<?php

declare(strict_types=1);

namespace OCA\AnalyticsHub\Controller;

use OCP\IRequest;
use OCP\IResponse;
use OCP\AppFramework\Http;
use OCP\AppFramework\Http\DataResponse;
use OCP\AppFramework\Http\JSONResponse;

use OCA\AnalyticsHub\Service\GoogleAnalyticsService;
use OCA\AnalyticsHub\Service\LLMService;
use OCA\AnalyticsHub\Service\DataProcessor;
use OCA\AnalyticsHub\Model\ClientConfig;
use OCA\AnalyticsHub\Model\Report;

/**
 * API V1 Controller - Exposes REST APIs for agent integration
 */
class ApiV1Controller {

    private GoogleAnalyticsService $gaService;
    private LLMService $llmService;
    private DataProcessor $dataProcessor;

    public function __construct(
        GoogleAnalyticsService $gaService,
        LLMService $llmService,
        DataProcessor $dataProcessor
    ) {
        $this->gaService = $gaService;
        $this->llmService = $llmService;
        $this->dataProcessor = $dataProcessor;
    }

    /**
     * Get all available reports
     * GET /api/reports
     */
    public function getReports(IRequest $request): DataResponse {
        $this->validateAgentAccess();

        $reports = $this->gaService->getAllReports();

        return new DataResponse([
            'success' => true,
            'data' => [
                'reports' => $reports
            ]
        ]);
    }

    /**
     * Get specific report by ID
     * GET /api/report/{id}
     */
    public function getReport(IRequest $request, int $id): DataResponse {
        $this->validateAgentAccess();

        $report = $this->gaService->getReportById($id);

        if (!$report) {
            return new DataResponse([
                'success' => false,
                'error' => 'Report not found'
            ], Http::STATUS_NOT_FOUND);
        }

        return new DataResponse([
            'success' => true,
            'data' => [
                'report' => $report
            ]
        ]);
    }

    /**
     * Generate new report
     * POST /api/generate
     */
    public function generateReport(IRequest $request): JSONResponse {
        $this->validateAgentAccess();

        $params = $request->getParams();

        $clientSlug = $params['client_slug'] ?? null;
        $dateRange = $params['date_range'] ?? '7d';

        if (!$clientSlug) {
            return new JSONResponse([
                'success' => false,
                'error' => 'client_slug is required'
            ], Http::STATUS_BAD_REQUEST);
        }

        try {
            // Get client configuration
            $client = $this->gaService->getClientBySlug($clientSlug);

            if (!$client) {
                return new JSONResponse([
                    'success' => false,
                    'error' => 'Client not found'
                ], Http::STATUS_NOT_FOUND);
            }

            // Fetch GA4 data
            $rawData = $this->gaService->fetchGA4Data($client, $dateRange);

            // Process and validate
            $processed = $this->dataProcessor->process($rawData, $client);

            // Generate report via LLM
            $markdown = $this->llmService->generate($processed, $client);

            // Save report to Nextcloud
            $report = $this->gaService->saveReport($client, $markdown);

            return new JSONResponse([
                'success' => true,
                'data' => [
                    'report_id' => $report->getId(),
                    'report_date' => date('Y-m-d'),
                    'file_path' => $report->getFilePath(),
                    'markdown_preview' => substr($markdown, 0, 500) . '...'
                ]
            ]);

        } catch (\Exception $e) {
            \OCP\Util::writeLog("Generate report failed: {$e->getMessage()}");

            return new JSONResponse([
                'success' => false,
                'error' => $e->getMessage()
            ], Http::STATUS_INTERNAL_SERVER_ERROR);
        }
    }

    /**
     * Get app status
     * GET /api/status
     */
    public function getStatus(IRequest $request): DataResponse {
        $this->validateAgentAccess();

        $status = [
            'app_name' => AppInfo::APP_NAME,
            'version' => AppInfo::getVersion(),
            'status' => 'operational',
            'google_analytics' => $this->gaService->isConfigured() ? 'configured' : 'not_configured',
            'llm_service' => $this->llmService->isConfigured() ? 'configured' : 'not_configured',
            'total_clients' => $this->gaService->getClientCount(),
            'last_report_time' => $this->gaService->getLastReportTime()
        ];

        return new DataResponse([
            'success' => true,
            'data' => $status
        ]);
    }

    /**
     * Validate agent access using app password
     */
    private function validateAgentAccess(): void {
        // Authentication will be handled by Nextcloud middleware
        // This is a placeholder for future enhancement
    }
}