//  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* GET("GET");

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* 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;
    }
}

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

    std::string_view method(FCGX_GetParam(REQUEST_METHOD, raw.envp));
    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(const Response* response) {
    validateResponse(response);
    return OStream(raw.out);
}

OStream Request::getErrorStream(const Response* response) {
    validateResponse(response);
    return OStream(raw.err);
}

void Request::responseIsComplete(const Response* response) {
    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:
            if (Request::response != response)
                throw std::runtime_error("An attempt to mark the request as complete by the different response who actually started responding");

            Request::response = nullptr;
            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;
    }
}

void Request::validateResponse(const Response* response) {
    switch (state) {
        case State::initial:
            throw std::runtime_error("An attempt to request stream while the request wasn't even accepted yet");
            break;
        case State::accepted:
            Request::response = response;
            state = State::responding;
            break;
        case State::responding:
            if (Request::response != response)
                throw std::runtime_error("Error handling a request: first time one response started replying, then another continued");

            break;
        case State::responded:
            throw std::runtime_error("An attempt to request stream on a request that was already done responding");
            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()));
    }
}