import { appendFile, readFile } from 'node:fs/promises';
import { existsSync } from 'node:fs';
import type { VideoProjectWorkspace } from './workspace.js';

export interface VideoProjectEvent {
  type: string;
  recordedAt: string;
  payload?: Record<string, unknown>;
}

export async function appendProjectEvent(
  workspace: VideoProjectWorkspace,
  event: Omit<VideoProjectEvent, 'recordedAt'> & { recordedAt?: string },
): Promise<void> {
  const record: VideoProjectEvent = {
    ...event,
    recordedAt: event.recordedAt ?? new Date().toISOString(),
  };
  await appendFile(workspace.eventsPath, `${JSON.stringify(record)}\n`);
}

export async function readProjectEvents(
  workspace: VideoProjectWorkspace,
): Promise<VideoProjectEvent[]> {
  if (!existsSync(workspace.eventsPath)) return [];
  const raw = await readFile(workspace.eventsPath, 'utf-8');
  const events: VideoProjectEvent[] = [];
  for (const line of raw.split('\n')) {
    const trimmed = line.trim();
    if (!trimmed) continue;
    try {
      events.push(JSON.parse(trimmed) as VideoProjectEvent);
    } catch {
      // Append-only logs can be left with a torn line when a writer is
      // interrupted or a concurrent append exceeds the atomic-write size
      // (PIPE_BUF). One bad line must not poison the whole timeline that
      // status/report/obsidian-export consume — skip it and keep the rest.
      continue;
    }
  }
  return events;
}