/*
 * Copyright (c) 2021, Peter Bocan  <me@pbocan.net>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/Base64.h>
#include <LibCore/ConfigFile.h>
#include <LibCore/EventLoop.h>
#include <LibCore/File.h>
#include <LibCrypto/ASN1/ASN1.h>
#include <LibTLS/TLSv12.h>
#include <LibTest/TestCase.h>

static char const* ca_certs_file = "./ca_certs.ini";
static int port = 443;

constexpr auto DEFAULT_SERVER = "www.google.com"sv;

static ByteBuffer operator""_b(char const* string, size_t length)
{
    return ByteBuffer::copy(string, length).release_value();
}

Vector<Certificate> load_certificates();
String locate_ca_certs_file();

String locate_ca_certs_file()
{
    if (Core::File::exists(ca_certs_file)) {
        return ca_certs_file;
    }
    auto on_target_path = String("/etc/ca_certs.ini");
    if (Core::File::exists(on_target_path)) {
        return on_target_path;
    }
    return "";
}

Vector<Certificate> load_certificates()
{
    Vector<Certificate> certificates;
    auto ca_certs_filepath = locate_ca_certs_file();
    if (ca_certs_filepath == "") {
        warnln("Could not locate ca_certs.ini file.");
        return certificates;
    }

    auto config = Core::ConfigFile::open(ca_certs_filepath).release_value_but_fixme_should_propagate_errors();
    for (auto& entity : config->groups()) {
        for (auto& subject : config->keys(entity)) {
            auto certificate_base64 = config->read_entry(entity, subject);
            auto certificate_data_result = decode_base64(certificate_base64);
            if (certificate_data_result.is_error()) {
                dbgln("Skipping CA Certificate {} {}: out of memory", entity, subject);
                continue;
            }
            auto certificate_data = certificate_data_result.release_value();
            auto certificate_result = Certificate::parse_asn1(certificate_data.bytes());
            // If the certificate does not parse it is likely using elliptic curve keys/signatures, which are not
            // supported right now. Currently, ca_certs.ini should only contain certificates with RSA keys/signatures.
            if (!certificate_result.has_value()) {
                dbgln("Skipping CA Certificate {} {}: unable to parse", entity, subject);
                continue;
            }
            auto certificate = certificate_result.release_value();
            certificates.append(move(certificate));
        }
    }
    return certificates;
}

static Vector<Certificate> s_root_ca_certificates = load_certificates();

TEST_CASE(test_TLS_hello_handshake)
{
    Core::EventLoop loop;
    TLS::Options options;
    options.set_root_certificates(s_root_ca_certificates);
    options.set_alert_handler([&](TLS::AlertDescription) {
        FAIL("Connection failure");
        loop.quit(1);
    });
    options.set_finish_callback([&] {
        loop.quit(0);
    });

    auto tls = MUST(TLS::TLSv12::connect(DEFAULT_SERVER, port, move(options)));
    ByteBuffer contents;
    tls->on_ready_to_read = [&] {
        auto read_bytes = MUST(tls->read(contents.must_get_bytes_for_writing(4 * KiB)));
        if (read_bytes.is_empty()) {
            FAIL("No data received");
            loop.quit(1);
        }
        loop.quit(0);
    };

    if (!tls->write_or_error("GET / HTTP/1.1\r\nHost: "_b)) {
        FAIL("write(0) failed");
        return;
    }

    auto the_server = DEFAULT_SERVER;
    if (!tls->write_or_error(the_server.bytes())) {
        FAIL("write(1) failed");
        return;
    }
    if (!tls->write_or_error("\r\nConnection : close\r\n\r\n"_b)) {
        FAIL("write(2) failed");
        return;
    }

    loop.exec();
}