/*****************************************************************************************
*                                                                                       *
* OpenSpace                                                                             *
*                                                                                       *
* Copyright (c) 2014-2016                                                               *
*                                                                                       *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify,    *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
* permit persons to whom the Software is furnished to do so, subject to the following   *
* conditions:                                                                           *
*                                                                                       *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software.                                              *
*                                                                                       *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
****************************************************************************************/

#include <modules/globebrowsing/geometry/geodetic2.h>
#include <modules/globebrowsing/tile/tileprovider/cachingtileprovider.h>
#include <modules/globebrowsing/tile/tileindex.h>

#include <ghoul/io/texture/texturereader.h>
#include <ghoul/filesystem/filesystem.h>
#include <ghoul/logging/logmanager.h>

#include <openspace/engine/openspaceengine.h>

namespace {
    const std::string _loggerCat = "CachingTileProvider";

    const std::string KeyDoPreProcessing = "DoPreProcessing";
    const std::string KeyMinimumPixelSize = "MinimumPixelSize";
    const std::string KeyFilePath = "FilePath";
    const std::string KeyCacheSize = "CacheSize";
    const std::string KeyFlushInterval = "FlushInterval";
}

namespace openspace {

    CachingTileProvider::CachingTileProvider(const ghoul::Dictionary& dictionary) 
    : _framesSinceLastRequestFlush(0)
    {
        std::string name = "Name unspecified";
        dictionary.getValue("Name", name);
        std::string _loggerCat = "CachingTileProvider : " + name;

        // 1. Get required Keys
        std::string filePath;
        if (!dictionary.getValue<std::string>(KeyFilePath, filePath)) {
            throw std::runtime_error("Must define key '" + KeyFilePath + "'");
        }

        // 2. Initialize default values for any optional Keys
        TileDataset::Configuration config;
        config.doPreProcessing = false;
        config.minimumTilePixelSize = 512;
        
        // getValue does not work for integers
        double minimumPixelSize; 
        double cacheSize = 512;
        double framesUntilRequestFlush = 60;

        // 3. Check for used spcified optional keys
        if (dictionary.getValue<bool>(KeyDoPreProcessing, config.doPreProcessing)) {
            LDEBUG("Default doPreProcessing overridden: " << config.doPreProcessing);
        }
        if (dictionary.getValue<double>(KeyMinimumPixelSize, minimumPixelSize)) {
            LDEBUG("Default minimumPixelSize overridden: " << minimumPixelSize);
            config.minimumTilePixelSize = static_cast<int>(minimumPixelSize); 
        }
        if (dictionary.getValue<double>(KeyCacheSize, cacheSize)) {
            LDEBUG("Default cacheSize overridden: " << cacheSize);
        }
        if (dictionary.getValue<double>(KeyFlushInterval, framesUntilRequestFlush)) {
            LDEBUG("Default framesUntilRequestFlush overridden: " <<
                framesUntilRequestFlush);
        }

        // Initialize instance variables
        auto tileDataset = std::make_shared<TileDataset>(filePath, config);

        // only one thread per provider supported atm
        // (GDAL does not handle multiple threads for a single dataset very well
        // currently)
        auto threadPool = std::make_shared<ThreadPool>(1);

        _asyncTextureDataProvider = std::make_shared<AsyncTileDataProvider>(
            tileDataset, threadPool);
        _tileCache = std::make_shared<TileCache>(cacheSize);
        _framesUntilRequestFlush = framesUntilRequestFlush;
    }

    CachingTileProvider::CachingTileProvider(
        std::shared_ptr<AsyncTileDataProvider> tileReader, 
        std::shared_ptr<TileCache> tileCache,
        int framesUntilFlushRequestQueue)
        : _asyncTextureDataProvider(tileReader)
        , _tileCache(tileCache)
        , _framesUntilRequestFlush(framesUntilFlushRequestQueue)
        , _framesSinceLastRequestFlush(0)
    {
        
    }

    CachingTileProvider::~CachingTileProvider(){
        clearRequestQueue();
    }

    void CachingTileProvider::update() {
        initTexturesFromLoadedData();
        if (_framesSinceLastRequestFlush++ > _framesUntilRequestFlush) {
            clearRequestQueue();
        }
    }

    void CachingTileProvider::reset() {
        _tileCache->clear();
        _asyncTextureDataProvider->reset();
    }

    int CachingTileProvider::maxLevel() {
        return _asyncTextureDataProvider->getTextureDataProvider()->maxChunkLevel();
    }

    Tile CachingTileProvider::getTile(const TileIndex& tileIndex) {
        Tile tile = Tile::TileUnavailable;

        if (tileIndex.level > maxLevel()) {
            tile.status = Tile::Status::OutOfRange;
            return tile;
        }

        TileHashKey key = tileIndex.hashKey();

        if (_tileCache->exist(key)) {
            return _tileCache->get(key);
        }
        else {
            _asyncTextureDataProvider->enqueueTileIO(tileIndex);
        }
        
        return tile;
    }

    Tile CachingTileProvider::getDefaultTile() {
        if (_defaultTile.texture == nullptr) {
            _defaultTile = createTile(_asyncTextureDataProvider->getTextureDataProvider()->defaultTileData());
        }
        return _defaultTile;
    }

    void CachingTileProvider::initTexturesFromLoadedData() {
        auto readyTileIOResults = _asyncTextureDataProvider->getTileIOResults();
        for(auto tileIOResult : readyTileIOResults){
            TileHashKey key = tileIOResult->tileIndex.hashKey();
            Tile tile = createTile(tileIOResult);
            _tileCache->put(key, tile);
        }
    }

    void CachingTileProvider::clearRequestQueue() {
        _asyncTextureDataProvider->clearRequestQueue();
        _framesSinceLastRequestFlush = 0;
    }

    Tile::Status CachingTileProvider::getTileStatus(const TileIndex& tileIndex) {
        auto tileDataset = _asyncTextureDataProvider->getTextureDataProvider();
        if (tileIndex.level > tileDataset->maxChunkLevel()) {
            return Tile::Status::OutOfRange;
        }

        TileHashKey key = tileIndex.hashKey();

        if (_tileCache->exist(key)) {
            return _tileCache->get(key).status;
        }

        return Tile::Status::Unavailable;
    }

    TileDepthTransform CachingTileProvider::depthTransform() {
        return _asyncTextureDataProvider->getTextureDataProvider()->getDepthTransform();
    }

    Tile CachingTileProvider::createTile(std::shared_ptr<TileIOResult> tileIOResult) {
        if (tileIOResult->error != CE_None) {
            return{ nullptr, nullptr, Tile::Status::IOError };
        }

        TileHashKey key = tileIOResult->tileIndex.hashKey();
        TileDataLayout dataLayout =
            _asyncTextureDataProvider->getTextureDataProvider()->getDataLayout();
        
        // The texture should take ownership of the data
        std::shared_ptr<Texture> texture = std::make_shared<Texture>(
            tileIOResult->imageData,
            tileIOResult->dimensions,
            dataLayout.textureFormat.ghoulFormat,
            dataLayout.textureFormat.glFormat,
            dataLayout.glType,
            Texture::FilterMode::Linear,
            Texture::WrappingMode::ClampToEdge);
        
        texture->uploadTexture();

        // AnisotropicMipMap must be set after texture is uploaded. Why?!
        texture->setFilter(ghoul::opengl::Texture::FilterMode::AnisotropicMipMap);

        Tile tile = {
            texture,
            tileIOResult->preprocessData,
            Tile::Status::OK
        };

        return tile;
    }

}  // namespace openspace