import { realpath } from 'node:fs/promises';
import { join, relative, resolve, sep } from 'node:path';
import { cinemaArtifactsDirFor } from './cinema-store.js';
import { readApprovedCinemaImageReference } from './cinema-image-jobs.js';
import type { CinemaPlanningPackage } from './cinema-project-planner.js';
import type { CinemaCharacterSheetArtifact, CinemaReferenceRole } from './cinema-types.js';
import { resolveProjectWorkspace } from './workspace.js';
import { VclawError } from './errors.js';

/** Preserve image-job approval when its output enters an active character sheet. */
export async function validateCinemaImageSheetBindings(
  root: string,
  planning: CinemaPlanningPackage,
  sheet: CinemaCharacterSheetArtifact,
): Promise<void> {
  const project = planning.receipt.projectSlug;
  const projectDir = resolveProjectWorkspace(project, root).projectDir;
  const jobsDir = join(cinemaArtifactsDirFor(root, project), 'image-jobs');
  const activeCharacter = planning.assetEvidence.assets.find(asset => asset.versionId === sheet.characterVersionId && (asset.kind === 'hero' || asset.kind === 'supporting'));
  const components: Array<{media: {assetId:string;path:string;contentHash:string};role:CinemaReferenceRole}> = [
    {media:sheet.identityAnchor,role:'identity_face'},
    ...sheet.bodyPlates.map(plate => ({media:plate,role:(plate.view === 'front' ? 'body_front_headless' : 'body_back_headless') as CinemaReferenceRole})),
  ];
  for (const {media,role} of components) {
    const path = resolve(projectDir, media.path);
    // realpath recognises a symlink to a job output as the same managed image.
    let canonicalPath: string;
    try { canonicalPath = await realpath(path); }
    catch { canonicalPath = path; }
    let canonicalJobsDir = jobsDir;
    try { canonicalJobsDir = await realpath(jobsDir); } catch { /* No image jobs in legacy projects. */ }
    const within = relative(canonicalJobsDir, canonicalPath);
    if (within.startsWith(`..${sep}`) || within === '..' || resolve(canonicalJobsDir, within) !== canonicalPath) continue;
    const parts = within.split(sep);
    if (parts.length !== 2) throw new VclawError('invalid_flag_value', 'Character sheet references an invalid image-job result path');
    try {
      const reference = await readApprovedCinemaImageReference(root, project, parts[0]);
      if (!activeCharacter || reference.subjectId !== activeCharacter.assetId || reference.characterVersionId !== sheet.characterVersionId || reference.role !== role || reference.contentHash !== media.contentHash || reference.assetId !== media.assetId || await realpath(reference.path) !== canonicalPath) {
        throw new VclawError('invalid_flag_value', 'Reviewed image does not match the active character sheet role, subject, version or hash');
      }
    } catch (error) {
      if (error instanceof VclawError) throw error;
      throw new VclawError('invalid_flag_value', `Image job ${parts[0]} needs a valid approved review before use in a character sheet`);
    }
  }
}