<?php

namespace App\Http\Controllers;

use App\Http\Controllers\Concerns\ParsesDateRange;
use App\Models\Website;
use App\Services\AnalyticsQueryService;
use Illuminate\Http\Request;
use Symfony\Component\HttpFoundation\StreamedResponse;

class ExportController extends Controller
{
    use ParsesDateRange;

    public function export(Request $request, Website $website, string $report): StreamedResponse
    {
        $this->authorize('view', $website);

        [$from, $to] = $this->parseDateRange($request);
        $service = AnalyticsQueryService::for($website, $from, $to);

        [$headers, $rows] = match ($report) {
            'pages' => $this->pagesExport($service),
            'landing-pages' => $this->landingPagesExport($service),
            'exit-pages' => $this->exitPagesExport($service),
            'sources' => $this->sourcesExport($service),
            'referrers' => $this->referrersExport($service),
            'campaigns' => $this->campaignsExport($service),
            'events' => $this->eventsExport($service),
            'countries' => $this->countriesExport($service),
            'browsers' => $this->browsersExport($service),
            'languages' => $this->languagesExport($service),
            'summary' => $this->summaryExport($service, $from, $to),
            default => abort(404, 'Unknown report type.'),
        };

        $filename = "{$website->domain}_{$report}_{$from->format('Y-m-d')}_to_{$to->format('Y-m-d')}.csv";

        return $this->streamCsv($filename, $headers, $rows);
    }

    private function streamCsv(string $filename, array $headers, iterable $rows): StreamedResponse
    {
        return response()->streamDownload(function () use ($headers, $rows) {
            $handle = fopen('php://output', 'w');
            fputcsv($handle, $headers);
            foreach ($rows as $row) {
                fputcsv($handle, $row);
            }
            fclose($handle);
        }, $filename, [
            'Content-Type' => 'text/csv',
        ]);
    }

    private function pagesExport(AnalyticsQueryService $service): array
    {
        $data = $service->topPages(500);

        return [
            ['Path', 'Views', 'Unique Views', 'Avg Time on Page (s)'],
            $data->map(fn ($r) => [
                $r->path,
                $r->views,
                $r->unique_views,
                round($r->avg_time ?? 0, 1),
            ]),
        ];
    }

    private function landingPagesExport(AnalyticsQueryService $service): array
    {
        $data = $service->landingPages(500);

        return [
            ['Path', 'Entrances', 'Bounce Rate (%)'],
            $data->map(fn ($r) => [
                $r->entry_page ?? $r->path ?? '—',
                $r->entrances ?? $r->sessions ?? 0,
                $r->bounce_rate ?? 0,
            ]),
        ];
    }

    private function exitPagesExport(AnalyticsQueryService $service): array
    {
        $data = $service->exitPages(500);

        return [
            ['Path', 'Exits'],
            $data->map(fn ($r) => [
                $r->exit_page ?? $r->path ?? '—',
                $r->exits ?? 0,
            ]),
        ];
    }

    private function sourcesExport(AnalyticsQueryService $service): array
    {
        $data = $service->trafficSources(500);

        return [
            ['Source', 'Sessions', 'Bounces', 'Avg Duration (s)', 'Avg Pages'],
            $data->map(fn ($r) => [
                $r->source,
                $r->sessions,
                $r->bounces,
                round($r->avg_duration ?? 0, 1),
                round($r->avg_pages ?? 0, 1),
            ]),
        ];
    }

    private function referrersExport(AnalyticsQueryService $service): array
    {
        $data = $service->referrers(500);

        return [
            ['Referrer Domain', 'Sessions', 'Bounces', 'Avg Duration (s)'],
            $data->map(fn ($r) => [
                $r->referrer_domain,
                $r->sessions,
                $r->bounces,
                round($r->avg_duration ?? 0, 1),
            ]),
        ];
    }

    private function campaignsExport(AnalyticsQueryService $service): array
    {
        $data = $service->campaigns(500);

        return [
            ['UTM Source', 'UTM Medium', 'UTM Campaign', 'Sessions', 'Bounces', 'Avg Duration (s)'],
            $data->map(fn ($r) => [
                $r->utm_source,
                $r->utm_medium,
                $r->utm_campaign,
                $r->sessions,
                $r->bounces,
                round($r->avg_duration ?? 0, 1),
            ]),
        ];
    }

    private function eventsExport(AnalyticsQueryService $service): array
    {
        $data = $service->eventsOverview(500);

        return [
            ['Event Name', 'Category', 'Total', 'Unique Visitors', 'Total Value'],
            $data->map(fn ($r) => [
                $r->name,
                $r->category,
                $r->total,
                $r->unique_visitors,
                $r->total_value,
            ]),
        ];
    }

    private function countriesExport(AnalyticsQueryService $service): array
    {
        $data = $service->visitorsByCountry(500);

        return [
            ['Country', 'Visitors'],
            $data->map(fn ($r) => [$r->country, $r->visitors]),
        ];
    }

    private function browsersExport(AnalyticsQueryService $service): array
    {
        $data = $service->visitorsByBrowser(100);

        return [
            ['Browser', 'Visitors'],
            $data->map(fn ($r) => [$r->browser, $r->visitors]),
        ];
    }

    private function languagesExport(AnalyticsQueryService $service): array
    {
        $data = $service->visitorsByLanguage(100);

        return [
            ['Language', 'Visitors'],
            $data->map(fn ($r) => [$r->language, $r->visitors]),
        ];
    }

    private function summaryExport(AnalyticsQueryService $service, $from, $to): array
    {
        $summary = $service->summary();

        return [
            ['Metric', 'Value'],
            collect([
                ['Period', $from->format('Y-m-d') . ' to ' . $to->format('Y-m-d')],
                ['Page Views', $summary['page_views']],
                ['Unique Visitors', $summary['visitors']],
                ['Sessions', $summary['sessions']],
                ['Bounce Rate (%)', $summary['bounce_rate']],
                ['Avg Duration (s)', $summary['avg_duration']],
                ['Pages / Session', $summary['avg_pages']],
            ]),
        ];
    }
}