import { readdirSync, readFileSync } from 'node:fs';
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';

/**
 * Prüft die hand-editierten SQL-Ergänzungen in den beiden Phase-15-
 * Migrationen (Plan 15-01, Task 1 + Task 3), ohne eine Datenbank zu
 * brauchen — reiner Textabgleich der generierten migration.sql-Dateien.
 * Stil folgt dem Repo-Muster hand-editierter Migrationen
 * (20260618112133_rls_policies, 20260721150000_tender_cpv_divisions_backfill).
 */

const MIGRATIONS_DIR = join(__dirname, '../../prisma/migrations');

function readMigrationSql(suffix: string): string {
  const dirs = readdirSync(MIGRATIONS_DIR, { withFileTypes: true })
    .filter((entry) => entry.isDirectory() && entry.name.endsWith(suffix))
    .map((entry) => entry.name);

  if (dirs.length !== 1) {
    throw new Error(
      `Expected exactly one migration directory ending in "${suffix}", found ${dirs.length}: ${dirs.join(', ')}`,
    );
  }

  return readFileSync(join(MIGRATIONS_DIR, dirs[0], 'migration.sql'), 'utf-8');
}

describe('add_groups_and_module_grants migration.sql (D-04, D-06, D-13)', () => {
  const sql = readMigrationSql('_add_groups_and_module_grants');

  it('erzwingt genau eine Standardgruppe pro Mandant (D-13, partieller Unique-Index)', () => {
    expect(sql).toContain('Group_one_default_per_tenant');
    expect(sql).toContain('WHERE "isDefault" = true');
  });

  it('erzwingt die Entweder-oder-Beziehung Gruppe XOR Benutzer per CHECK-Constraint (D-04)', () => {
    expect(sql).toContain('ModuleGrant_group_xor_user');
    expect(sql).toContain('num_nonnulls("groupId", "userId") = 1');
  });

  it('schützt beide ModuleGrant-Varianten (Gruppe/Benutzer) je Modul über partielle Unique-Indizes', () => {
    expect(sql).toContain('ModuleGrant_tenant_module_group_unique');
    expect(sql).toContain('ModuleGrant_tenant_module_user_unique');
  });

  it('D-06-Backfill: alle drei INSERT-Statements verwenden gen_random_uuid() für neue IDs', () => {
    const occurrences = sql.match(/gen_random_uuid\(\)/g) ?? [];
    expect(occurrences.length).toBe(3);
  });

  it('D-06-Backfill: alle drei INSERT-Statements tragen einen NOT-EXISTS-Wächter (idempotent bei Wiederholungslauf)', () => {
    const occurrences = sql.match(/NOT EXISTS/g) ?? [];
    expect(occurrences.length).toBe(3);
  });

  it('D-06-Backfill läuft in der Reihenfolge Group vor GroupMembership vor ModuleGrant', () => {
    const groupIdx = sql.indexOf('INSERT INTO "Group"');
    const membershipIdx = sql.indexOf('INSERT INTO "GroupMembership"');
    const grantIdx = sql.indexOf('INSERT INTO "ModuleGrant"');

    expect(groupIdx).toBeGreaterThan(-1);
    expect(membershipIdx).toBeGreaterThan(-1);
    expect(grantIdx).toBeGreaterThan(-1);
    expect(groupIdx).toBeLessThan(membershipIdx);
    expect(membershipIdx).toBeLessThan(grantIdx);
  });
});