#include <mbgl/test/util.hpp>
#include <mbgl/test/stub_file_source.hpp>
#include <mbgl/test/stub_style_observer.hpp>

#include <mbgl/text/glyph_atlas.hpp>
#include <mbgl/util/run_loop.hpp>
#include <mbgl/util/string.hpp>
#include <mbgl/util/io.hpp>
#include <mbgl/util/logging.hpp>

using namespace mbgl;

class StubGlyphRequestor : public GlyphRequestor {
public:
    void onGlyphsAvailable(GlyphPositionMap positions) override {
        if (glyphsAvailable) glyphsAvailable(std::move(positions));
    }

    std::function<void (GlyphPositionMap)> glyphsAvailable;
};

class GlyphAtlasTest {
public:
    util::RunLoop loop;
    StubFileSource fileSource;
    StubStyleObserver observer;
    StubGlyphRequestor requestor;
    GlyphAtlas glyphAtlas{ { 32, 32 }, fileSource };

    void run(const std::string& url, GlyphDependencies dependencies) {
        // Squelch logging.
        Log::setObserver(std::make_unique<Log::NullObserver>());

        glyphAtlas.setURL(url);
        glyphAtlas.setObserver(&observer);
        glyphAtlas.getGlyphs(requestor, std::move(dependencies));

        loop.run();
    }

    void end() {
        loop.stop();
    }
};

TEST(GlyphAtlas, LoadingSuccess) {
    GlyphAtlasTest test;

    test.fileSource.glyphsResponse = [&] (const Resource& resource) {
        EXPECT_EQ(Resource::Kind::Glyphs, resource.kind);
        Response response;
        response.data = std::make_shared<std::string>(util::read_file("test/fixtures/resources/glyphs.pbf"));
        return response;
    };

    test.observer.glyphsError = [&] (const FontStack&, const GlyphRange&, std::exception_ptr) {
        FAIL();
        test.end();
    };

    test.observer.glyphsLoaded = [&] (const FontStack& fontStack, const GlyphRange& range) {
        ASSERT_EQ(fontStack, FontStack {{"Test Stack"}});
        ASSERT_EQ(range, GlyphRange(0, 255));
    };

    test.requestor.glyphsAvailable = [&] (GlyphPositionMap positions) {
        const auto& testPositions = positions.at({{"Test Stack"}});

        ASSERT_EQ(testPositions.size(), 3u);
        ASSERT_EQ(testPositions.count(u'a'), 1u);
        ASSERT_EQ(testPositions.count(u'å'), 1u);
        ASSERT_EQ(testPositions.count(u' '), 1u);
        ASSERT_TRUE(bool(testPositions.at(u' ')));

        test.end();
    };

    test.run(
        "test/fixtures/resources/glyphs.pbf",
        GlyphDependencies {
            {{{"Test Stack"}}, {u'a', u'å', u' '}}
        });
}

TEST(GlyphAtlas, LoadingFail) {
    GlyphAtlasTest test;

    test.fileSource.glyphsResponse = [&] (const Resource&) {
        Response response;
        response.error = std::make_unique<Response::Error>(
            Response::Error::Reason::Other,
            "Failed by the test case");
        return response;
    };

    test.observer.glyphsError = [&] (const FontStack& fontStack, const GlyphRange& glyphRange, std::exception_ptr error) {
        EXPECT_EQ(fontStack, FontStack({"Test Stack"}));
        EXPECT_EQ(glyphRange, GlyphRange(0, 255));

        EXPECT_TRUE(error != nullptr);
        EXPECT_EQ(util::toString(error), "Failed by the test case");

        test.end();
    };

    test.requestor.glyphsAvailable = [&] (GlyphPositionMap) {
        FAIL();
        test.end();
    };

    test.run(
        "test/fixtures/resources/glyphs.pbf",
        GlyphDependencies {
            {{{"Test Stack"}}, {u'a', u'å'}}
        });
}

TEST(GlyphAtlas, LoadingCorrupted) {
    GlyphAtlasTest test;

    test.fileSource.glyphsResponse = [&] (const Resource&) {
        Response response;
        response.data = std::make_unique<std::string>("CORRUPTED");
        return response;
    };

    test.observer.glyphsError = [&] (const FontStack& fontStack, const GlyphRange& glyphRange, std::exception_ptr error) {
        EXPECT_EQ(fontStack, FontStack({"Test Stack"}));
        EXPECT_EQ(glyphRange, GlyphRange(0, 255));

        EXPECT_TRUE(error != nullptr);
        EXPECT_EQ(util::toString(error), "unknown pbf field type exception");

        test.end();
    };

    test.requestor.glyphsAvailable = [&] (GlyphPositionMap) {
        FAIL();
        test.end();
    };

    test.run(
        "test/fixtures/resources/glyphs.pbf",
        GlyphDependencies {
            {{{"Test Stack"}}, {u'a', u'å'}}
        });
}

TEST(GlyphAtlas, LoadingCancel) {
    GlyphAtlasTest test;

    test.fileSource.glyphsResponse = [&] (const Resource&) {
        test.end();
        return optional<Response>();
    };

    test.observer.glyphsLoaded = [&] (const FontStack&, const GlyphRange&) {
        FAIL() << "Should never be called";
    };

    test.run(
        "test/fixtures/resources/glyphs.pbf",
        GlyphDependencies {
            {{{"Test Stack"}}, {u'a', u'å'}}
        });
}

TEST(GlyphAtlas, LoadingInvalid) {
    GlyphAtlasTest test;

    test.fileSource.glyphsResponse = [&] (const Resource& resource) {
        EXPECT_EQ(Resource::Kind::Glyphs, resource.kind);
        Response response;
        response.data = std::make_shared<std::string>(util::read_file("test/fixtures/resources/fake_glyphs-0-255.pbf"));
        return response;
    };

    test.observer.glyphsError = [&] (const FontStack&, const GlyphRange&, std::exception_ptr) {
        FAIL();
        test.end();
    };

    test.observer.glyphsLoaded = [&] (const FontStack& fontStack, const GlyphRange& range) {
        ASSERT_EQ(fontStack, FontStack {{"Test Stack"}});
        ASSERT_EQ(range, GlyphRange(0, 255));
    };

    test.requestor.glyphsAvailable = [&] (GlyphPositionMap positions) {
        const auto& testPositions = positions.at({{"Test Stack"}});

        ASSERT_EQ(testPositions.size(), 2u);
        ASSERT_FALSE(bool(testPositions.at(u'A')));
        ASSERT_TRUE(bool(testPositions.at(u'E')));

        test.end();
    };

    test.run(
        "test/fixtures/resources/glyphs.pbf",
        GlyphDependencies {
            {{{"Test Stack"}}, {u'A', u'E'}}
        });
}