<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use App\Models\Branch;
use App\Models\AttendanceEmployee;
use Illuminate\Support\Facades\Log;

class AttendanceSyncController extends Controller
{
    public function sync(Request $request)
    {
        // 1. Verify API Key
        $apiKey = $request->header('X-API-Key') ?? $request->input('api_key');
        // You should store a master API key in your .env like ZKTECO_SYNC_KEY=xxx
        $validKey = env('ZKTECO_SYNC_KEY', 'default_secure_sync_key_123'); 
        
        if ($apiKey !== $validKey) {
            Log::warning('Unauthorized ZKTeco sync attempt', ['ip' => $request->ip()]);
            return response()->json(['error' => 'Unauthorized'], 401);
        }

        $branchId = $request->input('branch_id');
        $zktecoIp = $request->input('zkteco_ip');
        $attendances = $request->input('attendances', []);

        if (empty($attendances)) {
            return response()->json(['message' => 'No attendance records provided'], 400);
        }

        // 2. Find the branch
        $branchQuery = Branch::query();
        if ($branchId) {
            $branchQuery->where('id', $branchId);
        } elseif ($zktecoIp) {
            $branchQuery->where('zkteco_ip', $zktecoIp);
        } else {
            return response()->json(['error' => 'Must provide branch_id or zkteco_ip'], 400);
        }

        $branch = $branchQuery->first();

        if (!$branch) {
            return response()->json(['error' => 'Branch not found'], 404);
        }

        // 3. Process the logs into a standardized format for the dashboard
        $formattedAttendances = [];
        foreach ($attendances as $record) {
            $empCode = $record['deviceUserId'] ?? $record['id'] ?? null;
            $rawPunchTime = $record['recordTime'] ?? $record['timestamp'] ?? null;
            $punchTime = $this->parseDateSafe($rawPunchTime);
            $uid = $record['userSn'] ?? $record['uid'] ?? null;
            $type = $record['state'] ?? $record['type'] ?? 0;
            
            if ($empCode && $punchTime) {
                // We format it identically to how ZKTeco hardware outputs `$raw_attendance` 
                // so BiometricAttendanceController can process it natively.
                $formattedAttendances[] = [
                    'uid' => $uid,
                    'id' => (string) $empCode,
                    'timestamp' => $punchTime->toDateTimeString(), // Clean Y-m-d H:i:s format
                    'type' => $type
                ];
            }
        }

        // Save the formatted records to a JSON file cache for the branch
        if (!empty($formattedAttendances)) {
            $filePath = storage_path("app/biometric_cache_branch_{$branch->id}.json");
            
            // If the file exists, we merge the new records with the old ones, keeping only unique punches
            if (file_exists($filePath)) {
                $existing = json_decode(file_get_contents($filePath), true) ?? [];
                $merged = array_merge($existing, $formattedAttendances);
                
                // Remove exact duplicates by using a unique key
                $unique = collect($merged)->unique(function ($item) {
                    return $item['id'] . '_' . $item['timestamp'];
                })->values()->toArray();
                
                // Keep only the last 3000 records to prevent file bloat
                if (count($unique) > 3000) {
                    $unique = array_slice($unique, -3000);
                }
                
                file_put_contents($filePath, json_encode($unique));
            } else {
                file_put_contents($filePath, json_encode($formattedAttendances));
            }
        }

        $processed = count($formattedAttendances);

        return response()->json([
            'success' => true,
            'message' => "Successfully pushed {$processed} records to the Biometric Attendance waiting room for Branch {$branch->id}.",
        ]);
    }

    /**
     * Safely parse various date formats coming from ZKTeco devices or JS agents.
     */
    private function parseDateSafe($dateStr)
    {
        if (!$dateStr) {
            return null;
        }

        // Handle numeric timestamps (Unix seconds or milliseconds)
        if (is_numeric($dateStr)) {
            if (strlen((string)$dateStr) > 10) {
                // It's likely in milliseconds
                return \Carbon\Carbon::createFromTimestampMs($dateStr);
            }
            return \Carbon\Carbon::createFromTimestamp($dateStr);
        }

        // Remove JS-specific timezone names like "(China Standard Time)" to prevent Carbon parse errors
        $cleanDateStr = trim(explode('(', $dateStr)[0]);

        try {
            return \Carbon\Carbon::parse($cleanDateStr);
        } catch (\Exception $e) {
            return null;
        }
    }
}