/*
 * automapperwrapper.cpp
 * Copyright 2010-2011, Stefan Beller <stefanbeller@googlemail.com>
 * Copyright 2018-2022, Thorbjørn Lindeijer <bjorn@lindeijer.nl>
 *
 * This file is part of Tiled.
 *
 * This program 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 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "automapperwrapper.h"

#include "addremovelayer.h"
#include "addremovemapobject.h"
#include "addremovetileset.h"
#include "automapper.h"
#include "changeproperties.h"
#include "map.h"
#include "mapdocument.h"
#include "mapobject.h"
#include "objectreferenceshelper.h"
#include "tile.h"
#include "tilelayer.h"

using namespace Tiled;

AutoMapperWrapper::AutoMapperWrapper(MapDocument *mapDocument,
                                     const QVector<AutoMapper *> &autoMappers,
                                     const QRegion &where,
                                     const TileLayer *touchedLayer)
    : PaintTileLayer(mapDocument)
{
    AutoMappingContext context(mapDocument);

    for (const auto autoMapper : autoMappers)
        autoMapper->prepareAutoMap(context);

    // During "AutoMap while drawing", keep track of the touched layers, so we
    // can skip any rule maps that doesn't have these layers as input entirely.
    if (touchedLayer)
        context.touchedTileLayers.append(touchedLayer);

    // use a copy of the region, so each AutoMapper can manipulate it and the
    // following AutoMappers do see the impact
    QRegion region(where);
    QRegion appliedRegion;
    QRegion *appliedRegionPtr = &appliedRegion;
    const Map *map = mapDocument->map();
    const QRegion mapRect(0, 0, map->width(), map->height());

    for (const auto autoMapper : autoMappers) {
        // stop expanding region when it's already the entire fixed-size map
        if (appliedRegionPtr && (!map->infinite() && (mapRect - region).isEmpty()))
            appliedRegionPtr = nullptr;

        if (touchedLayer) {
            if (std::none_of(context.touchedTileLayers.cbegin(),
                             context.touchedTileLayers.cend(),
                             [&] (const TileLayer *tileLayer) { return autoMapper->ruleLayerNameUsed(tileLayer->name()); }))
                continue;
        }

        autoMapper->autoMap(region, appliedRegionPtr, context);

        if (appliedRegionPtr) {
            // expand where with modified area
            region |= std::exchange(appliedRegion, QRegion());

            if (!map->infinite())       // but keep within map boundaries
                region &= mapRect;
        }
    }

    QSet<SharedTileset> usedTilesets;   // keep track of tilesets used by pending changes

    // Apply the changes to existing tile layers
    for (auto& [original, outputLayer] : context.originalToOutputLayerMapping) {
        const QRegion diffRegion = original->computeDiffRegion(*outputLayer);
        if (!diffRegion.isEmpty()) {
            usedTilesets |= outputLayer->usedTilesets();
            paint(original, 0, 0, outputLayer.get(),
                  diffRegion.translated(original->position()));
        }

        // Apply any property changes
        auto propertiesIt = context.changedProperties.find(outputLayer.get());
        if (propertiesIt != context.changedProperties.end())
            new ChangeProperties(mapDocument, QString(), original, *propertiesIt, this);
    }

    auto anyObjectForObjectGroup = [&] (ObjectGroup *objectGroup) {
        for (const QVector<AddMapObjects::Entry> &entries : std::as_const(context.newMapObjects)) {
            for (const AddMapObjects::Entry &entry : entries) {
                if (entry.objectGroup == objectGroup)
                    return true;
            }
        }
        return false;
    };

    // Add any new non-empty layers to the map
    auto newLayerIndex = context.targetMap->layerCount();
    for (auto &layer : context.newLayers) {
        if (layer->isTileLayer() && layer->isEmpty())
            continue;

        if (ObjectGroup *objectGroup = layer->asObjectGroup())
            if (!anyObjectForObjectGroup(objectGroup))
                continue;

        usedTilesets |= layer->usedTilesets();
        new AddLayer(mapDocument,
                     newLayerIndex++,
                     layer.release(), nullptr, this);
    }

    // Add any newly placed objects
    if (!context.newMapObjects.isEmpty()) {
        QVector<AddMapObjects::Entry> allEntries;

        for (const QVector<AddMapObjects::Entry> &entries : std::as_const(context.newMapObjects)) {
            // Each group of copied objects needs to be rewired separately
            ObjectReferencesHelper objectRefs(mapDocument->map());
            for (auto &entry : std::as_const(entries)) {
                objectRefs.reassignId(entry.mapObject);

                if (Tile *tile = entry.mapObject->cell().tile())
                    usedTilesets.insert(tile->tileset()->sharedFromThis());
            }
            objectRefs.rewire();

            allEntries.append(entries);
        }

        new AddMapObjects(mapDocument, allEntries, this);
    }

    // Remove any objects that have been scheduled for removal
    if (!context.mapObjectsToRemove.isEmpty())
        new RemoveMapObjects(mapDocument, context.mapObjectsToRemove.values(), this);

    // Make sure to add any newly used tilesets to the map
    for (const SharedTileset &tileset : std::as_const(context.newTilesets))
        if (usedTilesets.contains(tileset))
            new AddTileset(mapDocument, tileset, this);
}
