/*
 * Copyright (C) 2024-2025 Petr Mironychev
 *
 * This file is part of QodeAssist.
 *
 * QodeAssist is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * QodeAssist is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with QodeAssist. If not, see <https://www.gnu.org/licenses/>.
 */

#include "OpenAIProvider.hpp"

#include "settings/ChatAssistantSettings.hpp"
#include "settings/CodeCompletionSettings.hpp"
#include "settings/ProviderSettings.hpp"

#include <QEventLoop>
#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>
#include <QNetworkReply>

#include "llmcore/OpenAIMessage.hpp"
#include "llmcore/ValidationUtils.hpp"
#include "logger/Logger.hpp"

namespace QodeAssist::Providers {

QString OpenAIProvider::name() const
{
    return "OpenAI";
}

QString OpenAIProvider::url() const
{
    return "https://api.openai.com";
}

QString OpenAIProvider::completionEndpoint() const
{
    return "/v1/chat/completions";
}

QString OpenAIProvider::chatEndpoint() const
{
    return "/v1/chat/completions";
}

bool OpenAIProvider::supportsModelListing() const
{
    return true;
}

void OpenAIProvider::prepareRequest(
    QJsonObject &request,
    LLMCore::PromptTemplate *prompt,
    LLMCore::ContextData context,
    LLMCore::RequestType type)
{
    if (!prompt->isSupportProvider(providerID())) {
        LOG_MESSAGE(QString("Template %1 doesn't support %2 provider").arg(name(), prompt->name()));
    }

    prompt->prepareRequest(request, context);

    auto applyModelParams = [&request](const auto &settings) {
        request["max_tokens"] = settings.maxTokens();
        request["temperature"] = settings.temperature();

        if (settings.useTopP())
            request["top_p"] = settings.topP();
        if (settings.useTopK())
            request["top_k"] = settings.topK();
        if (settings.useFrequencyPenalty())
            request["frequency_penalty"] = settings.frequencyPenalty();
        if (settings.usePresencePenalty())
            request["presence_penalty"] = settings.presencePenalty();
    };

    if (type == LLMCore::RequestType::CodeCompletion) {
        applyModelParams(Settings::codeCompletionSettings());
    } else {
        applyModelParams(Settings::chatAssistantSettings());
    }
}

bool OpenAIProvider::handleResponse(QNetworkReply *reply, QString &accumulatedResponse)
{
    QByteArray data = reply->readAll();
    if (data.isEmpty()) {
        return false;
    }

    bool isDone = false;
    QByteArrayList lines = data.split('\n');

    for (const QByteArray &line : lines) {
        if (line.trimmed().isEmpty()) {
            continue;
        }

        if (line == "data: [DONE]") {
            isDone = true;
            continue;
        }

        QByteArray jsonData = line;
        if (line.startsWith("data: ")) {
            jsonData = line.mid(6);
        }

        QJsonParseError error;
        QJsonDocument doc = QJsonDocument::fromJson(jsonData, &error);

        if (doc.isNull()) {
            continue;
        }

        auto message = LLMCore::OpenAIMessage::fromJson(doc.object());
        if (message.hasError()) {
            LOG_MESSAGE("Error in OpenAI response: " + message.error);
            continue;
        }

        QString content = message.getContent();
        if (!content.isEmpty()) {
            accumulatedResponse += content;
        }

        if (message.isDone()) {
            isDone = true;
        }
    }

    return isDone;
}

QList<QString> OpenAIProvider::getInstalledModels(const QString &url)
{
    QList<QString> models;
    QNetworkAccessManager manager;
    QNetworkRequest request(QString("%1/v1/models").arg(url));

    request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
    if (!apiKey().isEmpty()) {
        request.setRawHeader("Authorization", QString("Bearer %1").arg(apiKey()).toUtf8());
    }

    QNetworkReply *reply = manager.get(request);
    QEventLoop loop;
    QObject::connect(reply, &QNetworkReply::finished, &loop, &QEventLoop::quit);
    loop.exec();

    if (reply->error() == QNetworkReply::NoError) {
        QByteArray responseData = reply->readAll();
        QJsonDocument jsonResponse = QJsonDocument::fromJson(responseData);
        QJsonObject jsonObject = jsonResponse.object();

        if (jsonObject.contains("data")) {
            QJsonArray modelArray = jsonObject["data"].toArray();
            for (const QJsonValue &value : modelArray) {
                QJsonObject modelObject = value.toObject();
                if (modelObject.contains("id")) {
                    QString modelId = modelObject["id"].toString();
                    if (!modelId.contains("dall-e") && !modelId.contains("whisper")
                        && !modelId.contains("tts") && !modelId.contains("davinci")
                        && !modelId.contains("babbage") && !modelId.contains("omni")) {
                        models.append(modelId);
                    }
                }
            }
        }
    } else {
        LOG_MESSAGE(QString("Error fetching ChatGPT models: %1").arg(reply->errorString()));
    }

    reply->deleteLater();
    return models;
}

QList<QString> OpenAIProvider::validateRequest(const QJsonObject &request, LLMCore::TemplateType type)
{
    const auto templateReq = QJsonObject{
        {"model", {}},
        {"messages", QJsonArray{{QJsonObject{{"role", {}}, {"content", {}}}}}},
        {"temperature", {}},
        {"max_tokens", {}},
        {"top_p", {}},
        {"top_k", {}},
        {"frequency_penalty", {}},
        {"presence_penalty", {}},
        {"stop", QJsonArray{}},
        {"stream", {}}};

    return LLMCore::ValidationUtils::validateRequestFields(request, templateReq);
}

QString OpenAIProvider::apiKey() const
{
    return Settings::providerSettings().openAiApiKey();
}

void OpenAIProvider::prepareNetworkRequest(QNetworkRequest &networkRequest) const
{
    networkRequest.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");

    if (!apiKey().isEmpty()) {
        networkRequest.setRawHeader("Authorization", QString("Bearer %1").arg(apiKey()).toUtf8());
    }
}

LLMCore::ProviderID OpenAIProvider::providerID() const
{
    return LLMCore::ProviderID::OpenAI;
}

} // namespace QodeAssist::Providers