<?php

declare(strict_types=1);

function handleGetCurrent(PDO $pdo, int $userId): void
{
    $today = date('Y-m-d');

    $stmt = $pdo->prepare("
        SELECT id, user_id, shift_date, arrival_time, arrival_lat, arrival_lng,
               arrival_accuracy, arrival_address, break_start, break_end,
               departure_time, departure_lat, departure_lng, departure_accuracy,
               departure_address, notes, project_id, leave_type, leave_hours, created_at
        FROM attendance
        WHERE user_id = ? AND departure_time IS NULL AND (leave_type IS NULL OR leave_type = 'work')
        ORDER BY created_at DESC LIMIT 1
    ");
    $stmt->execute([$userId]);
    $ongoingShift = $stmt->fetch();

    $projectLogs = [];
    $activeProjectId = null;
    if ($ongoingShift) {
        $stmt = $pdo->prepare(
            'SELECT id, attendance_id, project_id, started_at, ended_at, hours, minutes
            FROM attendance_project_logs WHERE attendance_id = ? ORDER BY started_at ASC'
        );
        $stmt->execute([$ongoingShift['id']]);
        $projectLogs = $stmt->fetchAll();
        foreach ($projectLogs as $log) {
            if ($log['ended_at'] === null) {
                $activeProjectId = (int)$log['project_id'];
                break;
            }
        }
    }

    $stmt = $pdo->prepare("
        SELECT id, user_id, shift_date, arrival_time, arrival_lat, arrival_lng,
               arrival_accuracy, arrival_address, break_start, break_end,
               departure_time, departure_lat, departure_lng, departure_accuracy,
               departure_address, notes, project_id, leave_type, leave_hours, created_at
        FROM attendance
        WHERE user_id = ? AND shift_date = ?
            AND departure_time IS NOT NULL
            AND (leave_type IS NULL OR leave_type = 'work')
        ORDER BY arrival_time DESC
    ");
    $stmt->execute([$userId, $today]);
    $todayShifts = $stmt->fetchAll();

    $completedShiftIds = array_column($todayShifts, 'id');
    $completedProjectLogs = [];
    if (!empty($completedShiftIds)) {
        $placeholders = implode(',', array_fill(0, count($completedShiftIds), '?'));
        $stmt = $pdo->prepare(
            "SELECT id, attendance_id, project_id, started_at, ended_at, hours, minutes
            FROM attendance_project_logs
            WHERE attendance_id IN ($placeholders)
            ORDER BY started_at ASC"
        );
        $stmt->execute($completedShiftIds);
        $allLogs = $stmt->fetchAll();
        foreach ($allLogs as $log) {
            $completedProjectLogs[$log['attendance_id']][] = $log;
        }
    }

    $leaveBalance = getLeaveBalance($pdo, $userId);

    $currentYear = (int)date('Y');
    $currentMonth = (int)date('m');
    $fund = CzechHolidays::getMonthlyWorkFund($currentYear, $currentMonth);
    $businessDays = CzechHolidays::getBusinessDaysInMonth($currentYear, $currentMonth);

    $startDate = date('Y-m-01');
    $endDate = date('Y-m-t');

    $stmt = $pdo->prepare('
        SELECT id, user_id, shift_date, arrival_time, break_start, break_end,
               departure_time, notes, project_id, leave_type, leave_hours
        FROM attendance
        WHERE user_id = ? AND shift_date BETWEEN ? AND ?
    ');
    $stmt->execute([$userId, $startDate, $endDate]);
    $monthRecords = $stmt->fetchAll();

    $workedMinutes = 0;
    $leaveHoursMonth = 0;
    $vacationHours = 0;
    $sickHours = 0;
    $holidayHours = 0;
    $unpaidHours = 0;
    foreach ($monthRecords as $rec) {
        $lt = $rec['leave_type'] ?? 'work';
        $lh = (float)($rec['leave_hours'] ?? 0);
        if ($lt === 'work') {
            if ($rec['departure_time']) {
                $workedMinutes += calculateWorkMinutes($rec);
            }
        } elseif ($lt === 'vacation') {
            $vacationHours += $lh;
            $leaveHoursMonth += $lh;
        } elseif ($lt === 'sick') {
            $sickHours += $lh;
            $leaveHoursMonth += $lh;
        } elseif ($lt === 'holiday') {
            $holidayHours += $lh;
        } elseif ($lt === 'unpaid') {
            $unpaidHours += $lh;
        }
    }

    $workedHours = round($workedMinutes / 60, 1);
    $covered = $workedHours + $leaveHoursMonth;
    $remaining = max(0, $fund - $covered);
    $overtime = max(0, round($covered - $fund, 1));

    $monthlyFund = [
        'fund' => $fund,
        'business_days' => $businessDays,
        'worked' => $workedHours,
        'leave_hours' => $leaveHoursMonth,
        'vacation_hours' => $vacationHours,
        'sick_hours' => $sickHours,
        'holiday_hours' => $holidayHours,
        'unpaid_hours' => $unpaidHours,
        'covered' => $covered,
        'remaining' => $remaining,
        'overtime' => $overtime,
        'month_name' => getCzechMonthName($currentMonth) . ' ' . $currentYear,
    ];

    // Enrich project logs with names
    $allLogProjectIds = [];
    foreach ($projectLogs as $l) {
        $allLogProjectIds[$l['project_id']] = $l['project_id'];
    }
    foreach ($completedProjectLogs as $logs) {
        foreach ($logs as $l) {
            $allLogProjectIds[$l['project_id']] = $l['project_id'];
        }
    }
    $projNameMap = fetchProjectNames($allLogProjectIds);

    foreach ($projectLogs as &$l) {
        $l['project_name'] = $projNameMap[$l['project_id']] ?? null;
    }
    unset($l);
    foreach ($completedProjectLogs as &$logs) {
        foreach ($logs as &$l) {
            $l['project_name'] = $projNameMap[$l['project_id']] ?? null;
        }
        unset($l);
    }
    unset($logs);

    foreach ($todayShifts as &$shift) {
        $shift['project_logs'] = $completedProjectLogs[$shift['id']] ?? [];
    }
    unset($shift);

    successResponse([
        'ongoing_shift' => $ongoingShift,
        'today_shifts' => $todayShifts,
        'date' => $today,
        'leave_balance' => $leaveBalance,
        'monthly_fund' => $monthlyFund,
        'project_logs' => $projectLogs,
        'active_project_id' => $activeProjectId,
    ]);
}

function handleGetHistory(PDO $pdo, int $userId): void
{
    $month = validateMonth();
    $year = (int)substr($month, 0, 4);
    $monthNum = (int)substr($month, 5, 2);

    $startDate = "{$month}-01";
    $endDate = date('Y-m-t', strtotime($startDate));

    $stmt = $pdo->prepare('
        SELECT id, user_id, shift_date, arrival_time, arrival_address,
               break_start, break_end, departure_time, departure_address,
               notes, project_id, leave_type, leave_hours, created_at
        FROM attendance
        WHERE user_id = ? AND shift_date BETWEEN ? AND ?
        ORDER BY shift_date DESC
    ');
    $stmt->execute([$userId, $startDate, $endDate]);
    $records = $stmt->fetchAll();

    enrichRecordsWithProjectLogs($pdo, $records);

    $totalMinutes = 0;
    $vacationHours = 0;
    $sickHours = 0;
    $holidayHours = 0;
    $unpaidHours = 0;

    foreach ($records as $record) {
        $leaveType = $record['leave_type'] ?? 'work';
        $leaveHours = (float)($record['leave_hours'] ?? 0);

        if ($leaveType === 'vacation') {
            $vacationHours += $leaveHours;
        } elseif ($leaveType === 'sick') {
            $sickHours += $leaveHours;
        } elseif ($leaveType === 'holiday') {
            $holidayHours += $leaveHours;
        } elseif ($leaveType === 'unpaid') {
            $unpaidHours += $leaveHours;
        } else {
            $totalMinutes += calculateWorkMinutes($record);
        }
    }

    $fund = CzechHolidays::getMonthlyWorkFund($year, $monthNum);
    $businessDays = CzechHolidays::getBusinessDaysInMonth($year, $monthNum);
    $workedHours = round($totalMinutes / 60, 1);
    $leaveHoursCovered = $vacationHours + $sickHours;
    $covered = $workedHours + $leaveHoursCovered;
    $remaining = max(0, round($fund - $covered, 1));
    $overtime = max(0, round($covered - $fund, 1));

    $leaveBalance = getLeaveBalance($pdo, $userId, $year);

    successResponse([
        'records' => $records,
        'month' => $month,
        'year' => $year,
        'month_name' => getCzechMonthName($monthNum) . ' ' . $year,
        'total_minutes' => $totalMinutes,
        'vacation_hours' => $vacationHours,
        'sick_hours' => $sickHours,
        'holiday_hours' => $holidayHours,
        'unpaid_hours' => $unpaidHours,
        'leave_balance' => $leaveBalance,
        'monthly_fund' => [
            'fund' => $fund,
            'business_days' => $businessDays,
            'worked' => $workedHours,
            'leave_hours' => $leaveHoursCovered,
            'covered' => $covered,
            'remaining' => $remaining,
            'overtime' => $overtime,
        ],
    ]);
}

function handlePunch(PDO $pdo, int $userId): void
{
    $input = getJsonInput();
    $action = $input['punch_action'] ?? '';
    $today = date('Y-m-d');
    $rawNow = date('Y-m-d H:i:s');

    $lat = isset($input['latitude']) && $input['latitude'] !== '' ? (float)$input['latitude'] : null;
    $lng = isset($input['longitude']) && $input['longitude'] !== '' ? (float)$input['longitude'] : null;
    $accuracy = isset($input['accuracy']) && $input['accuracy'] !== '' ? (float)$input['accuracy'] : null;
    $address = !empty($input['address']) ? $input['address'] : null;

    $stmt = $pdo->prepare("
        SELECT id, user_id, shift_date, arrival_time, break_start, break_end,
               departure_time, notes, project_id, leave_type, created_at
        FROM attendance
        WHERE user_id = ? AND departure_time IS NULL AND (leave_type IS NULL OR leave_type = 'work')
        ORDER BY created_at DESC LIMIT 1
    ");
    $stmt->execute([$userId]);
    $ongoingShift = $stmt->fetch();

    if ($action === 'arrival' && !$ongoingShift) {
        $now = roundUpTo15Minutes($rawNow);
        $stmt = $pdo->prepare('
            INSERT INTO attendance
                (user_id, shift_date, arrival_time, arrival_lat, arrival_lng, arrival_accuracy, arrival_address)
            VALUES (?, ?, ?, ?, ?, ?, ?)
        ');
        $stmt->execute([$userId, $today, $now, $lat, $lng, $accuracy, $address]);

        AuditLog::logCreate('attendance', (int)$pdo->lastInsertId(), [
            'arrival_time' => $now,
            'location' => $address,
        ], 'Příchod zaznamenán');

        successResponse(null, 'Příchod zaznamenán');
    } elseif ($ongoingShift) {
        switch ($action) {
            case 'break_start':
                if ($ongoingShift['arrival_time'] && !$ongoingShift['break_start']) {
                    $breakStart = roundToNearest10Minutes($rawNow);
                    $breakEnd = date('Y-m-d H:i:s', strtotime($breakStart) + (30 * 60));

                    $stmt = $pdo->prepare('UPDATE attendance SET break_start = ?, break_end = ? WHERE id = ?');
                    $stmt->execute([$breakStart, $breakEnd, $ongoingShift['id']]);

                    successResponse(null, 'Pauza zaznamenána');
                } else {
                    errorResponse('Nelze zadat pauzu');
                }
                break;

            case 'departure':
                if ($ongoingShift['arrival_time'] && !$ongoingShift['departure_time']) {
                    $now = roundDownTo15Minutes($rawNow);

                    // Auto-add break if shift is longer than 6h and no break
                    if (!$ongoingShift['break_start'] && !$ongoingShift['break_end']) {
                        $arrivalTime = strtotime($ongoingShift['arrival_time']);
                        $departureTime = strtotime($now);
                        $hoursWorked = ($departureTime - $arrivalTime) / 3600;

                        if ($hoursWorked > 12) {
                            $midPoint = $arrivalTime + (($departureTime - $arrivalTime) / 2);
                            $breakStart = roundToNearest10Minutes(date('Y-m-d H:i:s', $midPoint - (30 * 60)));
                            $breakEnd = roundToNearest10Minutes(date('Y-m-d H:i:s', $midPoint + (30 * 60)));

                            $stmt = $pdo->prepare('UPDATE attendance SET break_start = ?, break_end = ? WHERE id = ?');
                            $stmt->execute([$breakStart, $breakEnd, $ongoingShift['id']]);
                        } elseif ($hoursWorked > 6) {
                            $midPoint = $arrivalTime + (($departureTime - $arrivalTime) / 2);
                            $breakStart = roundToNearest10Minutes(date('Y-m-d H:i:s', $midPoint - (15 * 60)));
                            $breakEnd = roundToNearest10Minutes(date('Y-m-d H:i:s', $midPoint + (15 * 60)));

                            $stmt = $pdo->prepare('UPDATE attendance SET break_start = ?, break_end = ? WHERE id = ?');
                            $stmt->execute([$breakStart, $breakEnd, $ongoingShift['id']]);
                        }
                    }

                    $stmt = $pdo->prepare('
                        UPDATE attendance
                        SET departure_time = ?, departure_lat = ?, departure_lng = ?,
                            departure_accuracy = ?, departure_address = ?
                        WHERE id = ?
                    ');
                    $stmt->execute([$now, $lat, $lng, $accuracy, $address, $ongoingShift['id']]);

                    // Close any open project log
                    $stmt = $pdo->prepare('
                        UPDATE attendance_project_logs SET ended_at = ? WHERE attendance_id = ? AND ended_at IS NULL
                    ');
                    $stmt->execute([$now, $ongoingShift['id']]);

                    AuditLog::logUpdate('attendance', $ongoingShift['id'], [], [
                        'departure_time' => $now,
                        'location' => $address,
                    ], 'Odchod zaznamenán');

                    successResponse(null, 'Odchod zaznamenán');
                } else {
                    errorResponse('Nelze zadat odchod');
                }
                break;

            default:
                errorResponse('Neplatná akce');
        }
    } else {
        errorResponse('Neplatná akce - nemáte aktivní směnu');
    }
}

function handleUpdateAddress(PDO $pdo, int $userId): void
{
    $input = getJsonInput();
    $address = trim($input['address'] ?? '');
    $punchAction = $input['punch_action'] ?? '';

    if (!$address) {
        successResponse(null);
        return;
    }

    if ($punchAction === 'arrival') {
        $stmt = $pdo->prepare("
            UPDATE attendance SET arrival_address = ?
            WHERE id = (
                SELECT id FROM (
                    SELECT id FROM attendance
                    WHERE user_id = ? AND (arrival_address IS NULL OR arrival_address = '')
                    ORDER BY created_at DESC LIMIT 1
                ) t
            )
        ");
    } else {
        $stmt = $pdo->prepare("
            UPDATE attendance SET departure_address = ?
            WHERE id = (
                SELECT id FROM (
                    SELECT id FROM attendance
                    WHERE user_id = ? AND (departure_address IS NULL OR departure_address = '')
                      AND departure_time IS NOT NULL
                    ORDER BY created_at DESC LIMIT 1
                ) t
            )
        ");
    }
    $stmt->execute([$address, $userId]);

    successResponse(null);
}

function handleAddLeave(PDO $pdo, int $userId): void
{
    $input = getJsonInput();

    $leaveType = $input['leave_type'] ?? '';
    $leaveDate = $input['leave_date'] ?? '';
    $leaveHours = (float)($input['leave_hours'] ?? 8);
    $notes = trim($input['notes'] ?? '');

    if (!$leaveType || !$leaveDate || $leaveHours <= 0) {
        errorResponse('Vyplňte všechna povinná pole');
    }

    if (!in_array($leaveType, ['vacation', 'sick', 'unpaid'])) {
        errorResponse('Neplatný typ nepřítomnosti');
    }

    if ($leaveType === 'vacation') {
        $year = (int)date('Y', strtotime($leaveDate));
        $balance = getLeaveBalance($pdo, $userId, $year);

        if ($balance['vacation_remaining'] < $leaveHours) {
            errorResponse(
                "Nemáte dostatek hodin dovolené. Zbývá vám "
                . "{$balance['vacation_remaining']} hodin, požadujete {$leaveHours} hodin."
            );
        }
    }

    $stmt = $pdo->prepare('
        INSERT INTO attendance (user_id, shift_date, leave_type, leave_hours, notes)
        VALUES (?, ?, ?, ?, ?)
    ');
    $stmt->execute([$userId, $leaveDate, $leaveType, $leaveHours, $notes ?: null]);

    updateLeaveBalance($pdo, $userId, $leaveDate, $leaveType, $leaveHours);

    AuditLog::logCreate('attendance', (int)$pdo->lastInsertId(), [
        'leave_type' => $leaveType,
        'leave_hours' => $leaveHours,
    ], "Zaznamenána nepřítomnost: $leaveType");

    successResponse(null, 'Nepřítomnost byla zaznamenána');
}

function handleSaveNotes(PDO $pdo, int $userId): void
{
    $input = getJsonInput();
    $notes = trim($input['notes'] ?? '');

    $stmt = $pdo->prepare('
        SELECT id FROM attendance
        WHERE user_id = ? AND departure_time IS NULL
        ORDER BY created_at DESC LIMIT 1
    ');
    $stmt->execute([$userId]);
    $currentShift = $stmt->fetch();

    if (!$currentShift) {
        errorResponse('Nemáte aktivní směnu');
    }

    $stmt = $pdo->prepare('UPDATE attendance SET notes = ? WHERE id = ?');
    $stmt->execute([$notes, $currentShift['id']]);

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

function handleGetProjects(): void
{
    try {
        $pdo = db();
        $stmt = $pdo->query(
            "SELECT id, project_number, name FROM projects
            WHERE status = 'aktivni' ORDER BY project_number ASC"
        );
        $projects = $stmt->fetchAll();
        successResponse(['projects' => $projects]);
    } catch (\Exception $e) {
        error_log('Failed to fetch projects: ' . $e->getMessage());
        successResponse(['projects' => []]);
    }
}

function handleSwitchProject(PDO $pdo, int $userId): void
{
    $input = getJsonInput();
    /** @var mixed $rawProjectId */
    $rawProjectId = $input['project_id'] ?? null;
    $projectId = isset($input['project_id']) && $rawProjectId !== '' && $rawProjectId !== null
        ? (int)$rawProjectId
        : null;

    $stmt = $pdo->prepare("
        SELECT id FROM attendance
        WHERE user_id = ? AND departure_time IS NULL AND (leave_type IS NULL OR leave_type = 'work')
        ORDER BY created_at DESC LIMIT 1
    ");
    $stmt->execute([$userId]);
    $currentShift = $stmt->fetch();

    if (!$currentShift) {
        errorResponse('Nemáte aktivní směnu');
    }

    $attendanceId = $currentShift['id'];
    $now = date('Y-m-d H:i:s');

    $stmt = $pdo->prepare(
        'UPDATE attendance_project_logs SET ended_at = ?
        WHERE attendance_id = ? AND ended_at IS NULL'
    );
    $stmt->execute([$now, $attendanceId]);

    if ($projectId) {
        $stmt = $pdo->prepare(
            'INSERT INTO attendance_project_logs
                (attendance_id, project_id, started_at) VALUES (?, ?, ?)'
        );
        $stmt->execute([$attendanceId, $projectId, $now]);
    }

    $stmt = $pdo->prepare('UPDATE attendance SET project_id = ? WHERE id = ?');
    $stmt->execute([$projectId, $attendanceId]);

    successResponse(null, $projectId ? 'Projekt přepnut' : 'Projekt zastaven');
}

/** @param array<string, mixed> $authData */
function handleGetProjectLogs(PDO $pdo, int $currentUserId, array $authData): void
{
    $attendanceId = (int)($_GET['attendance_id'] ?? 0);
    if (!$attendanceId) {
        errorResponse('attendance_id je povinné');
    }

    // Ověření vlastnictví záznamu nebo admin oprávnění
    if (!hasPermission($authData, 'attendance.admin')) {
        $ownerStmt = $pdo->prepare('SELECT user_id FROM attendance WHERE id = ?');
        $ownerStmt->execute([$attendanceId]);
        $owner = $ownerStmt->fetch();
        if (!$owner || (int)$owner['user_id'] !== $currentUserId) {
            errorResponse('Nemáte oprávnění zobrazit tyto záznamy', 403);
        }
    }

    $stmt = $pdo->prepare(
        'SELECT id, attendance_id, project_id, started_at, ended_at, hours, minutes
        FROM attendance_project_logs WHERE attendance_id = ? ORDER BY started_at ASC'
    );
    $stmt->execute([$attendanceId]);
    $logs = $stmt->fetchAll();

    $projectIds = [];
    foreach ($logs as $l) {
        $projectIds[$l['project_id']] = $l['project_id'];
    }
    $projNameMap = fetchProjectNames($projectIds);
    foreach ($logs as &$l) {
        $l['project_name'] = $projNameMap[$l['project_id']] ?? null;
    }
    unset($l);

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

function handleSaveProjectLogs(PDO $pdo): void
{
    $input = getJsonInput();
    $attendanceId = (int)($input['attendance_id'] ?? 0);
    $logs = $input['project_logs'] ?? [];

    if (!$attendanceId) {
        errorResponse('attendance_id je povinné');
    }

    $stmt = $pdo->prepare('SELECT id FROM attendance WHERE id = ?');
    $stmt->execute([$attendanceId]);
    $record = $stmt->fetch();
    if (!$record) {
        errorResponse('Záznam nebyl nalezen', 404);
    }

    $stmt = $pdo->prepare('DELETE FROM attendance_project_logs WHERE attendance_id = ?');
    $stmt->execute([$attendanceId]);

    if (!empty($logs)) {
        $stmt = $pdo->prepare(
            'INSERT INTO attendance_project_logs
                (attendance_id, project_id, hours, minutes) VALUES (?, ?, ?, ?)'
        );
        foreach ($logs as $log) {
            $projectId = (int)($log['project_id'] ?? 0);
            if (!$projectId) {
                continue;
            }
            $h = (int)($log['hours'] ?? 0);
            $m = (int)($log['minutes'] ?? 0);
            if ($h === 0 && $m === 0) {
                continue;
            }
            $stmt->execute([$attendanceId, $projectId, $h, $m]);
        }
    }

    successResponse(null, 'Projektové záznamy byly uloženy');
}