<?php

namespace App\Jobs;

use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;
use App\Models\User;
use App\Models\Expense;
use App\Models\CategoryRule; // 💡 假設這是你存自動分類規則的 Model
use App\Services\GmailParserService;
use Google\Client as GoogleClient;
use Google\Service\Gmail;
use Google\Service\Gmail\ModifyMessageRequest;
use Illuminate\Support\Facades\Log;

class FetchAndParseGmailInvoices implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    protected $user;

    /**
     * 這裡我們可以在初始化時傳入指定 User，或者在 handle 裡跑全部 User
     */
    public function __construct(User $user)
    {
        $this->user = $user;
    }

    public function handle(GmailParserService $parserService)
    {
        // 1. 檢查使用者憑證
        if (!$this->user->google_refresh_token) {
            Log::warning("User ID {$this->user->id} 試圖執行抓信任務，但缺乏 refresh_token。");
            return;
        }

        try {
            // 2. 初始化 Google Client 並刷新 Token
            $client = new GoogleClient();
            $client->setClientId(config('services.google.client_id'));
            $client->setClientSecret(config('services.google.client_secret'));
            $client->refreshToken($this->user->google_refresh_token);
            
            $gmailService = new Gmail($client);

            // 3. 搜尋帶有專屬標籤且「未讀」的信件
            $searchQuery = 'label:FinBuddy-Card is:unread';
            $response = $gmailService->users_messages->listUsersMessages('me', [
                'q' => $searchQuery,
                'maxResults' => 20 // 每次最多處理 20 筆，防爆
            ]);

            $messages = $response->getMessages();

            if (empty($messages)) {
                Log::info("User ID {$this->user->id}: 沒發現符合條件的未讀刷卡信件。");
                return;
            }

            // 4. 逐封拆解信件
            foreach ($messages as $msgItem) {
                $msgId = $msgItem->getId();
                $message = $gmailService->users_messages->get('me', $msgId, ['format' => 'full']);
                $payload = $message->getPayload();
                
                // 抓取主旨
                $subject = '';
                foreach ($payload->getHeaders() as $header) {
                    if ($header->getName() === 'Subject') {
                        $subject = $header->getValue();
                        break;
                    }
                }

                // 遞迴拿到內文
                $body = $this->getDecodedBody($payload);

                // 5. 丟給 Parser 進行 Regex 解析
                $parsedData = $parserService->parse($subject, $body);

                if ($parsedData) {
                    // 🟢 智慧分類：根據商家名稱反查資料庫裡的自動分類規則
                    // 假設你的規則表有關鍵字比對 (例如: keyword = 'PCHOME', category_id = 3)
                    $matchedRule = CategoryRule::where('user_id', $this->user->id)
                        ->get()
                        ->first(function ($rule) use ($parsedData) {
                            return Str::contains(strtoupper($parsedData['seller_name']), strtoupper($rule->keyword));
                        });

                    $categoryId = $matchedRule ? $matchedRule->category_id : null;

                    // 6. 寫入消費紀錄（我們已經補上了 $fillable，絕對暢行無阻！）
                    Expense::create([
                        'user_id'     => $this->user->id,
                        'amount'      => $parsedData['amount'],
                        'item_name'   => $parsedData['item_name'],
                        'seller_name' => $parsedData['seller_name'],
                        'date'        => $parsedData['date'],
                        'category_id' => $categoryId,
                        'note'        => 'Gmail背景自動記帳',
                    ]);

                    Log::info("User ID {$this->user->id}: 成功自動記帳一筆金額 {$parsedData['amount']}，商家: {$parsedData['seller_name']}");
                }

                // 7. 🟢 防重複防線：記帳成功後，立刻把信件在 Gmail 標記為「已讀」
                $mods = new ModifyMessageRequest();
                $mods->setRemoveLabelIds(['UNREAD']); // 移除未讀標籤 = 標記已讀
                $gmailService->users_messages->modify('me', $msgId, $mods);
            }

        } catch (\Exception $e) {
            Log::error("User ID {$this->user->id} Gmail 自動抓帳 Job 發生崩潰: " . $e->getMessage());
        }
    }

    /**
     * 遞迴解析內文的輔助方法
     */
    private function getDecodedBody($part)
    {
        $body = $part->getBody();
        if ($body && $body->getData()) {
            $sanitizedData = str_replace(['-', '_'], ['+', '/'], $body->getData());
            return base64_decode($sanitizedData);
        }
        $parts = $part->getParts();
        if ($parts) {
            foreach ($parts as $subPart) {
                $result = $this->getDecodedBody($subPart);
                if ($result) return $result;
            }
        }
        return '';
    }
}