//SPDX-License-Identifier: LGPL-3.0-only
//SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®

export module Crafter.Network:ClientHTTP1;
import std;
import :HTTP;
import :HTTP1;
import :TLS;

#ifndef CRAFTER_NETWORK_BROWSER
namespace Crafter {
    // HTTP/1.1 client over TCP, with or without TLS, for peers that cannot
    // speak HTTP/3. The request/response types are the ones the HTTP/3 client
    // uses, so swapping ClientHTTP for ClientHTTP1 is a one-line change at the
    // call site.
    //
    // The connection is persistent: the first Send() dials, and later calls
    // reuse the socket unless the peer asked for it to be closed
    // (`Connection: close`, or an HTTP/1.0 response without
    // `Connection: keep-alive`). A reused connection that turns out to have
    // been closed by the peer in the meantime — the unavoidable race in
    // HTTP/1.1 keep-alive — is redialled once and the request replayed;
    // a freshly dialled connection is never replayed on, so a genuinely
    // broken server surfaces as an exception rather than a retry loop.
    //
    // Thread-affinity matches ClientHTTP: one ClientHTTP1 serves one caller
    // at a time; distinct instances are independent.
    //
    // `http://` or `https://` is chosen by the constructor: pass
    // TLSClientCredentials and every byte goes through libssl (see :TLS),
    // leave them out and the transport is plaintext. TLS changes nothing
    // above the transport — the same keep-alive, replay and framing rules
    // apply, and `authority` still defaults to host:port with the scheme's
    // default port elided (443 under TLS, 80 without).
    export class ClientHTTP1 {
    public:
        std::string host;
        std::uint16_t port;

        ClientHTTP1(const char* host, std::uint16_t port);
        ClientHTTP1(std::string host, std::uint16_t port);

        // https://. The credentials verify the server's certificate chain and
        // its name against `host` by default; see TLSClientCredentials for
        // self-signed peers, private trust anchors and client certificates.
        // Throws TLSException if the certificate is rejected.
        ClientHTTP1(const char* host, std::uint16_t port, TLSClientCredentials credentials);
        ClientHTTP1(std::string host, std::uint16_t port, TLSClientCredentials credentials);

        ~ClientHTTP1();
        ClientHTTP1(const ClientHTTP1&) = delete;
        ClientHTTP1(ClientHTTP1&&) noexcept;

        // Send a request and read the full response. `authority` defaults to
        // the host:port this client was constructed with; `scheme` is ignored
        // — HTTP/1.1 request targets are origin-form and the transport was
        // already decided by the constructor.
        HTTPResponse Send(const HTTPRequest& request);

        // Send a request and deliver the response (or the error text) via
        // callback, on Crafter.Thread's ThreadPool.
        void SendAsync(const HTTPRequest& request,
                       std::function<void(HTTPResponse)> onSuccess,
                       std::function<void(std::string)> onError);

        // Whether a pooled connection is currently open. Mostly useful for
        // tests asserting that keep-alive actually kept the socket.
        bool Connected() const noexcept;

        // Whether this client speaks https://.
        bool Secure() const noexcept;

        // ALPN protocol the last connection negotiated, empty for plaintext
        // or when the server offered no ALPN. For an https:// client with the
        // default credentials this is "http/1.1".
        std::string_view Protocol() const noexcept;

        // Drop the pooled connection; the next Send() dials again.
        void Disconnect();

        // Limits applied to responses. Set before the first Send().
        HTTP1::MessageLimits limits;
        // How long to wait for the next piece of a response before giving
        // up on a server that accepted the connection and then went quiet.
        std::chrono::milliseconds timeout{30000};
        // How long the TLS handshake may take, on an https:// client. Separate
        // from `timeout` because it covers a multi-round-trip exchange before
        // any request has been written.
        std::chrono::milliseconds handshakeTimeout{15000};
        // How long the TCP connect may take, for each address the host
        // resolves to (see ClientTCP). Without it a host that drops the SYNs
        // held Send() for the kernel's retries, about two minutes, whatever
        // `timeout` said.
        std::chrono::milliseconds connectTimeout{15000};

    private:
        struct Impl;
        std::unique_ptr<Impl> impl;
    };

    // What FetchHTTP1 needs beyond the URL.
    export struct FetchOptionsHTTP1 {
        std::string method = "GET";
        // Lowercase names, as on HTTPRequest. Host comes from the URL.
        std::unordered_map<std::string, std::string> headers;
        std::string body;
        // As on ClientHTTP1, for every request of the chain.
        std::chrono::milliseconds connectTimeout{15000};
        std::chrono::milliseconds handshakeTimeout{15000};
        std::chrono::milliseconds timeout{30000};
        HTTP1::MessageLimits limits;
        // For every https:// request of the chain.
        TLSClientCredentials credentials;
        // Python urllib's limits: a chain stops at a redirect to a URL it has
        // already been sent to `maxRepeats` times, or once it has been sent
        // to `maxRedirects` different URLs.
        std::uint32_t maxRedirects = 10;
        std::uint32_t maxRepeats = 4;
    };

    export struct FetchResultHTTP1 {
        // The last response of the chain. A redirect only when it had nothing
        // to follow — no Location, a method urllib does not redirect, a
        // scheme other than http(s) — or when the limits stopped the chain.
        HTTPResponse response;
        // The URL that answered with `response`.
        std::string url;
        // Redirects followed to get there.
        std::uint32_t redirects = 0;
        // The limits stopped the chain; `response` is the redirect that would
        // have gone past them.
        bool limited = false;
    };

    // One request to an http:// or https:// URL, following redirects the way
    // Python's urllib does, so a port of urllib code keeps its behaviour:
    // 301, 302, 303, 307 and 308 are followed for GET and HEAD, the first
    // three also for POST; the redirected request is a GET (a HEAD stays a
    // HEAD) without the body and its content headers. A relative Location is
    // resolved against the URL that sent it, as urljoin resolves it; a
    // redirect may switch between http:// and https://. Each redirect's body
    // is read before the next request goes out. Proxies are not consulted.
    //
    // The URL is `scheme://[user@]host[:port][/path][?query][#fragment]`,
    // with an IPv6 host in brackets; the fragment is not sent and the user
    // part is dropped. Throws std::invalid_argument for a URL that is not
    // http(s) or has no host or a bad port, and whatever a request throws
    // (SocketErrorException, SocketTimeoutException, TLSException,
    // std::runtime_error) otherwise.
    export FetchResultHTTP1 FetchHTTP1(std::string_view url, const FetchOptionsHTTP1& options = {});
}
#endif