import { existsSync } from 'node:fs';
import { mkdir, readFile } from 'node:fs/promises';
import { dirname, join } from 'node:path';
import { writeTextFileAtomic } from './atomic-write.js';
import { cinemaArtifactsDirFor } from './cinema-store.js';
import { validateCinemaPreflightReport, type CinemaPreflightReportArtifact } from './cinema-preflight.js';
import { stableCinemaJson } from './cinema-shot-compiler.js';

export function cinemaPreflightReportPathFor(root: string, report: CinemaPreflightReportArtifact): string {
  return join(cinemaArtifactsDirFor(root, report.projectSlug), 'preflight', `${report.contentHash.slice('sha256:'.length)}.json`);
}

export async function writeCinemaPreflightReport(root: string, report: CinemaPreflightReportArtifact): Promise<string> {
  const validation = validateCinemaPreflightReport(report);
  if (!validation.ok) throw new Error(`Cinema preflight report failed validation: ${validation.issues.map((issue) => `${issue.path}: ${issue.message}`).join('; ')}`);
  const path = cinemaPreflightReportPathFor(root, report);
  await mkdir(dirname(path), { recursive: true });
  if (existsSync(path)) {
    const existing = JSON.parse(await readFile(path, 'utf8')) as CinemaPreflightReportArtifact;
    if (stableCinemaJson(existing) !== stableCinemaJson(report)) throw new Error(`Cinema preflight report hash collision at ${path}`);
    return path;
  }
  await writeTextFileAtomic(path, `${JSON.stringify(report, null, 2)}\n`);
  return path;
}