<?php
declare(strict_types=1);

class TaskCertAuthContext
{
    private int $contactId;
    private int $masterMandantId;
    private int $currentMandantId;

    public function __construct(int $contactId, int $masterMandantId, int $currentMandantId)
    {
        $this->contactId = $contactId;
        $this->masterMandantId = $masterMandantId;
        $this->currentMandantId = $currentMandantId;
    }

    public static function fromGlobals(): self
    {
        $mainContact = self::asArray($GLOBALS['main_contact'] ?? ($_SESSION['main_contact'] ?? []));

        $contactId = self::firstPositiveInt([
            $mainContact['id'] ?? null,
            $mainContact['main_contact_id'] ?? null,
            $GLOBALS['main_contact_id'] ?? null,
            $_SESSION['main_contact_id'] ?? null,
            $GLOBALS['contact_id'] ?? null,
            $_SESSION['contact_id'] ?? null,
            $_SESSION['id'] ?? null,
        ]);

        $masterMandantId = self::firstPositiveInt([
            $mainContact['master_mandant_id'] ?? null,
            $mainContact['main_mandant_id'] ?? null,
            $mainContact['mandant_id'] ?? null,
            $GLOBALS['master_mandant_id'] ?? null,
            $_SESSION['master_mandant_id'] ?? null,
            $GLOBALS['main_mandant_id'] ?? null,
            $_SESSION['main_mandant_id'] ?? null,
            self::extractMandantId($GLOBALS['mandant'] ?? null),
            self::extractMandantId($_SESSION['mandant'] ?? null),
        ]);

        $currentMandantId = self::firstPositiveInt([
            $mainContact['current_mandant_id'] ?? null,
            $mainContact['main_mandant_id'] ?? null,
            $GLOBALS['current_mandant_id'] ?? null,
            $_SESSION['current_mandant_id'] ?? null,
            self::extractMandantId($GLOBALS['current_mandant'] ?? null),
            self::extractMandantId($_SESSION['current_mandant'] ?? null),
            self::extractMandantId($GLOBALS['mandant'] ?? null),
            self::extractMandantId($_SESSION['mandant'] ?? null),
        ]);

        if ($currentMandantId <= 0) {
            $currentMandantId = $masterMandantId;
        }

        if ($masterMandantId <= 0) {
            $masterMandantId = $currentMandantId;
        }

        return new self($contactId, $masterMandantId, $currentMandantId);
    }

    public function contactId(): int
    {
        return $this->contactId;
    }

    public function masterMandantId(): int
    {
        return $this->masterMandantId;
    }

    public function currentMandantId(): int
    {
        return $this->currentMandantId;
    }

    public function isLoggedIn(): bool
    {
        return $this->contactId > 0;
    }

    public function hasPermission(string $permissionKey): bool
    {
        if (!$this->isLoggedIn()) {
            TaskCertLogger::warning('Permission denied: no contact id in auth context', [
                'permission' => $permissionKey,
                'contact_id' => $this->contactId,
                'master_mandant_id' => $this->masterMandantId,
                'current_mandant_id' => $this->currentMandantId,
                'request_uri' => (string) ($_SERVER['REQUEST_URI'] ?? ''),
            ]);
            return false;
        }

        $mandantIds = [];
        if ($this->currentMandantId > 0) {
            $mandantIds[] = $this->currentMandantId;
        }

        if ($this->masterMandantId > 0 && !in_array($this->masterMandantId, $mandantIds, true)) {
            $mandantIds[] = $this->masterMandantId;
        }

        if ($mandantIds === []) {
            $mandantIds[] = 0;
        }

        $usedFallback = !function_exists('get_permission_state');
        $checkedStates = [];

        foreach ($mandantIds as $mandantId) {
            try {
                $state = $usedFallback
                    ? $this->getPermissionStateFallback($permissionKey, $mandantId)
                    : (int) get_permission_state($permissionKey, $mandantId, $this->contactId);
                $checkedStates[] = [
                    'mandant_id' => $mandantId,
                    'state' => $state,
                ];

                if ($state === 1) {
                    if ($usedFallback) {
                        TaskCertLogger::info('Permission granted via SQL fallback', [
                            'permission' => $permissionKey,
                            'contact_id' => $this->contactId,
                            'mandant_id' => $mandantId,
                        ]);
                    }
                    return true;
                }
            } catch (Throwable $throwable) {
                TaskCertLogger::error('Permission check failed', [
                    'permission' => $permissionKey,
                    'contact_id' => $this->contactId,
                    'mandant_id' => $mandantId,
                    'fallback_used' => $usedFallback ? 1 : 0,
                    'exception' => $throwable,
                ]);
            }
        }

        TaskCertLogger::warning('Permission denied after check', [
            'permission' => $permissionKey,
            'contact_id' => $this->contactId,
            'master_mandant_id' => $this->masterMandantId,
            'current_mandant_id' => $this->currentMandantId,
            'checked_mandant_ids' => $mandantIds,
            'checked_states' => $checkedStates,
            'fallback_used' => $usedFallback ? 1 : 0,
            'request_uri' => (string) ($_SERVER['REQUEST_URI'] ?? ''),
        ]);

        return false;
    }

    private static function asArray($value): array
    {
        if (!is_array($value)) {
            return [];
        }

        return $value;
    }

    private static function firstPositiveInt(array $values): int
    {
        foreach ($values as $value) {
            $intValue = (int) $value;
            if ($intValue > 0) {
                return $intValue;
            }
        }

        return 0;
    }

    private static function extractMandantId($value): int
    {
        if (!is_array($value)) {
            return 0;
        }

        return self::firstPositiveInt([
            $value['id'] ?? null,
            $value['main_mandant_id'] ?? null,
            $value['mandant_id'] ?? null,
        ]);
    }

    private function getPermissionStateFallback(string $permissionKey, int $mandantId): int
    {
        $conn = $GLOBALS['mysql_con'] ?? null;
        if (!($conn instanceof mysqli)) {
            throw new RuntimeException('Kein mysqli-Handle für Permission-Fallback verfügbar.');
        }

        $defaultState = 0;
        $permissionId = 0;

        $stmtPermission = $conn->prepare(
            'SELECT id, default_active FROM main_permission WHERE code = ? LIMIT 1'
        );
        if (!($stmtPermission instanceof mysqli_stmt)) {
            throw new RuntimeException('Statement für main_permission konnte nicht erstellt werden.');
        }

        $stmtPermission->bind_param('s', $permissionKey);
        $stmtPermission->execute();
        $resultPermission = $stmtPermission->get_result();
        if ($resultPermission instanceof mysqli_result) {
            $permission = $resultPermission->fetch_assoc();
            if (is_array($permission)) {
                $permissionId = (int) ($permission['id'] ?? 0);
                $defaultState = (int) ($permission['default_active'] ?? 0) === 1 ? 1 : 0;
            }
            $resultPermission->free();
        }
        $stmtPermission->close();

        if ($permissionId <= 0) {
            return 0;
        }

        $state = $defaultState;
        $stmtContact = $conn->prepare(
            'SELECT active FROM main_contact_permission
             WHERE main_contact_id = ? AND main_mandant_id = ? AND main_permission_id = ?
             LIMIT 1'
        );
        if (!($stmtContact instanceof mysqli_stmt)) {
            throw new RuntimeException('Statement für main_contact_permission konnte nicht erstellt werden.');
        }

        $contactId = $this->contactId;
        $stmtContact->bind_param('iii', $contactId, $mandantId, $permissionId);
        $stmtContact->execute();
        $resultContact = $stmtContact->get_result();
        if ($resultContact instanceof mysqli_result) {
            $contactPermission = $resultContact->fetch_assoc();
            if (is_array($contactPermission)) {
                $state = (int) ($contactPermission['active'] ?? 0) === 1 ? 1 : 0;
            }
            $resultContact->free();
        }
        $stmtContact->close();

        return $state;
    }
}