<?php

namespace App\Services;

use App\Models\SyncLog;
use Exception;

abstract class BaseSyncService
{
    protected \PDO $pdo;
    protected array $source;
    protected SyncLog $syncLog;
    protected int $sourceId;

    public function __construct(\PDO $pdo, array $source)
    {
        $this->pdo = $pdo;
        $this->source = $source;

        if (!isset($source['id']) || empty($source['id'])) {
            throw new \Exception('Source ID is required for sync service');
        }

        $this->sourceId = (int) $source['id'];
    }

    public function startSync(string $syncType = 'full'): int
    {
        // Create sync log entry
        $this->syncLog = new SyncLog($this->pdo);
        $syncLogId = $this->createSyncLog($syncType, 'started');

        $this->syncLog->id = $syncLogId;

        try {
            $this->executeSync($syncType);

            // Update sync log as completed
            $this->updateSyncLog($syncLogId, 'completed', [
                'processed_items' => $this->getProcessedCount(),
                'new_items' => $this->getNewCount(),
                'updated_items' => $this->getUpdatedCount(),
                'deleted_items' => $this->getDeletedCount()
            ]);

        } catch (Exception $e) {
            // Update sync log as failed
            $this->updateSyncLog($syncLogId, 'failed', [
                'message' => $e->getMessage(),
                'errors' => [$e->getMessage()]
            ]);

            throw $e;
        }

        return $syncLogId;
    }

    private function createSyncLog(string $syncType, string $status): int
    {
        $data = [
            'source_id' => $this->sourceId,
            'sync_type' => $syncType,
            'status' => $status,
            'total_items' => 0,
            'processed_items' => 0,
            'new_items' => 0,
            'updated_items' => 0,
            'deleted_items' => 0,
            'started_at' => date('Y-m-d H:i:s')
        ];

        $columns = array_keys($data);
        $placeholders = array_map(fn($col) => ":$col", $columns);
        $sql = "INSERT INTO sync_logs (" . implode(', ', $columns) . ") VALUES (" . implode(', ', $placeholders) . ")";

        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($data);

        return (int) $this->pdo->lastInsertId();
    }

    private function updateSyncLog(int $syncLogId, string $status, array $stats = []): bool
    {
        $data = [
            'status' => $status,
            'processed_items' => $stats['processed_items'] ?? 0,
            'new_items' => $stats['new_items'] ?? 0,
            'updated_items' => $stats['updated_items'] ?? 0,
            'deleted_items' => $stats['deleted_items'] ?? 0,
            'completed_at' => date('Y-m-d H:i:s')
        ];

        if (!empty($stats['errors'])) {
            $data['errors'] = json_encode($stats['errors']);
        }

        if (!empty($stats['message'])) {
            $data['message'] = $stats['message'];
        }

        $setClause = array_map(fn($col) => "$col = :$col", array_keys($data));
        $sql = "UPDATE sync_logs SET " . implode(', ', $setClause) . " WHERE id = :id";
        $data['id'] = $syncLogId;

        $stmt = $this->pdo->prepare($sql);
        return $stmt->execute($data);
    }

    abstract protected function executeSync(string $syncType): void;

    protected function getProcessedCount(): int
    {
        return 0; // Override in subclasses
    }

    protected function getNewCount(): int
    {
        return 0; // Override in subclasses
    }

    protected function getUpdatedCount(): int
    {
        return 0; // Override in subclasses
    }

    protected function getDeletedCount(): int
    {
        return 0; // Override in subclasses
    }

    protected function logProgress(string $message): void
    {
        // Update sync log with progress message
        if ($this->syncLog) {
            $this->updateSyncLog($this->syncLog->id, 'running', [
                'message' => $message
            ]);
        }
    }
}