<?php

declare(strict_types=1);

function generateProjectNumber(PDO $pdo): string
{
    return generateSharedNumber($pdo);
}

function handleGetNextNumber(PDO $pdo): void
{
    $number = generateProjectNumber($pdo);
    successResponse(['number' => $number]);
}

function handleCreateProject(PDO $pdo): void
{
    $input = getJsonInput();

    $name = trim($input['name'] ?? '');
    if (!$name) {
        errorResponse('Název projektu je povinný');
    }
    if (mb_strlen($name) > 255) {
        errorResponse('Název projektu je příliš dlouhý (max 255 znaků)');
    }

    $customerId = isset($input['customer_id']) ? (int)$input['customer_id'] : null;
    if (!$customerId) {
        errorResponse('Zákazník je povinný');
    }

    // Verify customer exists
    $stmt = $pdo->prepare('SELECT id FROM customers WHERE id = ?');
    $stmt->execute([$customerId]);
    if (!$stmt->fetch()) {
        errorResponse('Zákazník nebyl nalezen', 404);
    }

    $startDate = $input['start_date'] ?? date('Y-m-d');
    if (!preg_match('/^\d{4}-\d{2}-\d{2}$/', $startDate)) {
        errorResponse('Neplatný formát data zahájení');
    }

    $projectNumber = trim($input['project_number'] ?? '');
    if ($projectNumber && mb_strlen($projectNumber) > 50) {
        errorResponse('Číslo projektu je příliš dlouhé (max 50 znaků)');
    }

    // Lock for concurrent number generation
    $locked = $pdo->query("SELECT GET_LOCK('boha_project_number', 5)")->fetchColumn();
    if (!$locked) {
        errorResponse('Nepodařilo se získat zámek pro číslo projektu, zkuste to znovu', 503);
    }

    $pdo->beginTransaction();
    try {
        // Generate or validate number
        if (!$projectNumber) {
            $projectNumber = generateProjectNumber($pdo);
        } else {
            // Validate uniqueness against both tables
            $stmt = $pdo->prepare('SELECT id FROM orders WHERE order_number = ?');
            $stmt->execute([$projectNumber]);
            if ($stmt->fetch()) {
                $pdo->rollBack();
                $pdo->query("SELECT RELEASE_LOCK('boha_project_number')");
                errorResponse('Číslo projektu je již použito jako číslo objednávky');
            }

            $stmt = $pdo->prepare('SELECT id FROM projects WHERE project_number = ?');
            $stmt->execute([$projectNumber]);
            if ($stmt->fetch()) {
                $pdo->rollBack();
                $pdo->query("SELECT RELEASE_LOCK('boha_project_number')");
                errorResponse('Číslo projektu je již použito');
            }
        }

        $stmt = $pdo->prepare("
            INSERT INTO projects (
                project_number, name, customer_id,
                status, start_date, created_at, modified_at
            ) VALUES (?, ?, ?, 'aktivni', ?, NOW(), NOW())
        ");
        $stmt->execute([
            $projectNumber,
            $name,
            $customerId,
            $startDate,
        ]);
        $projectId = (int)$pdo->lastInsertId();


        $pdo->commit();
        $pdo->query("SELECT RELEASE_LOCK('boha_project_number')");

        AuditLog::logCreate('projects_project', $projectId, [
            'project_number' => $projectNumber,
            'name' => $name,
            'customer_id' => $customerId,
        ], "Ručně vytvořen projekt '$projectNumber'");

        successResponse([
            'project_id' => $projectId,
            'project_number' => $projectNumber,
        ], 'Projekt byl vytvořen');
    } catch (PDOException $e) {
        $pdo->rollBack();
        $pdo->query("SELECT RELEASE_LOCK('boha_project_number')");
        throw $e;
    }
}

function handleDeleteProject(PDO $pdo, int $id): void
{
    $stmt = $pdo->prepare('SELECT * FROM projects WHERE id = ?');
    $stmt->execute([$id]);
    $project = $stmt->fetch();

    if (!$project) {
        errorResponse('Projekt nebyl nalezen', 404);
    }

    // Only manually created projects (without order_id) can be deleted
    if (!empty($project['order_id'])) {
        errorResponse('Projekt propojený s objednávkou nelze smazat. Smažte objednávku.', 400);
    }

    $pdo->beginTransaction();
    try {
        // Delete project notes
        $stmt = $pdo->prepare('DELETE FROM project_notes WHERE project_id = ?');
        $stmt->execute([$id]);

        // Delete project
        $stmt = $pdo->prepare('DELETE FROM projects WHERE id = ?');
        $stmt->execute([$id]);

        $pdo->commit();

        AuditLog::logUpdate(
            'projects_project',
            $id,
            ['status' => $project['status']],
            ['status' => 'deleted'],
            "Smazán ruční projekt '{$project['project_number']}'"
        );

        successResponse(null, 'Projekt byl smazán');
    } catch (PDOException $e) {
        $pdo->rollBack();
        throw $e;
    }
}

function handleGetList(PDO $pdo): void
{
    $search = trim($_GET['search'] ?? '');
    $sort = $_GET['sort'] ?? 'created_at';
    $order = strtoupper($_GET['order'] ?? 'DESC') === 'ASC' ? 'ASC' : 'DESC';
    $page = max(1, (int) ($_GET['page'] ?? 1));
    $perPage = min(500, max(1, (int) ($_GET['per_page'] ?? 500)));

    $sortMap = [
        'ProjectNumber' => 'p.project_number',
        'project_number' => 'p.project_number',
        'Name' => 'p.name',
        'name' => 'p.name',
        'Status' => 'p.status',
        'status' => 'p.status',
        'StartDate' => 'p.start_date',
        'start_date' => 'p.start_date',
        'EndDate' => 'p.end_date',
        'end_date' => 'p.end_date',
        'CreatedAt' => 'p.created_at',
        'created_at' => 'p.created_at',
    ];
    if (!isset($sortMap[$sort])) {
        errorResponse('Neplatný parametr řazení', 400);
    }
    $sortCol = $sortMap[$sort];

    $where = 'WHERE 1=1';
    $params = [];

    if ($search) {
        $search = mb_substr($search, 0, 100);
        $where .= ' AND (p.project_number LIKE ? OR p.name LIKE ? OR c.name LIKE ?)';
        $searchParam = "%{$search}%";
        $params = [$searchParam, $searchParam, $searchParam];
    }

    $countSql = "
        SELECT COUNT(*)
        FROM projects p
        LEFT JOIN customers c ON p.customer_id = c.id
        LEFT JOIN orders o ON p.order_id = o.id
        $where
    ";
    $stmt = $pdo->prepare($countSql);
    $stmt->execute($params);
    $total = (int) $stmt->fetchColumn();

    $offset = ($page - 1) * $perPage;

    $sql = "
        SELECT p.id, p.project_number, p.name, p.status, p.start_date, p.end_date,
               p.order_id, p.quotation_id, p.created_at,
               c.name as customer_name,
               o.order_number
        FROM projects p
        LEFT JOIN customers c ON p.customer_id = c.id
        LEFT JOIN orders o ON p.order_id = o.id
        $where
        ORDER BY $sortCol $order
        LIMIT $perPage OFFSET $offset
    ";

    $stmt = $pdo->prepare($sql);
    $stmt->execute($params);
    $projects = $stmt->fetchAll();

    successResponse([
        'projects' => $projects,
        'total' => $total,
        'page' => $page,
        'per_page' => $perPage,
    ]);
}

function handleGetDetail(PDO $pdo, int $id): void
{
    $stmt = $pdo->prepare('
        SELECT p.*,
               c.name as customer_name,
               o.order_number, o.status as order_status,
               q.quotation_number
        FROM projects p
        LEFT JOIN customers c ON p.customer_id = c.id
        LEFT JOIN orders o ON p.order_id = o.id
        LEFT JOIN quotations q ON p.quotation_id = q.id
        WHERE p.id = ?
    ');
    $stmt->execute([$id]);
    $project = $stmt->fetch();

    if (!$project) {
        errorResponse('Projekt nebyl nalezen', 404);
    }

    successResponse($project);
}

function handleUpdateProject(PDO $pdo, int $id): void
{
    $stmt = $pdo->prepare('SELECT * FROM projects WHERE id = ?');
    $stmt->execute([$id]);
    $project = $stmt->fetch();

    if (!$project) {
        errorResponse('Projekt nebyl nalezen', 404);
    }

    $input = getJsonInput();

    // Validace statusu
    if (isset($input['status'])) {
        $validStatuses = ['aktivni', 'dokonceny', 'zruseny'];
        if (!in_array($input['status'], $validStatuses)) {
            errorResponse('Neplatný stav projektu');
        }
    }

    // Validace dat
    if (
        isset($input['start_date'])
        && $input['start_date'] !== null // @phpstan-ignore notIdentical.alwaysTrue
        && !preg_match('/^\d{4}-\d{2}-\d{2}$/', $input['start_date'])
    ) {
        errorResponse('Neplatný formát data zahájení');
    }
    if (
        isset($input['end_date'])
        && $input['end_date'] !== null // @phpstan-ignore notIdentical.alwaysTrue
        && $input['end_date'] !== ''
        && !preg_match('/^\d{4}-\d{2}-\d{2}$/', $input['end_date'])
    ) {
        errorResponse('Neplatný formát data ukončení');
    }

    // Delkove limity
    $name = $input['name'] ?? $project['name'];
    if (mb_strlen($name) > 255) {
        errorResponse('Název projektu je příliš dlouhý (max 255 znaků)');
    }
    $notes = $input['notes'] ?? $project['notes'];
    if ($notes !== null && mb_strlen($notes) > 5000) {
        errorResponse('Poznámky jsou příliš dlouhé (max 5000 znaků)');
    }

    $pdo->beginTransaction();
    try {
        $stmt = $pdo->prepare('
            UPDATE projects SET
                name = ?,
                status = ?,
                start_date = ?,
                end_date = ?,
                notes = ?,
                modified_at = NOW()
            WHERE id = ?
        ');
        $stmt->execute([
            $name,
            $input['status'] ?? $project['status'],
            $input['start_date'] ?? $project['start_date'],
            $input['end_date'] ?? $project['end_date'],
            $notes,
            $id,
        ]);

        $pdo->commit();

        AuditLog::logUpdate(
            'projects_project',
            $id,
            ['name' => $project['name'], 'status' => $project['status']],
            ['name' => $input['name'] ?? $project['name'], 'status' => $input['status'] ?? $project['status']],
            "Upraven projekt '{$project['project_number']}'"
        );

        successResponse(null, 'Projekt byl aktualizován');
    } catch (PDOException $e) {
        $pdo->rollBack();
        throw $e;
    }
}

function handleGetNotes(PDO $pdo, int $projectId): void
{
    // Verify project exists
    $stmt = $pdo->prepare('SELECT id FROM projects WHERE id = ?');
    $stmt->execute([$projectId]);
    if (!$stmt->fetch()) {
        errorResponse('Projekt nebyl nalezen', 404);
    }

    $stmt = $pdo->prepare('
        SELECT id, project_id, user_id, user_name, content, created_at
        FROM project_notes
        WHERE project_id = ?
        ORDER BY created_at DESC
    ');
    $stmt->execute([$projectId]);
    $notes = $stmt->fetchAll();

    successResponse(['notes' => $notes]);
}

/** @param array<string, mixed> $authData */
function handleAddNote(PDO $pdo, int $projectId, array $authData): void
{
    // Verify project exists
    $stmt = $pdo->prepare('SELECT id FROM projects WHERE id = ?');
    $stmt->execute([$projectId]);
    if (!$stmt->fetch()) {
        errorResponse('Projekt nebyl nalezen', 404);
    }

    $input = getJsonInput();
    $content = trim($input['content'] ?? '');

    if (!$content) {
        errorResponse('Text poznámky je povinný');
    }

    if (mb_strlen($content) > 5000) {
        errorResponse('Poznámka je příliš dlouhá (max 5000 znaků)');
    }

    $userName = $authData['user']['full_name'] ?? $authData['user']['username'] ?? 'Neznámý';

    $stmt = $pdo->prepare('
        INSERT INTO project_notes (project_id, user_id, user_name, content, created_at)
        VALUES (?, ?, ?, ?, NOW())
    ');
    $stmt->execute([$projectId, $authData['user_id'], $userName, $content]);

    $noteId = (int)$pdo->lastInsertId();

    // Fetch the new note
    $stmt = $pdo->prepare(
        'SELECT id, project_id, user_id, user_name, content, created_at FROM project_notes WHERE id = ?'
    );
    $stmt->execute([$noteId]);
    $note = $stmt->fetch();

    successResponse(['note' => $note], 'Poznámka byla přidána');
}

/** @param array<string, mixed> $authData */
function handleDeleteNote(PDO $pdo, int $noteId, array $authData): void
{
    // Only admins can delete notes
    $isAdmin = $authData['user']['is_admin'] ?? false;
    if (!$isAdmin) {
        errorResponse('Pouze administrátoři mohou mazat poznámky', 403);
    }

    $stmt = $pdo->prepare('SELECT id, project_id, content FROM project_notes WHERE id = ?');
    $stmt->execute([$noteId]);
    $note = $stmt->fetch();

    if (!$note) {
        errorResponse('Poznámka nebyla nalezena', 404);
    }

    $stmt = $pdo->prepare('DELETE FROM project_notes WHERE id = ?');
    $stmt->execute([$noteId]);

    successResponse(null, 'Poznámka byla smazána');
}