<?php
require __DIR__ . '/session.php';
require __DIR__ . '/db.php';
start_app_session();

if (!isset($_SESSION['username']) || !isset($_SESSION['user_id'])) {
    header('Location: /');
    exit;
}

$isLoggedIn = isset($_SESSION['username']) && isset($_SESSION['user_id']);

const DAILY_CRITTER_LIMIT = 30;
const CRITTER_COOLDOWN_SECONDS = 15;

$pdo = getDbConnection();

$creditsStmt = $pdo->prepare('SELECT credits FROM users WHERE id = :id');
$creditsStmt->execute(['id' => $_SESSION['user_id']]);
$userCredits = (int) $creditsStmt->fetchColumn();

$pdo->exec('CREATE TABLE IF NOT EXISTS critters (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    noun_id INTEGER NOT NULL REFERENCES nouns(id),
    adjective_id INTEGER NOT NULL REFERENCES adjectives(id),
    verb_id INTEGER NOT NULL REFERENCES verbs(id),
    location_id INTEGER NOT NULL REFERENCES locations(id),
    author_id INTEGER NOT NULL REFERENCES users(id),
    image TEXT,
    isFavorite INTEGER NOT NULL DEFAULT 0,
    isArchived INTEGER NOT NULL DEFAULT 0,
    datetime TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
)');

$critterColumns = $pdo->query('PRAGMA table_info(critters)')->fetchAll(PDO::FETCH_COLUMN, 1);
if (!in_array('author_id', $critterColumns, true)) {
    $pdo->exec('ALTER TABLE critters ADD COLUMN author_id INTEGER REFERENCES users(id)');
}
if (!in_array('image', $critterColumns, true)) {
    $pdo->exec('ALTER TABLE critters ADD COLUMN image TEXT');
}
if (!in_array('isFavorite', $critterColumns, true)) {
    $pdo->exec('ALTER TABLE critters ADD COLUMN isFavorite INTEGER NOT NULL DEFAULT 0');
}
if (!in_array('isArchived', $critterColumns, true)) {
    $pdo->exec('ALTER TABLE critters ADD COLUMN isArchived INTEGER NOT NULL DEFAULT 0');
}
if (!in_array('datetime', $critterColumns, true)) {
    $pdo->exec('ALTER TABLE critters ADD COLUMN datetime TEXT');
    $pdo->exec("UPDATE critters SET datetime = CURRENT_TIMESTAMP WHERE datetime IS NULL");
}

$pdo->exec('CREATE INDEX IF NOT EXISTS idx_critters_noun_id ON critters (noun_id)');
$pdo->exec('CREATE INDEX IF NOT EXISTS idx_critters_adjective_id ON critters (adjective_id)');
$pdo->exec('CREATE INDEX IF NOT EXISTS idx_critters_verb_id ON critters (verb_id)');
$pdo->exec('CREATE INDEX IF NOT EXISTS idx_critters_location_id ON critters (location_id)');
$pdo->exec('CREATE INDEX IF NOT EXISTS idx_critters_author_id ON critters (author_id)');

function countCrittersCreatedToday(PDO $pdo): int
{
    return (int) $pdo->query("SELECT COUNT(*) FROM critters WHERE date(datetime) = date('now')")->fetchColumn();
}

function secondsSinceLastCritterByAuthor(PDO $pdo, int $authorId): ?int
{
    $stmt = $pdo->prepare("SELECT CAST(strftime('%s', 'now') - strftime('%s', datetime) AS INTEGER) FROM critters WHERE author_id = :author_id ORDER BY datetime DESC LIMIT 1");
    $stmt->execute(['author_id' => $authorId]);
    $seconds = $stmt->fetchColumn();
    return $seconds === false ? null : (int) $seconds;
}

$dailyLimitReached = countCrittersCreatedToday($pdo) >= DAILY_CRITTER_LIMIT;

$cooldownRemaining = 0;
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $secondsSinceLast = secondsSinceLastCritterByAuthor($pdo, (int) $_SESSION['user_id']);
    if ($secondsSinceLast !== null && $secondsSinceLast < CRITTER_COOLDOWN_SECONDS) {
        $cooldownRemaining = CRITTER_COOLDOWN_SECONDS - $secondsSinceLast;
    }
}

function isAllowedReplicateUrl(string $url): bool
{
    $parts = parse_url($url);
    if ($parts === false || ($parts['scheme'] ?? '') !== 'https' || empty($parts['host'])) {
        return false;
    }
    $host = strtolower($parts['host']);
    return $host === 'api.replicate.com'
        || $host === 'replicate.delivery'
        || substr($host, -strlen('.replicate.delivery')) === '.replicate.delivery';
}

function getValueById(PDO $pdo, string $table, $id): string
{
    $stmt = $pdo->prepare("SELECT value FROM {$table} WHERE id = :id");
    $stmt->execute(['id' => $id]);
    return (string) $stmt->fetchColumn();
}

$adjectives = $pdo->query('SELECT id, value FROM adjectives ORDER BY value')->fetchAll(PDO::FETCH_ASSOC);
$nouns = $pdo->query('SELECT id, value FROM nouns ORDER BY value')->fetchAll(PDO::FETCH_ASSOC);
$verbs = $pdo->query('SELECT id, value FROM verbs ORDER BY value')->fetchAll(PDO::FETCH_ASSOC);
$locations = $pdo->query('SELECT id, value FROM locations ORDER BY value')->fetchAll(PDO::FETCH_ASSOC);

$fields = [
    'adjective_id' => ['table' => 'adjectives', 'label' => 'adjective'],
    'noun_id' => ['table' => 'nouns', 'label' => 'noun'],
    'verb_id' => ['table' => 'verbs', 'label' => 'verb'],
    'location_id' => ['table' => 'locations', 'label' => 'location'],
];

$errors = [];
$selected = [
    'adjective_id' => '',
    'noun_id' => '',
    'verb_id' => '',
    'location_id' => '',
];

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    foreach ($fields as $field => $info) {
        $value = $_GET[$field] ?? '';
        if ($value !== '' && ctype_digit((string) $value) && rowExistsById($pdo, $info['table'], $value)) {
            $selected[$field] = (int) $value;
        }
    }

    $hasRemixParams = $selected['adjective_id'] !== ''
        || $selected['noun_id'] !== ''
        || $selected['verb_id'] !== ''
        || $selected['location_id'] !== '';

    if (!$hasRemixParams) {
        $optionLists = [
            'adjective_id' => $adjectives,
            'noun_id' => $nouns,
            'verb_id' => $verbs,
            'location_id' => $locations,
        ];

        foreach ($optionLists as $field => $rows) {
            if (!empty($rows)) {
                $selected[$field] = (int) $rows[array_rand($rows)]['id'];
            }
        }
    }
}

if ($_SERVER['REQUEST_METHOD'] === 'POST' && $userCredits > 0 && !$dailyLimitReached) {
    foreach ($fields as $field => $info) {
        $value = $_POST[$field] ?? '';
        $selected[$field] = $value;

        if ($value === '' || !ctype_digit((string) $value) || !rowExistsById($pdo, $info['table'], $value)) {
            $errors[$field] = 'Please choose a valid ' . $info['label'] . '.';
        }
    }

    if (empty($errors) && countCrittersCreatedToday($pdo) >= DAILY_CRITTER_LIMIT) {
        $dailyLimitReached = true;
    }

    if (empty($errors) && $cooldownRemaining > 0) {
        $errors['cooldown'] = "Please wait {$cooldownRemaining} more second(s) before creating another critter.";
    }

    $creditReserved = false;

    if (empty($errors) && !$dailyLimitReached) {
        // Atomically reserve one credit in the same statement that checks for it, so
        // concurrent requests can't all read "1 credit" before any of them writes the
        // deduction. SQLite serializes writes, so only as many of these UPDATEs can
        // match "credits > 0" as there are credits actually available; everyone else
        // gets 0 rows affected and is turned away before the expensive Replicate call.
        $reserveStmt = $pdo->prepare('UPDATE users SET credits = credits - 1 WHERE id = :id AND credits > 0');
        $reserveStmt->execute(['id' => $_SESSION['user_id']]);
        $creditReserved = $reserveStmt->rowCount() === 1;

        if (!$creditReserved) {
            $userCredits = 0;
            $errors['credits'] = 'You do not have enough credits to create a critter.';
        }
    }

    if (empty($errors) && !$dailyLimitReached && $creditReserved) {
        $adjectiveValue = getValueById($pdo, 'adjectives', $selected['adjective_id']);
        $nounValue = getValueById($pdo, 'nouns', $selected['noun_id']);
        $verbValue = getValueById($pdo, 'verbs', $selected['verb_id']);
        $locationValue = getValueById($pdo, 'locations', $selected['location_id']);

        $prompt = "A {$adjectiveValue} {$nounValue} {$verbValue} {$locationValue} in a high quality 3d animation art style. The image should be vibrant and colorful, capturing the essence of the action and setting.";

        $ch = curl_init('https://api.replicate.com/v1/models/black-forest-labs/flux-schnell/predictions');
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_CAINFO, '/etc/ssl/certs/ca-certificates.crt');
        curl_setopt($ch, CURLOPT_PROTOCOLS, CURLPROTO_HTTPS);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            'Authorization: Bearer ' . getenv('REPLICATE_API_TOKEN'),
            'Content-Type: application/json',
            'Prefer: wait',
        ]);
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
            'input' => [
                'prompt' => $prompt,
            ],
        ]));

        $replicateResponse = curl_exec($ch);
        $imageUrl = null;

        if ($replicateResponse !== false) {
            $prediction = json_decode($replicateResponse, true);

            $pollAttempt = 0;
            while (
                isset($prediction['status'])
                && !in_array($prediction['status'], ['succeeded', 'failed', 'canceled'], true)
                && $pollAttempt < 30
            ) {
                $pollUrl = $prediction['urls']['get'] ?? '';
                if (!is_string($pollUrl) || !isAllowedReplicateUrl($pollUrl)) {
                    $prediction['status'] = 'failed';
                    break;
                }

                sleep(2);

                $pollCh = curl_init($pollUrl);
                curl_setopt($pollCh, CURLOPT_RETURNTRANSFER, true);
                curl_setopt($pollCh, CURLOPT_CAINFO, '/etc/ssl/certs/ca-certificates.crt');
                curl_setopt($pollCh, CURLOPT_PROTOCOLS, CURLPROTO_HTTPS);
                curl_setopt($pollCh, CURLOPT_TIMEOUT, 15);
                curl_setopt($pollCh, CURLOPT_HTTPHEADER, [
                    'Authorization: Bearer ' . getenv('REPLICATE_API_TOKEN'),
                ]);

                $pollResponse = curl_exec($pollCh);
                if ($pollResponse !== false) {
                    $prediction = json_decode($pollResponse, true);
                }

                $pollAttempt++;
            }

            if (($prediction['status'] ?? null) === 'succeeded') {
                $output = $prediction['output'] ?? null;
                $imageUrl = is_array($output) ? ($output[0] ?? null) : $output;
            }
        } else {
            // The Replicate request never went through, so give the reserved credit back.
            $refundStmt = $pdo->prepare('UPDATE users SET credits = credits + 1 WHERE id = :id');
            $refundStmt->execute(['id' => $_SESSION['user_id']]);
        }

        $imageFilename = null;

        if (is_string($imageUrl) && isAllowedReplicateUrl($imageUrl)) {
            $imageCh = curl_init($imageUrl);
            curl_setopt($imageCh, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($imageCh, CURLOPT_CAINFO, '/etc/ssl/certs/ca-certificates.crt');
            curl_setopt($imageCh, CURLOPT_PROTOCOLS, CURLPROTO_HTTPS);
            curl_setopt($imageCh, CURLOPT_TIMEOUT, 30);
            curl_setopt($imageCh, CURLOPT_MAXFILESIZE, 15 * 1024 * 1024);
            $imageData = curl_exec($imageCh);

            if ($imageData !== false && strlen($imageData) > 0 && strlen($imageData) <= 15 * 1024 * 1024) {
                $imageInfo = @getimagesizefromstring($imageData);
                $allowedImageTypes = ['image/webp', 'image/png', 'image/jpeg'];

                if ($imageInfo !== false && in_array($imageInfo['mime'] ?? '', $allowedImageTypes, true)) {
                    $imagesDir = __DIR__ . '/critter-images';
                    if (!is_dir($imagesDir)) {
                        mkdir($imagesDir, 0755, true);
                    }

                    $imageFilename = bin2hex(random_bytes(16)) . '.webp';
                    file_put_contents($imagesDir . '/' . $imageFilename, $imageData);
                }
            }
        }

        $stmt = $pdo->prepare('INSERT INTO critters (noun_id, adjective_id, verb_id, location_id, author_id, image, datetime) VALUES (:noun_id, :adjective_id, :verb_id, :location_id, :author_id, :image, :datetime)');
        $stmt->execute([
            'noun_id' => $selected['noun_id'],
            'adjective_id' => $selected['adjective_id'],
            'verb_id' => $selected['verb_id'],
            'location_id' => $selected['location_id'],
            'author_id' => $_SESSION['user_id'],
            'image' => $imageFilename,
            'datetime' => gmdate('Y-m-d H:i:s'),
        ]);

        header('Location: /');
        exit;
    }
}

function renderOptions(array $rows, $selectedId): void
{
    foreach ($rows as $row) {
        $isSelected = (string) $selectedId === (string) $row['id'];
        echo '<option value="' . (int) $row['id'] . '"' . ($isSelected ? ' selected' : '') . '>'
            . htmlspecialchars($row['value'], ENT_QUOTES, 'UTF-8')
            . '</option>';
    }
}

$pageTitle = 'Create Critter';
?>
<!DOCTYPE html>
<html lang="en">
<?php require __DIR__ . '/lib/head.php'; ?>
<body class="bg-amber-50 min-h-screen flex flex-col">
    <?php require __DIR__ . '/lib/header.php'; ?>
    <main class="flex-1">
    <?php if ($dailyLimitReached): ?>
        <div class="max-w-md mx-auto px-6 py-20 text-center">
            <div class="flex h-16 w-16 items-center justify-center rounded-full bg-purple-50 text-purple-300 mx-auto mb-4">
                <i data-lucide="calendar-clock" class="h-8 w-8"></i>
            </div>
            <h1 class="text-2xl font-extrabold text-gray-900 mb-2">Critter limit reached for the day</h1>
            <p class="text-gray-600">Critter limit reached for the day, please come back tomorrow.</p>
        </div>
    <?php elseif ($userCredits <= 0): ?>
        <div class="max-w-md mx-auto px-6 py-20 text-center">
            <div class="flex h-16 w-16 items-center justify-center rounded-full bg-purple-50 text-purple-300 mx-auto mb-4">
                <i data-lucide="coins" class="h-8 w-8"></i>
            </div>
            <h1 class="text-2xl font-extrabold text-gray-900 mb-2">Out of credits</h1>
            <p class="text-gray-600">You have 0 credits remaining, so you can't create a new critter right now.</p>
            <a href="#" onClick="openCheckout(itemsList)" class="mt-6 inline-flex items-center gap-2 rounded-xl bg-gradient-to-r from-purple-600 to-pink-500 text-white font-semibold px-5 py-2.5 shadow-sm hover:from-purple-700 hover:to-pink-600">
                <i data-lucide="shopping-cart" class="h-4 w-4"></i> Buy Credits
            </a>
        </div>
    <?php else: ?>
    <div class="max-w-xl mx-auto px-6 py-12">
        <div class="text-center mb-8">
            <p class="text-sm font-semibold tracking-widest text-purple-600 uppercase mb-2">Imagine &middot; Mix &middot; Create</p>
            <h1 class="text-3xl sm:text-4xl font-extrabold text-gray-900">Create Your New Critter</h1>
            <p class="mt-2 text-gray-500">Pick a recipe and we'll bring it to life.</p>
        </div>

        <div class="rounded-3xl bg-white ring-1 ring-gray-100 shadow-sm p-6 sm:p-8">
            <?php if (isset($errors['credits']) || isset($errors['cooldown'])): ?>
                <div class="mb-5 rounded-lg bg-red-50 text-red-700 text-sm px-4 py-3">
                    <?php echo htmlspecialchars($errors['credits'] ?? $errors['cooldown'], ENT_QUOTES, 'UTF-8'); ?>
                </div>
            <?php endif; ?>
            <form id="createCritterForm" action="create-critter.php" method="post" novalidate class="space-y-5">
                <div>
                    <label for="adjective_id" class="block text-sm font-medium text-gray-700 mb-1">Adjective</label>
                    <div class="relative">
                        <i data-lucide="wand" class="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-pink-500"></i>
                        <select id="adjective_id" name="adjective_id" class="w-full appearance-none rounded-xl border border-gray-300 pl-10 pr-9 py-2.5 text-gray-900 focus:outline-none focus:ring-2 focus:ring-purple-400 transition-shadow">
                            <option value="">-- Select an adjective --</option>
                            <?php renderOptions($adjectives, $selected['adjective_id']); ?>
                        </select>
                    <i data-lucide="chevron-down" class="pointer-events-none absolute right-3 top-1/2 -translate-y-1/2 h-4 w-4 text-gray-400"></i>
                    </div>
                    <?php if (isset($errors['adjective_id'])): ?>
                        <div class="text-sm text-red-600 mt-1"><?php echo htmlspecialchars($errors['adjective_id'], ENT_QUOTES, 'UTF-8'); ?></div>
                    <?php endif; ?>
                </div>
                <div>
                    <label for="noun_id" class="block text-sm font-medium text-gray-700 mb-1">Animal</label>
                    <div class="relative">
                        <i data-lucide="paw-print" class="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-blue-500"></i>
                        <select id="noun_id" name="noun_id" class="w-full appearance-none rounded-xl border border-gray-300 pl-10 pr-9 py-2.5 text-gray-900 focus:outline-none focus:ring-2 focus:ring-purple-400 transition-shadow">
                            <option value="">-- Select a noun --</option>
                            <?php renderOptions($nouns, $selected['noun_id']); ?>
                        </select>
                    <i data-lucide="chevron-down" class="pointer-events-none absolute right-3 top-1/2 -translate-y-1/2 h-4 w-4 text-gray-400"></i>
                    </div>
                    <?php if (isset($errors['noun_id'])): ?>
                        <div class="text-sm text-red-600 mt-1"><?php echo htmlspecialchars($errors['noun_id'], ENT_QUOTES, 'UTF-8'); ?></div>
                    <?php endif; ?>
                </div>
                <div>
                    <label for="verb_id" class="block text-sm font-medium text-gray-700 mb-1">Action</label>
                    <div class="relative">
                        <i data-lucide="play" class="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-green-500"></i>
                        <select id="verb_id" name="verb_id" class="w-full appearance-none rounded-xl border border-gray-300 pl-10 pr-9 py-2.5 text-gray-900 focus:outline-none focus:ring-2 focus:ring-purple-400 transition-shadow">
                            <option value="">-- Select a verb --</option>
                            <?php renderOptions($verbs, $selected['verb_id']); ?>
                        </select>
                    <i data-lucide="chevron-down" class="pointer-events-none absolute right-3 top-1/2 -translate-y-1/2 h-4 w-4 text-gray-400"></i>
                    </div>
                    <?php if (isset($errors['verb_id'])): ?>
                        <div class="text-sm text-red-600 mt-1"><?php echo htmlspecialchars($errors['verb_id'], ENT_QUOTES, 'UTF-8'); ?></div>
                    <?php endif; ?>
                </div>
                <div>
                    <label for="location_id" class="block text-sm font-medium text-gray-700 mb-1">Location</label>
                    <div class="relative">
                        <i data-lucide="map-pin" class="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-purple-500"></i>
                        <select id="location_id" name="location_id" class="w-full appearance-none rounded-xl border border-gray-300 pl-10 pr-9 py-2.5 text-gray-900 focus:outline-none focus:ring-2 focus:ring-purple-400 transition-shadow">
                            <option value="">-- Select a location --</option>
                            <?php renderOptions($locations, $selected['location_id']); ?>
                        </select>
                    <i data-lucide="chevron-down" class="pointer-events-none absolute right-3 top-1/2 -translate-y-1/2 h-4 w-4 text-gray-400"></i>
                    </div>
                    <?php if (isset($errors['location_id'])): ?>
                        <div class="text-sm text-red-600 mt-1"><?php echo htmlspecialchars($errors['location_id'], ENT_QUOTES, 'UTF-8'); ?></div>
                    <?php endif; ?>
                </div>
                <button type="submit" id="createCritterSubmit" class="w-full inline-flex items-center justify-center gap-2 rounded-xl bg-gradient-to-r from-purple-600 to-pink-500 text-white font-semibold py-3 shadow-sm hover:from-purple-700 hover:to-pink-600 focus:outline-none focus-visible:ring-2 focus-visible:ring-purple-400 focus-visible:ring-offset-2">
                    <i data-lucide="sparkles" class="h-4 w-4"></i> Create Critter
                </button>
            </form>
        </div>
    </div>

    <div id="creatingOverlay" class="hidden fixed inset-0 z-50 flex items-center justify-center bg-gradient-to-br from-purple-600 via-pink-500 to-amber-500 p-6">
        <div class="w-full max-w-sm rounded-3xl bg-white shadow-2xl p-8 text-center">
            <div class="mx-auto flex h-16 w-16 items-center justify-center rounded-full bg-pink-50 text-pink-500 mb-5" style="animation: critter-bounce 1.1s ease-in-out infinite;">
                <i data-lucide="paw-print" class="h-8 w-8"></i>
            </div>
            <h2 class="text-xl font-extrabold text-gray-900">Creating your critter&hellip;</h2>
            <p id="creatingMessage" class="mt-2 text-gray-500 min-h-[1.5em]">Mixing colors&hellip;</p>
            <div class="mt-6 h-2 w-full rounded-full bg-gray-100 overflow-hidden">
                <div class="h-full w-1/3 rounded-full bg-gradient-to-r from-purple-600 via-pink-500 to-amber-500" style="animation: critter-progress 1.4s ease-in-out infinite;"></div>
            </div>
            <p class="mt-5 text-xs text-gray-400">This can take up to a minute &mdash; hang tight!</p>
        </div>
    </div>

    <style>
        @keyframes critter-bounce {
            0%, 100% { transform: translateY(0) scale(1); }
            50% { transform: translateY(-10px) scale(1.08); }
        }
        @keyframes critter-progress {
            0% { transform: translateX(-110%); }
            50% { transform: translateX(60%); }
            100% { transform: translateX(310%); }
        }
    </style>

    <script>
        (function () {
            const form = document.getElementById('createCritterForm');
            if (!form) return;

            const messages = [
                'Mixing colors…',
                'Sketching whiskers…',
                'Adding a sprinkle of magic…',
                'Choosing the perfect pose…',
                'Bringing your critter to life…',
                'Almost there…',
            ];

            form.addEventListener('submit', function () {
                const overlay = document.getElementById('creatingOverlay');
                const messageEl = document.getElementById('creatingMessage');
                const submitBtn = document.getElementById('createCritterSubmit');

                overlay.classList.remove('hidden');
                if (window.lucide) lucide.createIcons();
                if (submitBtn) submitBtn.disabled = true;

                let index = 0;
                setInterval(function () {
                    index = (index + 1) % messages.length;
                    messageEl.textContent = messages[index];
                }, 2200);
            });
        })();
    </script>
    <?php endif; ?>
    </main>
    <?php require __DIR__ . '/lib/footer.php'; ?>
</body>
</html>