//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
//  SPDX-License-Identifier: GPL-3.0-or-later

#include "request.h"

#include "response/response.h"

constexpr static const char* REQUEST_METHOD("REQUEST_METHOD");
constexpr static const char* SCRIPT_FILENAME("SCRIPT_FILENAME");
constexpr static const char* SERVER_NAME("SERVER_NAME");
constexpr static const char* CONTENT_TYPE("CONTENT_TYPE");
constexpr static const char* CONTENT_LENGTH("CONTENT_LENGTH");

constexpr static const char* urlEncoded("application/x-www-form-urlencoded");

// constexpr static const char* REQUEST_URI("REQUEST_URI");
//
// constexpr static const char* DOCUMENT_URI("DOCUMENT_URI");
// constexpr static const char* DOCUMENT_ROOT("DOCUMENT_ROOT");
//
// constexpr static const char* SCRIPT_NAME("SCRIPT_NAME");

constexpr std::array<
    std::pair<std::string_view, Request::Method>,
    static_cast<uint8_t>(Request::Method::unknown)
> methods = {{
    {"GET", Request::Method::get},
    {"POST", Request::Method::post}
}};

Request::Request ():
    state(State::initial),
    raw(),
    response(nullptr)
{}

Request::~Request() {
    terminate();
}

void Request::terminate() {
    switch (state) {
        case State::accepted:
        case State::responded:
            FCGX_Finish_r(&raw);
            break;
        default:
            break;
    }
}

std::string_view Request::methodName() const {
    if (state == State::initial)
        throw std::runtime_error("An attempt to read request method on not accepted request");

    return FCGX_GetParam(REQUEST_METHOD, raw.envp);
}

Request::Method Request::method() const {
    std::string_view method =  methodName();
    for (const auto& pair : methods) {
        if (pair.first == method)
            return pair.second;
    }

    return Request::Method::unknown;
}

bool Request::wait(int socketDescriptor) {
    if (state != State::initial)
        throw std::runtime_error("An attempt to wait for new incomming request on a wrong request state");

    FCGX_Request* request = &raw;
    FCGX_InitRequest(request, socketDescriptor, 0);
    int rc = FCGX_Accept_r(request);

    bool result = rc == 0;
    if (result)
        state = State::accepted;

    return result;
}

OStream Request::getOutputStream() {
    return OStream(raw.out);
}

OStream Request::getErrorStream() {
    return OStream(raw.err);
}

Response& Request::createResponse() {
    if (state != State::accepted)
        throw std::runtime_error("An attempt create response to the request in the wrong state");

    response = std::unique_ptr<Response>(new Response(*this));
    state = State::responding;

    return *response.get();
}

Response& Request::createResponse(Response::Status status) {
    if (state != State::accepted)
        throw std::runtime_error("An attempt create response to the request in the wrong state");

    response = std::unique_ptr<Response>(new Response(*this, status));
    state = State::responding;

    return *response.get();
}

uint16_t Request::responseCode() const {
    if (state != State::responded)
        throw std::runtime_error("An attempt create read response code on the wrong state");

    return response->statusCode();
}

void Request::responseIsComplete() {
    switch (state) {
        case State::initial:
            throw std::runtime_error("An attempt to mark the request as complete, but it wasn't even accepted yet");
            break;
        case State::accepted:
            throw std::runtime_error("An attempt to mark the request as complete, but it wasn't responded");
            break;
        case State::responding:
            state = State::responded;
            break;
        case State::responded:
            throw std::runtime_error("An attempt to mark the request as a complete for the second time");
            break;
    }
}

Request::State Request::currentState() const {
    return state;
}

std::string Request::getPath(const std::string& serverName) const {
    if (state != State::accepted)
        throw std::runtime_error("An attempt to request path on a wrong request state");

    std::string path;
    std::string_view scriptFileName(FCGX_GetParam(SCRIPT_FILENAME, raw.envp));
    std::string::size_type snLocation = scriptFileName.find(serverName);

    if (snLocation != std::string::npos) {
        if (snLocation + serverName.size() < scriptFileName.size())
            path = scriptFileName.substr(snLocation + serverName.size() + 1);

    }

    if (!path.empty()) {
        while (path.back() == '/')
            path.erase(path.end() - 1);
    }

    return path;
}

std::string Request::getServerName() const {
    if (state != State::accepted)
        throw std::runtime_error("An attempt to request server name on a wrong request state");

    return FCGX_GetParam(SERVER_NAME, raw.envp);;
}

void Request::printEnvironment(std::ostream& out) {
    char **envp = raw.envp;
    for (int i = 0; envp[i] != nullptr; ++i) {
        out << envp[i] << "\n";
    }
}

void Request::printEnvironment(nlohmann::json& out) {
    if (!out.is_object())
        return;

    char **envp = raw.envp;
    for (int i = 0; envp[i] != nullptr; ++i) {
        std::string_view value(envp[i]);
        std::string::size_type pos = value.find('=');
        if (pos != std::string::npos)
            out[std::string(value.substr(0, pos))] = std::string(value.substr(pos + 1, value.size()));
    }
}

bool Request::isFormUrlEncoded() const {
    if (state == State::initial)
        throw std::runtime_error("An attempt to read request content type on not accepted request");

    std::string_view contentType(FCGX_GetParam(CONTENT_TYPE, raw.envp));
    if (!contentType.empty() && contentType.find(urlEncoded) != std::string_view::npos) {
        return true;
    }

    return false;
}

unsigned int Request::contentLength() const {
    if (state == State::initial)
        throw std::runtime_error("An attempt to read request content length on not accepted request");

    return atoi(FCGX_GetParam(CONTENT_LENGTH, raw.envp));
}

std::map<std::string, std::string> Request::getForm() const {
    if (state == State::initial)
        throw std::runtime_error("An attempt to read form on not accepted request");

    std::map<std::string, std::string> result;
    std::string_view contentType(FCGX_GetParam(CONTENT_TYPE, raw.envp));
    if (contentType.empty())
        return result;

    unsigned int length = contentLength();
    if (contentType.find(urlEncoded) != std::string_view::npos) {
        std::string postData(length, '\0');
        FCGX_GetStr(&postData[0], length, raw.in);
        result = urlDecodeAndParse(postData);
    }

    return result;
}