<?php

namespace Acme\Dhl\Services;

use Acme\Dhl\Support\DhlClient;
use Acme\Dhl\Models\DhlShipment;
use Acme\Dhl\Models\DhlTrackingEvent;
use InvalidArgumentException;
use Exception;
use Acme\Dhl\Jobs\SyncTrackingJob;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\DB;

/**
 * DHL Tracking Service for fetching and managing tracking information
 */
class TrackingService
{
    public function __construct(protected DhlClient $client) {}

    /**
     * Fetch tracking status for a shipment
     *
     * @param string $trackingNumber DHL tracking number
     * @return array Tracking data from DHL API
     * @throws InvalidArgumentException When tracking number is empty
     * @throws Exception When API request fails
     */
    public function fetchStatus(string $trackingNumber): array
    {
        if (empty($trackingNumber)) {
            throw new InvalidArgumentException('Tracking number is required');
        }
        if (config('dhl.use_queue')) {
            SyncTrackingJob::dispatch($trackingNumber);
            return ['queued' => true];
        }

        $response = $this->client->request('get', '/post-tracking/api/shipments', [], [
            'trackingNumber' => $trackingNumber
        ]);
        Log::info('Fetched tracking status', ['trackingNumber' => $trackingNumber]);

        $events = data_get($response, 'shipments.0.events', []);
        $shipment = $this->findOrCreateShipment($trackingNumber);

        $this->updateTrackingEvents($shipment, $events);

        return $response;
    }

    /**
     * Update tracking status for multiple shipments
     *
     * @param array $trackingNumbers Array of tracking numbers to update
     * @return array Results for each tracking number
     */
    public function updateMultipleStatus(array $trackingNumbers): array
    {
        $results = [];

        foreach ($trackingNumbers as $trackingNumber) {
            try {
                $results[$trackingNumber] = $this->fetchStatus($trackingNumber);
            } catch (Exception $e) {
                Log::error('Tracking update failed', ['trackingNumber' => $trackingNumber, 'error' => $e->getMessage()]);
                $results[$trackingNumber] = ['error' => $e->getMessage()];
            }
        }

        return $results;
    }

    /**
     * Get latest tracking status for a shipment
     *
     * @param string $trackingNumber DHL tracking number
     * @return array|null Latest tracking event or null if not found
     */
    public function getLatestStatus(string $trackingNumber): ?array
    {
        $shipment = DhlShipment::where('dhl_shipment_no', $trackingNumber)->first();

        if (!$shipment) {
            return null;
        }

        $latestEvent = $shipment->trackingEvents()
            ->orderBy('event_time', 'desc')
            ->first();

        return $latestEvent ? $latestEvent->toArray() : null;
    }

    /**
     * Find existing shipment or create new one
     */
    private function findOrCreateShipment(string $trackingNumber): DhlShipment
    {
        return DB::transaction(function () use ($trackingNumber) {
            return DhlShipment::firstOrCreate(
                ['dhl_shipment_no' => $trackingNumber],
                [
                    'type' => 'outbound',
                    'status' => 'unknown'
                ]
            );
        });
    }

    /**
     * Update tracking events for a shipment
     */
    private function updateTrackingEvents(DhlShipment $shipment, array $events): void
    {
        foreach ($events as $eventData) {
            $this->createOrUpdateTrackingEvent($shipment, $eventData);
        }

        // Update shipment status based on latest event
        $this->updateShipmentStatus($shipment, $events);
    }

    /**
     * Create or update a tracking event
     */
    private function createOrUpdateTrackingEvent(DhlShipment $shipment, array $eventData): void
    {
        DhlTrackingEvent::updateOrCreate(
            [
                'shipment_id' => $shipment->id,
                'status_code' => $eventData['statusCode'] ?? null,
                'event_time' => $eventData['timestamp'] ?? null
            ],
            [
                'status_text' => $eventData['status'] ?? null,
                'location' => $this->extractLocation($eventData),
                'raw' => $eventData
            ]
        );
    }

    /**
     * Extract location from event data
     */
    private function extractLocation(array $eventData): ?string
    {
        return data_get($eventData, 'location.address.addressLocality')
            ?? data_get($eventData, 'location')
            ?? null;
    }

    /**
     * Update shipment status based on latest tracking event
     */
    private function updateShipmentStatus(DhlShipment $shipment, array $events): void
    {
        if (empty($events)) {
            return;
        }

        // Sort events by timestamp to get the latest
        usort($events, function ($a, $b) {
            return strtotime($b['timestamp'] ?? '0') <=> strtotime($a['timestamp'] ?? '0');
        });

        $latestEvent = $events[0];
        $statusCode = $latestEvent['statusCode'] ?? null;

        // Map DHL status codes to our internal status
        $status = DhlShipment::STATUS_MAP[$statusCode] ?? 'unknown';

        $shipment->update([
            'status' => $status,
            'tracking_status' => $latestEvent['status'] ?? null,
            'last_tracked_at' => now()
        ]);
        Log::info('Updated shipment status', ['shipmentId' => $shipment->id, 'newStatus' => $status]);
    }
}