export const wallboardColumns = 24;
export const wallboardRowsPerSlide = 13;

export type WallboardPlacement = { columnStart: number; columnSpan: number; rowStart: number; rowSpan: number };

function boundedInteger(value: unknown, fallback: number, minimum: number, maximum: number): number {
  const number = Number(value);
  if (!Number.isFinite(number)) return fallback;
  return Math.min(maximum, Math.max(minimum, Math.floor(number)));
}

export function wallboardSlideIndex(y: unknown): number {
  const row = boundedInteger(y, 0, 0, Number.MAX_SAFE_INTEGER);
  return Math.floor(row / wallboardRowsPerSlide);
}

export function wallboardPlacement(layout: Record<string, unknown>): WallboardPlacement {
  const columnStart = boundedInteger(layout.x, 0, 0, wallboardColumns - 1) + 1;
  const row = boundedInteger(layout.y, 0, 0, Number.MAX_SAFE_INTEGER) % wallboardRowsPerSlide;
  const requestedWidth = boundedInteger(layout.w, 6, 1, wallboardColumns);
  const requestedHeight = boundedInteger(layout.h, 4, 1, wallboardRowsPerSlide);
  return {
    columnStart,
    columnSpan: Math.min(requestedWidth, wallboardColumns - columnStart + 1),
    rowStart: row + 1,
    rowSpan: Math.min(requestedHeight, wallboardRowsPerSlide - row),
  };
}