/* This file is part of Spectacle, the KDE screenshot utility
 * SPDX-FileCopyrightText: 2015 Boudhayan Gupta <bgupta@kde.org>
 * SPDX-License-Identifier: LGPL-2.0-or-later
 */

#pragma once

#include "settings.h"
#include <KLocalizedString>
#include <QDateTime>
class QLockFile;
class QIODevice;
#include <QMap>
#include <QObject>
class QPrinter;
#include <QUrl>

class QTemporaryDir;

class ExportManager : public QObject
{
    Q_OBJECT

    // singleton-ize the class

public:
    static ExportManager *instance();

private:
    explicit ExportManager(QObject *parent = nullptr);
    ~ExportManager() override;

    ExportManager(ExportManager const &) = delete;
    void operator=(ExportManager const &) = delete;

    // now the usual stuff

public:
    enum Action {
        NoActions   = 0b00000,
        Save        = 0b00001,
        SaveAs      = 0b00010,
        CopyImage   = 0b00100,
        CopyPath    = 0b01000,
        UserAction  = 0b10000,
        AnySave     = Save | SaveAs,
        AnyAction   = AnySave | CopyImage | CopyPath,
    };
    Q_DECLARE_FLAGS(Actions, Action)
    Q_FLAG(Action)

    static QString defaultSaveLocation();
    static QString defaultVideoSaveLocation();
    bool isFileExists(const QUrl &url) const;
    bool isImageSavedNotInTemp() const;
    void setImage(const QImage &image);
    QImage image() const;
    void updateTimestamp();
    void setTimestamp(const QDateTime &timestamp);
    QDateTime timestamp() const;

    /**
     * Returns a formatted filename using a template string.
     */
    static QString formattedFilename(const QString &nameTemplate, const QDateTime &dateTime = {}, const QString &windowTitle = {}, const QUrl &saveLocation = {});

    /**
     * The URL to use for an automatically named and saved file.
     */
    QUrl getAutosaveFilename() const;

    /**
     * The URL to record a video with before it is exported.
     */
    QUrl tempVideoUrl(const QString &filename);

    const QTemporaryDir *temporaryDir();

    /**
     * Save a temporary screenshot file and return its URL.
     */
    QUrl tempSave();

    struct Placeholder {
        enum Flag {
            Other = 0,
            Date = 1,
            Time = 1 << 1,
            Extra = 1 << 28, //< Placeholders that are extras are hidden by default.
            Hidden = 1 << 29, //< Placeholders that won't be shown
            QDateTime = 1 << 30, //< Can be put directly into QDateTime::toString.
        };
        using Flags = QFlags<Flag>;

        const Flags flags;
        const QString token;
        const QStringView base;
        // Placeholders with empty descriptions will not be visible in the config UI
        const KLocalizedString description;

        Placeholder(const Flags &flags, const QString &key, const KLocalizedString &description)
            : flags(flags)
            , token(u"<" % key % u">")
            , base(token.cbegin() + 1, key.size())
            , description(description)
        {
        }

        Placeholder(const Flags &flags, const QString &key)
            : flags(flags | Hidden)
            , token(u"<" % key % u">")
            , base(token.cbegin() + 1, key.size())
        {
        }
    };

    static const QList<Placeholder> filenamePlaceholders;

    /**
     * Export an image with the given actions using the given URL or an automatically generated URL.
     */
    void exportImage(ExportManager::Actions actions, QUrl url = {});

    /**
     * Export an video with the given actions using the given URL or an automatically generated URL.
     */
    void exportVideo(ExportManager::Actions actions, const QUrl &inputUrl, QUrl outputUrl = {});

    /**
     * Scan the current image for a QR code.
     */
    void scanQRCode();

    /**
     * Print the current image with the given printer.
     */
    void doPrint(QPrinter *printer);

Q_SIGNALS:
    void imageChanged();

    void errorMessage(const QString &str);
    void imageExported(const ExportManager::Actions &actions, const QUrl &url = {});
    void videoExported(const ExportManager::Actions &actions, const QUrl &url = {});
    void qrCodeScanned(const QVariant &content);

private:
    static QString truncatedFilename(const QString &filename);
    using FileNameAlreadyUsedCheck = bool (ExportManager::*)(const QUrl &) const;
    QString autoIncrementFilename(const QString &baseName, const QString &extension, FileNameAlreadyUsedCheck isFileNameUsed) const;
    QString imageFileSuffix(const QUrl &url) const;
    bool writeImage(QIODevice *device, const QByteArray &suffix);
    bool save(const QUrl &url);
    bool localSave(const QUrl &url, const QString &suffix);
    bool remoteSave(const QUrl &url, const QString &suffix);
    bool isTempFileAlreadyUsed(const QUrl &url) const;

    bool m_imageSavedNotInTemp;
    QImage m_saveImage;
    QDateTime m_timestamp;
    QUrl m_tempFile;
    std::unique_ptr<QLockFile> m_tempDirLock;
    std::unique_ptr<QTemporaryDir> m_tempDir;
    QList<QUrl> m_usedTempFileNames;
};

Q_DECLARE_OPERATORS_FOR_FLAGS(ExportManager::Actions)
Q_DECLARE_OPERATORS_FOR_FLAGS(ExportManager::Placeholder::Flags)
