/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/

#include "ArticleViewContainer.h"
#include "ArticleView.h"
#include "NewsShared/ResourceManagement/ResourceManifest.h"
#include "NewsShared/ResourceManagement/ArticleDescriptor.h"
#include "NewsShared/ResourceManagement/Resource.h"
#include "NewsShared/Qt/ArticleErrorView.h"
#include "NewsShared/Qt/KeepInTouchView.h"
#include "NewsShared/Qt/ui_ArticleViewContainer.h"

#include <QLabel>
#include <QMap>

namespace News
{

    ArticleViewContainer::ArticleViewContainer(QWidget* parent, ResourceManifest& manifest)
        : QWidget(parent)
        , m_ui(new Ui::ArticleViewContainerWidget)
        , m_manifest(manifest)
        , m_loadingLabel(nullptr)
        , m_errorMessage(nullptr)
    {
        m_ui->setupUi(this);
        AddLoadingMessage();

        m_keepInTouchViewWidget = new KeepInTouchView(this);
        m_keepInTouchViewWidget->setVisible(false);
        connect(m_keepInTouchViewWidget, &KeepInTouchView::linkActivatedSignal,
            this, &ArticleViewContainer::linkActivatedSignal);
    }

    ArticleViewContainer::~ArticleViewContainer() {}

    void ArticleViewContainer::PopulateArticles()
    {
        Clear();

        bool articlesFound = false;
        for (auto id : m_manifest.GetOrder())
        {
            auto pResource = m_manifest.FindById(id);
            if (pResource && pResource->GetType().compare("article") == 0)
            {
                AddArticleView(ArticleDescriptor(*pResource));
                articlesFound = true;
            }
        }

        if (!articlesFound)
        {
            AddErrorMessage();
        }
        else
        {
            auto layout = static_cast<QVBoxLayout*>(m_ui->articleViewContents->layout());
            layout->insertWidget(layout->count() - 1, m_keepInTouchViewWidget);
            m_keepInTouchViewWidget->setVisible(true);
        }

        qApp->processEvents();
    }

    ArticleView* ArticleViewContainer::FindById(const QString& id)
    {
        auto it = std::find_if(
            m_articles.begin(),
            m_articles.end(),
            [id](ArticleView* articleView) -> bool
        {
            if (!articleView)
            {
                return false;
            }
            return articleView->GetArticle()->GetResource().GetId().compare(id) == 0;
        });
        if (it == m_articles.end())
        {
            return nullptr;
        }
        return *it;
    }

    void ArticleViewContainer::AddArticleView(const ArticleDescriptor& articleDesc, int articlePosition)
    {
        ClearError();

        ArticleView* view = CreateArticleView(articleDesc);
        if (view == nullptr)
        {
            return;
        }

        m_articles.append(view);

        connect(view, &ArticleView::articleSelectedSignal,
            this, &ArticleViewContainer::articleSelectedSlot);
        connect(view, &ArticleView::linkActivatedSignal,
            this, &ArticleViewContainer::linkActivatedSignal);

        auto layout = static_cast<QVBoxLayout*>(m_ui->articleViewContents->layout());
        if (articlePosition == -1)
        {
            articlePosition = layout->count() - 1;
        }

        layout->insertWidget(articlePosition, view);
        qApp->processEvents();
    }

    void ArticleViewContainer::DeleteArticleView(ArticleView* view)
    {
        m_articles.removeAll(view);
        m_ui->articleViewContents->layout()->removeWidget(view);
        delete view;
    }

    void ArticleViewContainer::ForceRefreshArticleView(ArticleView* articleView)
    {
        if (articleView == nullptr)
        {
            return;
        }

        QSharedPointer<const ArticleDescriptor> articleDesc = articleView->GetArticle();
        auto layout = static_cast<QVBoxLayout*>(m_ui->articleViewContents->layout());
        const int viewIndex = layout->indexOf(articleView);

        DeleteArticleView(articleView);
        AddArticleView(*articleDesc, viewIndex);
    }

    void ArticleViewContainer::ScrollToView(ArticleView* view) const
    {
        m_ui->previewArea->ensureWidgetVisible(view);
    }

    void ArticleViewContainer::ClearError()
    {
        //delete loading label
        if (m_loadingLabel)
        {
            delete m_loadingLabel;
            m_loadingLabel = nullptr;
        }

        //delete error message
        if (m_errorMessage)
        {
            delete m_errorMessage;
            m_errorMessage = nullptr;
        }
    }

    void ArticleViewContainer::articleSelectedSlot(QString id)
    {
        emit articleSelectedSignal(id);
    }

    void ArticleViewContainer::UpdateArticleOrder(ArticleView* view, bool direction) const
    {
        QVBoxLayout* layout = qobject_cast<QVBoxLayout*>(m_ui->articleViewContents->layout());

        const int index = layout->indexOf(view);

        if (direction && index == 0)
        {
            return;
        }

        if (!direction && index == layout->count() - 2)
        {
            return;
        }

        const int newIndex = direction ? index - 1 : index + 1;
        layout->removeWidget(view);
        layout->insertWidget(newIndex, view);
    }

    void ArticleViewContainer::AddLoadingMessage()
    {
        if (m_errorMessage)
        {
            delete m_errorMessage;
            m_errorMessage = nullptr;
        }

        if (!m_loadingLabel)
        {
            m_loadingLabel = new QLabel(this);
            m_loadingLabel->setText("Retrieving news...");
            auto layout = static_cast<QVBoxLayout*>(m_ui->articleViewContents->layout());
            layout->insertWidget(0, m_loadingLabel);
        }
    }

    void ArticleViewContainer::AddErrorMessage()
    {
        if (m_loadingLabel)
        {
            delete m_loadingLabel;
            m_loadingLabel = nullptr;
        }

        if (!m_errorMessage)
        {
            m_errorMessage = new ArticleErrorView(this);
            auto layout = static_cast<QVBoxLayout*>(m_ui->articleViewContents->layout());
            layout->insertWidget(0, m_errorMessage);
        }
    }

    void ArticleViewContainer::Clear()
    {
        ClearError();

        for (auto articleView : m_articles)
        {
            delete articleView;
        }

        m_articles.clear();
    }

    ArticleViewContainer::ArticleStyle ArticleViewContainer::GetArticleStyleEnumFromString(const QString& articleStyleStr) const
    {
        static const QMap<QString, ArticleStyle> articleStyleStringEnumMap = {
            { "default", ArticleStyle::Default },
            { "pinned", ArticleStyle::Pinned }
        };

        if (articleStyleStringEnumMap.contains(articleStyleStr) == false)
        {
            Q_ASSERT(false);
            return ArticleStyle::Default;
        }

        return articleStyleStringEnumMap.value(articleStyleStr);
    }

    ArticleView* ArticleViewContainer::CreateArticleView(const ArticleDescriptor& articleDesc)
    {
        ArticleStyle articleStyle = GetArticleStyleEnumFromString(articleDesc.GetArticleStyle());

        switch(articleStyle)
        {
        case ArticleStyle::Default:
            return new ArticleViewDefaultWidget(this, articleDesc, m_manifest);
        case ArticleStyle::Pinned:
            return new ArticleViewPinnedWidget(this, articleDesc, m_manifest);
        default:
            Q_ASSERT(false);
            return nullptr;
        }
    }

}

#include "NewsShared/Qt/ArticleViewContainer.moc"