid) {
    zs.push(i);
  }

  let points = [];

  points = points.concat(ys.map((i) => [x, i, -z, 1]));
  points = points.concat(ys.map((i) => [x, i, z, 1]));
  points = points.concat(ys.map((i) => [-x, i, -z, 1]));
  points = points.concat(ys.map((i) => [-x, i, z, 1]));

  points = points.concat(xs.map((i) => [i, y, -z, 1]));
  points = points.concat(xs.map((i) => [i, y, z, 1]));
  points = points.concat(xs.map((i) => [i, -y, -z, 1]));
  points = points.concat(xs.map((i) => [i, -y, z, 1]));

  points = points.concat(zs.map((i) => [x, y, i, 1]));
  points = points.concat(zs.map((i) => [x, -y, i, 1]));
  points = points.concat(zs.map((i) => [-x, -y, i, 1]));
  points = points.concat(zs.map((i) => [-x, y, i, 1]));

  points = points.reduce((a, b) => a.concat(b));

  let world_coord = matmul(trans_matrix, points, 4);

  return vector4to3(world_coord);
}

function cornersAinB(boxA, boxB) {
  let minGrid = Math.min(
    boxA.scale.x,
    boxA.scale.y,
    boxA.scale.z,
    boxB.scale.x,
    boxB.scale.y,
    boxB.scale.z
  );

  minGrid = minGrid / 2;

  // in world coord, offset by b pos
  let boxAPosInB = {
    x: boxA.position.x - boxB.position.x,
    y: boxA.position.y - boxB.position.y,
    z: boxA.position.z - boxB.position.z,
  };

  let cornersA = psr_to_xyz_face_points(
    boxAPosInB,
    boxA.scale,
    boxA.rotation,
    minGrid
  ); // in world coordinates

  cornersA.push(boxAPosInB.x, boxAPosInB.y, boxAPosInB.z); //center point

  // in box b coord
  let matrixB = euler_angle_to_rotate_matrix_3by3(boxB.rotation);
  matrixB = transpose(matrixB, 3);
  let cornersAInB = matmul(matrixB, cornersA, 3);

  for (let i = 0; i < cornersAInB.length; i += 3) {
    let [x, y, z] = cornersAInB.slice(i, i + 3);

    if (
      Math.abs(x) < boxB.scale.x / 2 &&
      Math.abs(y) < boxB.scale.y / 2 &&
      Math.abs(z) < boxB.scale.z / 2
    ) {
      return true;
    }
  }

  return false;
}

// check if 2 boxes has non-empty intersection
// the idea is to check if any corner of one box is inside the other one
// when boxA contains B entirely, we shoudl test the opposite way.
function intersect(boxA, boxB) {
  return cornersAinB(boxA, boxB) || cornersAinB(boxB, boxA);
}

export {
  dotproduct,
  vector_range,
  array_as_vector_range,
  array_as_vector_index_range,
  vector4to3,
  vector3_nomalize,
  psr_to_xyz,
  matmul,
  matmul2,
  euler_angle_to_rotate_matrix_3by3,
  euler_angle_to_rotate_matrix,
  rotation_matrix_to_euler_angle,
  linalg_std,
  transpose,
  mat,
  normalizeAngle,
  intersect,
};