import { mkdir, writeFile } from 'node:fs/promises';
import { dirname } from 'node:path';

import { probeMedia } from '../final-media.js';
import { buildSuggestedReframePlan, detectSceneBoundaries } from './suggest.js';
import type { ReframeCaptionProfile } from './types.js';

export interface SuggestedReframePlanResult {
  sourcePath: string;
  planPath: string;
  shotCount: number;
  strictReady: false;
  warnings: string[];
}

export async function writeSuggestedReframePlan(input: {
  sourcePath: string;
  planPath: string;
  captionsPath?: string;
  captionProfile?: ReframeCaptionProfile;
  ffmpegPath?: string;
}): Promise<SuggestedReframePlanResult> {
  const metadata = await probeMedia(input.sourcePath);
  if (!metadata.durationSeconds || !metadata.width || !metadata.height) {
    throw new Error('Source duration and dimensions are required to suggest a reframe plan.');
  }
  const frameRateParts = metadata.frameRate?.split('/').map(Number) ?? [];
  const frameRate = frameRateParts.length === 2 && frameRateParts[1]
    ? (frameRateParts[0] ?? 0) / frameRateParts[1]
    : Number(metadata.frameRate ?? 25);
  const context = {
    sourceDurationSeconds: metadata.durationSeconds,
    sourceWidth: metadata.width,
    sourceHeight: metadata.height,
    frameRate: Number.isFinite(frameRate) && frameRate > 0 ? frameRate : 25,
  };
  const boundaries = await detectSceneBoundaries({
    sourcePath: input.sourcePath,
    durationSeconds: metadata.durationSeconds,
    ...(input.ffmpegPath ? { ffmpegPath: input.ffmpegPath } : {}),
  });
  const plan = buildSuggestedReframePlan({
    sourcePath: input.sourcePath,
    context,
    boundaries,
    ...(input.captionsPath ? { captionsPath: input.captionsPath } : {}),
    ...(input.captionProfile ? { captionProfile: input.captionProfile } : {}),
  });
  await mkdir(dirname(input.planPath), { recursive: true });
  await writeFile(input.planPath, `${JSON.stringify(plan, null, 2)}\n`, 'utf8');
  return {
    sourcePath: input.sourcePath,
    planPath: input.planPath,
    shotCount: plan.shots.length,
    strictReady: false,
    warnings: [
      'Scene boundaries are automatic suggestions.',
      'Every subject anchor is unverified; inspect each shot, correct the anchor and set verified=true before strict rendering.',
    ],
  };
}