/**
 * Fixture corpus access for evidence-source tests.
 *
 * The corpus is owned by the sibling `citation-evidence` checkout (ADR-0002);
 * it is not duplicated into this repo. Resolution order:
 *   1. `EVIDENCE_SOURCE_FIXTURE_DIR` env var, if set.
 *   2. `<repo>/../citation-evidence/fixtures/pdfs` (sibling-checkout default).
 *
 * When the corpus is unavailable, `fixtureCorpusAvailable()` returns false so
 * fixture-driven suites can skip cleanly instead of failing.
 */

import { existsSync, readFileSync } from "node:fs";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = dirname(fileURLToPath(import.meta.url));

export const FIXTURE_DIR = process.env.EVIDENCE_SOURCE_FIXTURE_DIR
  ? resolve(process.env.EVIDENCE_SOURCE_FIXTURE_DIR)
  : resolve(__dirname, "../../citation-evidence/fixtures/pdfs");

export interface Fixture {
  readonly id: string;
  readonly filename: string;
  readonly page_count: number;
  readonly known_good_quote: string;
  readonly known_good_quote_page: number;
}

interface Manifest {
  readonly fixtures: readonly Fixture[];
}

export function fixturePath(filename: string): string {
  return resolve(FIXTURE_DIR, filename);
}

export function fixtureBytes(filename: string): Uint8Array {
  return new Uint8Array(readFileSync(fixturePath(filename)));
}

export function fixtureCorpusAvailable(): boolean {
  return existsSync(resolve(FIXTURE_DIR, "manifest.json"));
}

export function loadFixtures(): readonly Fixture[] {
  const manifestPath = resolve(FIXTURE_DIR, "manifest.json");
  const manifest = JSON.parse(readFileSync(manifestPath, "utf8")) as Manifest;
  return manifest.fixtures;
}