import { readdirSync, readFileSync } from 'fs';
import { join } from 'path';
import { applyHiveOps } from './hive-ops';
import { validateHiveState } from './hive-validate';
import type { HiveOp, HiveState } from './hive-types';
import { FIXTURE_DIR, deepFreeze, loadFixtureCatalog } from './hive-test-utils';

interface FixtureCase {
  name: string;
  inactivePartTypeIds?: string[];
  state: HiveState;
  ops: HiveOp[];
  expect:
    | { ok: true; state: HiveState }
    | { ok: false; opIndex: number; reasonCode: string };
}

const cases = readdirSync(FIXTURE_DIR)
  .filter((file) => file.endsWith('.json') && file !== 'catalog.json')
  .sort()
  .map((file) => ({
    file,
    data: JSON.parse(
      readFileSync(join(FIXTURE_DIR, file), 'utf8'),
    ) as FixtureCase,
  }));

function findCase(name: string): FixtureCase {
  const found = cases.find((c) => c.data.name === name);
  if (!found) throw new Error(`fixture not found: ${name}`);
  return found.data;
}

describe('applyHiveOps fixtures', () => {
  it('has at least 20 cases', () => {
    expect(cases.length).toBeGreaterThanOrEqual(20);
  });

  it.each(cases.map((c) => [c.file, c.data] as const))('%s', (_file, data) => {
    const catalog = loadFixtureCatalog(data.inactivePartTypeIds);
    const result = applyHiveOps(
      deepFreeze(structuredClone(data.state)),
      deepFreeze(structuredClone(data.ops)),
      catalog,
    );
    if (data.expect.ok) {
      expect(result).toEqual({ ok: true, state: data.expect.state });
      // The expected end state must itself be valid.
      expect(validateHiveState(data.expect.state, catalog)).toEqual([]);
    } else {
      expect(result.ok).toBe(false);
      if (!result.ok) {
        expect(result.opIndex).toBe(data.expect.opIndex);
        expect(result.reason.split(':')[0]).toBe(data.expect.reasonCode);
      }
    }
  });
});

describe('applyHiveOps purity', () => {
  it('does not mutate a deep-frozen input state or ops', () => {
    const catalog = loadFixtureCatalog();
    const sample = findCase('multiple ops apply in order');
    const state = deepFreeze(structuredClone(sample.state));
    const ops = deepFreeze(structuredClone(sample.ops));
    const before = JSON.stringify(state);
    const result = applyHiveOps(state, ops, catalog);
    expect(result.ok).toBe(true);
    expect(JSON.stringify(state)).toBe(before);
  });

  it('does not share references between input and result', () => {
    const catalog = loadFixtureCatalog();
    const state = structuredClone(
      findCase('setLabel sets and clears a label').state,
    );
    const result = applyHiveOps(state, [], catalog);
    expect(result.ok).toBe(true);
    if (result.ok) {
      expect(result.state).not.toBe(state);
      expect(result.state.stack[0]).not.toBe(state.stack[0]);
    }
  });
});

describe('validateHiveState', () => {
  const catalog = loadFixtureCatalog();

  it('rejects non-objects and wrong schemaVersion', () => {
    expect(validateHiveState(null, catalog).length).toBeGreaterThan(0);
    expect(
      validateHiveState({ schemaVersion: 2, stack: [] }, catalog).length,
    ).toBeGreaterThan(0);
  });

  it('collects several violations', () => {
    const state = {
      schemaVersion: 1,
      stack: [
        { id: 'a', partTypeId: 'hive-part-zl10-roof', state: {} },
        { id: 'a', partTypeId: 'hive-part-zl10-floor', state: { x: 1 } },
      ],
    };
    const codes = validateHiveState(state, catalog).map((r) => r.split(':')[0]);
    expect(codes).toEqual(
      expect.arrayContaining([
        'DUPLICATE_ID',
        'RULE_FLOOR_BOTTOM',
        'RULE_ROOF_TOP',
        'STATE_UNKNOWN_KEY',
      ]),
    );
  });
});