/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef WEBGL_MEMORY_TRACKER_H_
#define WEBGL_MEMORY_TRACKER_H_

#include "mozilla/StaticPtr.h"
#include "nsIMemoryReporter.h"
#include "WebGLBuffer.h"
#include "WebGLContext.h"
#include "WebGLVertexAttribData.h"
#include "WebGLProgram.h"
#include "WebGLRenderbuffer.h"
#include "WebGLShader.h"
#include "WebGLTexture.h"
#include "WebGLUniformLocation.h"

namespace mozilla {

class WebGLMemoryTracker : public nsIMemoryReporter
{
    NS_DECL_THREADSAFE_ISUPPORTS
    NS_DECL_NSIMEMORYREPORTER

    WebGLMemoryTracker();
    static StaticRefPtr<WebGLMemoryTracker> sUniqueInstance;

    // Here we store plain pointers, not RefPtrs: we don't want the
    // WebGLMemoryTracker unique instance to keep alive all
    // WebGLContexts ever created.
    typedef nsTArray<const WebGLContext*> ContextsArrayType;
    ContextsArrayType mContexts;

    void InitMemoryReporter();

    static WebGLMemoryTracker* UniqueInstance();

    static ContextsArrayType& Contexts() { return UniqueInstance()->mContexts; }

    friend class WebGLContext;

  public:

    static void AddWebGLContext(const WebGLContext* c) {
        Contexts().AppendElement(c);
    }

    static void RemoveWebGLContext(const WebGLContext* c) {
        ContextsArrayType & contexts = Contexts();
        contexts.RemoveElement(c);
        if (contexts.IsEmpty()) {
            sUniqueInstance = nullptr;
        }
    }

  private:
    virtual ~WebGLMemoryTracker();

    static int64_t GetTextureMemoryUsed() {
        const ContextsArrayType & contexts = Contexts();
        int64_t result = 0;
        for(size_t i = 0; i < contexts.Length(); ++i) {
            for (const WebGLTexture* texture = contexts[i]->mTextures.getFirst();
                 texture;
                 texture = texture->getNext())
            {
                result += texture->MemoryUsage();
            }
        }
        return result;
    }

    static int64_t GetTextureCount() {
        const ContextsArrayType & contexts = Contexts();
        int64_t result = 0;
        for(size_t i = 0; i < contexts.Length(); ++i) {
            for (const WebGLTexture* texture = contexts[i]->mTextures.getFirst();
                 texture;
                 texture = texture->getNext())
            {
                result++;
            }
        }
        return result;
    }

    static int64_t GetBufferMemoryUsed() {
        const ContextsArrayType & contexts = Contexts();
        int64_t result = 0;
        for(size_t i = 0; i < contexts.Length(); ++i) {
            for (const WebGLBuffer* buffer = contexts[i]->mBuffers.getFirst();
                 buffer;
                 buffer = buffer->getNext())
            {
                result += buffer->ByteLength();
            }
        }
        return result;
    }

    static int64_t GetBufferCacheMemoryUsed();

    static int64_t GetBufferCount() {
        const ContextsArrayType & contexts = Contexts();
        int64_t result = 0;
        for(size_t i = 0; i < contexts.Length(); ++i) {
            for (const WebGLBuffer* buffer = contexts[i]->mBuffers.getFirst();
                 buffer;
                 buffer = buffer->getNext())
            {
                result++;
            }
        }
        return result;
    }

    static int64_t GetRenderbufferMemoryUsed() {
        const ContextsArrayType & contexts = Contexts();
        int64_t result = 0;
        for(size_t i = 0; i < contexts.Length(); ++i) {
            for (const WebGLRenderbuffer* rb = contexts[i]->mRenderbuffers.getFirst();
                 rb;
                 rb = rb->getNext())
            {
                result += rb->MemoryUsage();
            }
        }
        return result;
    }

    static int64_t GetRenderbufferCount() {
        const ContextsArrayType & contexts = Contexts();
        int64_t result = 0;
        for(size_t i = 0; i < contexts.Length(); ++i) {
            for (const WebGLRenderbuffer* rb = contexts[i]->mRenderbuffers.getFirst();
                 rb;
                 rb = rb->getNext())
            {
                result++;
            }
        }
        return result;
    }

    static int64_t GetShaderSize();

    static int64_t GetShaderCount() {
        const ContextsArrayType & contexts = Contexts();
        int64_t result = 0;
        for(size_t i = 0; i < contexts.Length(); ++i) {
            for (const WebGLShader* shader = contexts[i]->mShaders.getFirst();
                 shader;
                 shader = shader->getNext())
            {
                result++;
            }
        }
        return result;
    }

    static int64_t GetContextCount() {
        return Contexts().Length();
    }
};

} // namespace mozilla

#endif // WEBGL_MEMORY_TRACKER_H_