<?php

declare(strict_types=1);

namespace App\Services\Pdf;

use Illuminate\Http\Client\ConnectionException;
use Illuminate\Http\Client\Response;
use Illuminate\Support\Facades\Http;

final class PdfRendererClient
{
    public function healthCheck(?string $correlationId = null): PdfRenderResult
    {
        try {
            $response = Http::timeout($this->timeoutSeconds())
                ->connectTimeout($this->connectTimeoutSeconds())
                ->withHeaders($this->correlationHeaders($correlationId))
                ->get($this->url($this->configString('health_path', '/health')));
        } catch (ConnectionException) {
            return PdfRenderResult::failure(
                PdfRenderResult::RENDERER_UNAVAILABLE,
                'PDF renderer is unavailable.',
                correlationId: $correlationId,
            );
        }

        if ($response->successful()) {
            return PdfRenderResult::success(
                pdfBytes: '',
                contentType: (string) $response->header('Content-Type', 'text/plain'),
                correlationId: $this->responseCorrelationId($response, $correlationId),
                statusCode: $response->status(),
            );
        }

        return PdfRenderResult::failure(
            PdfRenderResult::RENDERER_UNAVAILABLE,
            'PDF renderer health check failed.',
            statusCode: $response->status(),
            correlationId: $this->responseCorrelationId($response, $correlationId),
        );
    }

    public function render(PdfRenderRequest $request): PdfRenderResult
    {
        try {
            $pending = Http::timeout($this->timeoutSeconds())
                ->connectTimeout($this->connectTimeoutSeconds())
                ->accept('application/pdf')
                ->withHeaders(array_filter(array_merge(
                    $this->correlationHeaders($request->correlationId),
                    [
                        'Gotenberg-Output-Filename' => $request->outputFilename
                            ?? $this->configString('output_filename', 'tenantpilot-management-report'),
                    ],
                )));

            $pending->attach('files', $request->html, 'index.html', [
                'Content-Type' => 'text/html; charset=UTF-8',
            ]);

            foreach ($request->assets as $filename => $contents) {
                $pending->attach('files', $contents, $filename);
            }

            $response = $pending->post(
                $this->url($this->configString('html_route', '/forms/chromium/convert/html')),
                $this->stringFormOptions($request->options),
            );
        } catch (ConnectionException) {
            return PdfRenderResult::failure(
                PdfRenderResult::RENDERER_UNAVAILABLE,
                'PDF renderer did not respond before the configured timeout or was unavailable.',
                correlationId: $request->correlationId,
            );
        }

        return $this->resultFromResponse($response, $request->correlationId);
    }

    private function resultFromResponse(Response $response, ?string $fallbackCorrelationId): PdfRenderResult
    {
        $correlationId = $this->responseCorrelationId($response, $fallbackCorrelationId);

        if ($response->successful()) {
            $body = $response->body();
            $contentType = (string) $response->header('Content-Type', 'application/pdf');

            if ($body === '' || (! str_contains(strtolower($contentType), 'pdf') && ! str_starts_with($body, '%PDF'))) {
                return PdfRenderResult::failure(
                    PdfRenderResult::INVALID_RESPONSE,
                    'PDF renderer returned an invalid PDF response.',
                    statusCode: $response->status(),
                    correlationId: $correlationId,
                );
            }

            return PdfRenderResult::success(
                pdfBytes: $body,
                contentType: $contentType,
                outputFilename: $this->filenameFromDisposition((string) $response->header('Content-Disposition', '')),
                correlationId: $correlationId,
                statusCode: $response->status(),
            );
        }

        if ($response->status() === 400) {
            return PdfRenderResult::failure(
                PdfRenderResult::INVALID_REQUEST,
                'PDF renderer rejected the HTML render request.',
                statusCode: $response->status(),
                correlationId: $correlationId,
            );
        }

        if ($response->status() === 503) {
            return PdfRenderResult::failure(
                PdfRenderResult::RENDERER_TIMEOUT,
                'PDF renderer did not complete within the configured timeout.',
                statusCode: $response->status(),
                correlationId: $correlationId,
            );
        }

        return PdfRenderResult::failure(
            PdfRenderResult::RENDERER_FAILED,
            'PDF renderer failed to create the document.',
            statusCode: $response->status(),
            correlationId: $correlationId,
        );
    }

    /**
     * @param  array<string, bool|float|int|string>  $options
     * @return array<string, string>
     */
    private function stringFormOptions(array $options): array
    {
        $formatted = [];

        foreach ($options as $key => $value) {
            $formatted[$key] = is_bool($value) ? ($value ? 'true' : 'false') : (string) $value;
        }

        return $formatted;
    }

    /**
     * @return array<string, string>
     */
    private function correlationHeaders(?string $correlationId): array
    {
        if ($correlationId === null || trim($correlationId) === '') {
            return [];
        }

        return [
            $this->configString('correlation_header', 'Gotenberg-Trace') => trim($correlationId),
        ];
    }

    private function responseCorrelationId(Response $response, ?string $fallback): ?string
    {
        $header = $this->configString('correlation_header', 'Gotenberg-Trace');
        $value = $response->header($header);

        return is_string($value) && trim($value) !== '' ? trim($value) : $fallback;
    }

    private function url(string $path): string
    {
        return rtrim($this->configString('base_url', 'http://gotenberg:3000'), '/').'/'.ltrim($path, '/');
    }

    private function timeoutSeconds(): int
    {
        return max(1, (int) config('tenantpilot.pdf_renderer.timeout_seconds', 30));
    }

    private function connectTimeoutSeconds(): int
    {
        return max(1, (int) config('tenantpilot.pdf_renderer.connect_timeout_seconds', 5));
    }

    private function configString(string $key, string $default): string
    {
        $value = config('tenantpilot.pdf_renderer.'.$key, $default);

        return is_string($value) && trim($value) !== '' ? trim($value) : $default;
    }

    private function filenameFromDisposition(string $disposition): ?string
    {
        if (preg_match('/filename="?([^";]+)"?/i', $disposition, $matches) !== 1) {
            return null;
        }

        return basename($matches[1]);
    }
}