import { isKeyRelease, matchesKey } from "@earendil-works/pi-tui";

export interface SgrMousePacket {
  code: number;
  col: number;
  row: number;
  final: "M" | "m";
}

export function parseKeyboardScrollDelta(data: string): number {
  if (isKeyRelease(data)) return 0;
  if (matchesKey(data, "pageUp")) return 10;
  if (matchesKey(data, "pageDown")) return -10;
  return 0;
}

export function parseSgrMousePackets(data: string): SgrMousePacket[] | null {
  const pattern = /\x1b\[<(\d+);(\d+);(\d+)([Mm])/g;
  const packets: SgrMousePacket[] = [];
  let offset = 0;

  for (const match of data.matchAll(pattern)) {
    if (match.index !== offset) return null;
    offset = match.index + match[0].length;
    packets.push({
      code: Number(match[1]),
      col: Number(match[2]),
      row: Number(match[3]),
      final: match[4] === "m" ? "m" : "M",
    });
  }

  return packets.length > 0 && offset === data.length ? packets : null;
}

function mouseBaseButton(code: number): number {
  return code & ~(4 | 8 | 16 | 32);
}

export function mouseScrollDelta(packet: SgrMousePacket): number {
  if (packet.final !== "M") return 0;
  const baseButton = mouseBaseButton(packet.code);
  if (baseButton === 64) return 1;
  if (baseButton === 65) return -1;
  return 0;
}

export function isLeftPress(packet: SgrMousePacket): boolean {
  return packet.final === "M" && mouseBaseButton(packet.code) === 0 && (packet.code & 32) === 0;
}

export function isLeftDrag(packet: SgrMousePacket): boolean {
  return packet.final === "M" && mouseBaseButton(packet.code) === 0 && (packet.code & 32) !== 0;
}

export function isRightPress(packet: SgrMousePacket): boolean {
  return packet.final === "M" && mouseBaseButton(packet.code) === 2 && (packet.code & 32) === 0;
}

export function isMouseRelease(packet: SgrMousePacket): boolean {
  return packet.final === "m";
}