#pragma once

#include <mapbox/std/weak.hpp>
#include <mapbox/util/type_wrapper.hpp>
#include <mbgl/storage/resource.hpp>
#include <mbgl/style/source_data.hpp>
#include <mbgl/style/source_parameters.hpp>
#include <mbgl/style/types.hpp>
#include <mbgl/tile/tile_kind.hpp>
#include <mbgl/util/chrono.hpp>
#include <mbgl/util/feature.hpp>
#include <mbgl/util/immutable.hpp>
#include <mbgl/util/optional.hpp>
#include <mbgl/util/variant.hpp>
#include <memory>
#include <string>

namespace mbgl {

class FileSource;
class Tileset;

namespace style {

class VectorSource;
class RasterSource;
class RasterDEMSource;
class GeoJSONSource;
class SourceObserver;
struct LayerTypeInfo;

/**
 * @brief Holds static data for a certain source type.
 */
struct SourceTypeInfo {
    /**
     * @brief contains the source type as defined in the style specification;
     */
    const char* type;

    /**
     * @brief specifies whether the source supports tile prefetching;
     */
    const enum class TilePrefetch : bool { No, Yes } tilePrefetch;

    /**
     * @brief specifies whether the source operates with the loaded tile set;
     */
    const enum class TileSet : bool { No, Yes } tileSet;

    /**
     * @brief specifies source's tile kind;
     */
    const optional<TileKind> tileKind;
};

/**
 * The runtime representation of a [source](https://www.mapbox.com/mapbox-gl-style-spec/#sources) from the Mapbox Style
 * Specification.
 *
 * `Source` is an abstract base class; concrete derived classes are provided for each source type. `Source` contains
 * functionality that is common to all layer types:
 *
 * * Runtime type information: type predicates and casting
 * * Accessors for properties common to all source types: ID, etc.
 * * Cloning and copying
 *
 * All other functionality lives in the derived classes. To instantiate a source, create an instance of the desired
 * type, passing the ID:
 *
 *     auto vectorSource = std::make_unique<VectorSource>("my-vector-source");
 */
class Source : public Serializable {
public:
    Source(const Source&) = delete;
    Source& operator=(const Source&) = delete;

    virtual ~Source();

    std::string getID() const;
    optional<std::string> getAttribution() const;

    // The data from the volatile sources are not stored in a persistent storage.
    bool isVolatile() const noexcept;
    void setVolatile(bool) noexcept;

    // Private implementation
    class Impl;
    Immutable<Impl> baseImpl;

    void setObserver(SourceObserver*);
    SourceObserver* observer = nullptr;

    virtual void loadDescription(FileSource&) = 0;

    virtual void setSourceData(SourceData) {}

    /**
     * @brief Returns resource for loading, if required by this source; returns `nullopt` otherwise.
     *
     * If already loaded, this will return nullopt as well for Tiled sources (SourceTypeInfo::TileSet == Yes)
     *
     * @return optional<Resource>
     */
    virtual optional<Resource> getResource() const { return nullopt; }

    /**
     * @brief for tiled sources (SourceTypeInfo::TileSet == Yes) this will return the TileSet when
     * loaded, nullptr in any other case.
     *
     * @return Tileset* or nullptr
     */
    virtual const Tileset* getTileset() const { return nullptr; }

    /**
     * @brief Returns the GeoJSON data, if this source supports GeoJSON format; returns `nullptr` otherwise.
     *
     * @return const GeoJSONData*
     */
    virtual const GeoJSONData* getGeoJSONData() const { return nullptr; }
    virtual void setSourceParameters(SourceParameters) {}

    virtual void invalidateTile(const CanonicalTileID&) {}
    virtual void invalidateRegion(const LatLngBounds&) {}

    void setPrefetchZoomDelta(optional<uint8_t> delta) noexcept;
    optional<uint8_t> getPrefetchZoomDelta() const noexcept;

    int32_t getCoveringZoomLevel(double z) const noexcept;

    uint16_t getTileSize() const;

    // If the given source supports loading tiles from a server,
    // sets the minimum tile update interval.
    // Update network requests that are more frequent than the
    // minimum tile update interval are suppressed.
    //
    // Default value is `Duration::zero()`.
    void setMinimumTileUpdateInterval(Duration) noexcept;
    Duration getMinimumTileUpdateInterval() const noexcept;

    // Sets a limit for how much a parent tile can be overscaled.
    //
    // When a set of tiles for a current zoom level is being rendered and some of the
    // ideal tiles that cover the screen are not yet loaded, parent tile could be
    // used instead. This might introduce unwanted rendering side-effects, especially
    // for raster tiles that are overscaled multiple times.
    //
    // For example, an overscale factor of 3 would mean that on zoom level 3, the
    // minimum zoom level of a parent tile that could be used in place of an ideal
    // tile during rendering would be zoom 0. By default, no limit is set, so any
    // parent tile may be used.
    void setMaxOverscaleFactorForParentTiles(optional<uint8_t> overscaleFactor) noexcept;
    optional<uint8_t> getMaxOverscaleFactorForParentTiles() const noexcept;

    void dumpDebugLogs() const;

    virtual bool supportsLayerType(const mbgl::style::LayerTypeInfo*) const = 0;

    bool loaded = false;

    // For use in SDK bindings, which store a reference to a platform-native peer
    // object here, so that separately-obtained references to this object share
    // identical platform-native peers.
    mapbox::base::TypeWrapper peer;

    optional<conversion::Error> setProperty(const std::string& name, const conversion::Convertible& value);
    Value getProperty(const std::string&) const;
    Value getPropertyDefaultValue(const std::string&) const;

    virtual mapbox::base::WeakPtr<Source> makeWeakPtr() = 0;
    const SourceTypeInfo* getTypeInfo() const noexcept;

    Value serialize() const override;

protected:
    explicit Source(Immutable<Impl>);

    virtual Mutable<Impl> createMutable() const noexcept = 0;
    virtual optional<conversion::Error> setPropertyInternal(const std::string& name,
                                                            const conversion::Convertible& value);
    virtual Value getPropertyInternal(const std::string&) const;
    virtual Value getPropertyDefaultValueInternal(const std::string&) const;
};

} // namespace style
} // namespace mbgl