// Chip select component for the LogicSimulator used on the 8-bit-computer
// Copyright (C) 2022 Sascha Nitsch

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

// eslint-disable-next-line @typescript-eslint/no-unused-vars
class ChipSelect extends BaseComponent {
  private addr = 0;
  private rom = true;
  private ram = true;
  constructor(simulator: Simulator, id: string, param: BaseComponentParam) {
    super(simulator, id, param);
    for (let a = 0; a < 8; ++a) {
      this.pins.set('A' + (15 - a), new TriState(this, -40, a * 10 - 35));
    }
    this.pins.set('rom', new TriState(this, 40, -25));
    this.pins.set('ram', new TriState(this, 40, -35));
  }

  setup(canvas: SVGElement) {
    super.doSetup('chipselect', canvas);
  }

  update(): boolean {
    const addr = this.addr;
    let changed = false;
    if (addr < 0x3fff) {
      // ROM
      changed ||= this.rom !== false || this.ram !== true;
      this.getPin('rom').setBool(false);
      this.getPin('ram').setBool(true);
    } else if (addr < 0x7fff) {
      // RAM
      changed ||= this.rom !== false || this.ram !== true;
      this.getPin('rom').setBool(true);
      this.getPin('ram').setBool(false);
    } else {
      this.getPin('rom').setBool(true);
      this.getPin('ram').setBool(true);
    }
    return changed;
  }

  io() {
    this.getPin('rom').getAndReset();
    this.getPin('ram').getAndReset();
    this.addr = 0;
    let multi = 256;
    for (let i = 8; i < 16; ++i) {
      this.addr += this.asint(this.binary(this.getPin('A' + i).getAndReset(), true), multi);
      multi <<= 1;
    }
  }
}