// Copyright 2019 Google LLC
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

#include "tests/Test.h"

#include "include/core/SkData.h"
#include "include/core/SkFont.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkSpan.h"
#include "include/core/SkStream.h"
#include "include/core/SkTypeface.h"
#include "include/core/SkTypes.h"
#include "include/private/SkTo.h"
#include "modules/skshaper/include/SkShaper.h"
#include "modules/skshaper/include/SkShaper_harfbuzz.h"
#include "modules/skshaper/include/SkShaper_skunicode.h"
#include "modules/skunicode/include/SkUnicode.h"
#include "src/core/SkZip.h"
#include "tools/Resources.h"
#include "tools/fonts/FontToolUtils.h"

#include <cinttypes>
#include <cstdint>
#include <memory>
#include <limits>
#include <set>
#include <vector>

#if defined(SK_UNICODE_ICU_IMPLEMENTATION)
#include "modules/skunicode/include/SkUnicode_icu.h"
#endif

#if defined(SK_UNICODE_LIBGRAPHEME_IMPLEMENTATION)
#include "modules/skunicode/include/SkUnicode_libgrapheme.h"
#endif

#if defined(SK_UNICODE_ICU4X_IMPLEMENTATION)
#include "modules/skunicode/include/SkUnicode_icu4x.h"
#endif

namespace {

sk_sp<SkUnicode> get_unicode() {
#if defined(SK_UNICODE_ICU_IMPLEMENTATION)
    if (auto unicode = SkUnicodes::ICU::Make()) {
        return unicode;
    }
#endif  // defined(SK_UNICODE_ICU_IMPLEMENTATION)
#if defined(SK_UNICODE_LIBGRAPHEME_IMPLEMENTATION)
    if (auto unicode = SkUnicodes::Libgrapheme::Make()) {
        return unicode;
    }
#endif
#if defined(SK_UNICODE_ICU4X_IMPLEMENTATION)
    if (auto unicode = SkUnicodes::ICU4X::Make()) {
        return unicode;
    }
#endif
    return nullptr;
}

struct RunHandler final : public SkShaper::RunHandler {
    const char* fResource;
    skiatest::Reporter* fReporter;
    const char* fUtf8;
    size_t fUtf8Size;
    std::unique_ptr<SkGlyphID[]> fGlyphs;
    std::unique_ptr<SkPoint[]> fPositions;
    std::unique_ptr<uint32_t[]> fClusters;
    SkShaper::RunHandler::Range fRange;
    unsigned fGlyphCount = 0;

    bool fBeginLine = false;
    bool fCommitRunInfo = false;
    bool fCommitLine = false;

    RunHandler(const char* resource, skiatest::Reporter* reporter, const char* utf8,size_t utf8Size)
        : fResource(resource), fReporter(reporter), fUtf8(utf8), fUtf8Size(utf8Size) {}

    void beginLine() override { fBeginLine = true;}
    void runInfo(const SkShaper::RunHandler::RunInfo& info) override {}
    void commitRunInfo() override { fCommitRunInfo = true; }
    SkShaper::RunHandler::Buffer runBuffer(const SkShaper::RunHandler::RunInfo& info) override {
        fGlyphCount = SkToUInt(info.glyphCount);
        fRange = info.utf8Range;
        fGlyphs = std::make_unique<SkGlyphID[]>(info.glyphCount);
        fPositions = std::make_unique<SkPoint[]>(info.glyphCount);
        fClusters = std::make_unique<uint32_t[]>(info.glyphCount);
        return SkShaper::RunHandler::Buffer{fGlyphs.get(),
                                            fPositions.get(),
                                            nullptr,
                                            fClusters.get(),
                                            {0, 0}};
    }
    void commitRunBuffer(const RunInfo& info) override {
        REPORTER_ASSERT(fReporter, fGlyphCount == info.glyphCount, "%s", fResource);
        REPORTER_ASSERT(fReporter, fRange.begin() == info.utf8Range.begin(), "%s", fResource);
        REPORTER_ASSERT(fReporter, fRange.size() == info.utf8Range.size(), "%s", fResource);
        if (!(fRange.begin() + fRange.size() <= fUtf8Size)) {
            REPORTER_ASSERT(fReporter, fRange.begin() + fRange.size() <= fUtf8Size, "%s",fResource);
            return;
        }

        if ((false)) {
            SkString familyName;
            SkString postscriptName;
            SkTypeface* typeface = info.fFont.getTypeface();
            int ttcIndex = 0;
            size_t fontSize = 0;
            if (typeface) {
                typeface->getFamilyName(&familyName);
                typeface->getPostScriptName(&postscriptName);
                std::unique_ptr<SkStreamAsset> stream = typeface->openStream(&ttcIndex);
                if (stream) {
                    fontSize = stream->getLength();
                }
            }
            SkString glyphs;
            for (auto&& [glyph, cluster] : SkZip(info.glyphCount, fGlyphs.get(), fClusters.get())) {
                glyphs.appendU32(glyph);
                glyphs.append(":");
                glyphs.appendU32(cluster);
                glyphs.append(" ");
            }
            SkString chars;
            for (const char c : SkSpan(fUtf8 + fRange.begin(), fRange.size())) {
                chars.appendHex((unsigned char)c, 2);
                chars.append(" ");
            }
            SkDebugf(
                "%s range: %zu-%zu(%zu) glyphCount:%u font: \"%s\" \"%s\" #%d %zuB\n"
                "rangeText: \"%.*s\"\n"
                "rangeBytes: %s\n"
                "glyphs:%s\n\n",
                fResource, fRange.begin(), fRange.end(), fRange.size(), fGlyphCount,
                familyName.c_str(), postscriptName.c_str(), ttcIndex, fontSize,
                (int)fRange.size(), fUtf8 + fRange.begin(),
                chars.c_str(),
                glyphs.c_str());
        }

        for (unsigned i = 0; i < fGlyphCount; ++i) {
            REPORTER_ASSERT(fReporter, fClusters[i] >= fRange.begin(),
                            "%" PRIu32 " >= %zu %s i:%u glyphCount:%u",
                            fClusters[i], fRange.begin(), fResource, i, fGlyphCount);
            REPORTER_ASSERT(fReporter, fClusters[i] < fRange.end(),
                            "%" PRIu32 " < %zu %s i:%u glyphCount:%u",
                            fClusters[i], fRange.end(), fResource, i, fGlyphCount);
        }
    }
    void commitLine() override { fCommitLine = true; }
};

#if defined(SK_SHAPER_HARFBUZZ_AVAILABLE) && defined(SK_SHAPER_UNICODE_AVAILABLE)
void shaper_test(skiatest::Reporter* reporter, const char* name, SkData* data) {
    skiatest::ReporterContext context(reporter, name);
    auto unicode = get_unicode();
    if (!unicode) {
        ERRORF(reporter, "Could not create unicode.");
        return;
    }

    auto shaper = SkShapers::HB::ShaperDrivenWrapper(unicode,
                                                     SkFontMgr::RefEmpty());  // no fallback
    if (!shaper) {
        ERRORF(reporter, "Could not create shaper.");
        return;
    }
    if (!unicode) {
        ERRORF(reporter, "Could not create unicode.");
        return;
    }
    constexpr float kWidth = 400;
    SkFont font = ToolUtils::DefaultFont();
    const char* utf8 = (const char*)data->data();
    size_t utf8Bytes = data->size();

    RunHandler rh(name, reporter, utf8, utf8Bytes);

    const SkBidiIterator::Level defaultLevel = SkBidiIterator::kLTR;
    std::unique_ptr<SkShaper::BiDiRunIterator> bidi =
            SkShapers::unicode::BidiRunIterator(unicode, utf8, utf8Bytes, defaultLevel);
    SkASSERT(bidi);

    std::unique_ptr<SkShaper::LanguageRunIterator> language =
            SkShaper::MakeStdLanguageRunIterator(utf8, utf8Bytes);
    SkASSERT(language);

    std::unique_ptr<SkShaper::ScriptRunIterator> script =
            SkShapers::HB::ScriptRunIterator(utf8, utf8Bytes);
    SkASSERT(script);

    std::unique_ptr<SkShaper::FontRunIterator> fontRuns =
            SkShaper::MakeFontMgrRunIterator(utf8, utf8Bytes, font, SkFontMgr::RefEmpty());
    SkASSERT(fontRuns);
    shaper->shape(utf8, utf8Bytes, *fontRuns, *bidi, *script, *language, nullptr, 0, kWidth, &rh);

    // Even on empty input, expect that the line is started, that the zero run infos are committed,
    // and the empty line is committed. This allows the user to properly handle empty runs.
    REPORTER_ASSERT(reporter, rh.fBeginLine);
    REPORTER_ASSERT(reporter, rh.fCommitRunInfo);
    REPORTER_ASSERT(reporter, rh.fCommitLine);

    constexpr SkFourByteTag latn = SkSetFourByteTag('l','a','t','n');
    auto fontIterator = SkShaper::TrivialFontRunIterator(font, data->size());
    auto bidiIterator = SkShaper::TrivialBiDiRunIterator(0, data->size());
    auto scriptIterator = SkShaper::TrivialScriptRunIterator(latn, data->size());
    auto languageIterator = SkShaper::TrivialLanguageRunIterator("en-US", data->size());
    shaper->shape((const char*)data->data(),
                  data->size(),
                  fontIterator,
                  bidiIterator,
                  scriptIterator,
                  languageIterator,
                  nullptr,
                  0,
                  kWidth,
                  &rh);
}

void cluster_test(skiatest::Reporter* reporter, const char* resource) {
    auto data = GetResourceAsData(resource);
    if (!data) {
        ERRORF(reporter, "Could not get resource %s.", resource);
        return;
    }

    shaper_test(reporter, resource, data.get());
}

#endif  // defined(SK_SHAPER_HARFBUZZ_AVAILABLE) && defined(SK_SHAPER_UNICODE_AVAILABLE)

}  // namespace

#if defined(SK_SHAPER_HARFBUZZ_AVAILABLE) && defined(SK_SHAPER_UNICODE_AVAILABLE)

DEF_TEST(Shaper_cluster_empty, r) { shaper_test(r, "empty", SkData::MakeEmpty().get()); }

#define SHAPER_TEST(X) DEF_TEST(Shaper_cluster_ ## X, r) { cluster_test(r, "text/" #X ".txt"); }
SHAPER_TEST(arabic)
SHAPER_TEST(armenian)
SHAPER_TEST(balinese)
SHAPER_TEST(buginese)
SHAPER_TEST(cherokee)
SHAPER_TEST(cyrillic)
SHAPER_TEST(emoji)
SHAPER_TEST(english)
SHAPER_TEST(ethiopic)
SHAPER_TEST(greek)
SHAPER_TEST(hangul)
SHAPER_TEST(han_simplified)
SHAPER_TEST(han_traditional)
SHAPER_TEST(hebrew)
SHAPER_TEST(javanese)
SHAPER_TEST(kana)
SHAPER_TEST(lao)
SHAPER_TEST(mandaic)
SHAPER_TEST(newtailue)
SHAPER_TEST(nko)
SHAPER_TEST(sinhala)
SHAPER_TEST(sundanese)
SHAPER_TEST(syriac)
SHAPER_TEST(thaana)
SHAPER_TEST(thai)
SHAPER_TEST(tibetan)
SHAPER_TEST(tifnagh)
SHAPER_TEST(vai)
SHAPER_TEST(bengali)
SHAPER_TEST(devanagari)
SHAPER_TEST(khmer)
SHAPER_TEST(myanmar)
SHAPER_TEST(taitham)
SHAPER_TEST(tamil)
#undef SHAPER_TEST

DEF_TEST(Shaper_LineBreaks, reporter) {
    auto unicode = get_unicode();
    if (!unicode) {
        return;
    }

    auto shaper = SkShapers::HB::ShaperDrivenWrapper(unicode, SkFontMgr::RefEmpty());
    if (!shaper) {
        return;
    }

    SkFont font = ToolUtils::DefaultFont();

    class CustomScriptRunIterator final : public SkShaper::ScriptRunIterator {
    public:
        CustomScriptRunIterator(const std::vector<size_t>& boundaries,
                                size_t total, SkFourByteTag script)
            : fBoundaries(boundaries)
            , fTotal(total)
            , fCurrent(0)
            , fIndex(0)
            , fAtEnd(false)
            , fScript(script) {}

        void consume() override {
            if (fIndex < fBoundaries.size()) {
                fCurrent = fBoundaries[fIndex++];
            } else {
                fCurrent = fTotal;
                fAtEnd = true;
            }
        }
        size_t endOfCurrentRun() const override { return fCurrent; }
        bool atEnd() const override { return fAtEnd; }
        SkFourByteTag currentScript() const override { return fScript; }

    private:
        std::vector<size_t> fBoundaries;
        size_t fTotal;
        size_t fCurrent;
        size_t fIndex;
        bool fAtEnd;
        SkFourByteTag fScript;
    };

    struct LineBreakTracker final : public SkShaper::RunHandler {
        struct Run {
            size_t start;
            size_t end;
        };
        struct Line {
            size_t start;
            std::vector<Run> runs;
        };
        std::vector<Line> fLines;
        size_t fCurrentLineStart = 0;

        void beginLine() override {
            fLines.push_back({fCurrentLineStart, {}});
        }
        void runInfo(const RunInfo&) override {}
        void commitRunInfo() override {}
        Buffer runBuffer(const RunInfo& info) override {
            static SkGlyphID glyphs[100];
            static SkPoint pos[100];
            fLines.back().runs.push_back({info.utf8Range.begin(), info.utf8Range.end()});
            return {glyphs, pos, nullptr, nullptr, {0, 0}};
        }
        void commitRunBuffer(const RunInfo& info) override {
            fCurrentLineStart = info.utf8Range.end();
        }
        void commitLine() override {}
    };

    auto check_line_breaks = [&](const char* txt,
                                 const std::vector<size_t>& script_boundaries,
                                 const std::vector<size_t>& expected_line_breaks) {
        size_t len = strlen(txt);
        std::vector<size_t> breaks;

        size_t previousLineCount = std::numeric_limits<size_t>::max();
        for (size_t i = 0; i < 100; ++i) {
            const float width = 5.f + i * 5;

            auto fontIter = SkShaper::TrivialFontRunIterator(font, len);
            auto bidi = SkShaper::TrivialBiDiRunIterator(0, len);
            CustomScriptRunIterator scriptIter(script_boundaries, len,
                                               SkSetFourByteTag('L','a','t','n'));
            auto lang = SkShaper::TrivialLanguageRunIterator("en-US", len);

            LineBreakTracker tracker;
            shaper->shape(txt, len, fontIter, bidi, scriptIter, lang, nullptr, 0, width, &tracker);

            // Line counts should be monotonic.
            const size_t lineCount = tracker.fLines.size();
            REPORTER_ASSERT(reporter, lineCount <= previousLineCount,
                            "Line count should be monotonic. Width: %f, Line count: %zu, Prev: %zu",
                             width, lineCount, previousLineCount);
            previousLineCount = lineCount;

            for (const auto& line : tracker.fLines) {
                if (line.start > 0) {
                    if (!i) {
                        // The first iteration (minimal width) is expected to produce the maximal
                        // line break set - so we just collect them here.
                        breaks.push_back(line.start);
                    } else {
                        // Subsequent iterations are expected to produce a subset.
                        REPORTER_ASSERT(
                            reporter,
                            std::find(breaks.begin(), breaks.end(), line.start) != breaks.end(),
                            "Break at offset %zu for width %f is unexpected for '%s'!",
                            line.start, width, txt);
                    }
                }
            }
        }

        REPORTER_ASSERT(reporter, previousLineCount == 1,
                        "Text '%s' should fit on a single line at max width, but had %zu lines",
                        txt, previousLineCount);

        REPORTER_ASSERT(reporter, breaks == expected_line_breaks,
                        "Observed breaks did not match expected breaks for: '%s'",
                        txt);
    };

    static struct {
        const char* fText;
        std::vector<size_t> fScriptBoundaries;
        std::vector<size_t> fExpectedLineBreaks;
    } gTests[] = {
        { "foo", { }, { } },
        { "foo", {1}, { } },
        { "foo", {2}, { } },
        { "foobar", {1, 2, 3, 4, 5}, { } },

        { "foo bar", { }, {4} },
        { "foo bar", {1}, {4} },
        { "foo bar", {2}, {4} },
        { "foo bar", {3}, {4} },
        { "foo bar", {4}, {4} },
        { "foo bar", {5}, {4} },
        { "foo bar", {6}, {4} },
        { "foo bar", {1, 2, 3, 4, 5, 6}, {4} },

        { "foo, bar baz", {     }, {5, 9} },
        { "foo, bar baz", {6,  7}, {5, 9} },
        { "foo, bar baz", {2, 10}, {5, 9} },
        { "foo, bar baz", {3, 10}, {5, 9} },
        { "foo, bar baz", {3, 11}, {5, 9} },
        { "foo, bar baz", {2, 11}, {5, 9} },
        { "foo, bar baz", {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}, {5, 9} },

        { "abra cadabra", {         }, {5} },
        { "abra cadabra", {1,  2,  3}, {5} },
        { "abra cadabra", {1,  2,  4}, {5} },
        { "abra cadabra", {1,  2,  5}, {5} },
        { "abra cadabra", {1,  2,  6}, {5} },
        { "abra cadabra", {1,  2,  7}, {5} },
        { "abra cadabra", {1,  2,  8}, {5} },
        { "abra cadabra", {1,  2,  9}, {5} },
        { "abra cadabra", {1,  2, 10}, {5} },
        { "abra cadabra", {1,  2, 11}, {5} },

        { "abra cadabra", {1,  3, 11}, {5} },
        { "abra cadabra", {1,  4, 11}, {5} },
        { "abra cadabra", {1,  5, 11}, {5} },
        { "abra cadabra", {1,  6, 11}, {5} },
        { "abra cadabra", {1,  7, 11}, {5} },
        { "abra cadabra", {1,  8, 11}, {5} },
        { "abra cadabra", {1,  9, 11}, {5} },
        { "abra cadabra", {1, 10, 11}, {5} },

        { "abra cadabra", {2, 10, 11}, {5} },
        { "abra cadabra", {3, 10, 11}, {5} },
        { "abra cadabra", {4, 10, 11}, {5} },
        { "abra cadabra", {5, 10, 11}, {5} },
        { "abra cadabra", {6, 10, 11}, {5} },
        { "abra cadabra", {7, 10, 11}, {5} },
        { "abra cadabra", {8, 10, 11}, {5} },
        { "abra cadabra", {9, 10, 11}, {5} },
    };

    for (const auto& test : gTests) {
        check_line_breaks(test.fText, test.fScriptBoundaries, test.fExpectedLineBreaks);
    }

    {
        static const char* kText = "abra cadabra";
        static const std::vector<size_t> expected_breaks = { 5 };
        static const size_t kLen = strlen(kText);

        // exhaustive combinatorics for 3 runs
        for (size_t i0 = 1; i0 < kLen - 2; ++i0) {
            for (size_t i1 = i0 + 1; i1 < kLen - 1; ++i1) {
                check_line_breaks(kText, {i0, i1}, expected_breaks);
            }
        }
    }
}

#endif  // #if defined(SK_SHAPER_HARFBUZZ_AVAILABLE) && defined(SK_SHAPER_UNICODE_AVAILABLE)