<?php

declare(strict_types=1);

namespace DocFast;

/**
 * DocFast API client for HTML/Markdown to PDF conversion.
 *
 * @see https://docfast.dev/docs
 */
class Client
{
    private string $apiKey;
    private string $baseUrl;
    private int $timeout;

    public function __construct(string $apiKey, string $baseUrl = 'https://docfast.dev', int $timeout = 60)
    {
        if (empty($apiKey)) {
            throw new \InvalidArgumentException('API key is required');
        }
        $this->apiKey = $apiKey;
        $this->baseUrl = rtrim($baseUrl, '/');
        $this->timeout = $timeout;
    }

    /**
     * Convert HTML to PDF.
     *
     * @param string $html HTML content
     * @param string|null $css Optional CSS to inject
     * @param PdfOptions|null $options PDF options
     * @return string Raw PDF bytes
     * @throws DocFastException
     */
    public function html(string $html, ?string $css = null, ?PdfOptions $options = null): string
    {
        $body = ['html' => $html];
        if ($css !== null) {
            $body['css'] = $css;
        }
        return $this->convert('/v1/convert/html', $body, $options);
    }

    /**
     * Convert Markdown to PDF.
     *
     * @param string $markdown Markdown content
     * @param string|null $css Optional CSS to inject
     * @param PdfOptions|null $options PDF options
     * @return string Raw PDF bytes
     * @throws DocFastException
     */
    public function markdown(string $markdown, ?string $css = null, ?PdfOptions $options = null): string
    {
        $body = ['markdown' => $markdown];
        if ($css !== null) {
            $body['css'] = $css;
        }
        return $this->convert('/v1/convert/markdown', $body, $options);
    }

    /**
     * Convert a URL to PDF.
     *
     * @param string $url URL to convert
     * @param PdfOptions|null $options PDF options
     * @return string Raw PDF bytes
     * @throws DocFastException
     */
    public function url(string $url, ?PdfOptions $options = null): string
    {
        return $this->convert('/v1/convert/url', ['url' => $url], $options);
    }

    /**
     * List available templates.
     *
     * @return array<array{id: string, name: string, description?: string}>
     * @throws DocFastException
     */
    public function templates(): array
    {
        $data = $this->get('/v1/templates');
        $result = json_decode($data, true);
        return $result['templates'] ?? [];
    }

    /**
     * Render a template to PDF.
     *
     * @param string $templateId Template ID
     * @param array $data Template data
     * @return string Raw PDF bytes
     * @throws DocFastException
     */
    public function renderTemplate(string $templateId, array $data = []): string
    {
        return $this->post('/v1/templates/' . urlencode($templateId), ['data' => $data]);
    }

    private function convert(string $path, array $body, ?PdfOptions $options): string
    {
        if ($options !== null) {
            $body = array_merge($body, $options->toArray());
        }
        return $this->post($path, $body);
    }

    private function post(string $path, array $body): string
    {
        $ch = curl_init($this->baseUrl . $path);
        curl_setopt_array($ch, [
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => json_encode($body),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => $this->timeout,
            CURLOPT_HTTPHEADER => [
                'Authorization: Bearer ' . $this->apiKey,
                'Content-Type: application/json',
                'Accept: application/pdf',
            ],
        ]);

        $response = curl_exec($ch);
        $statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $error = curl_error($ch);
        curl_close($ch);

        if ($response === false) {
            throw new DocFastException('Request failed: ' . $error, 0);
        }

        if ($statusCode >= 400) {
            $this->handleError($response, $statusCode);
        }

        return $response;
    }

    private function get(string $path): string
    {
        $ch = curl_init($this->baseUrl . $path);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => $this->timeout,
            CURLOPT_HTTPHEADER => [
                'Authorization: Bearer ' . $this->apiKey,
                'Accept: application/json',
            ],
        ]);

        $response = curl_exec($ch);
        $statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $error = curl_error($ch);
        curl_close($ch);

        if ($response === false) {
            throw new DocFastException('Request failed: ' . $error, 0);
        }

        if ($statusCode >= 400) {
            $this->handleError($response, $statusCode);
        }

        return $response;
    }

    private function handleError(string $response, int $statusCode): never
    {
        $message = "HTTP $statusCode";
        $code = null;

        $data = json_decode($response, true);
        if (is_array($data)) {
            $message = $data['error'] ?? $message;
            $code = $data['code'] ?? null;
        }

        throw new DocFastException($message, $statusCode, $code);
    }
}