/* 
 * 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 "GoogleAIProvider.hpp"

#include <QEventLoop>
#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>
#include <QNetworkReply>
#include <QtCore/qurlquery.h>

#include "llmcore/ValidationUtils.hpp"
#include "logger/Logger.hpp"
#include "settings/ChatAssistantSettings.hpp"
#include "settings/CodeCompletionSettings.hpp"
#include "settings/ProviderSettings.hpp"

namespace QodeAssist::Providers {

QString GoogleAIProvider::name() const
{
    return "Google AI";
}

QString GoogleAIProvider::url() const
{
    return "https://generativelanguage.googleapis.com/v1beta";
}

QString GoogleAIProvider::completionEndpoint() const
{
    return {};
}

QString GoogleAIProvider::chatEndpoint() const
{
    return {};
}

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

void GoogleAIProvider::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) {
        QJsonObject generationConfig;
        generationConfig["maxOutputTokens"] = settings.maxTokens();
        generationConfig["temperature"] = settings.temperature();

        if (settings.useTopP())
            generationConfig["topP"] = settings.topP();
        if (settings.useTopK())
            generationConfig["topK"] = settings.topK();

        request["generationConfig"] = generationConfig;
    };

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

QList<QString> GoogleAIProvider::getInstalledModels(const QString &url)
{
    QList<QString> models;

    QNetworkAccessManager manager;
    QNetworkRequest request(QString("%1/models?key=%2").arg(url, apiKey()));

    request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");

    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("models")) {
            QJsonArray modelArray = jsonObject["models"].toArray();
            models.clear();

            for (const QJsonValue &value : modelArray) {
                QJsonObject modelObject = value.toObject();
                if (modelObject.contains("name")) {
                    QString modelName = modelObject["name"].toString();
                    if (modelName.contains("/")) {
                        modelName = modelName.split("/").last();
                    }
                    models.append(modelName);
                }
            }
        }
    } else {
        LOG_MESSAGE(QString("Error fetching Google AI models: %1").arg(reply->errorString()));
    }

    reply->deleteLater();
    return models;
}

QList<QString> GoogleAIProvider::validateRequest(
    const QJsonObject &request, LLMCore::TemplateType type)
{
    QJsonObject templateReq;

    templateReq = QJsonObject{
        {"contents", QJsonArray{}},
        {"system_instruction", QJsonArray{}},
        {"generationConfig",
         QJsonObject{{"temperature", {}}, {"maxOutputTokens", {}}, {"topP", {}}, {"topK", {}}}},
        {"safetySettings", QJsonArray{}}};

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

QString GoogleAIProvider::apiKey() const
{
    return Settings::providerSettings().googleAiApiKey();
}

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

    QUrl url = networkRequest.url();
    QUrlQuery query(url.query());
    query.addQueryItem("key", apiKey());
    url.setQuery(query);
    networkRequest.setUrl(url);
}

LLMCore::ProviderID GoogleAIProvider::providerID() const
{
    return LLMCore::ProviderID::GoogleAI;
}

void GoogleAIProvider::sendRequest(
    const LLMCore::RequestID &requestId, const QUrl &url, const QJsonObject &payload)
{
    m_dataBuffers[requestId].clear();
    m_requestUrls[requestId] = url;

    QNetworkRequest networkRequest(url);
    prepareNetworkRequest(networkRequest);

    LLMCore::HttpRequest
        request{.networkRequest = networkRequest, .requestId = requestId, .payload = payload};

    LOG_MESSAGE(
        QString("GoogleAIProvider: Sending request %1 to %2").arg(requestId, url.toString()));

    emit httpClient()->sendRequest(request);
}

void GoogleAIProvider::onDataReceived(
    const QodeAssist::LLMCore::RequestID &requestId, const QByteArray &data)
{
    if (data.isEmpty()) {
        return;
    }

    QJsonParseError parseError;
    QJsonDocument doc = QJsonDocument::fromJson(data, &parseError);
    if (!doc.isNull() && doc.isObject()) {
        QJsonObject obj = doc.object();
        if (obj.contains("error")) {
            QJsonObject error = obj["error"].toObject();
            QString errorMessage = error["message"].toString();
            int errorCode = error["code"].toInt();
            QString fullError
                = QString("Google AI API Error %1: %2").arg(errorCode).arg(errorMessage);

            LOG_MESSAGE(fullError);
            emit requestFailed(requestId, fullError);
            m_dataBuffers.remove(requestId);
            return;
        }
    }

    bool isDone = handleStreamResponse(requestId, data);

    if (isDone) {
        LLMCore::DataBuffers &buffers = m_dataBuffers[requestId];
        emit fullResponseReceived(requestId, buffers.responseContent);
        m_dataBuffers.remove(requestId);
    }
}

void GoogleAIProvider::onRequestFinished(
    const QodeAssist::LLMCore::RequestID &requestId, bool success, const QString &error)
{
    if (!success) {
        LOG_MESSAGE(QString("GoogleAIProvider request %1 failed: %2").arg(requestId, error));
        emit requestFailed(requestId, error);
    } else {
        if (m_dataBuffers.contains(requestId)) {
            const LLMCore::DataBuffers &buffers = m_dataBuffers[requestId];
            if (!buffers.responseContent.isEmpty()) {
                emit fullResponseReceived(requestId, buffers.responseContent);
            }
        }
    }

    m_dataBuffers.remove(requestId);
    m_requestUrls.remove(requestId);
}

bool GoogleAIProvider::handleStreamResponse(
    const LLMCore::RequestID &requestId, const QByteArray &data)
{
    LLMCore::DataBuffers &buffers = m_dataBuffers[requestId];
    QStringList lines = buffers.rawStreamBuffer.processData(data);

    bool isDone = false;
    QString tempResponse;

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

        QJsonObject responseObj = parseEventLine(line);
        if (responseObj.isEmpty())
            continue;

        if (responseObj.contains("candidates")) {
            QJsonArray candidates = responseObj["candidates"].toArray();
            for (const QJsonValue &candidate : candidates) {
                QJsonObject candidateObj = candidate.toObject();
                if (candidateObj.contains("content")) {
                    QJsonObject content = candidateObj["content"].toObject();
                    if (content.contains("parts")) {
                        QJsonArray parts = content["parts"].toArray();
                        for (const QJsonValue &part : parts) {
                            QJsonObject partObj = part.toObject();
                            if (partObj.contains("text")) {
                                tempResponse += partObj["text"].toString();
                            }
                        }
                    }
                }

                if (candidateObj.contains("finishReason")) {
                    isDone = true;
                }
            }
        }
    }

    if (!tempResponse.isEmpty()) {
        buffers.responseContent += tempResponse;
        emit partialResponseReceived(requestId, tempResponse);
    }

    return isDone;
}

} // namespace QodeAssist::Providers