#include <mbgl/renderer/sources/render_tile_source.hpp>

#include <mbgl/renderer/buckets/debug_bucket.hpp>
#include <mbgl/renderer/render_tile.hpp>
#include <mbgl/renderer/render_tree.hpp>
#include <mbgl/renderer/paint_parameters.hpp>
#include <mbgl/renderer/tile_parameters.hpp>
#include <mbgl/renderer/tile_render_data.hpp>
#include <mbgl/tile/vector_tile.hpp>
#include <mbgl/util/constants.hpp>
#include <mbgl/util/math.hpp>

namespace mbgl {

using namespace style;

class TileSourceRenderItem : public RenderItem {
public:
    TileSourceRenderItem(Immutable<std::vector<RenderTile>> renderTiles_, std::string name_)
        : renderTiles(std::move(renderTiles_))
        , name(std::move(name_)) {}

private:
    void upload(gfx::UploadPass&) const override;
    void render(PaintParameters&) const override;
    bool hasRenderPass(RenderPass) const override { return false; }
    const std::string& getName() const override { return name; }

    Immutable<std::vector<RenderTile>> renderTiles;
    std::string name;
};

void TileSourceRenderItem::upload(gfx::UploadPass& parameters) const {
    for (auto& tile : *renderTiles) {
        tile.upload(parameters);
    }
}

void TileSourceRenderItem::render(PaintParameters& parameters) const {
    for (auto& tile : *renderTiles) {
        tile.finishRender(parameters);
    }
}

RenderTileSource::RenderTileSource(Immutable<style::Source::Impl> impl_)
    : RenderSource(std::move(impl_))
    , renderTiles(makeMutable<std::vector<RenderTile>>()) {
    tilePyramid.setObserver(this);
}

RenderTileSource::~RenderTileSource() = default;

bool RenderTileSource::isLoaded() const {
    return tilePyramid.isLoaded();
}

std::unique_ptr<RenderItem> RenderTileSource::createRenderItem() {
    return std::make_unique<TileSourceRenderItem>(renderTiles, baseImpl->id);
}

void RenderTileSource::prepare(const SourcePrepareParameters& parameters) {
    bearing = parameters.transform.state.getBearing();
    filteredRenderTiles = nullptr;
    renderTilesSortedByY = nullptr;
    auto tiles = makeMutable<std::vector<RenderTile>>();
    tiles->reserve(tilePyramid.getRenderedTiles().size());
    for (auto& entry : tilePyramid.getRenderedTiles()) {
        tiles->emplace_back(entry.first, entry.second);
        tiles->back().prepare(parameters);
    }
    renderTiles = std::move(tiles);
}

void RenderTileSource::updateFadingTiles() {
    tilePyramid.updateFadingTiles();
}

bool RenderTileSource::hasFadingTiles() const {
    return tilePyramid.hasFadingTiles();
}

RenderTiles RenderTileSource::getRenderTiles() const {
    if (!filteredRenderTiles) {
        auto result = std::make_shared<std::vector<std::reference_wrapper<const RenderTile>>>();
        for (const auto& renderTile : *renderTiles) {
            if (renderTile.holdForFade()) {
                continue;
            }
            result->emplace_back(renderTile);
        }
        filteredRenderTiles = std::move(result);
    }
    return filteredRenderTiles;
}

RenderTiles RenderTileSource::getRenderTilesSortedByYPosition() const {
    if (!renderTilesSortedByY) {
        const auto comp = [bearing = this->bearing](const RenderTile& a, const RenderTile& b) {
            Point<float> pa(a.id.canonical.x, a.id.canonical.y);
            Point<float> pb(b.id.canonical.x, b.id.canonical.y);

            auto par = util::rotate(pa, bearing);
            auto pbr = util::rotate(pb, bearing);

            return std::tie(b.id.canonical.z, par.y, par.x) < std::tie(a.id.canonical.z, pbr.y, pbr.x);
        };

        auto result = std::make_shared<std::vector<std::reference_wrapper<const RenderTile>>>();
        result->reserve(renderTiles->size());
        for (const auto& renderTile : *renderTiles) {
            result->emplace_back(renderTile);
        }
        std::sort(result->begin(), result->end(), comp);
        renderTilesSortedByY = std::move(result);
    }
    return renderTilesSortedByY;
}

const Tile* RenderTileSource::getRenderedTile(const UnwrappedTileID& tileID) const {
    return tilePyramid.getRenderedTile(tileID);
}

std::unordered_map<std::string, std::vector<Feature>>
RenderTileSource::queryRenderedFeatures(const ScreenLineString& geometry,
                                          const TransformState& transformState,
                                          const std::unordered_map<std::string, const RenderLayer*>& layers,
                                          const RenderedQueryOptions& options,
                                          const mat4& projMatrix) const {
    return tilePyramid.queryRenderedFeatures(geometry, transformState, layers, options, projMatrix);
}

std::vector<Feature> RenderTileSource::querySourceFeatures(const SourceQueryOptions& options) const {
    return tilePyramid.querySourceFeatures(options);
}

void RenderTileSource::reduceMemoryUse() {
    tilePyramid.reduceMemoryUse();
}

void RenderTileSource::dumpDebugLogs() const {
    tilePyramid.dumpDebugLogs();
}

// RenderTileSetSource implementation

RenderTileSetSource::RenderTileSetSource(Immutable<style::Source::Impl> impl_)
    : RenderTileSource(std::move(impl_)) {
}

RenderTileSetSource::~RenderTileSetSource() = default;

uint8_t RenderTileSetSource::getMaxZoom() const {
    return cachedTileset ? cachedTileset->zoomRange.max : util::TERRAIN_RGB_MAXZOOM;
}

void RenderTileSetSource::update(Immutable<style::Source::Impl> baseImpl_,
                                const std::vector<Immutable<style::LayerProperties>>& layers,
                                const bool needsRendering,
                                const bool needsRelayout,
                                const TileParameters& parameters) {
    std::swap(baseImpl, baseImpl_);

    enabled = needsRendering;

    const optional<Tileset>& implTileset = getTileset();
    // In Continuous mode, keep the existing tiles if the new cachedTileset is not
    // yet available, thus providing smart style transitions without flickering.
    // In other modes, allow clearing the tile pyramid first, before the early
    // return in order to avoid render tests being flaky.
    bool canUpdateTileset = implTileset || parameters.mode != MapMode::Continuous;
    if (canUpdateTileset && cachedTileset != implTileset) {
        cachedTileset = implTileset;

        // TODO: this removes existing buckets, and will cause flickering.
        // Should instead refresh tile data in place.
        tilePyramid.clearAll();
    }

    if (!cachedTileset) return;

    updateInternal(*cachedTileset, layers, needsRendering, needsRelayout, parameters);
}

} // namespace mbgl