<?php
// src/models/userModel.php

require_once PROJECT_ROOT . '/config/config.php';

class userModel
{
    /**
     * Retrieve all users (username + role).
     */
    public static function getAllUsers()
    {
        $usersFile = USERS_DIR . USERS_FILE;
        $users = [];
        if (file_exists($usersFile)) {
            $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
            foreach ($lines as $line) {
                $parts = explode(':', trim($line));
                if (count($parts) >= 3 && preg_match(REGEX_USER, $parts[0])) {
                    $users[] = [
                        "username" => $parts[0],
                        "role"     => trim($parts[2])
                    ];
                }
            }
        }
        return $users;
    }

    /**
     * Add a user.
     *
     * @param string $username
     * @param string $password
     * @param string $isAdmin   "1" or "0"
     * @param bool   $setupMode overwrite file if true
     */
    public static function addUser($username, $password, $isAdmin, $setupMode)
    {
        $usersFile = USERS_DIR . USERS_FILE;

        // Defense in depth
        if (!preg_match(REGEX_USER, $username)) {
            return ["error" => "Invalid username"];
        }
        if (!is_string($password) || $password === '') {
            return ["error" => "Password required"];
        }
        $isAdmin = $isAdmin === '1' ? '1' : '0';

        if (!file_exists($usersFile)) {
            @file_put_contents($usersFile, '', LOCK_EX);
        }

        // Check duplicates
        $existingUsers = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [];
        foreach ($existingUsers as $line) {
            $parts = explode(':', trim($line));
            if (isset($parts[0]) && $username === $parts[0]) {
                return ["error" => "User already exists"];
            }
        }

        $hashedPassword = password_hash($password, PASSWORD_BCRYPT);
        $newUserLine    = $username . ":" . $hashedPassword . ":" . $isAdmin . PHP_EOL;

        if ($setupMode) {
            if (file_put_contents($usersFile, $newUserLine, LOCK_EX) === false) {
                return ["error" => "Failed to write users file"];
            }
        } else {
            if (file_put_contents($usersFile, $newUserLine, FILE_APPEND | LOCK_EX) === false) {
                return ["error" => "Failed to write users file"];
            }
        }

        return ["success" => "User added successfully"];
    }

    /**
     * Remove a user and update encrypted userPermissions.json.
     */
    public static function removeUser($usernameToRemove)
{
    global $encryptionKey;

    if (!preg_match(REGEX_USER, $usernameToRemove)) {
        return ["error" => "Invalid username"];
    }

    $usersFile = USERS_DIR . USERS_FILE;
    if (!file_exists($usersFile)) {
        return ["error" => "Users file not found"];
    }

    $existingUsers = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [];
    $newUsers = [];
    $userFound = false;

    foreach ($existingUsers as $line) {
        $parts = explode(':', trim($line));
        if (count($parts) < 3) {
            continue;
        }
        if (strcasecmp($parts[0], $usernameToRemove) === 0) {
            $userFound = true;
            continue; // skip this user
        }
        $newUsers[] = $line;
    }

    if (!$userFound) {
        return ["error" => "User not found"];
    }

    $newContent = $newUsers ? (implode(PHP_EOL, $newUsers) . PHP_EOL) : '';
    if (file_put_contents($usersFile, $newContent, LOCK_EX) === false) {
        return ["error" => "Failed to update users file"];
    }

    // Update encrypted userPermissions.json — remove any key matching case-insensitively
    $permissionsFile = USERS_DIR . "userPermissions.json";
    if (file_exists($permissionsFile)) {
        $raw = file_get_contents($permissionsFile);
        $decrypted = decryptData($raw, $encryptionKey);
        $permissionsArray = $decrypted !== false
            ? json_decode($decrypted, true)
            : (json_decode($raw, true) ?: []); // tolerate legacy plaintext

        if (is_array($permissionsArray)) {
            foreach (array_keys($permissionsArray) as $k) {
                if (strcasecmp($k, $usernameToRemove) === 0) {
                    unset($permissionsArray[$k]);
                }
            }
            $plain = json_encode($permissionsArray, JSON_PRETTY_PRINT);
            $enc   = encryptData($plain, $encryptionKey);
            file_put_contents($permissionsFile, $enc, LOCK_EX);
        }
    }

    // Purge from ACL (remove from every bucket in every folder)
    require_once PROJECT_ROOT . '/src/lib/ACL.php';
    if (method_exists('ACL', 'purgeUser')) {
        ACL::purgeUser($usernameToRemove);
    } else {
        // Fallback inline purge if you haven't added ACL::purgeUser yet:
        $aclPath = rtrim(META_DIR, '/\\') . DIRECTORY_SEPARATOR . 'folder_acl.json';
        $acl = is_file($aclPath) ? json_decode((string)file_get_contents($aclPath), true) : [];
        if (!is_array($acl)) $acl = ['folders' => [], 'groups' => []];
        $buckets = ['owners','read','write','share','read_own'];

        $changed = false;
        foreach ($acl['folders'] ?? [] as $f => &$rec) {
            foreach ($buckets as $b) {
                if (!isset($rec[$b]) || !is_array($rec[$b])) { $rec[$b] = []; continue; }
                $before = $rec[$b];
                $rec[$b] = array_values(array_filter($rec[$b], fn($u) => strcasecmp((string)$u, $usernameToRemove) !== 0));
                if ($rec[$b] !== $before) $changed = true;
            }
        }
        unset($rec);

        if ($changed) {
            @file_put_contents($aclPath, json_encode($acl, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES), LOCK_EX);
        }
    }

    return ["success" => "User removed successfully"];
}

    /**
     * Get permissions for current user (or all, if admin).
     */
    public static function getUserPermissions()
    {
        global $encryptionKey;
        $permissionsFile = USERS_DIR . "userPermissions.json";
        $permissionsArray = [];

        if (file_exists($permissionsFile)) {
            $content = file_get_contents($permissionsFile);
            $decrypted = decryptData($content, $encryptionKey);
            if ($decrypted === false) {
                // tolerate legacy plaintext
                $permissionsArray = json_decode($content, true);
            } else {
                $permissionsArray = json_decode($decrypted, true);
            }
            if (!is_array($permissionsArray)) {
                $permissionsArray = [];
            }
        }

        if (!empty($_SESSION['isAdmin'])) {
            return $permissionsArray;
        }

        $username = $_SESSION['username'] ?? '';
        foreach ($permissionsArray as $storedUsername => $data) {
            if (strcasecmp($storedUsername, $username) === 0) {
                return $data;
            }
        }

        return new stdClass();
    }

    /**
     * Update permissions (encrypted on disk). Skips admins.
     */
    public static function updateUserPermissions($permissions)
{
    global $encryptionKey;
    $permissionsFile = USERS_DIR . "userPermissions.json";
    $existingPermissions = [];

    // Load existing (decrypt if needed)
    if (file_exists($permissionsFile)) {
        $encryptedContent = file_get_contents($permissionsFile);
        $json = decryptData($encryptedContent, $encryptionKey);
        if ($json === false) $json = $encryptedContent; // legacy plaintext
        $existingPermissions = json_decode($json, true) ?: [];
    }

    // Load roles to skip admins
    $usersFile = USERS_DIR . USERS_FILE;
    $userRoles = [];
    if (file_exists($usersFile)) {
        foreach (file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) as $line) {
            $parts = explode(':', trim($line));
            if (count($parts) >= 3 && preg_match(REGEX_USER, $parts[0])) {
                $userRoles[strtolower($parts[0])] = trim($parts[2]);
            }
        }
    }

    $knownKeys = [
        'folderOnly','readOnly','disableUpload',
        'bypassOwnership','canShare','canZip','viewOwnOnly'
    ];

    // Build a map of lowercase->actual key to update existing entries case-insensitively
    $lcIndex = [];
    foreach ($existingPermissions as $k => $_) {
        $lcIndex[strtolower($k)] = $k;
    }

    foreach ($permissions as $perm) {
        if (empty($perm['username'])) continue;

        $unameOrig = (string)$perm['username'];             // preserve original case
        $unameLc   = strtolower($unameOrig);
        $role      = $userRoles[$unameLc] ?? null;
        if ($role === "1") continue; // skip admins

        // Find existing key case-insensitively; otherwise use original case as canonical
        $storeKey = $lcIndex[$unameLc] ?? $unameOrig;

        $current = $existingPermissions[$storeKey] ?? [];
        foreach ($knownKeys as $k) {
            if (array_key_exists($k, $perm)) {
                $current[$k] = (bool)$perm[$k];
            } elseif (!isset($current[$k])) {
                $current[$k] = false;
            }
        }

        $existingPermissions[$storeKey] = $current;
        $lcIndex[$unameLc] = $storeKey; // keep index up to date
    }

    $plain = json_encode($existingPermissions, JSON_PRETTY_PRINT);
    $encrypted = encryptData($plain, $encryptionKey);
    if (file_put_contents($permissionsFile, $encrypted) === false) {
        return ["error" => "Failed to save user permissions."];
    }
    return ["success" => "User permissions updated successfully."];
}

    /**
     * Change password (preserve TOTP + extra fields).
     */
    public static function changePassword($username, $oldPassword, $newPassword)
    {
        if (!preg_match(REGEX_USER, $username)) {
            return ["error" => "Invalid username"];
        }

        $usersFile = USERS_DIR . USERS_FILE;
        if (!file_exists($usersFile)) {
            return ["error" => "Users file not found"];
        }

        $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [];
        $userFound = false;
        $newLines = [];

        foreach ($lines as $line) {
            $parts = explode(':', trim($line));
            if (count($parts) < 3) {
                $newLines[] = $line;
                continue;
            }
            $storedUser = $parts[0];
            $storedHash = $parts[1];

            if ($storedUser === $username) {
                $userFound = true;
                if (!password_verify($oldPassword, $storedHash)) {
                    return ["error" => "Old password is incorrect."];
                }
                $parts[1] = password_hash($newPassword, PASSWORD_BCRYPT);
                $newLines[] = implode(':', $parts);
            } else {
                $newLines[] = $line;
            }
        }

        if (!$userFound) {
            return ["error" => "User not found."];
        }

        $payload = implode(PHP_EOL, $newLines) . PHP_EOL;
        if (file_put_contents($usersFile, $payload, LOCK_EX) === false) {
            return ["error" => "Could not update password."];
        }

        return ["success" => "Password updated successfully."];
    }

    /**
     * Update panel: if TOTP disabled, clear secret.
     */
    public static function updateUserPanel($username, $totp_enabled)
    {
        if (!preg_match(REGEX_USER, $username)) {
            return ["error" => "Invalid username"];
        }

        $usersFile = USERS_DIR . USERS_FILE;
        if (!file_exists($usersFile)) {
            return ["error" => "Users file not found"];
        }

        if (!$totp_enabled) {
            $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [];
            $newLines = [];

            foreach ($lines as $line) {
                $parts = explode(':', trim($line));
                if (count($parts) < 3) {
                    $newLines[] = $line;
                    continue;
                }
                if ($parts[0] === $username) {
                    while (count($parts) < 4) {
                        $parts[] = "";
                    }
                    $parts[3] = "";
                    $newLines[] = implode(':', $parts);
                } else {
                    $newLines[] = $line;
                }
            }

            if (file_put_contents($usersFile, implode(PHP_EOL, $newLines) . PHP_EOL, LOCK_EX) === false) {
                return ["error" => "Failed to disable TOTP secret"];
            }
            return ["success" => "User panel updated: TOTP disabled"];
        }

        return ["success" => "User panel updated: TOTP remains enabled"];
    }

    /**
     * Clear TOTP secret.
     */
    public static function disableTOTPSecret($username)
    {
        $usersFile = USERS_DIR . USERS_FILE;
        if (!file_exists($usersFile)) {
            return false;
        }
        $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [];
        $modified = false;
        $newLines = [];

        foreach ($lines as $line) {
            $parts = explode(':', trim($line));
            if (count($parts) < 3) {
                $newLines[] = $line;
                continue;
            }
            if ($parts[0] === $username) {
                while (count($parts) < 4) {
                    $parts[] = "";
                }
                $parts[3] = "";
                $modified = true;
                $newLines[] = implode(":", $parts);
            } else {
                $newLines[] = $line;
            }
        }

        if ($modified) {
            return file_put_contents($usersFile, implode(PHP_EOL, $newLines) . PHP_EOL, LOCK_EX) !== false;
        }
        return $modified;
    }

    /**
     * Recover via recovery code.
     */
    public static function recoverTOTP($userId, $recoveryCode)
    {
        // Rate limit storage
        $attemptsFile = rtrim(USERS_DIR, '/\\') . '/recovery_attempts.json';
        $attempts = is_file($attemptsFile) ? (json_decode(@file_get_contents($attemptsFile), true) ?: []) : [];
        $key = ($_SERVER['REMOTE_ADDR'] ?? '0.0.0.0') . '|' . $userId;
        $now = time();

        if (isset($attempts[$key])) {
            $attempts[$key] = array_values(array_filter($attempts[$key], fn($ts) => $ts > $now - 900));
        }
        if (count($attempts[$key] ?? []) >= 5) {
            return ['status' => 'error', 'message' => 'Too many attempts. Try again later.'];
        }

        // User JSON file
        $userFile = rtrim(USERS_DIR, '/\\') . DIRECTORY_SEPARATOR . $userId . '.json';
        if (!file_exists($userFile)) {
            return ['status' => 'error', 'message' => 'User not found'];
        }

        $fp = fopen($userFile, 'c+');
        if (!$fp || !flock($fp, LOCK_EX)) {
            if ($fp) fclose($fp);
            return ['status' => 'error', 'message' => 'Server error'];
        }

        $fileContents = stream_get_contents($fp);
        $data = json_decode($fileContents, true) ?: [];

        if (empty($recoveryCode)) {
            flock($fp, LOCK_UN);
            fclose($fp);
            return ['status' => 'error', 'message' => 'Recovery code required'];
        }

        $storedHash = $data['totp_recovery_code'] ?? null;
        if (!$storedHash || !password_verify($recoveryCode, $storedHash)) {
            // record failed attempt
            $attempts[$key][] = $now;
            @file_put_contents($attemptsFile, json_encode($attempts, JSON_PRETTY_PRINT), LOCK_EX);
            flock($fp, LOCK_UN);
            fclose($fp);
            return ['status' => 'error', 'message' => 'Invalid recovery code'];
        }

        // Invalidate code
        $data['totp_recovery_code'] = null;
        rewind($fp);
        ftruncate($fp, 0);
        fwrite($fp, json_encode($data, JSON_PRETTY_PRINT));
        fflush($fp);
        flock($fp, LOCK_UN);
        fclose($fp);

        return ['status' => 'ok'];
    }

    /**
     * Generate random recovery code.
     */
    private static function generateRecoveryCode($length = 12)
    {
        $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
        $max   = strlen($chars) - 1;
        $code  = '';
        for ($i = 0; $i < $length; $i++) {
            $code .= $chars[random_int(0, $max)];
        }
        return $code;
    }

    /**
     * Save new TOTP recovery code (hash on disk) and return plaintext to caller.
     */
    public static function saveTOTPRecoveryCode($userId)
    {
        $userFile = rtrim(USERS_DIR, '/\\') . DIRECTORY_SEPARATOR . $userId . '.json';

        if (!file_exists($userFile)) {
            if (file_put_contents($userFile, json_encode([], JSON_PRETTY_PRINT), LOCK_EX) === false) {
                return ['status' => 'error', 'message' => 'Server error: could not create user file'];
            }
        }

        $recoveryCode = self::generateRecoveryCode();
        $recoveryHash = password_hash($recoveryCode, PASSWORD_DEFAULT);

        $fp = fopen($userFile, 'c+');
        if (!$fp || !flock($fp, LOCK_EX)) {
            if ($fp) fclose($fp);
            return ['status' => 'error', 'message' => 'Server error: could not lock user file'];
        }

        $contents = stream_get_contents($fp);
        $data = json_decode($contents, true) ?: [];
        $data['totp_recovery_code'] = $recoveryHash;

        rewind($fp);
        ftruncate($fp, 0);
        fwrite($fp, json_encode($data, JSON_PRETTY_PRINT));
        fflush($fp);
        flock($fp, LOCK_UN);
        fclose($fp);

        return ['status' => 'ok', 'recoveryCode' => $recoveryCode];
    }

    /**
     * Setup TOTP & build QR PNG.
     */
    public static function setupTOTP($username)
    {
        global $encryptionKey;
        $usersFile = USERS_DIR . USERS_FILE;

        if (!file_exists($usersFile)) {
            return ['error' => 'Users file not found'];
        }

        $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [];
        $totpSecret = null;

        foreach ($lines as $line) {
            $parts = explode(':', trim($line));
            if (count($parts) >= 4 && $parts[0] === $username && !empty($parts[3])) {
                $totpSecret = decryptData($parts[3], $encryptionKey);
                break;
            }
        }

        $tfa = new \RobThree\Auth\TwoFactorAuth(
            new \RobThree\Auth\Providers\Qr\GoogleChartsQrCodeProvider(),
            'FileRise',
            6,
            30,
            \RobThree\Auth\Algorithm::Sha1
        );

        if (!$totpSecret) {
            $totpSecret = $tfa->createSecret();
            $encryptedSecret = encryptData($totpSecret, $encryptionKey);

            $newLines = [];
            foreach ($lines as $line) {
                $parts = explode(':', trim($line));
                if (count($parts) >= 3 && $parts[0] === $username) {
                    if (count($parts) >= 4) {
                        $parts[3] = $encryptedSecret;
                    } else {
                        $parts[] = $encryptedSecret;
                    }
                    $newLines[] = implode(':', $parts);
                } else {
                    $newLines[] = $line;
                }
            }
            file_put_contents($usersFile, implode(PHP_EOL, $newLines) . PHP_EOL, LOCK_EX);
        }

        // Prefer admin-configured otpauth template if present
        $adminConfigFile = USERS_DIR . 'adminConfig.json';
        $globalOtpauthUrl = "";
        if (file_exists($adminConfigFile)) {
            $encryptedContent = file_get_contents($adminConfigFile);
            $decryptedContent = decryptData($encryptedContent, $encryptionKey);
            if ($decryptedContent !== false) {
                $config = json_decode($decryptedContent, true);
                if (!empty($config['globalOtpauthUrl'])) {
                    $globalOtpauthUrl = $config['globalOtpauthUrl'];
                }
            }
        }

        if (!empty($globalOtpauthUrl)) {
            $label = "FileRise:" . $username;
            $otpauthUrl = str_replace(
                ["{label}", "{secret}"],
                [urlencode($label), $totpSecret],
                $globalOtpauthUrl
            );
        } else {
            $label  = urlencode("FileRise:" . $username);
            $issuer = urlencode("FileRise");
            $otpauthUrl = "otpauth://totp/{$label}?secret={$totpSecret}&issuer={$issuer}";
        }

        $result = \Endroid\QrCode\Builder\Builder::create()
            ->writer(new \Endroid\QrCode\Writer\PngWriter())
            ->data($otpauthUrl)
            ->build();

        return [
            'imageData' => $result->getString(),
            'mimeType'  => $result->getMimeType()
        ];
    }

    /**
     * Get decrypted TOTP secret.
     */
    public static function getTOTPSecret($username)
    {
        global $encryptionKey;
        $usersFile = USERS_DIR . USERS_FILE;
        if (!file_exists($usersFile)) {
            return null;
        }
        $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [];
        foreach ($lines as $line) {
            $parts = explode(':', trim($line));
            if (count($parts) >= 4 && $parts[0] === $username && !empty($parts[3])) {
                return decryptData($parts[3], $encryptionKey);
            }
        }
        return null;
    }

    /**
     * Get role ('1' admin, '0' user) or null.
     */
    public static function getUserRole($username)
    {
        $usersFile = USERS_DIR . USERS_FILE;
        if (!file_exists($usersFile)) {
            return null;
        }
        foreach (file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) as $line) {
            $parts = explode(':', trim($line));
            if (count($parts) >= 3 && $parts[0] === $username) {
                return trim($parts[2]);
            }
        }
        return null;
    }

    /**
     * Get a single user’s info (admin flag, TOTP status, profile picture).
     */
    public static function getUser(string $username): array
    {
        $usersFile = USERS_DIR . USERS_FILE;
        if (!file_exists($usersFile)) {
            return [];
        }

        foreach (file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) as $line) {
            $parts = explode(':', $line);
            if ($parts[0] !== $username) {
                continue;
            }
            $isAdmin     = (isset($parts[2]) && $parts[2] === '1');
            $totpEnabled = !empty($parts[3]);
            $pic         = isset($parts[4]) ? $parts[4] : '';

            // Normalize to a leading slash (UI expects /uploads/…)
            if ($pic !== '' && $pic[0] !== '/') {
                $pic = '/' . $pic;
            }

            return [
                'username'        => $parts[0],
                'isAdmin'         => $isAdmin,
                'totp_enabled'    => $totpEnabled,
                'profile_picture' => $pic,
            ];
        }

        return [];
    }

    /**
     * Persist profile picture URL as 5th field (keeps TOTP secret intact).
     *
     * users.txt: username:hash:isAdmin:totp_secret:profile_picture
     */
    public static function setProfilePicture(string $username, string $url): array
    {
        $usersFile = USERS_DIR . USERS_FILE;
        if (!file_exists($usersFile)) {
            return ['success' => false, 'error' => 'Users file not found'];
        }

        // Ensure leading slash (consistent with controller response)
        $url = '/' . ltrim($url, '/');

        $lines = file($usersFile, FILE_IGNORE_NEW_LINES) ?: [];
        $out   = [];
        $found = false;

        foreach ($lines as $line) {
            if ($line === '') { $out[] = $line; continue; }
            $parts = explode(':', $line);
            if ($parts[0] === $username) {
                $found = true;
                while (count($parts) < 5) {
                    $parts[] = '';
                }
                $parts[4] = $url;
                $line = implode(':', $parts);
            }
            $out[] = $line;
        }

        if (!$found) {
            return ['success' => false, 'error' => 'User not found'];
        }

        $newContent = implode(PHP_EOL, $out) . PHP_EOL;
        if (file_put_contents($usersFile, $newContent, LOCK_EX) === false) {
            return ['success' => false, 'error' => 'Failed to write users file'];
        }

        return ['success' => true];
    }
}