<?php

namespace App\Services;

use App\Models\Report;
use App\Repositories\Interfaces\ReportRepositoryInterface;
use App\Validators\ReportValidator;
use App\Exceptions\ValidationException;
use Illuminate\Pagination\LengthAwarePaginator;

class ReportService
{
    private ReportRepositoryInterface $reportRepository;
    private ReportValidator $validator;

    public function __construct(ReportRepositoryInterface $reportRepository, ReportValidator $validator)
    {
        $this->reportRepository = $reportRepository;
        $this->validator = $validator;
    }

    /**
     * Get report by ID
     */
    public function getReportById(int $id): ?Report
    {
        return $this->reportRepository->findById($id);
    }

    /**
     * Get all reports with pagination and filters
     */
    public function getReports(int $page = 1, int $limit = 20, array $filters = []): LengthAwarePaginator
    {
        return $this->reportRepository->getAll($page, $limit, $filters);
    }

    /**
     * Create a new report
     */
    public function createReport(array $data): Report
    {
        // Validate data
        $validatedData = $this->validator->validateCreateData($data);
        
        // Add default values
        $validatedData['status'] = $validatedData['status'] ?? 'draft';
        $validatedData['priority'] = $validatedData['priority'] ?? 'medium';

        return $this->reportRepository->create($validatedData);
    }

    /**
     * Update a report
     */
    public function updateReport(int $id, array $data): bool
    {
        $report = $this->reportRepository->findById($id);
        if (!$report) {
            throw new \Exception("Report not found", 404);
        }

        // Validate data
        $validatedData = $this->validator->validateUpdateData($data);

        return $this->reportRepository->update($id, $validatedData);
    }

    /**
     * Delete a report
     */
    public function deleteReport(int $id): bool
    {
        $report = $this->reportRepository->findById($id);
        if (!$report) {
            throw new \Exception("Report not found", 404);
        }

        return $this->reportRepository->delete($id);
    }

    /**
     * Get reports by company
     */
    public function getReportsByCompany(int $companyId): array
    {
        $reports = $this->reportRepository->getByCompany($companyId);
        return $reports->toArray();
    }

    /**
     * Get reports by user
     */
    public function getReportsByUser(int $userId): array
    {
        $reports = $this->reportRepository->getByUser($userId);
        return $reports->toArray();
    }

    /**
     * Search reports
     */
    public function searchReports(string $query, array $filters = []): array
    {
        $reports = $this->reportRepository->search($query, $filters);
        return $reports->toArray();
    }

    /**
     * Generate report
     */
    public function generateReport(int $id): array
    {
        $report = $this->reportRepository->findById($id);
        if (!$report) {
            throw new \Exception("Report not found", 404);
        }

        // Update status to generating
        $this->reportRepository->update($id, ['status' => 'generating']);

        try {
            // Here you would implement the actual report generation logic
            // This is a placeholder for the report generation process
            $generatedData = $this->performReportGeneration($report);

            // Update status to completed
            $this->reportRepository->update($id, [
                'status' => 'completed',
                'file_path' => $generatedData['file_path'] ?? null,
                'file_size' => $generatedData['file_size'] ?? null
            ]);

            return $generatedData;

        } catch (\Exception $e) {
            // Update status to failed
            $this->reportRepository->update($id, ['status' => 'failed']);
            throw $e;
        }
    }

    /**
     * Get report statistics
     */
    public function getStatistics(): array
    {
        return $this->reportRepository->getStatistics();
    }

    /**
     * Schedule report generation
     */
    public function scheduleReport(array $data): Report
    {
        $validatedData = $this->validator->validateCreateData($data);
        $validatedData['status'] = 'scheduled';

        return $this->reportRepository->create($validatedData);
    }

    /**
     * Export report
     */
    public function exportReport(int $id, string $format = 'pdf'): array
    {
        $report = $this->reportRepository->findById($id);
        if (!$report) {
            throw new \Exception("Report not found", 404);
        }

        if ($report->status !== 'completed') {
            throw new \Exception("Report is not ready for export", 400);
        }

        // Here you would implement the export logic based on format
        return [
            'file_path' => $report->file_path,
            'format' => $format,
            'download_url' => "/reports/{$id}/download"
        ];
    }

    /**
     * Perform the actual report generation
     * This is a placeholder - implement your specific report generation logic
     */
    private function performReportGeneration(Report $report): array
    {
        // Placeholder implementation
        // You would implement specific report generation logic here
        
        $fileName = "report_{$report->report_id}_{$report->type}_" . date('Y-m-d_H-i-s') . '.pdf';
        $filePath = "storage/reports/{$fileName}";
        
        // Simulate report generation
        // In real implementation, you would:
        // 1. Query the data based on report type
        // 2. Generate charts/graphs if needed
        // 3. Create PDF/Excel file
        // 4. Save to storage
        
        return [
            'file_path' => $filePath,
            'file_size' => 1024 * 50, // 50KB placeholder
            'download_url' => "/reports/{$report->report_id}/download"
        ];
    }

    /**
     * Get reports by status
     */
    public function getReportsByStatus(string $status): array
    {
        $reports = $this->reportRepository->getByStatus($status);
        return $reports->toArray();
    }

    /**
     * Bulk update report status
     */
    public function bulkUpdateStatus(array $reportIds, string $status): int
    {
        $updated = 0;
        foreach ($reportIds as $id) {
            if ($this->reportRepository->update($id, ['status' => $status])) {
                $updated++;
            }
        }
        return $updated;
    }

    /**
     * Get user's report analytics
     */
    public function getUserReportAnalytics(int $userId): array
    {
        $userReports = $this->reportRepository->getByUser($userId);
        
        return [
            'total_reports' => $userReports->count(),
            'by_status' => $userReports->groupBy('status')->map->count(),
            'by_type' => $userReports->groupBy('type')->map->count(),
            'recent_reports' => $userReports->where('created_at', '>=', now()->subDays(30))->count()
        ];
    }
}