// Zero-residue guard: the e2e suite must leave the dev database exactly as
// it found it. globalSetup snapshots row counts, globalTeardown re-counts
// and fails the run on any difference.
//
// Documented exception: done/failed rows in `jobs` are execution history
// (the queue's audit trail); only unprocessed jobs count as residue.

import { execSync } from 'node:child_process';
import fs from 'node:fs';
import path from 'node:path';

const TABLES = [
	'users',
	'departments',
	'templates',
	'conversations',
	'messages',
	'documents',
	'chunks',
	'doc_permissions',
	'auth_sessions',
	'llm_settings'
];

const SNAPSHOT = path.join(import.meta.dirname, '..', 'test-results', 'row-counts.json');

function query(sql: string): string {
	return execSync(`docker exec pablan-dev-postgres-1 psql -tA -U pablan -d pablan -c "${sql}"`)
		.toString()
		.trim();
}

export function snapshotCounts(): Record<string, number> {
	const counts: Record<string, number> = {};
	for (const table of TABLES) {
		counts[table] = Number(query(`SELECT count(*) FROM ${table}`));
	}
	counts['jobs (unprocessed)'] = Number(
		query(`SELECT count(*) FROM jobs WHERE status IN ('pending','running')`)
	);
	return counts;
}

export async function globalSetup(): Promise<void> {
	fs.mkdirSync(path.dirname(SNAPSHOT), { recursive: true });
	fs.writeFileSync(SNAPSHOT, JSON.stringify(snapshotCounts(), null, 2));
}

export async function globalTeardown(): Promise<void> {
	const before = JSON.parse(fs.readFileSync(SNAPSHOT, 'utf-8')) as Record<string, number>;
	const after = snapshotCounts();
	const diffs = Object.keys(after)
		.filter((key) => before[key] !== after[key])
		.map((key) => `  ${key}: ${before[key]} -> ${after[key]}`);
	if (diffs.length > 0) {
		throw new Error(`e2e suite left residue in the database:\n${diffs.join('\n')}`);
	}
}