/*

 * Copyright 2016 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#ifndef SkUrlDataManager_DEFINED

#define SkUrlDataManager_DEFINED

#include "include/core/SkData.h"

#include "include/core/SkImage.h"

#include "include/core/SkString.h"

#include "src/core/SkChecksum.h"

#include "src/core/SkTDynamicHash.h"

#include <unordered_map>

#include <vector>

/*

 * A simple class which allows clients to add opaque data types, and returns a url where this data

 * will be hosted.  Its up to the owner of this class to actually serve the data.

 */

bool operator==(const SkData& a, const SkData& b);

class UrlDataManager {

public:

    UrlDataManager(SkString rootUrl);

    ~UrlDataManager() { this->reset(); }

    /*

     * Adds a data blob to the cache with a particular content type.  UrlDataManager will hash

     * the blob data to ensure uniqueness

     */

    SkString addData(SkData*, const char* contentType);

    struct UrlData : public SkRefCnt {

        SkString fUrl;

        SkString fContentType;

        sk_sp<SkData> fData;

    };

    /*

     * returns the UrlData object which should be hosted at 'url'

     */

    UrlData* getDataFromUrl(const SkString& url) {

        return fUrlLookup.find(url);

    }

    void reset();

    // Methods used to identify images differently in wasm debugger for mskp animations.

    // serving is uncessary, as a collection of images with identifiers is already present, we

    // just want to use it when serializing commands.

    /*

     * Construct an index from a list of images

     * (expected to be the list that was loaded from the mskp file)

     * Use only once.

     */

    void indexImages(const std::vector<sk_sp<SkImage>>&);

    /*

     * Reports whether this UDM has an initialized image index (effevitely whether we're in wasm)

     */

    bool hasImageIndex() { return imageMap.size() > 0; }

    /*

     * Return the file id (index of the image in the originally provided list) of an SkImage

     */

    int lookupImage(const SkImage*);

private:

    struct LookupTrait {

        // We use the data as a hash, this is not really optimal but is fine until proven otherwise

        static const SkData& GetKey(const UrlData& data) {

            return *data.fData;

        }

        static uint32_t Hash(const SkData& key) {

            return SkChecksum::Hash32(key.bytes(), key.size());

        }

    };

    struct ReverseLookupTrait {

        static const SkString& GetKey(const UrlData& data) {

            return data.fUrl;

        }

        static uint32_t Hash(const SkString& key) {

            return SkChecksum::Hash32(key.c_str(), strlen(key.c_str()));

        }

    };

    SkString fRootUrl;

    SkTDynamicHash<UrlData, SkData, LookupTrait> fCache;

    SkTDynamicHash<UrlData, SkString, ReverseLookupTrait> fUrlLookup;

    uint32_t fDataId;

    std::unordered_map<const SkImage*, int> imageMap;

};

#endif