/*
 * 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 "SkCanvas.h"
#include "SkData.h"
#include "SkDiscardableMemoryPool.h"
#include "SkImageDecoder.h"
#include "SkImageGeneratorPriv.h"
#include "SkResourceCache.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 nullptr;
}

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

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, b1.getPixels());
    REPORTER_ASSERT(reporter, 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() != nullptr);
        if (nullptr == encoded.get()) {
            continue;
        }
        SkBitmap lazy;
        bool installSuccess = install(encoded.get(), &lazy);
        REPORTER_ASSERT(reporter, installSuccess);
        if (!installSuccess) {
            continue;
        }
        REPORTER_ASSERT(reporter, nullptr == lazy.getPixels());
        {
            SkAutoLockPixels autoLockPixels(lazy);  // now pixels are good.
            REPORTER_ASSERT(reporter, lazy.getPixels());
            if (nullptr == lazy.getPixels()) {
                continue;
            }
        }
        // pixels should be gone!
        REPORTER_ASSERT(reporter, nullptr == lazy.getPixels());
        {
            SkAutoLockPixels autoLockPixels(lazy);  // now pixels are good.
            REPORTER_ASSERT(reporter, lazy.getPixels());
            if (nullptr == lazy.getPixels()) {
                continue;
            }
        }
        bool comparePixels = (SkImageEncoder::kPNG_Type == type);
        compare_bitmaps(reporter, original, lazy, comparePixels);
    }
}

////////////////////////////////////////////////////////////////////////////////
static bool install_skDiscardablePixelRef(SkData* encoded, SkBitmap* dst) {
    // Use system-default discardable memory.
    return SkDEPRECATED_InstallDiscardablePixelRef(encoded, dst);
}

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

class TestImageGenerator : public SkImageGenerator {
public:
    enum TestType {
        kFailGetPixels_TestType,
        kSucceedGetPixels_TestType,
        kLast_TestType = kSucceedGetPixels_TestType
    };
    static int Width() { return 10; }
    static int Height() { return 10; }
    // value choosen so that there is no loss when converting to to RGB565 and back
    static SkColor Color() { return 0xff10345a; }
    static SkPMColor PMColor() { return SkPreMultiplyColor(Color()); }

    TestImageGenerator(TestType type, skiatest::Reporter* reporter,
                       SkColorType colorType = kN32_SkColorType)
    : INHERITED(GetMyInfo(colorType)), fType(type), fReporter(reporter) {
        SkASSERT((fType <= kLast_TestType) && (fType >= 0));
    }
    virtual ~TestImageGenerator() { }

protected:
    static SkImageInfo GetMyInfo(SkColorType colorType) {
        return SkImageInfo::Make(TestImageGenerator::Width(), TestImageGenerator::Height(),
                                 colorType, kOpaque_SkAlphaType);
    }

    bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                     SkPMColor ctable[], int* ctableCount) override {
        REPORTER_ASSERT(fReporter, pixels != nullptr);
        REPORTER_ASSERT(fReporter, rowBytes >= info.minRowBytes());
        if (fType != kSucceedGetPixels_TestType) {
            return false;
        }
        if (info.colorType() != kN32_SkColorType && info.colorType() != getInfo().colorType()) {
            return false;
        }
        char* bytePtr = static_cast<char*>(pixels);
        switch (info.colorType()) {
            case kN32_SkColorType:
                for (int y = 0; y < info.height(); ++y) {
                    sk_memset32((uint32_t*)bytePtr,
                                TestImageGenerator::PMColor(), info.width());
                    bytePtr += rowBytes;
                }
                break;
            case kIndex_8_SkColorType:
                *ctableCount = 1;
                ctable[0] = TestImageGenerator::PMColor();
                for (int y = 0; y < info.height(); ++y) {
                    memset(bytePtr, 0, info.width());
                    bytePtr += rowBytes;
                }
                break;
            case kRGB_565_SkColorType:
                for (int y = 0; y < info.height(); ++y) {
                    sk_memset16((uint16_t*)bytePtr,
                        SkPixel32ToPixel16(TestImageGenerator::PMColor()), info.width());
                    bytePtr += rowBytes;
                }
                break;
            default:
                return false;
        }
        return true;
    }

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

    typedef SkImageGenerator INHERITED;
};

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, bm.getPixels());
    if (nullptr == 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.getColor(x, y)) {
                ++errors;
            }
        }
    }
    REPORTER_ASSERT(reporter, 0 == errors);
}

static void check_pixelref(TestImageGenerator::TestType type,
                           skiatest::Reporter* reporter,
                           SkDiscardableMemory::Factory* factory,
                           SkColorType colorType) {
    SkAutoTDelete<SkImageGenerator> gen(new TestImageGenerator(type, reporter, colorType));
    REPORTER_ASSERT(reporter, gen.get() != nullptr);
    SkBitmap lazy;
    bool success = SkDEPRECATED_InstallDiscardablePixelRef(gen.detach(), nullptr, &lazy, factory);

    REPORTER_ASSERT(reporter, success);
    if (TestImageGenerator::kSucceedGetPixels_TestType == type) {
        check_test_image_generator_bitmap(reporter, lazy);
    } else if (TestImageGenerator::kFailGetPixels_TestType == type) {
        SkAutoLockPixels autoLockPixels(lazy);
        REPORTER_ASSERT(reporter, nullptr == lazy.getPixels());
    }
}

/**
 *  This tests the basic functionality of SkDiscardablePixelRef with a
 *  basic SkImageGenerator implementation and several
 *  SkDiscardableMemory::Factory choices.
 */
DEF_TEST(DiscardableAndCachingPixelRef, reporter) {
    const SkColorType testColorTypes[] = {
        kN32_SkColorType,
        kIndex_8_SkColorType,
        kRGB_565_SkColorType
    };
    for (const SkColorType testColorType : testColorTypes) {
        check_pixelref(TestImageGenerator::kFailGetPixels_TestType, reporter, nullptr,
                       testColorType);
        check_pixelref(TestImageGenerator::kSucceedGetPixels_TestType, reporter, nullptr,
                       testColorType);

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

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

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

DEF_TEST(Image_NewFromGenerator, r) {
    const TestImageGenerator::TestType testTypes[] = {
        TestImageGenerator::kFailGetPixels_TestType,
        TestImageGenerator::kSucceedGetPixels_TestType,
    };
    const SkColorType testColorTypes[] = {
        kN32_SkColorType,
        kIndex_8_SkColorType,
        kRGB_565_SkColorType
    };
    for (size_t i = 0; i < SK_ARRAY_COUNT(testTypes); ++i) {
        TestImageGenerator::TestType test = testTypes[i];
        for (const SkColorType testColorType : testColorTypes) {
            SkImageGenerator* gen = new TestImageGenerator(test, r, testColorType);
            SkAutoTUnref<SkImage> image(SkImage::NewFromGenerator(gen));
            if (nullptr == image.get()) {
                ERRORF(r, "SkImage::NewFromGenerator unexpecedly failed ["
                    SK_SIZE_T_SPECIFIER "]", i);
                continue;
            }
            REPORTER_ASSERT(r, TestImageGenerator::Width() == image->width());
            REPORTER_ASSERT(r, TestImageGenerator::Height() == image->height());
            REPORTER_ASSERT(r, image->isLazyGenerated());

            SkBitmap bitmap;
            bitmap.allocN32Pixels(TestImageGenerator::Width(), TestImageGenerator::Height());
            SkCanvas canvas(bitmap);
            const SkColor kDefaultColor = 0xffabcdef;
            canvas.clear(kDefaultColor);
            canvas.drawImage(image, 0, 0, nullptr);
            if (TestImageGenerator::kSucceedGetPixels_TestType == test) {
                REPORTER_ASSERT(
                    r, TestImageGenerator::Color() == bitmap.getColor(0, 0));
            }
            else {
                REPORTER_ASSERT(r, kDefaultColor == bitmap.getColor(0, 0));
            }
        }
    }
}