#include <mbgl/test/util.hpp>
#include <mbgl/algorithm/update_tile_masks.hpp>

#include <algorithm>

using namespace mbgl;

namespace {

class FakeTile {
public:
    FakeTile(TileMask mask_)
        : mask(std::move(mask_)) {}
    void setMask(TileMask mask_) { mask = std::move(mask_); }

    const bool usedByRenderedLayers = true;
    TileMask mask;
};

bool operator==(const FakeTile& lhs, const FakeTile& rhs) {
    return lhs.mask == rhs.mask;
}

} // namespace

void validate(std::map<UnwrappedTileID, FakeTile> expected) {
    auto actual = expected;
    std::ranges::for_each(actual, [](auto& renderable) { renderable.second.mask.clear(); });

    algorithm::updateTileMasks(actual);
    EXPECT_EQ(expected, actual);
}

TEST(UpdateTileMasks, NoChildren) {
    validate({{UnwrappedTileID{0, 0, 0}, TileMask{CanonicalTileID{0, 0, 0}}}});

    validate({
        {UnwrappedTileID{4, 3, 8}, TileMask{CanonicalTileID{0, 0, 0}}},
    });

    validate({
        {UnwrappedTileID{1, 0, 0}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{1, 1, 1}, TileMask{CanonicalTileID{0, 0, 0}}},
    });

    validate({
        {UnwrappedTileID{1, 0, 0}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{2, 2, 3}, TileMask{CanonicalTileID{0, 0, 0}}},
    });
}

TEST(UpdateTileMasks, ParentAndFourChildren) {
    validate({
        // Mask is empty (== not rendered!) because we have four covering children.
        {UnwrappedTileID{0, 0, 0}, TileMask{}},
        // All four covering children
        {UnwrappedTileID{1, 0, 0}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{1, 0, 1}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{1, 1, 0}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{1, 1, 1}, TileMask{CanonicalTileID{0, 0, 0}}},
    });
}

TEST(UpdateTileMasks, OneChild) {
    validate({
        {UnwrappedTileID{0, 0, 0},
         // Only render the three children that aren't covering the other tile.
         TileMask{CanonicalTileID{1, 0, 1}, CanonicalTileID{1, 1, 0}, CanonicalTileID{1, 1, 1}}},
        {UnwrappedTileID{1, 0, 0}, TileMask{CanonicalTileID{0, 0, 0}}},
    });
}

TEST(UpdateTileMasks, Complex) {
    validate({
        {UnwrappedTileID{0, 0, 0},
         TileMask{CanonicalTileID{1, 0, 1},
                  CanonicalTileID{1, 1, 0},
                  CanonicalTileID{2, 2, 3},
                  CanonicalTileID{2, 3, 2},
                  CanonicalTileID{3, 6, 7},
                  CanonicalTileID{3, 7, 6}}},
        {UnwrappedTileID{0, {1, 0, 0}}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{0, {2, 2, 2}}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{0, {3, 7, 7}}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{0, {3, 6, 6}}, TileMask{CanonicalTileID{0, 0, 0}}},
    });

    validate({
        {UnwrappedTileID{0, 0, 0},
         TileMask{CanonicalTileID{1, 0, 1},
                  CanonicalTileID{1, 1, 0},
                  CanonicalTileID{1, 1, 1},
                  CanonicalTileID{2, 0, 0},
                  CanonicalTileID{2, 0, 1},
                  CanonicalTileID{2, 1, 0},
                  CanonicalTileID{3, 2, 3},
                  CanonicalTileID{3, 3, 2},
                  CanonicalTileID{3, 3, 3},
                  CanonicalTileID{4, 4, 5},
                  CanonicalTileID{4, 5, 4},
                  CanonicalTileID{4, 5, 5}}},
        {UnwrappedTileID{4, 4, 4}, TileMask{CanonicalTileID{0, 0, 0}}},
    });

    validate({
        {UnwrappedTileID{12, 1028, 1456},
         TileMask{CanonicalTileID{1, 1, 1}, CanonicalTileID{2, 3, 0}, CanonicalTileID{2, 3, 1}}},
        {UnwrappedTileID{13, 2056, 2912},
         TileMask{CanonicalTileID{1, 0, 1}, CanonicalTileID{1, 1, 0}, CanonicalTileID{1, 1, 1}}},
        {UnwrappedTileID{13, 2056, 2913},
         TileMask{CanonicalTileID{1, 0, 0}, CanonicalTileID{1, 1, 0}, CanonicalTileID{1, 1, 1}}},
        {UnwrappedTileID{14, 4112, 5824}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{14, 4112, 5827}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{14, 4114, 5824}, TileMask{CanonicalTileID{0, 0, 0}}},
        {UnwrappedTileID{14, 4114, 5825}, TileMask{CanonicalTileID{0, 0, 0}}},
    });
}