<?php
require_once __DIR__ . '/uuid.php';
require_once __DIR__ . '/audit_helpers.php';

function post_journal_entry(PDO $pdo, array $payload): array
{
    try {
        if (empty($payload['entry_date']) || empty($payload['description']) || empty($payload['lines'])) {
            return ['error' => 'Missing required fields for journal entry'];
        }

        // --- Accounting Period Control ---
        $stmt_period_check = $pdo->prepare(
            "SELECT COUNT(*) FROM accounting_periods WHERE status = 'closed' AND :entry_date BETWEEN start_date AND end_date"
        );
        $stmt_period_check->execute([':entry_date' => $payload['entry_date']]);
        if ($stmt_period_check->fetchColumn() > 0) {
            return ['error' => 'Cannot post transaction to a closed accounting period.'];
        }
        // --- End Control ---

        $total_debits = 0;
        $total_credits = 0;
        foreach ($payload['lines'] as $line) {
            $debit = isset($line['debit']) ? $line['debit'] : 0;
            $credit = isset($line['credit']) ? $line['credit'] : 0;
            $total_debits += $debit;
            $total_credits += $credit;
        }

        if (round($total_debits, 2) !== round($total_credits, 2) || $total_debits === 0) {
            return ['error' => 'Debits and credits must balance and not be zero.'];
        }

        $journal_entry_id = uuid_v4();
        $stmt_je = $pdo->prepare("INSERT INTO journal_entries (id, entry_date, description, status) VALUES (?, ?, ?, 'posted')");
        $stmt_je->execute([$journal_entry_id, $payload['entry_date'], $payload['description']]);

        $stmt_lines = $pdo->prepare("INSERT INTO journal_lines (id, journal_entry_id, account_code, debit_amount, credit_amount) VALUES (?, ?, ?, ?, ?)");
        $stmt_subledger = $pdo->prepare("INSERT INTO journal_line_subledgers (journal_line_id, subledger_id) VALUES (?, ?)");

        foreach ($payload['lines'] as $line) {
            $journal_line_id = uuid_v4();
            $debit = $line['debit'] ?? 0;
            $credit = $line['credit'] ?? 0;
            $stmt_lines->execute([$journal_line_id, $journal_entry_id, $line['account_code'], $debit, $credit]);
            
            if (!empty($line['subledger_id'])) {
                $stmt_subledger->execute([$journal_line_id, $line['subledger_id']]);
            }
        }
        
        // Log audit trail
        log_audit_trail($pdo, 'post_journal_entry', ['journal_entry_id' => $journal_entry_id, 'description' => $payload['description']]);

        return ['success' => true, 'journal_entry_id' => $journal_entry_id];

    } catch (PDOException $e) {
        return ['error' => 'Database error in post_journal_entry: ' . $e->getMessage()];
    }
}