/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "Resources.h"
#include "SkBitmap.h"
#include "SkCodec.h"
#include "SkMD5.h"
#include "SkRandom.h"
#include "SkScanlineDecoder.h"
#include "Test.h"

static SkStreamAsset* resource(const char path[]) {
    SkString fullPath = GetResourcePath(path);
    return SkStream::NewFromFile(fullPath.c_str());
}

static void md5(const SkBitmap& bm, SkMD5::Digest* digest) {
    SkAutoLockPixels autoLockPixels(bm);
    SkASSERT(bm.getPixels());
    SkMD5 md5;
    size_t rowLen = bm.info().bytesPerPixel() * bm.width();
    for (int y = 0; y < bm.height(); ++y) {
        md5.update(static_cast<uint8_t*>(bm.getAddr(0, y)), rowLen);
    }
    md5.finish(*digest);
}

/**
 *  Compute the digest for bm and compare it to a known good digest.
 *  @param r Reporter to assert that bm's digest matches goodDigest.
 *  @param goodDigest The known good digest to compare to.
 *  @param bm The bitmap to test.
 */
static void compare_to_good_digest(skiatest::Reporter* r, const SkMD5::Digest& goodDigest,
                           const SkBitmap& bm) {
    SkMD5::Digest digest;
    md5(bm, &digest);
    REPORTER_ASSERT(r, digest == goodDigest);
}

SkIRect generate_random_subset(SkRandom* rand, int w, int h) {
    SkIRect rect;
    do {
        rect.fLeft = rand->nextRangeU(0, w);
        rect.fTop = rand->nextRangeU(0, h);
        rect.fRight = rand->nextRangeU(0, w);
        rect.fBottom = rand->nextRangeU(0, h);
        rect.sort();
    } while (rect.isEmpty());
    return rect;
}

static void check(skiatest::Reporter* r,
                  const char path[],
                  SkISize size,
                  bool supportsScanlineDecoding,
                  bool supportsSubsetDecoding) {
    SkAutoTDelete<SkStream> stream(resource(path));
    if (!stream) {
        SkDebugf("Missing resource '%s'\n", path);
        return;
    }
    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
    if (!codec) {
        ERRORF(r, "Unable to decode '%s'", path);
        return;
    }

    // This test is used primarily to verify rewinding works properly.  Using kN32 allows
    // us to test this without the added overhead of creating different bitmaps depending
    // on the color type (ex: building a color table for kIndex8).  DM is where we test
    // decodes to all possible destination color types.
    SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
    REPORTER_ASSERT(r, info.dimensions() == size);
    SkBitmap bm;
    bm.allocPixels(info);
    SkAutoLockPixels autoLockPixels(bm);
    SkCodec::Result result =
        codec->getPixels(info, bm.getPixels(), bm.rowBytes(), NULL, NULL, NULL);
    REPORTER_ASSERT(r, result == SkCodec::kSuccess);

    SkMD5::Digest digest;
    md5(bm, &digest);

    bm.eraseColor(SK_ColorYELLOW);

    result =
        codec->getPixels(info, bm.getPixels(), bm.rowBytes(), NULL, NULL, NULL);

    REPORTER_ASSERT(r, result == SkCodec::kSuccess);
    // verify that re-decoding gives the same result.
    compare_to_good_digest(r, digest, bm);

    SkAutoTDelete<SkScanlineDecoder> scanlineDecoder(codec->getScanlineDecoder(info));
    if (supportsScanlineDecoding) {
        bm.eraseColor(SK_ColorYELLOW);
        REPORTER_ASSERT(r, scanlineDecoder);

        // Regular decodes should not be affected by creating a scanline decoder
        result = codec->getPixels(info, bm.getPixels(), bm.rowBytes(), NULL, NULL, NULL);
        REPORTER_ASSERT(r, SkCodec::kSuccess == result);
        compare_to_good_digest(r, digest, bm);

        bm.eraseColor(SK_ColorYELLOW);

        for (int y = 0; y < info.height(); y++) {
            result = scanlineDecoder->getScanlines(bm.getAddr(0, y), 1, 0);
            REPORTER_ASSERT(r, result == SkCodec::kSuccess);
        }
        // verify that scanline decoding gives the same result.
        compare_to_good_digest(r, digest, bm);
    } else {
        REPORTER_ASSERT(r, !scanlineDecoder);
    }

    // The rest of this function tests decoding subsets, and will decode an arbitrary number of
    // random subsets.
    // Do not attempt to decode subsets of an image of only once pixel, since there is no
    // meaningful subset.
    if (size.width() * size.height() == 1) {
        return;
    }

    SkRandom rand;
    SkIRect subset;
    SkCodec::Options opts;
    opts.fSubset = &subset;
    for (int i = 0; i < 5; i++) {
        subset = generate_random_subset(&rand, size.width(), size.height());
        SkASSERT(!subset.isEmpty());
        const bool supported = codec->getValidSubset(&subset);
        REPORTER_ASSERT(r, supported == supportsSubsetDecoding);

        SkImageInfo subsetInfo = info.makeWH(subset.width(), subset.height());
        SkBitmap bm;
        bm.allocPixels(subsetInfo);
        const SkCodec::Result result = codec->getPixels(bm.info(), bm.getPixels(), bm.rowBytes(),
                                                        &opts, NULL, NULL);

        if (supportsSubsetDecoding) {
            REPORTER_ASSERT(r, result == SkCodec::kSuccess);
            // Webp is the only codec that supports subsets, and it will have modified the subset
            // to have even left/top.
            REPORTER_ASSERT(r, SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
        } else {
            // No subsets will work.
            REPORTER_ASSERT(r, result == SkCodec::kUnimplemented);
        }
    }
}

DEF_TEST(Codec, r) {
    // WBMP
    check(r, "mandrill.wbmp", SkISize::Make(512, 512), false, false);

    // WEBP
    check(r, "baby_tux.webp", SkISize::Make(386, 395), false, true);
    check(r, "color_wheel.webp", SkISize::Make(128, 128), false, true);
    check(r, "yellow_rose.webp", SkISize::Make(400, 301), false, true);

    // BMP
    check(r, "randPixels.bmp", SkISize::Make(8, 8), false, false);

    // ICO
    // These two tests examine interestingly different behavior:
    // Decodes an embedded BMP image
    check(r, "color_wheel.ico", SkISize::Make(128, 128), false, false);
    // Decodes an embedded PNG image
    check(r, "google_chrome.ico", SkISize::Make(256, 256), false, false);

    // GIF
    check(r, "box.gif", SkISize::Make(200, 55), false, false);
    check(r, "color_wheel.gif", SkISize::Make(128, 128), false, false);
    check(r, "randPixels.gif", SkISize::Make(8, 8), false, false);

    // JPG
    check(r, "CMYK.jpg", SkISize::Make(642, 516), true, false);
    check(r, "color_wheel.jpg", SkISize::Make(128, 128), true, false);
    check(r, "grayscale.jpg", SkISize::Make(128, 128), true, false);
    check(r, "mandrill_512_q075.jpg", SkISize::Make(512, 512), true, false);
    check(r, "randPixels.jpg", SkISize::Make(8, 8), true, false);

    // PNG
    check(r, "arrow.png", SkISize::Make(187, 312), true, false);
    check(r, "baby_tux.png", SkISize::Make(240, 246), true, false);
    check(r, "color_wheel.png", SkISize::Make(128, 128), true, false);
    check(r, "half-transparent-white-pixel.png", SkISize::Make(1, 1), true, false);
    check(r, "mandrill_128.png", SkISize::Make(128, 128), true, false);
    check(r, "mandrill_16.png", SkISize::Make(16, 16), true, false);
    check(r, "mandrill_256.png", SkISize::Make(256, 256), true, false);
    check(r, "mandrill_32.png", SkISize::Make(32, 32), true, false);
    check(r, "mandrill_512.png", SkISize::Make(512, 512), true, false);
    check(r, "mandrill_64.png", SkISize::Make(64, 64), true, false);
    check(r, "plane.png", SkISize::Make(250, 126), true, false);
    check(r, "randPixels.png", SkISize::Make(8, 8), true, false);
    check(r, "yellow_rose.png", SkISize::Make(400, 301), true, false);
}

static void test_invalid_stream(skiatest::Reporter* r, const void* stream, size_t len) {
    SkCodec* codec = SkCodec::NewFromStream(new SkMemoryStream(stream, len, false));
    // We should not have gotten a codec. Bots should catch us if we leaked anything.
    REPORTER_ASSERT(r, !codec);
}

// Ensure that SkCodec::NewFromStream handles freeing the passed in SkStream,
// even on failure. Test some bad streams.
DEF_TEST(Codec_leaks, r) {
    // No codec should claim this as their format, so this tests SkCodec::NewFromStream.
    const char nonSupportedStream[] = "hello world";
    // The other strings should look like the beginning of a file type, so we'll call some
    // internal version of NewFromStream, which must also delete the stream on failure.
    const unsigned char emptyPng[] = { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a };
    const unsigned char emptyJpeg[] = { 0xFF, 0xD8, 0xFF };
    const char emptyWebp[] = "RIFF1234WEBPVP";
    const char emptyBmp[] = { 'B', 'M' };
    const char emptyIco[] = { '\x00', '\x00', '\x01', '\x00' };
    const char emptyGif[] = "GIFVER";

    test_invalid_stream(r, nonSupportedStream, sizeof(nonSupportedStream));
    test_invalid_stream(r, emptyPng, sizeof(emptyPng));
    test_invalid_stream(r, emptyJpeg, sizeof(emptyJpeg));
    test_invalid_stream(r, emptyWebp, sizeof(emptyWebp));
    test_invalid_stream(r, emptyBmp, sizeof(emptyBmp));
    test_invalid_stream(r, emptyIco, sizeof(emptyIco));
    test_invalid_stream(r, emptyGif, sizeof(emptyGif));
}

static void test_dimensions(skiatest::Reporter* r, const char path[]) {
    // Create the codec from the resource file
    SkAutoTDelete<SkStream> stream(resource(path));
    if (!stream) {
        SkDebugf("Missing resource '%s'\n", path);
        return;
    }
    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
    if (!codec) {
        ERRORF(r, "Unable to create codec '%s'", path);
        return;
    }

    // Check that the decode is successful for a variety of scales
    for (float scale = -0.05f; scale < 2.0f; scale += 0.05f) {
        // Scale the output dimensions
        SkISize scaledDims = codec->getScaledDimensions(scale);
        SkImageInfo scaledInfo = codec->getInfo().makeWH(scaledDims.width(), scaledDims.height());

        // Set up for the decode
        size_t rowBytes = scaledDims.width() * sizeof(SkPMColor);
        size_t totalBytes = scaledInfo.getSafeSize(rowBytes);
        SkAutoTMalloc<SkPMColor> pixels(totalBytes);

        SkCodec::Result result =
                codec->getPixels(scaledInfo, pixels.get(), rowBytes, NULL, NULL, NULL);
        REPORTER_ASSERT(r, SkCodec::kSuccess == result);
    }
}

// Ensure that onGetScaledDimensions returns valid image dimensions to use for decodes
DEF_TEST(Codec_Dimensions, r) {
    // JPG
    test_dimensions(r, "CMYK.jpg");
    test_dimensions(r, "color_wheel.jpg");
    test_dimensions(r, "grayscale.jpg");
    test_dimensions(r, "mandrill_512_q075.jpg");
    test_dimensions(r, "randPixels.jpg");
}

static void test_empty(skiatest::Reporter* r, const char path[]) {
    SkAutoTDelete<SkStream> stream(resource(path));
    if (!stream) {
        SkDebugf("Missing resource '%s'\n", path);
        return;
    }
    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
    REPORTER_ASSERT(r, NULL == codec);
}

DEF_TEST(Codec_Empty, r) {
    // Test images that should not be able to create a codec
    test_empty(r, "empty_images/zero-dims.gif");
    test_empty(r, "empty_images/zero-embedded.ico");
    test_empty(r, "empty_images/zero-width.bmp");
    test_empty(r, "empty_images/zero-height.bmp");
    test_empty(r, "empty_images/zero-width.jpg");
    test_empty(r, "empty_images/zero-height.jpg");
    test_empty(r, "empty_images/zero-width.png");
    test_empty(r, "empty_images/zero-height.png");
    test_empty(r, "empty_images/zero-width.wbmp");
    test_empty(r, "empty_images/zero-height.wbmp");
}