// Redstone input detection for the transmitter.
//
// Mirrors the approach already proven in hemp-addon's sun lamp: try the script
// API's getRedstonePower() first, and fall back to inspecting the six
// neighbouring blocks when it is unavailable or reports nothing.

export const REDSTONE_FACES = [
  [1, 0, 0], [-1, 0, 0],
  [0, 1, 0], [0, -1, 0],
  [0, 0, 1], [0, 0, -1],
];

export function isPowerSource(b) {
  if (!b) return false;
  const t = b.typeId;
  if (t === "minecraft:redstone_block") return true;
  if (t === "minecraft:lit_redstone_torch" || t === "minecraft:redstone_torch") {
    try { return b.permutation.getState("toggle_bit") !== false; } catch (_) {}
    return t === "minecraft:lit_redstone_torch";
  }
  if (t === "minecraft:powered_repeater") return true;
  if (t === "minecraft:powered_comparator") return true;
  if (t === "minecraft:lever") {
    try { return b.permutation.getState("open_bit") === true; } catch (_) { return false; }
  }
  if (t.endsWith("_button")) {
    try { return b.permutation.getState("button_pressed_bit") === true; } catch (_) { return false; }
  }
  if (t.endsWith("_pressure_plate")) {
    try {
      const r = b.permutation.getState("redstone_signal") ?? 0;
      return r > 0;
    } catch (_) { return false; }
  }
  if (t === "minecraft:redstone_wire") {
    try {
      const p = b.permutation.getState("redstone_signal") ?? 0;
      return p > 0;
    } catch (_) { return false; }
  }
  if (t === "minecraft:daylight_detector_inverted") return true;
  return false;
}

/**
 * Is this transmitter receiving power?
 *
 * `ignoreKeys` holds the position keys of receivers on the SAME channel. A
 * powered receiver is a real redstone block, so without this guard a
 * transmitter sitting next to its own channel's receiver would latch itself on
 * forever. We skip those positions, and when one is adjacent we also skip the
 * getRedstonePower() fast path, because that call cannot exclude a position.
 */
export function isTransmitterPowered(block, ignoreKeys) {
  const dim = block.dimension;
  const dimId = dim.id;
  const { x, y, z } = block.location;

  let adjacentSameChannelReceiver = false;
  if (ignoreKeys && ignoreKeys.size > 0) {
    for (const [dx, dy, dz] of REDSTONE_FACES) {
      if (ignoreKeys.has(`${dimId}|${x + dx}|${y + dy}|${z + dz}`)) {
        adjacentSameChannelReceiver = true;
        break;
      }
    }
  }

  if (!adjacentSameChannelReceiver) {
    try {
      const p = block.getRedstonePower();
      if (typeof p === "number" && p > 0) return true;
    } catch (_) {}
  }

  for (const [dx, dy, dz] of REDSTONE_FACES) {
    const pos = { x: x + dx, y: y + dy, z: z + dz };
    if (ignoreKeys && ignoreKeys.has(`${dimId}|${pos.x}|${pos.y}|${pos.z}`)) continue;
    let nb;
    try { nb = dim.getBlock(pos); } catch (_) { continue; }
    if (isPowerSource(nb)) return true;
  }
  return false;
}