<?php
declare(strict_types=1);

require_once __DIR__ . '/app/db.php';

$pageTitle = 'Payment View';
$pageSubtitle = 'View a single payment record with defensive schema detection and workflow shortcuts.';

if (!function_exists('fourps_h')) {
    function fourps_h($value): string
    {
        return htmlspecialchars((string)$value, ENT_QUOTES, 'UTF-8');
    }
}

if (!function_exists('fourps_db')) {
    function fourps_db(): ?PDO
    {
        global $pdo;
        return ($pdo instanceof PDO) ? $pdo : null;
    }
}

if (!function_exists('fourps_table_exists')) {
    function fourps_table_exists(string $table): bool
    {
        static $cache = [];
        if (array_key_exists($table, $cache)) {
            return $cache[$table];
        }

        $db = fourps_db();
        if (!$db) {
            return $cache[$table] = false;
        }

        try {
            $stmt = $db->prepare('SHOW TABLES LIKE ?');
            $stmt->execute([$table]);
            return $cache[$table] = (bool)$stmt->fetchColumn();
        } catch (Throwable $e) {
            return $cache[$table] = false;
        }
    }
}

if (!function_exists('fourps_column_exists')) {
    function fourps_column_exists(string $table, string $column): bool
    {
        static $cache = [];
        $key = $table . '.' . $column;
        if (array_key_exists($key, $cache)) {
            return $cache[$key];
        }

        if (!fourps_table_exists($table)) {
            return $cache[$key] = false;
        }

        $db = fourps_db();
        if (!$db) {
            return $cache[$key] = false;
        }

        try {
            $stmt = $db->prepare("SHOW COLUMNS FROM `{$table}` LIKE ?");
            $stmt->execute([$column]);
            return $cache[$key] = (bool)$stmt->fetch(PDO::FETCH_ASSOC);
        } catch (Throwable $e) {
            return $cache[$key] = false;
        }
    }
}

if (!function_exists('fourps_pick_first_existing_column')) {
    function fourps_pick_first_existing_column(string $table, array $columns): ?string
    {
        foreach ($columns as $column) {
            if (fourps_column_exists($table, $column)) {
                return $column;
            }
        }
        return null;
    }
}

if (!function_exists('fourps_first_existing_table')) {
    function fourps_first_existing_table(array $tables): ?string
    {
        foreach ($tables as $table) {
            if (fourps_table_exists($table)) {
                return $table;
            }
        }
        return null;
    }
}

if (!function_exists('fourps_money')) {
    function fourps_money($amount): string
    {
        return '$' . number_format((float)$amount, 2);
    }
}

if (!function_exists('fourps_fmt_datetime')) {
    function fourps_fmt_datetime(?string $value): string
    {
        if (!$value) {
            return '—';
        }

        $ts = strtotime($value);
        if ($ts === false) {
            return (string)$value;
        }

        return date('M j, Y g:i A', $ts);
    }
}

if (!function_exists('fourps_query_one')) {
    function fourps_query_one(string $sql, array $params = []): ?array
    {
        $db = fourps_db();
        if (!$db) {
            return null;
        }

        try {
            $stmt = $db->prepare($sql);
            $stmt->execute($params);
            $row = $stmt->fetch(PDO::FETCH_ASSOC);
            return $row ?: null;
        } catch (Throwable $e) {
            return null;
        }
    }
}

if (!function_exists('fourps_query_all')) {
    function fourps_query_all(string $sql, array $params = []): array
    {
        $db = fourps_db();
        if (!$db) {
            return [];
        }

        try {
            $stmt = $db->prepare($sql);
            $stmt->execute($params);
            return $stmt->fetchAll(PDO::FETCH_ASSOC) ?: [];
        } catch (Throwable $e) {
            return [];
        }
    }
}

$table = fourps_first_existing_table(['fourps_payments', 'payments']);
$id = isset($_GET['id']) ? (int)$_GET['id'] : 0;

$titleColumn = $table ? fourps_pick_first_existing_column($table, ['title', 'name', 'payment_name', 'reference', 'number', 'payment_reference', 'transaction_id']) : null;
$statusColumn = $table ? fourps_pick_first_existing_column($table, ['status', 'payment_status', 'state']) : null;
$amountColumn = $table ? fourps_pick_first_existing_column($table, ['amount', 'payment_amount', 'total']) : null;
$methodColumn = $table ? fourps_pick_first_existing_column($table, ['payment_method', 'method', 'tender_type']) : null;
$createdColumn = $table ? fourps_pick_first_existing_column($table, ['created_at', 'date_created', 'received_at', 'payment_date']) : null;
$updatedColumn = $table ? fourps_pick_first_existing_column($table, ['updated_at', 'modified_at', 'last_updated_at', 'posted_at', 'cleared_at']) : null;
$customerColumn = $table ? fourps_pick_first_existing_column($table, ['customer_name', 'client_name', 'member_name', 'owner_name', 'payer_name']) : null;
$emailColumn = $table ? fourps_pick_first_existing_column($table, ['customer_email', 'client_email', 'member_email', 'owner_email', 'payer_email']) : null;
$phoneColumn = $table ? fourps_pick_first_existing_column($table, ['customer_phone', 'client_phone', 'member_phone', 'owner_phone', 'payer_phone']) : null;
$invoiceRefColumn = $table ? fourps_pick_first_existing_column($table, ['invoice_id', 'invoice_number', 'invoice_reference']) : null;
$claimRefColumn = $table ? fourps_pick_first_existing_column($table, ['claim_id', 'claim_number', 'claim_reference']) : null;
$noteColumn = $table ? fourps_pick_first_existing_column($table, ['notes', 'note', 'description', 'details', 'payment_notes']) : null;
$processorColumn = $table ? fourps_pick_first_existing_column($table, ['processor', 'gateway', 'payment_processor']) : null;

$record = null;
if ($table && $id > 0 && fourps_column_exists($table, 'id')) {
    $select = ['`id`'];
    $fieldsToCheck = [
        'titleColumn' => $titleColumn,
        'statusColumn' => $statusColumn,
        'amountColumn' => $amountColumn,
        'methodColumn' => $methodColumn,
        'createdColumn' => $createdColumn,
        'updatedColumn' => $updatedColumn,
        'customerColumn' => $customerColumn,
        'emailColumn' => $emailColumn,
        'phoneColumn' => $phoneColumn,
        'invoiceRefColumn' => $invoiceRefColumn,
        'claimRefColumn' => $claimRefColumn,
        'noteColumn' => $noteColumn,
        'processorColumn' => $processorColumn,
    ];

    foreach ($fieldsToCheck as $alias => $column) {
        if ($column) {
            $select[] = "`{$column}` AS {$alias}";
        } else {
            $select[] = "NULL AS {$alias}";
        }
    }

    $sql = "SELECT " . implode(', ', $select) . " FROM `{$table}` WHERE `id` = ? LIMIT 1";
    $record = fourps_query_one($sql, [$id]);
}

$searchTitle = $record['titleColumn'] ?? null;
if ($searchTitle && is_string($searchTitle)) {
    $searchTitle = trim($searchTitle);
}

function fourps_related_rows(array $tables, ?string $searchTitle, int $limit = 5): array
{
    if (!$searchTitle) {
        return [];
    }

    $all = [];
    foreach ($tables as $tableInfo) {
        $table = fourps_first_existing_table($tableInfo['tables']);
        if (!$table) {
            continue;
        }

        $idColumn = fourps_pick_first_existing_column($table, ['id']);
        $titleColumn = fourps_pick_first_existing_column($table, ['title', 'name', 'reference', 'number', 'plan_number', 'claim_number', 'invoice_number', 'payment_reference', 'transaction_id']);
        $statusColumn = fourps_pick_first_existing_column($table, ['status', 'plan_status', 'claim_status', 'invoice_status', 'payment_status', 'state']);
        $dateColumn = fourps_pick_first_existing_column($table, ['updated_at', 'created_at', 'date_created', 'submitted_at', 'invoice_date', 'payment_date', 'received_at']);

        if (!$idColumn || !$titleColumn) {
            continue;
        }

        $select = [
            "`{$idColumn}` AS row_id",
            "`{$titleColumn}` AS row_title",
            $statusColumn ? "`{$statusColumn}` AS row_status" : "'' AS row_status",
            $dateColumn ? "`{$dateColumn}` AS row_date" : "NULL AS row_date",
        ];

        $sql = "SELECT " . implode(', ', $select) . " FROM `{$table}` WHERE `{$titleColumn}` LIKE ? ORDER BY " . ($dateColumn ? "`{$dateColumn}` DESC" : "`{$idColumn}` DESC") . " LIMIT " . (int)$limit;
        $rows = fourps_query_all($sql, ['%' . $searchTitle . '%']);

        foreach ($rows as &$row) {
            $row['module_label'] = $tableInfo['label'];
            $row['view_file'] = $tableInfo['view'];
            $row['table_name'] = $table;
        }
        unset($row);

        $all = array_merge($all, $rows);
    }

    return $all;
}

$relatedClaims = [];
$relatedPlans = [];
$relatedInvoices = [];

if ($record && $searchTitle) {
    $relatedClaims = fourps_related_rows([
        ['label' => 'Claims', 'tables' => ['fourps_claims', 'claims'], 'view' => 'claim-view.php']
    ], $searchTitle);

    $relatedPlans = fourps_related_rows([
        ['label' => 'Plans', 'tables' => ['fourps_plans', 'plans'], 'view' => 'plan-view.php']
    ], $searchTitle);

    $relatedInvoices = fourps_related_rows([
        ['label' => 'Invoices', 'tables' => ['fourps_invoices', 'invoices'], 'view' => 'invoice-view.php']
    ], $searchTitle);
}

$displayTitle = $record['titleColumn'] ?? null;
if (!$displayTitle && $id > 0) {
    $displayTitle = 'Payment #' . $id;
}
if (!$displayTitle) {
    $displayTitle = 'Payment Record';
}
?>
<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title><?= fourps_h($pageTitle) ?></title>
    <style>
        :root{
            --bg:#f4f7fb;
            --panel:#ffffff;
            --line:#d9e3f0;
            --text:#16324f;
            --muted:#60758b;
            --blue:#1f6fd6;
            --blue-dark:#1859ab;
            --blue-soft:#eef5ff;
            --shadow:0 12px 28px rgba(19,54,94,.08);
        }
        *{box-sizing:border-box}
        body{
            margin:0;
            font-family:Arial, Helvetica, sans-serif;
            background:var(--bg);
            color:var(--text);
        }
        .page{
            max-width:1350px;
            margin:0 auto;
            padding:24px;
        }
        .hero,.panel,.stat{
            background:var(--panel);
            border:1px solid var(--line);
            border-radius:22px;
            box-shadow:var(--shadow);
        }
        .hero{
            padding:26px;
            margin-bottom:20px;
            background:linear-gradient(135deg,#ffffff 0%,#eef5ff 100%);
        }
        .hero-row{
            display:flex;
            justify-content:space-between;
            align-items:flex-start;
            gap:16px;
            flex-wrap:wrap;
        }
        h1{
            margin:0 0 8px;
            font-size:32px;
            line-height:1.1;
        }
        .subtitle{
            margin:0;
            color:var(--muted);
            font-size:15px;
            max-width:780px;
        }
        .actions{
            display:flex;
            gap:10px;
            flex-wrap:wrap;
        }
        .btn{
            display:inline-flex;
            align-items:center;
            justify-content:center;
            padding:12px 16px;
            border-radius:12px;
            border:1px solid transparent;
            font-size:14px;
            font-weight:700;
            text-decoration:none;
        }
        .btn-primary{background:var(--blue);color:#fff}
        .btn-primary:hover{background:var(--blue-dark)}
        .btn-light{background:#fff;color:var(--text);border-color:var(--line)}
        .stats{
            display:grid;
            grid-template-columns:repeat(4,minmax(0,1fr));
            gap:16px;
            margin-bottom:20px;
        }
        .stat{padding:18px}
        .stat .label{
            color:var(--muted);
            font-size:12px;
            text-transform:uppercase;
            font-weight:700;
            letter-spacing:.04em;
            margin-bottom:8px;
        }
        .stat .value{
            font-size:24px;
            font-weight:800;
            line-height:1.1;
        }
        .layout{
            display:grid;
            grid-template-columns:1.1fr .9fr;
            gap:20px;
        }
        .panel-head{
            padding:18px 20px;
            border-bottom:1px solid var(--line);
        }
        .panel-head h2{
            margin:0;
            font-size:20px;
        }
        .panel-head p{
            margin:6px 0 0;
            color:var(--muted);
            font-size:14px;
        }
        .panel-body{
            padding:20px;
        }
        .detail-grid{
            display:grid;
            grid-template-columns:repeat(2,minmax(0,1fr));
            gap:14px;
        }
        .detail-box{
            border:1px solid var(--line);
            border-radius:16px;
            background:#fbfdff;
            padding:14px;
        }
        .detail-box .k{
            font-size:11px;
            text-transform:uppercase;
            font-weight:700;
            color:var(--muted);
            margin-bottom:6px;
        }
        .detail-box .v{
            font-size:16px;
            font-weight:700;
            line-height:1.35;
            word-break:break-word;
        }
        .note-box{
            margin-top:16px;
            border:1px solid var(--line);
            border-radius:16px;
            background:#fbfdff;
            padding:16px;
        }
        .note-box h3{
            margin:0 0 10px;
            font-size:17px;
        }
        .empty{
            padding:18px;
            border:1px dashed var(--line);
            border-radius:16px;
            background:#fafcff;
            color:var(--muted);
        }
        table{
            width:100%;
            border-collapse:collapse;
        }
        th,td{
            padding:12px 10px;
            border-bottom:1px solid #e9eef5;
            text-align:left;
            vertical-align:top;
            font-size:14px;
        }
        th{
            color:var(--muted);
            font-size:12px;
            text-transform:uppercase;
            letter-spacing:.04em;
        }
        .badge{
            display:inline-block;
            padding:6px 10px;
            border-radius:999px;
            background:var(--blue-soft);
            color:var(--blue-dark);
            font-size:12px;
            font-weight:700;
        }
        .small{
            color:var(--muted);
            font-size:12px;
        }
        @media (max-width: 980px){
            .layout{grid-template-columns:1fr}
            .stats{grid-template-columns:repeat(2,minmax(0,1fr))}
        }
        @media (max-width: 640px){
            .stats{grid-template-columns:1fr}
            .detail-grid{grid-template-columns:1fr}
        }
    </style>
</head>
<body>
<?php require __DIR__ . '/includes/fourps-nav.php'; ?>

<div class="page">
    <section class="hero">
        <div class="hero-row">
            <div>
                <h1><?= fourps_h($displayTitle) ?></h1>
                <p class="subtitle"><?= fourps_h($pageSubtitle) ?></p>
            </div>
            <div class="actions">
                <a class="btn btn-primary" href="workflow-search.php?module=payments">Search Payments</a>
                <a class="btn btn-light" href="queue.php?module=payments">Payment Queue</a>
                <a class="btn btn-light" href="workflow-index.php">Workflow Home</a>
            </div>
        </div>
    </section>

    <section class="stats">
        <div class="stat">
            <div class="label">Record ID</div>
            <div class="value"><?= $record ? (int)$record['id'] : ($id > 0 ? $id : '—') ?></div>
        </div>
        <div class="stat">
            <div class="label">Status</div>
            <div class="value"><?= fourps_h((string)($record['statusColumn'] ?? '—')) ?></div>
        </div>
        <div class="stat">
            <div class="label">Amount</div>
            <div class="value"><?= fourps_money((float)($record['amountColumn'] ?? 0)) ?></div>
        </div>
        <div class="stat">
            <div class="label">Method</div>
            <div class="value"><?= fourps_h((string)($record['methodColumn'] ?? '—')) ?></div>
        </div>
    </section>

    <section class="layout">
        <div class="panel">
            <div class="panel-head">
                <h2>Payment Details</h2>
                <p>Single-record detail view that checks for supported columns before reading them.</p>
            </div>
            <div class="panel-body">
                <?php if (!$table): ?>
                    <div class="empty">No supported payment table was found. This page checks for <code>fourps_payments</code> first and then <code>payments</code>.</div>
                <?php elseif ($id <= 0): ?>
                    <div class="empty">No payment ID was provided. Open this page with a URL like <code>payment-view.php?id=123</code>.</div>
                <?php elseif (!$record): ?>
                    <div class="empty">No payment record was found for ID <?= (int)$id ?> in table <strong><?= fourps_h($table) ?></strong>.</div>
                <?php else: ?>
                    <div class="detail-grid">
                        <div class="detail-box">
                            <div class="k">Title / Reference</div>
                            <div class="v"><?= fourps_h((string)($record['titleColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Status</div>
                            <div class="v"><?= fourps_h((string)($record['statusColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Amount</div>
                            <div class="v"><?= fourps_money((float)($record['amountColumn'] ?? 0)) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Method</div>
                            <div class="v"><?= fourps_h((string)($record['methodColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Received / Created</div>
                            <div class="v"><?= fourps_fmt_datetime(isset($record['createdColumn']) ? (string)$record['createdColumn'] : null) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Updated / Posted</div>
                            <div class="v"><?= fourps_fmt_datetime(isset($record['updatedColumn']) ? (string)$record['updatedColumn'] : null) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Customer / Payer</div>
                            <div class="v"><?= fourps_h((string)($record['customerColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Email</div>
                            <div class="v"><?= fourps_h((string)($record['emailColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Phone</div>
                            <div class="v"><?= fourps_h((string)($record['phoneColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Invoice Reference</div>
                            <div class="v"><?= fourps_h((string)($record['invoiceRefColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Claim Reference</div>
                            <div class="v"><?= fourps_h((string)($record['claimRefColumn'] ?? '—')) ?></div>
                        </div>
                        <div class="detail-box">
                            <div class="k">Processor / Gateway</div>
                            <div class="v"><?= fourps_h((string)($record['processorColumn'] ?? '—')) ?></div>
                        </div>
                    </div>

                    <div class="note-box">
                        <h3>Notes / Description</h3>
                        <div><?= nl2br(fourps_h((string)($record['noteColumn'] ?? 'No notes field found or no notes saved.'))) ?></div>
                    </div>
                <?php endif; ?>
            </div>
        </div>

        <div style="display:grid; gap:20px;">
            <div class="panel">
                <div class="panel-head">
                    <h2>Related Records</h2>
                    <p>Best-effort related matches based on the payment title or reference text.</p>
                </div>
                <div class="panel-body">
                    <?php
                    $groups = [
                        ['label' => 'Claims', 'rows' => $relatedClaims],
                        ['label' => 'Plans', 'rows' => $relatedPlans],
                        ['label' => 'Invoices', 'rows' => $relatedInvoices],
                    ];
                    ?>
                    <?php foreach ($groups as $group): ?>
                        <div style="margin-bottom:18px;">
                            <div style="margin-bottom:10px;"><span class="badge"><?= fourps_h($group['label']) ?></span></div>
                            <?php if (!$group['rows']): ?>
                                <div class="empty">No related <?= strtolower($group['label']) ?> found.</div>
                            <?php else: ?>
                                <table>
                                    <thead>
                                        <tr>
                                            <th>Record</th>
                                            <th>Status</th>
                                            <th>Date</th>
                                        </tr>
                                    </thead>
                                    <tbody>
                                        <?php foreach ($group['rows'] as $row): ?>
                                            <tr>
                                                <td>
                                                    <a href="<?= fourps_h((string)$row['view_file']) ?>?id=<?= (int)($row['row_id'] ?? 0) ?>">
                                                        <?= fourps_h((string)($row['row_title'] ?: ('Record #' . (int)($row['row_id'] ?? 0)))) ?>
                                                    </a>
                                                    <div class="small"><?= fourps_h((string)$row['table_name']) ?></div>
                                                </td>
                                                <td><?= fourps_h((string)($row['row_status'] ?? '—')) ?></td>
                                                <td><?= fourps_fmt_datetime(isset($row['row_date']) ? (string)$row['row_date'] : null) ?></td>
                                            </tr>
                                        <?php endforeach; ?>
                                    </tbody>
                                </table>
                            <?php endif; ?>
                        </div>
                    <?php endforeach; ?>
                </div>
            </div>

            <div class="panel">
                <div class="panel-head">
                    <h2>Workflow Shortcuts</h2>
                    <p>Quick paths from this payment record into the utility pages.</p>
                </div>
                <div class="panel-body">
                    <div style="display:grid; gap:10px;">
                        <a class="btn btn-light" href="workflow-open-items.php">Open Items</a>
                        <a class="btn btn-light" href="workflow-recent-activity.php">Recent Activity</a>
                        <a class="btn btn-light" href="workflow-aging.php">Aging</a>
                        <a class="btn btn-light" href="workflow-exceptions.php">Exceptions</a>
                        <a class="btn btn-light" href="workflow-financial-exposure.php">Financial Exposure</a>
                        <a class="btn btn-light" href="workflow-reconciliation.php">Reconciliation</a>
                    </div>
                </div>
            </div>
        </div>
    </section>
</div>
</body>
</html>