// Aseprite
// Copyright (C) 2018-2020  Igara Studio S.A.
// Copyright (C) 2001-2018  David Capello
//
// This program is distributed under the terms of
// the End-User License Agreement for Aseprite.

#ifndef APP_DOC_H_INCLUDED
#define APP_DOC_H_INCLUDED
#pragma once

#include "app/doc_observer.h"
#include "app/extra_cel.h"
#include "app/file/format_options.h"
#include "app/transformation.h"
#include "base/disable_copying.h"
#include "base/mutex.h"
#include "base/rw_lock.h"
#include "doc/blend_mode.h"
#include "doc/color.h"
#include "doc/document.h"
#include "doc/frame.h"
#include "doc/mask_boundaries.h"
#include "doc/pixel_format.h"
#include "gfx/rect.h"
#include "obs/observable.h"
#include "os/color_space.h"

#include <atomic>
#include <memory>
#include <string>

namespace doc {
  class Cel;
  class Layer;
  class Mask;
  class Sprite;
}

namespace gfx {
  class Region;
}

namespace app {

  class Context;
  class DocApi;
  class DocUndo;
  class Transaction;

  using namespace doc;

  enum DuplicateType {
    DuplicateExactCopy,
    DuplicateWithFlattenLayers,
  };

  // An application document. It is the class used to contain one file
  // opened and being edited by the user (a sprite).
  class Doc : public doc::Document,
              public obs::observable<DocObserver> {
    enum Flags {
      kAssociatedToFile = 1, // This sprite is associated to a file in the file-system
      kMaskVisible      = 2, // The mask wasn't hidden by the user
      kInhibitBackup    = 4, // Inhibit the backup process
      kFullyBackedUp    = 8, // Full backup was done
    };
  public:
    Doc(Sprite* sprite);
    ~Doc();

    Context* context() const { return m_ctx; }
    void setContext(Context* ctx);

    // Lock/unlock API (RWLock wrapper)
    bool canWriteLockFromRead() const;
    bool readLock(int timeout);
    bool writeLock(int timeout);
    bool upgradeToWrite(int timeout);
    void downgradeToRead();
    void unlock();

    bool weakLock(std::atomic<base::RWLock::WeakLock>* weak_lock_flag);
    void weakUnlock();

    // Sets active/running transaction.
    void setTransaction(Transaction* transaction);
    Transaction* transaction() { return m_transaction; }

    // Returns a high-level API: observable and undoable methods.
    DocApi getApi(Transaction& transaction);

    //////////////////////////////////////////////////////////////////////
    // Main properties

    const DocUndo* undoHistory() const { return m_undo.get(); }
    DocUndo* undoHistory() { return m_undo.get(); }

    color_t bgColor() const;
    color_t bgColor(Layer* layer) const;

    os::ColorSpaceRef osColorSpace() const { return m_osColorSpace; }

    //////////////////////////////////////////////////////////////////////
    // Notifications

    void notifyGeneralUpdate();
    void notifyColorSpaceChanged();
    void notifyPaletteChanged();
    void notifySpritePixelsModified(Sprite* sprite, const gfx::Region& region, frame_t frame);
    void notifyExposeSpritePixels(Sprite* sprite, const gfx::Region& region);
    void notifyLayerMergedDown(Layer* srcLayer, Layer* targetLayer);
    void notifyCelMoved(Layer* fromLayer, frame_t fromFrame, Layer* toLayer, frame_t toFrame);
    void notifyCelCopied(Layer* fromLayer, frame_t fromFrame, Layer* toLayer, frame_t toFrame);
    void notifySelectionChanged();
    void notifySelectionBoundariesChanged();

    //////////////////////////////////////////////////////////////////////
    // File related properties

    bool isModified() const;
    bool isAssociatedToFile() const;
    void markAsSaved();

    // You can use this to indicate that we've destroyed (or we cannot
    // trust) the file associated with the document (e.g. when we
    // cancel a Save operation in the middle). So it's impossible to
    // back to the saved state using the UndoHistory.
    void impossibleToBackToSavedState();

    // Returns true if it does make sense to create a backup in this
    // document. For example, it doesn't make sense to create a backup
    // for an unmodified document.
    bool needsBackup() const;

    // Can be used to avoid creating a backup when the file is in a
    // unusual temporary state (e.g. when the file is resized to be
    // exported with other size)
    bool inhibitBackup() const;
    void setInhibitBackup(const bool inhibitBackup);

    void markAsBackedUp();
    bool isFullyBackedUp() const;

    //////////////////////////////////////////////////////////////////////
    // Loaded options from file

    void setFormatOptions(const FormatOptionsPtr& format_options);
    FormatOptionsPtr formatOptions() const { return m_format_options; }

    //////////////////////////////////////////////////////////////////////
    // Boundaries

    void destroyMaskBoundaries();
    void generateMaskBoundaries(const Mask* mask = nullptr);

    const MaskBoundaries& maskBoundaries() const {
      return m_maskBoundaries;
    }

    MaskBoundaries& maskBoundaries() {
      return m_maskBoundaries;
    }

    bool hasMaskBoundaries() const {
      return !m_maskBoundaries.isEmpty();
    }

    //////////////////////////////////////////////////////////////////////
    // Extra Cel (it is used to draw pen preview, pixels in movement, etc.)

    ExtraCelRef extraCel() const { return m_extraCel; }
    void setExtraCel(const ExtraCelRef& extraCel) { m_extraCel = extraCel; }

    //////////////////////////////////////////////////////////////////////
    // Mask

    // Returns the current mask, it can be empty. The mask could be not
    // empty but hidden to the user if the setMaskVisible(false) was
    // used called before.
    Mask* mask() const { return m_mask.get(); }

    // Sets the current mask. The new mask will be visible by default,
    // so you don't need to call setMaskVisible(true).
    void setMask(const Mask* mask);

    // Returns true only when the mask is not empty, and was not yet
    // hidden using setMaskVisible (e.g. when the user "deselect the
    // mask").
    bool isMaskVisible() const;

    // Changes the visibility state of the mask (it is useful only if
    // the getMask() is not empty and the user can see that the mask is
    // being hidden and shown to him).
    void setMaskVisible(bool visible);

    //////////////////////////////////////////////////////////////////////
    // Transformation

    Transformation getTransformation() const;
    void setTransformation(const Transformation& transform);
    void resetTransformation();

    //////////////////////////////////////////////////////////////////////
    // Last point used to draw straight lines using freehand tools + Shift key
    // (EditorCustomizationDelegate::isStraightLineFromLastPoint() modifier)

    static gfx::Point NoLastDrawingPoint();
    gfx::Point lastDrawingPoint() const { return m_lastDrawingPoint; }
    void setLastDrawingPoint(const gfx::Point& pos) { m_lastDrawingPoint = pos; }

    //////////////////////////////////////////////////////////////////////
    // Copying

    void copyLayerContent(const Layer* sourceLayer, Doc* destDoc, Layer* destLayer) const;
    Doc* duplicate(DuplicateType type) const;

    void close();

  protected:
    void onFileNameChange() override;
    virtual void onContextChanged();

  private:
    void removeFromContext();
    void updateOSColorSpace(bool appWideSignal);

    // The document is in the collection of documents of this context.
    Context* m_ctx;

    // Internal states of the document.
    int m_flags;

    // Read-Write locks.
    base::RWLock m_rwLock;

    // Undo and redo information about the document.
    std::unique_ptr<DocUndo> m_undo;

    // Current transaction for this document (when this is commit(), a
    // new undo command is added to m_undo).
    Transaction* m_transaction;

    // Selected mask region boundaries
    doc::MaskBoundaries m_maskBoundaries;

    // Data to save the file in the same format that it was loaded
    FormatOptionsPtr m_format_options;

    // Extra cel used to draw extra stuff (e.g. editor's pen preview, pixels in movement, etc.)
    ExtraCelRef m_extraCel;

    // Current mask.
    std::unique_ptr<doc::Mask> m_mask;

    // Current transformation.
    Transformation m_transformation;

    gfx::Point m_lastDrawingPoint;

    // Last used color space to render a sprite.
    os::ColorSpaceRef m_osColorSpace;

    DISABLE_COPYING(Doc);
  };

} // namespace app

#endif
