/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkBitmap.h"
#include "SkCachingPixelRef.h"
#include "SkCanvas.h"
#include "SkData.h"
#include "SkDecodingImageGenerator.h"
#include "SkDiscardableMemoryPool.h"
#include "SkImageDecoder.h"
#include "SkImageGeneratorPriv.h"
#include "SkScaledImageCache.h"
#include "SkStream.h"
#include "SkUtils.h"

#include "Test.h"

/**
 * Fill this bitmap with some color.
 */
static void make_test_image(SkBitmap* bm) {
    const int W = 50, H = 50;
    bm->allocN32Pixels(W, H);
    bm->eraseColor(SK_ColorBLACK);
    SkCanvas canvas(*bm);
    SkPaint paint;
    paint.setColor(SK_ColorBLUE);
    canvas.drawRectCoords(0, 0, SkIntToScalar(W/2),
                          SkIntToScalar(H/2), paint);
    paint.setColor(SK_ColorWHITE);
    canvas.drawRectCoords(SkIntToScalar(W/2), SkIntToScalar(H/2),
                          SkIntToScalar(W), SkIntToScalar(H), paint);
}

/**
 * encode this bitmap into some data via SkImageEncoder
 */
static SkData* create_data_from_bitmap(const SkBitmap& bm,
                                       SkImageEncoder::Type type) {
    SkDynamicMemoryWStream stream;
    if (SkImageEncoder::EncodeStream(&stream, bm, type, 100)) {
        return stream.copyToData();
    }
    return NULL;
}

////////////////////////////////////////////////////////////////////////////////

static void compare_bitmaps(skiatest::Reporter* reporter,
                            const SkBitmap& b1, const SkBitmap& b2,
                            bool pixelPerfect = true) {
    REPORTER_ASSERT(reporter, b1.empty() == b2.empty());
    REPORTER_ASSERT(reporter, b1.width() == b2.width());
    REPORTER_ASSERT(reporter, b1.height() == b2.height());
    REPORTER_ASSERT(reporter, b1.isNull() == b2.isNull());
    SkAutoLockPixels autoLockPixels1(b1);
    SkAutoLockPixels autoLockPixels2(b2);
    REPORTER_ASSERT(reporter, b1.isNull() == b2.isNull());
    if (b1.isNull() || b1.empty()) {
        return;
    }
    REPORTER_ASSERT(reporter, NULL != b1.getPixels());
    REPORTER_ASSERT(reporter, NULL != b2.getPixels());
    if ((!(b1.getPixels())) || (!(b2.getPixels()))) {
        return;
    }
    if ((b1.width() != b2.width()) ||
        (b1.height() != b2.height())) {
        return;
    }
    if (!pixelPerfect) {
        return;
    }

    int pixelErrors = 0;
    for (int y = 0; y < b2.height(); ++y) {
        for (int x = 0; x < b2.width(); ++x) {
            if (b1.getColor(x, y) != b2.getColor(x, y)) {
                ++pixelErrors;
            }
        }
    }
    REPORTER_ASSERT(reporter, 0 == pixelErrors);
}

typedef bool (*InstallEncoded)(SkData* encoded, SkBitmap* dst);

/**
   This function tests three differently encoded images against the
   original bitmap */
static void test_three_encodings(skiatest::Reporter* reporter,
                                 InstallEncoded install) {
    SkBitmap original;
    make_test_image(&original);
    REPORTER_ASSERT(reporter, !original.empty());
    REPORTER_ASSERT(reporter, !original.isNull());
    if (original.empty() || original.isNull()) {
        return;
    }
    static const SkImageEncoder::Type types[] = {
        SkImageEncoder::kPNG_Type,
        SkImageEncoder::kJPEG_Type,
        SkImageEncoder::kWEBP_Type
    };
    for (size_t i = 0; i < SK_ARRAY_COUNT(types); i++) {
        SkImageEncoder::Type type = types[i];
        SkAutoDataUnref encoded(create_data_from_bitmap(original, type));
        REPORTER_ASSERT(reporter, encoded.get() != NULL);
        if (NULL == encoded.get()) {
            continue;
        }
        SkBitmap lazy;
        bool installSuccess = install(encoded.get(), &lazy);
        REPORTER_ASSERT(reporter, installSuccess);
        if (!installSuccess) {
            continue;
        }
        REPORTER_ASSERT(reporter, NULL == lazy.getPixels());
        {
            SkAutoLockPixels autoLockPixels(lazy);  // now pixels are good.
            REPORTER_ASSERT(reporter, NULL != lazy.getPixels());
            if (NULL == lazy.getPixels()) {
                continue;
            }
        }
        // pixels should be gone!
        REPORTER_ASSERT(reporter, NULL == lazy.getPixels());
        {
            SkAutoLockPixels autoLockPixels(lazy);  // now pixels are good.
            REPORTER_ASSERT(reporter, NULL != lazy.getPixels());
            if (NULL == lazy.getPixels()) {
                continue;
            }
        }
        bool comparePixels = (SkImageEncoder::kPNG_Type == type);
        compare_bitmaps(reporter, original, lazy, comparePixels);
    }
}

////////////////////////////////////////////////////////////////////////////////
static bool install_skCachingPixelRef(SkData* encoded, SkBitmap* dst) {
    return SkCachingPixelRef::Install(
        SkDecodingImageGenerator::Create(
            encoded, SkDecodingImageGenerator::Options()), dst);
}
static bool install_skDiscardablePixelRef(SkData* encoded, SkBitmap* dst) {
    // Use system-default discardable memory.
    return SkInstallDiscardablePixelRef(
        SkDecodingImageGenerator::Create(
            encoded, SkDecodingImageGenerator::Options()), dst);
}

////////////////////////////////////////////////////////////////////////////////
/**
 *  This checks to see that a SkCachingPixelRef and a
 *  SkDiscardablePixelRef works as advertised with a
 *  SkDecodingImageGenerator.
 */
DEF_TEST(DecodingImageGenerator, reporter) {
    test_three_encodings(reporter, install_skCachingPixelRef);
    test_three_encodings(reporter, install_skDiscardablePixelRef);
}

class TestImageGenerator : public SkImageGenerator {
public:
    enum TestType {
        kFailGetInfo_TestType,
        kFailGetPixels_TestType,
        kSucceedGetPixels_TestType,
        kLast_TestType = kSucceedGetPixels_TestType
    };
    static int Width() { return 10; }
    static int Height() { return 10; }
    static SkColor Color() { return SK_ColorCYAN; }
    TestImageGenerator(TestType type, skiatest::Reporter* reporter)
        : fType(type), fReporter(reporter) {
        SkASSERT((fType <= kLast_TestType) && (fType >= 0));
    }
    virtual ~TestImageGenerator() { }

protected:
    virtual bool onGetInfo(SkImageInfo* info) SK_OVERRIDE {
        REPORTER_ASSERT(fReporter, NULL != info);
        if ((NULL == info) || (kFailGetInfo_TestType == fType)) {
            return false;
        }
        info->fWidth = TestImageGenerator::Width();
        info->fHeight = TestImageGenerator::Height();
        info->fColorType = kN32_SkColorType;
        info->fAlphaType = kOpaque_SkAlphaType;
        return true;
    }

    virtual bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                             SkPMColor ctable[], int* ctableCount) SK_OVERRIDE {
        REPORTER_ASSERT(fReporter, pixels != NULL);
        size_t minRowBytes
            = static_cast<size_t>(info.fWidth * info.bytesPerPixel());
        REPORTER_ASSERT(fReporter, rowBytes >= minRowBytes);
        if ((NULL == pixels)
            || (fType != kSucceedGetPixels_TestType)
            || (info.fColorType != kN32_SkColorType)) {
            return false;
        }
        char* bytePtr = static_cast<char*>(pixels);
        for (int y = 0; y < info.fHeight; ++y) {
            sk_memset32(reinterpret_cast<SkColor*>(bytePtr),
                        TestImageGenerator::Color(), info.fWidth);
            bytePtr += rowBytes;
        }
        return true;
    }

private:
    const TestType fType;
    skiatest::Reporter* const fReporter;
};

static void check_test_image_generator_bitmap(skiatest::Reporter* reporter,
                                              const SkBitmap& bm) {
    REPORTER_ASSERT(reporter, TestImageGenerator::Width() == bm.width());
    REPORTER_ASSERT(reporter, TestImageGenerator::Height() == bm.height());
    SkAutoLockPixels autoLockPixels(bm);
    REPORTER_ASSERT(reporter, NULL != bm.getPixels());
    if (NULL == bm.getPixels()) {
        return;
    }
    int errors = 0;
    for (int y = 0; y < bm.height(); ++y) {
        for (int x = 0; x < bm.width(); ++x) {
            if (TestImageGenerator::Color() != *bm.getAddr32(x, y)) {
                ++errors;
            }
        }
    }
    REPORTER_ASSERT(reporter, 0 == errors);
}

enum PixelRefType {
    kSkCaching_PixelRefType,
    kSkDiscardable_PixelRefType,
    kLast_PixelRefType = kSkDiscardable_PixelRefType
};

static void check_pixelref(TestImageGenerator::TestType type,
                           skiatest::Reporter* reporter,
                           PixelRefType pixelRefType,
                           SkDiscardableMemory::Factory* factory) {
    SkASSERT((pixelRefType >= 0) && (pixelRefType <= kLast_PixelRefType));
    SkAutoTDelete<SkImageGenerator> gen(SkNEW_ARGS(TestImageGenerator,
                                                   (type, reporter)));
    REPORTER_ASSERT(reporter, gen.get() != NULL);
    SkBitmap lazy;
    bool success;
    if (kSkCaching_PixelRefType == pixelRefType) {
        // Ignore factory; use global SkScaledImageCache.
        success = SkCachingPixelRef::Install(gen.detach(), &lazy);
    } else {
        success = SkInstallDiscardablePixelRef(gen.detach(), &lazy, factory);
    }
    REPORTER_ASSERT(reporter, success
                    == (TestImageGenerator::kFailGetInfo_TestType != type));
    if (TestImageGenerator::kSucceedGetPixels_TestType == type) {
        check_test_image_generator_bitmap(reporter, lazy);
    } else if (TestImageGenerator::kFailGetPixels_TestType == type) {
        SkAutoLockPixels autoLockPixels(lazy);
        REPORTER_ASSERT(reporter, NULL == lazy.getPixels());
    }
}

// new/lock/delete is an odd pattern for a pixelref, but it needs to not assert
static void test_newlockdelete(skiatest::Reporter* reporter) {
    SkBitmap bm;
    SkImageGenerator* ig = new TestImageGenerator(
        TestImageGenerator::kSucceedGetPixels_TestType, reporter);
    SkInstallDiscardablePixelRef(ig, &bm);
    bm.pixelRef()->lockPixels();
}

/**
 *  This tests the basic functionality of SkDiscardablePixelRef with a
 *  basic SkImageGenerator implementation and several
 *  SkDiscardableMemory::Factory choices.
 */
DEF_TEST(DiscardableAndCachingPixelRef, reporter) {
    test_newlockdelete(reporter);

    check_pixelref(TestImageGenerator::kFailGetInfo_TestType,
                   reporter, kSkCaching_PixelRefType, NULL);
    check_pixelref(TestImageGenerator::kFailGetPixels_TestType,
                   reporter, kSkCaching_PixelRefType, NULL);
    check_pixelref(TestImageGenerator::kSucceedGetPixels_TestType,
                   reporter, kSkCaching_PixelRefType, NULL);

    check_pixelref(TestImageGenerator::kFailGetInfo_TestType,
                   reporter, kSkDiscardable_PixelRefType, NULL);
    check_pixelref(TestImageGenerator::kFailGetPixels_TestType,
                   reporter, kSkDiscardable_PixelRefType, NULL);
    check_pixelref(TestImageGenerator::kSucceedGetPixels_TestType,
                   reporter, kSkDiscardable_PixelRefType, NULL);

    SkAutoTUnref<SkDiscardableMemoryPool> pool(
        SkDiscardableMemoryPool::Create(1, NULL));
    REPORTER_ASSERT(reporter, 0 == pool->getRAMUsed());
    check_pixelref(TestImageGenerator::kFailGetPixels_TestType,
                   reporter, kSkDiscardable_PixelRefType, pool);
    REPORTER_ASSERT(reporter, 0 == pool->getRAMUsed());
    check_pixelref(TestImageGenerator::kSucceedGetPixels_TestType,
                   reporter, kSkDiscardable_PixelRefType, pool);
    REPORTER_ASSERT(reporter, 0 == pool->getRAMUsed());

    SkDiscardableMemoryPool* globalPool = SkGetGlobalDiscardableMemoryPool();
    // Only acts differently from NULL on a platform that has a
    // default discardable memory implementation that differs from the
    // global DM pool.
    check_pixelref(TestImageGenerator::kFailGetPixels_TestType,
                   reporter, kSkDiscardable_PixelRefType, globalPool);
    check_pixelref(TestImageGenerator::kSucceedGetPixels_TestType,
                   reporter, kSkDiscardable_PixelRefType, globalPool);
}