/**
 * Unit Tests — graph-db.js
 * Asserts the three P0 tables exist and that GRAPH_DB_PATH env override
 * actually redirects the underlying sqlite file (regression guard against
 * the benchmark-db.js "declared but never read" bug).
 */
import { describe, it, expect, beforeAll, afterAll } from 'vitest';
import fs from 'fs';
import path from 'path';
import Database from 'better-sqlite3';

describe('graph-db', () => {
  let graphDb;
  const TEST_DB_PATH = '/tmp/test-graph-db.sqlite';
  const DEFAULT_DB_PATH = path.resolve(__dirname, '../../../data/graph.sqlite');

  beforeAll(() => {
    if (fs.existsSync(TEST_DB_PATH)) fs.unlinkSync(TEST_DB_PATH);
    process.env.GRAPH_DB_PATH = TEST_DB_PATH;
    delete require.cache[require.resolve('../../services/graph-db')];
    graphDb = require('../../services/graph-db');
  });

  afterAll(() => {
    try { fs.unlinkSync(TEST_DB_PATH); } catch {}
    try { fs.unlinkSync(`${TEST_DB_PATH}-shm`); } catch {}
    try { fs.unlinkSync(`${TEST_DB_PATH}-wal`); } catch {}
    delete process.env.GRAPH_DB_PATH;
  });

  it('should create all three tables', () => {
    const d = graphDb.getDb();
    const tables = d.prepare("SELECT name FROM sqlite_master WHERE type='table'").all().map(r => r.name);
    expect(tables).toContain('system_agents');
    expect(tables).toContain('org_graph_nodes');
    expect(tables).toContain('org_graph_edges');
  });

  it('should honor GRAPH_DB_PATH env override for reads/writes', () => {
    const d = graphDb.getDb();
    const now = new Date().toISOString();
    d.prepare(`
      INSERT INTO system_agents (id, name, scope, owner_company_id, source_kind, legacy_path, status, benchmark_score, created_at, updated_at)
      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
    `).run('test-agent-env-check', 'Test Agent', 'public', null, 'global_agent', 'system/agents/test-agent-env-check', 'active', null, now, now);

    // The row must have landed in the overridden file, not the default one.
    expect(fs.existsSync(TEST_DB_PATH)).toBe(true);

    // Prove the override actually redirected the file: the default-path DB
    // (opened independently, never touched by graph-db in this test run)
    // must NOT contain the row we just wrote.
    if (fs.existsSync(DEFAULT_DB_PATH)) {
      const defaultDb = new Database(DEFAULT_DB_PATH, { readonly: true });
      try {
        const row = defaultDb.prepare('SELECT 1 FROM system_agents WHERE id = ?').get('test-agent-env-check');
        expect(row).toBeUndefined();
      } finally {
        defaultDb.close();
      }
    } else {
      // Default DB file was never created at all -- also proves the write
      // went to the overridden path instead of the default one.
      expect(fs.existsSync(DEFAULT_DB_PATH)).toBe(false);
    }
  });
});