/**
 * THE SCREEN's base content: procedural "clean programming".
 * Sterile SMPTE-ish test pattern + camcorder overlay, ported from the prototype's
 * makeBaseTexture and widened to 16:9. This is what the factory's output is painted
 * ONTO — it must be bland enough that any corruption reads instantly.
 *
 * Cost control: the pattern is static, so we only repaint when a visible glyph changes
 * (timecode ticks ~1/sec, chyron toggles once). Motion comes from the shader's slow
 * drift, not from re-uploading 640x360 pixels every frame.
 */

export const BASE_W = 640;
export const BASE_H = 360;

export interface BaseFeed {
  canvas: HTMLCanvasElement;
  /** Repaint if anything visible changed. Returns true when the texture needs re-upload. */
  update(timeMs: number, idle: boolean): boolean;
}

function timecode(timeMs: number): string {
  // Tape-style running timecode, starting at a suspiciously specific point.
  const total = Math.floor(timeMs / 1000) + 754; // 0:12:34
  const h = Math.floor(total / 3600);
  const m = Math.floor((total % 3600) / 60);
  const s = total % 60;
  return `SP ${h}:${String(m).padStart(2, '0')}:${String(s).padStart(2, '0')}`;
}

export function createBaseFeed(): BaseFeed {
  const canvas = document.createElement('canvas');
  canvas.width = BASE_W;
  canvas.height = BASE_H;
  const g = canvas.getContext('2d')!;
  let lastTC = '';
  let lastIdle: boolean | null = null;

  function paint(tc: string, idle: boolean) {
    const bars = ['#c0c0c0', '#c0c000', '#00c0c0', '#00c000', '#c000c0', '#c00000', '#0000c0'];
    const bw = BASE_W / bars.length;
    bars.forEach((col, i) => {
      g.fillStyle = col;
      g.fillRect(i * bw, 0, bw + 1, BASE_H * 0.62);
    });
    // castellations strip
    const casts = ['#0000c0', '#131313', '#c000c0', '#131313', '#00c0c0', '#131313', '#c0c0c0'];
    casts.forEach((col, i) => {
      g.fillStyle = col;
      g.fillRect(i * bw, BASE_H * 0.62, bw + 1, BASE_H * 0.1);
    });
    // pluge / ramp
    g.fillStyle = '#101010';
    g.fillRect(0, BASE_H * 0.72, BASE_W, BASE_H * 0.28);
    const ramp = g.createLinearGradient(0, 0, BASE_W, 0);
    ramp.addColorStop(0, '#000');
    ramp.addColorStop(1, '#fff');
    g.fillStyle = ramp;
    g.fillRect(BASE_W * 0.55, BASE_H * 0.8, BASE_W * 0.4, 18);

    // camcorder overlay
    g.fillStyle = '#eee';
    g.font = "bold 22px 'Courier New', monospace";
    g.fillText('PLAY ▶', 20, BASE_H * 0.86);
    g.fillText(tc, 20, BASE_H * 0.95);
    g.font = "bold 18px 'Courier New', monospace";
    g.fillStyle = '#f4f4f4';
    g.fillText('WIMVEE FKTRY', BASE_W * 0.55, BASE_H * 0.95);
    g.fillStyle = '#ff4444';
    g.beginPath();
    g.arc(BASE_W - 26, BASE_H * 0.83, 7, 0, Math.PI * 2);
    g.fill();

    // Idle chyron: OSHA-poster deadpan. Disappears forever once the factory ships.
    if (idle) {
      g.fillStyle = 'rgba(8,8,12,0.82)';
      g.fillRect(0, BASE_H * 0.5, BASE_W, 34);
      g.fillStyle = '#d8ffd8';
      g.font = "bold 20px 'Courier New', monospace";
      g.fillText('NOTHING IS WRONG', 18, BASE_H * 0.5 + 24);
    }
  }

  return {
    canvas,
    update(timeMs: number, idle: boolean) {
      const tc = timecode(timeMs);
      if (tc === lastTC && idle === lastIdle) return false;
      lastTC = tc;
      lastIdle = idle;
      paint(tc, idle);
      return true;
    },
  };
}