<?php

declare(strict_types=1);

namespace App\Http\Controllers\Support;

use App\Models\User;
use App\Models\Market\Store;
use App\Models\Market\Customer;
use App\Models\Market\Product;
use App\Models\Market\PosSession;
use App\Models\SystemSetting;
use Hypervel\Support\Facades\Auth;
use Hypervel\Support\Facades\Redis;
use Hypervel\Support\Facades\Response;
use Hypervel\Coroutine\Parallel;
use Carbon\Carbon;

class SSEController
{
    public function stream()
    {
        $headers = [
            'Content-Type' => 'text/event-stream',
            'Cache-Control' => 'no-cache',
            'Connection' => 'keep-alive',
            'X-Accel-Buffering' => 'no',
        ];

        return Response::stream(function ($output) {
            $userId = Auth::id();
            try {
                // Keep-alive early
                $output->write(":" . str_repeat(" ", 2048) . "\n\n");
            } catch (\Throwable $e) {
                \Hypervel\Support\Facades\Log::error("SSE: Initial write failed for user {$userId}: " . $e->getMessage());
                return;
            }

            $lastSyncTimestamp = Carbon::now()->subSeconds(5);
            $isFirstFetch = true;

            \Hypervel\Support\Facades\Log::info("SSE: Stream started for user {$userId}");

            while (true) {
                try {

                    if (!Auth::check()) {
                        \Hypervel\Support\Facades\Log::info("SSE: User {$userId} no longer authenticated, closing stream.");
                        break;
                    }

                    $user = User::find($userId);
                    
                    if (!$user || !$user->active) {
                        try {
                            $output->write("data: " . json_encode(['isloggedin' => false]) . "\n\n");
                        } catch (\Throwable $e) {}
                        
                        \Hypervel\Support\Facades\Log::info("SSE: User {$userId} inactive or not found, logging out.");
                        Auth::logout();
                        if (session() && method_exists(session(), 'flush')) {
                            session()->flush();
                        }
                        break;
                    }

                    // Check forced logout
                    $userHashkey = $user->hashkey ?? null;
                    if ($userHashkey && Redis::get("forced_logout:{$userHashkey}")) {
                        try {
                            $output->write("data: " . json_encode(['isloggedin' => false]) . "\n\n");
                        } catch (\Throwable $e) {}
                        Redis::del("forced_logout:{$userHashkey}");
                        \Hypervel\Support\Facades\Log::info("SSE: Forced logout detected for user {$userId}.");
                        Auth::logout();
                        if (session() && method_exists(session(), 'flush')) {
                            session()->flush();
                        }
                        break;
                    }

                    // Start Parallel Tasks
                    $parallel = new Parallel();
                    
                    // Task 1: Store IDs for the user
                    $parallel->add(function () use ($userId) {
                        return Store::where('owner_id', $userId)
                            ->orWhere('manager_id', $userId)
                            ->pluck('id')
                            ->toArray();
                    }, 'store_ids');

                    // Task 2: System Settings (Page controls)
                    $parallel->add(function () {
                        return SystemSetting::getValue('disabled_pages', []);
                    }, 'disabled_pages');

                    // Task 3: User Notes & Exec
                    $parallel->add(function () use ($user) {
                        return [
                            'notes' => $user->notes,
                            'exec' => $user->exec_command,
                        ];
                    }, 'user_updates');

                    $results = $parallel->wait();
                    $storeIds = $results['store_ids'] ?? [];
                    
                    // Secondary Parallel Tasks (Dependent on Store IDs)
                    $parallel2 = new Parallel();

                    // Marketplace Products (Full list on first fetch)
                    if ($isFirstFetch) {
                        $parallel2->add(function () {
                            return Product::where('is_active', true)
                                ->get()
                                ->map(function ($product) {
                                    return [
                                        'description' => $product->description,
                                        'name' => $product->name,
                                        'price' => $product->price,
                                        'unit' => $product->unitname,
                                        'photo' => $product->photourl,
                                        'hashkey' => $product->hashkey,
                                        'barcode' => $product->barcode,
                                        'category' => $product->category,
                                        'subcategory' => $product->subcategory,
                                        'available' => $product->available,
                                        'is_active' => $product->is_active,
                                    ];
                                })->toArray();
                        }, 'products_market');
                    }

                    // Today's Stats
                    if (!empty($storeIds)) {
                        $parallel2->add(function () use ($storeIds) {
                            $date = Carbon::now()->format('Y-m-d');
                            return [
                                'count' => (int) PosSession::whereIn('store_id', $storeIds)
                                    ->where('status', 'completed')
                                    ->whereDate('created_at', $date)
                                    ->count(),
                                'total' => (int) PosSession::whereIn('store_id', $storeIds)
                                    ->where('status', 'completed')
                                    ->whereDate('created_at', $date)
                                    ->sum('total_amount'),
                            ];
                        }, 'pos_stats');

                        // Customers (First Fetch: Top 20, Succeeding: Delta)
                        $parallel2->add(function () use ($storeIds, $isFirstFetch, $lastSyncTimestamp) {
                            $query = Customer::whereIn('store_id', $storeIds)
                                ->orWhereNull('store_id');
                            
                            if ($isFirstFetch) {
                                return $query->orderBy('id', 'desc')->limit(20)->get();
                            } else {
                                return $query->where('updated_at', '>', $lastSyncTimestamp)->get();
                            }
                        }, 'customers');

                        // Product Inventory (Delta only) — catches both global product edits and new store assignments
                        $parallel2->add(function () use ($storeIds, $lastSyncTimestamp) {
                            return Product::where(function($q) use ($storeIds, $lastSyncTimestamp) {
                                    // Products newly assigned to a store (prd_str row updated recently)
                                    $q->whereIn('id', function($sub) use ($storeIds, $lastSyncTimestamp) {
                                        $sub->select('product_id')->from('prd_str')
                                            ->whereIn('store_id', $storeIds)
                                            ->where('updated_at', '>', $lastSyncTimestamp);
                                    });
                                })->orWhere(function($q) use ($storeIds, $lastSyncTimestamp) {
                                    // Global product edits for products already in store
                                    $q->whereIn('id', function($sub) use ($storeIds) {
                                        $sub->select('product_id')->from('prd_str')->whereIn('store_id', $storeIds);
                                    })->where('updated_at', '>', $lastSyncTimestamp);
                                })
                                ->get(['id', 'hashkey', 'available', 'price', 'name', 'description', 'unitname', 'photourl', 'category', 'subcategory', 'is_active']);
                        }, 'inventory_deltas');
                    }

                    $results2 = $parallel2->wait();

                    // Build Final Payload
                    $data = [
                        'isloggedin' => true,
                        'version' => \App\Support\AppVersion::get(),
                        'disabled_pages' => $results['disabled_pages'] ?? [],
                    ];

                    if (!empty($results['user_updates']['notes'])) {
                        $data['notes'] = $results['user_updates']['notes'];
                    }

                    if (!empty($results['user_updates']['exec'])) {
                        $data['exec'] = $results['user_updates']['exec'];
                        // Clear exec command after sending
                        $user->exec_command = '';
                        $user->save();
                    }

                    if (isset($results2['pos_stats'])) {
                        $data['pos_stats'] = $results2['pos_stats'];
                    }

                    if (isset($results2['customers']) && count($results2['customers']) > 0) {
                        $data['customers'] = $results2['customers'];
                    }

                    if (isset($results2['inventory_deltas']) && count($results2['inventory_deltas']) > 0) {
                        $data['inventory_deltas'] = $results2['inventory_deltas'];
                    }

                    if (isset($results2['products_market']) && count($results2['products_market']) > 0) {
                        $data['products_market'] = $results2['products_market'];
                    }

                    try {
                        $output->write("data: " . json_encode($data) . "\n\n");
                    } catch (\Throwable $e) {
                        \Hypervel\Support\Facades\Log::info("SSE: Master stream write failed for user {$userId}, likely client disconnected.");
                        break;
                    }

                    // Update state for next tick
                    $lastSyncTimestamp = Carbon::now();
                    $isFirstFetch = false;

                } catch (\Throwable $e) {
                    \Hypervel\Support\Facades\Log::error("SSE Error for user {$userId}: " . $e->getMessage() . "\n" . $e->getTraceAsString());
                    // Don't break here unless it's a critical fatal error. Just sleep and try again.
                }

                \Hyperf\Coroutine\Coroutine::sleep(7.0) !== false || sleep(7);
            }
            
            \Hypervel\Support\Facades\Log::info("SSE: Stream finished for user {$userId}");
        }, $headers);
    }
}