/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import random from "../random/random.ts";

export default class typed {
  static byte(limit = null) {
    // [-128, 127]
    let value = limit !== null ? random.number(limit) : random.number(129);
    value = random.chance(10) ? -value : value;
    return `new Uint8Array([${value}])[0]`;
  }

  static octet(limit = null) {
    // [0, 255]
    let value = limit !== null ? random.number(limit) : random.number(256);
    return `new Int8Array([${value}])[0]`;
  }

  static short(limit = null) {
    // [-32768, 32767]
    let value = limit !== null ? random.number(limit) : random.number(32769);
    value = random.chance(10) ? -value : value;
    return `new Int16Array([${value}])[0]`;
  }

  static unsignedShort(limit = null) {
    // [0, 65535]
    let value = limit !== null ? random.number(limit) : random.number(65535);
    return `new Uint16Array([${value}])[0]`;
  }

  static long(limit = null) {
    // [-2147483648, 2147483647]
    let value =
      limit !== null ? random.number(limit) : random.number(2147483649);
    value = random.chance(10) ? -value : value;
    return `new Int32Array([${value}])[0]`;
  }

  static unsignedLong(limit = null) {
    // [0, 4294967295]
    let value =
      limit !== null ? random.number(limit) : random.number(4294967296);
    return `new Uint32Array([${value}])[0]`;
  }

  static float(limit = null) {
    let base = limit !== null ? random.number(limit) : random.number();
    let value = random.chance(10)
      ? -(base + random.float())
      : base + random.float();
    return `new Float32Array([${value}])[0]`;
  }

  static unrestrictedFloat(limit = null) {
    if (random.chance(100)) {
      return random.pick([NaN, +Infinity, -Infinity]);
    } else {
      let base = limit !== null ? random.number(limit) : random.number();
      return `new Float32Array([${base + random.float()}])[0]`;
    }
  }

  static double(limit = null) {
    let base = limit !== null ? random.number(limit) : random.number();
    let value = random.chance(10)
      ? -(base + random.float())
      : base + random.float();
    return `new Float64Array([${value}])[0]`;
  }

  static unrestrictedDouble(limit = null) {
    if (random.chance(100)) {
      return random.pick([NaN, +Infinity, -Infinity]);
    } else {
      let base = limit !== null ? random.number(limit) : random.number();
      let value = random.chance(10)
        ? -(base + random.float())
        : base + random.float();
      return `new Float64Array([${value}])[0]`;
    }
  }

  static any() {
    return random.choose([
      [1, [typed.byte, typed.octet]],
      [1, [typed.short, typed.unsignedShort]],
      [1, [typed.long, typed.unsignedLong]],
      [1, [typed.float, typed.unrestrictedFloat]],
      [1, [typed.double, typed.unrestrictedDouble]]
    ]);
  }

  static arrayBuffer(byteLength = null) {
    let length = byteLength !== null ? byteLength : typed.unsignedShort();
    return `new ArrayBuffer(${length})`;
  }

  static dataView(byteLength = null) {
    let length = byteLength !== null ? byteLength : typed.unsignedShort();
    return `new DataView(${typed.arrayBuffer(length)})`;
  }

  static typedArray(byteLength = null) {
    let length = byteLength !== null ? byteLength : typed.unsignedShort();
    let arrType = random.item([
      "Int8",
      "Uint8",
      "Uint8Clamped",
      "Int16",
      "Uint16",
      "Int32",
      "Uint32",
      "Float32",
      "Float64"
    ]);
    let method = `new ${arrType}Array`;
    switch (random.number(16)) {
      case 0:
        return `${method}()`;
      case 1:
        return `${method}(${this.typedArray()})`;
      default:
        return `${method}(${length})`;
    }
  }

  static bufferSource() {
    switch (random.number(4)) {
      case 0:
        return typed.arrayBuffer();
      case 1:
        return typed.dataView();
      default:
        return typed.typedArray();
    }
  }
}