#ifndef slic3r_SLAPrint_hpp_
#define slic3r_SLAPrint_hpp_

#include <mutex>
#include "PrintBase.hpp"
#include "PrintExport.hpp"
#include "Point.hpp"
#include "MTUtils.hpp"
#include <iterator>

namespace Slic3r {

enum SLAPrintStep : unsigned int {
	slapsRasterize,
	slapsValidate,
	slapsCount
};

enum SLAPrintObjectStep : unsigned int {
	slaposObjectSlice,
	slaposSupportPoints,
	slaposSupportTree,
	slaposBasePool,
	slaposSliceSupports,
    slaposIndexSlices,
	slaposCount
};

class SLAPrint;
class GLCanvas;

using _SLAPrintObjectBase =
    PrintObjectBaseWithState<SLAPrint, SLAPrintObjectStep, slaposCount>;

// Layers according to quantized height levels. This will be consumed by
// the printer (rasterizer) in the SLAPrint class.
// using coord_t = long long;

enum SliceOrigin { soSupport, soModel };

class SLAPrintObject;

// The public Slice record structure. It corresponds to one printable layer.
class SliceRecord {
public:
    // this will be the max limit of size_t
    static const size_t NONE = size_t(-1);

    static const SliceRecord EMPTY;

private:
    coord_t   m_print_z = 0;      // Top of the layer
    float     m_slice_z = 0.f;    // Exact level of the slice
    float     m_height  = 0.f;     // Height of the sliced layer

    size_t m_model_slices_idx = NONE;
    size_t m_support_slices_idx = NONE;
    const SLAPrintObject *m_po = nullptr;

public:

    SliceRecord(coord_t key, float slicez, float height):
        m_print_z(key), m_slice_z(slicez), m_height(height) {}

    // The key will be the integer height level of the top of the layer.
    coord_t print_level() const { return m_print_z; }

    // Returns the exact floating point Z coordinate of the slice
    float slice_level() const { return m_slice_z; }

    // Returns the current layer height
    float layer_height() const { return m_height; }

    bool is_valid() const { return std::isnan(m_slice_z); }

    const SLAPrintObject* print_obj() const { return m_po; }

    // Methods for setting the indices into the slice vectors.
    void set_model_slice_idx(const SLAPrintObject &po, size_t id) {
        m_po = &po; m_model_slices_idx = id;
    }

    void set_support_slice_idx(const SLAPrintObject& po, size_t id) {
        m_po = &po; m_support_slices_idx = id;
    }

    const ExPolygons& get_slice(SliceOrigin o) const;
};


class SLAPrintObject : public _SLAPrintObjectBase
{
private: // Prevents erroneous use by other classes.
    using Inherited = _SLAPrintObjectBase;

public:

    // I refuse to grantee copying (Tamas)
    SLAPrintObject(const SLAPrintObject&) = delete;
    SLAPrintObject& operator=(const SLAPrintObject&) = delete;

    const SLAPrintObjectConfig& config() const { return m_config; }
    const Transform3d&          trafo()  const { return m_trafo; }

    struct Instance {
    	Instance(ModelID instance_id, const Point &shift, float rotation) : instance_id(instance_id), shift(shift), rotation(rotation) {}
		bool operator==(const Instance &rhs) const { return this->instance_id == rhs.instance_id && this->shift == rhs.shift && this->rotation == rhs.rotation; }
    	// ID of the corresponding ModelInstance.
		ModelID instance_id;
		// Slic3r::Point objects in scaled G-code coordinates
    	Point 	shift;
    	// Rotation along the Z axis, in radians.
    	float 	rotation;
	};
    const std::vector<Instance>& instances() const { return m_instances; }

    bool                    has_mesh(SLAPrintObjectStep step) const;
    TriangleMesh            get_mesh(SLAPrintObjectStep step) const;

    // Get a support mesh centered around origin in XY, and with zero rotation around Z applied.
    // Support mesh is only valid if this->is_step_done(slaposSupportTree) is true.
    const TriangleMesh&     support_mesh() const;
    // Get a pad mesh centered around origin in XY, and with zero rotation around Z applied.
    // Support mesh is only valid if this->is_step_done(slaposBasePool) is true.
    const TriangleMesh&     pad_mesh() const;

    // This will return the transformed mesh which is cached
    const TriangleMesh&     transformed_mesh() const;

    std::vector<sla::SupportPoint>      transformed_support_points() const;

    // Get the needed Z elevation for the model geometry if supports should be
    // displayed. This Z offset should also be applied to the support
    // geometries. Note that this is not the same as the value stored in config
    // as the pad height also needs to be considered.
    double get_elevation() const;

    // This method returns the needed elevation according to the processing
    // status. If the supports are not ready, it is zero, if they are and the
    // pad is not, then without the pad, otherwise the full value is returned.
    double get_current_elevation() const;

    // This method returns the support points of this SLAPrintObject.
    const std::vector<sla::SupportPoint>& get_support_points() const;

private:

    template <class T> inline static T level(const SliceRecord& sr) {
        static_assert(std::is_arithmetic<T>::value, "Arithmetic only!");
        return std::is_integral<T>::value ? T(sr.print_level()) : T(sr.slice_level());
    }

    template <class T> inline static SliceRecord create_slice_record(T val) {
        static_assert(std::is_arithmetic<T>::value, "Arithmetic only!");
        return std::is_integral<T>::value ? SliceRecord{ coord_t(val), 0.f, 0.f } : SliceRecord{ 0, float(val), 0.f };
    }

    // This is a template method for searching the slice index either by
    // an integer key: print_level or a floating point key: slice_level.
    // The eps parameter gives the max deviation in + or - direction.
    //
    // This method can be used in const or non-const contexts as well.
    template<class Container, class T>
    static auto closest_slice_record(Container& cont, T lvl, T eps) -> decltype (cont.begin())
    {
        if(cont.empty()) return cont.end();
        if(cont.size() == 1 && std::abs(level<T>(cont.front()) - lvl) > eps)
            return cont.end();

        SliceRecord query = create_slice_record(lvl);

        auto it = std::lower_bound(cont.begin(), cont.end(), query,
                                   [](const SliceRecord& r1,
                                      const SliceRecord& r2)
        {
            return level<T>(r1) < level<T>(r2);
        });

        T diff = std::abs(level<T>(*it) - lvl);

        if(it != cont.begin()) {
            auto it_prev = std::prev(it);
            T diff_prev = std::abs(level<T>(*it_prev) - lvl);
            if(diff_prev < diff) { diff = diff_prev; it = it_prev; }
        }

        if(diff > eps) it = cont.end();

        return it;
    }

public:

    // /////////////////////////////////////////////////////////////////////////
    //
    // These methods should be callable on the client side (e.g. UI thread)
    // when the appropriate steps slaposObjectSlice and slaposSliceSupports
    // are ready. All the print objects are processed before slapsRasterize so
    // it is safe to call them during and/or after slapsRasterize.
    //
    // /////////////////////////////////////////////////////////////////////////

    // Retrieve the slice index.
    const std::vector<SliceRecord>& get_slice_index() const;

    const std::vector<ExPolygons>& get_model_slices() const;
    const std::vector<ExPolygons>& get_support_slices() const;

    // Search slice index for the closest slice to given print_level.
    // max_epsilon gives the allowable deviation of the returned slice record's
    // level.
    const SliceRecord& closest_slice_to_print_level(
            coord_t print_level, coord_t max_epsilon = coord_t(SCALED_EPSILON)) const
    {
        auto it = closest_slice_record(m_slice_index, print_level, max_epsilon);
        if (it == m_slice_index.end()) return SliceRecord::EMPTY;
        return *it;
    }

    // Search slice index for the closest slice to given slice_level.
    // max_epsilon gives the allowable deviation of the returned slice record's
    // level.
    const SliceRecord& closest_slice_to_slice_level(
            float slice_level, float max_epsilon = float(EPSILON)) const
    {
        auto it = closest_slice_record(m_slice_index, slice_level, max_epsilon);
        if (it == m_slice_index.end()) return SliceRecord::EMPTY;
        return *it;
    }

protected:
    // to be called from SLAPrint only.
    friend class SLAPrint;

	SLAPrintObject(SLAPrint* print, ModelObject* model_object);
    ~SLAPrintObject();

    void                    config_apply(const ConfigBase &other, bool ignore_nonexistent = false) { this->m_config.apply(other, ignore_nonexistent); }
    void                    config_apply_only(const ConfigBase &other, const t_config_option_keys &keys, bool ignore_nonexistent = false) 
    	{ this->m_config.apply_only(other, keys, ignore_nonexistent); }

    void                    set_trafo(const Transform3d& trafo) {
        m_transformed_rmesh.invalidate([this, &trafo](){ m_trafo = trafo; });
    }

    void                    set_instances(const std::vector<Instance> &instances) { m_instances = instances; }
    // Invalidates the step, and its depending steps in SLAPrintObject and SLAPrint.
    bool                    invalidate_step(SLAPrintObjectStep step);
    bool                    invalidate_all_steps();
    // Invalidate steps based on a set of parameters changed.
    bool                    invalidate_state_by_config_options(const std::vector<t_config_option_key> &opt_keys);

    // Which steps have to be performed. Implicitly: all
    // to be accessible from SLAPrint
    std::vector<bool>                       m_stepmask;

private:
    // Object specific configuration, pulled from the configuration layer.
    SLAPrintObjectConfig                    m_config;

    // Translation in Z + Rotation by Y and Z + Scaling / Mirroring.
    Transform3d                             m_trafo = Transform3d::Identity();

    std::vector<Instance> 					m_instances;

    // Individual 2d slice polygons from lower z to higher z levels
    std::vector<ExPolygons>                 m_model_slices;

    // Exact (float) height levels mapped to the slices. Each record contains
    // the index to the model and the support slice vectors.
    std::vector<SliceRecord>                m_slice_index;

    std::vector<float>                      m_model_height_levels;

    // Caching the transformed (m_trafo) raw mesh of the object
    mutable CachedObject<TriangleMesh>      m_transformed_rmesh;

    class SupportData;
    std::unique_ptr<SupportData> m_supportdata;
};

using PrintObjects = std::vector<SLAPrintObject*>;

class TriangleMesh;

struct SLAPrintStatistics
{
    SLAPrintStatistics() { clear(); }
    std::string                     estimated_print_time;
    double                          objects_used_material;
    double                          support_used_material;
    size_t                          slow_layers_count;
    size_t                          fast_layers_count;
    double                          total_cost;
    double                          total_weight;

    // Config with the filled in print statistics.
    DynamicConfig           config() const;
    // Config with the statistics keys populated with placeholder strings.
    static DynamicConfig    placeholders();
    // Replace the print statistics placeholders in the path.
    std::string             finalize_output_path(const std::string &path_in) const;

    void clear() {
        estimated_print_time.clear();
        objects_used_material = 0.;
        support_used_material = 0.;
        slow_layers_count = 0;
        fast_layers_count = 0;
        total_cost = 0.;
        total_weight = 0.;
    }
};

/**
 * @brief This class is the high level FSM for the SLA printing process.
 *
 * It should support the background processing framework and contain the
 * metadata for the support geometries and their slicing. It should also
 * dispatch the SLA printing configuration values to the appropriate calculation
 * steps.
 */
class SLAPrint : public PrintBaseWithState<SLAPrintStep, slapsCount>
{
private: // Prevents erroneous use by other classes.
    typedef PrintBaseWithState<SLAPrintStep, slapsCount> Inherited;

public:

    // An aggregation of SliceRecord-s from all the print objects for each
    // occupied layer. Slice record levels dont have to match exactly.
    // They are unified if the level difference is within +/- SCALED_EPSILON
    struct PrintLayer {
        coord_t level;

        // The collection of slice records for the current level.
        std::vector<std::reference_wrapper<const SliceRecord>> slices;

        explicit PrintLayer(coord_t lvl) : level(lvl) {}

        // for being sorted in their container (see m_printer_input)
        bool operator<(const PrintLayer& other) const {
            return level < other.level;
        }
    };

    SLAPrint(): m_stepmask(slapsCount, true) {}

    virtual ~SLAPrint() override { this->clear(); }

    PrinterTechnology	technology() const noexcept override { return ptSLA; }

    void                clear() override;
    bool                empty() const override { return m_objects.empty(); }
    ApplyStatus         apply(const Model &model, const DynamicPrintConfig &config) override;
    void                set_task(const TaskParams &params) override;
    void                process() override;
    void                finalize() override;
    // Returns true if an object step is done on all objects and there's at least one object.    
    bool                is_step_done(SLAPrintObjectStep step) const;
    // Returns true if the last step was finished with success.
	bool                finished() const override { return this->is_step_done(slaposIndexSlices) && this->Inherited::is_step_done(slapsRasterize); }

    template<class Fmt> void export_raster(const std::string& fname) {
        if(m_printer) m_printer->save<Fmt>(fname);
    }
    const PrintObjects& objects() const { return m_objects; }

    const SLAPrintConfig&       print_config() const { return m_print_config; }
    const SLAPrinterConfig&     printer_config() const { return m_printer_config; }
    const SLAMaterialConfig&    material_config() const { return m_material_config; }
    const SLAPrintObjectConfig& default_object_config() const { return m_default_object_config; }

	std::string         output_filename() const override;

    const SLAPrintStatistics&      print_statistics() const { return m_print_statistics; }

    std::string validate() const override;

    // The aggregated and leveled print records from various objects.
    // TODO: use this structure for the preview in the future.
    const std::vector<PrintLayer>& print_layers() const { return m_printer_input; }

private:
    using SLAPrinter = FilePrinter<FilePrinterFormat::SLA_PNGZIP>;
    using SLAPrinterPtr = std::unique_ptr<SLAPrinter>;

    // Invalidate steps based on a set of parameters changed.
    bool invalidate_state_by_config_options(const std::vector<t_config_option_key> &opt_keys);

    void fill_statistics();

    SLAPrintConfig                  m_print_config;
    SLAPrinterConfig                m_printer_config;
    SLAMaterialConfig               m_material_config;
    SLAPrintObjectConfig            m_default_object_config;

    PrintObjects                    m_objects;
    std::vector<bool>               m_stepmask;

    // Ready-made data for rasterization.
    std::vector<PrintLayer>                 m_printer_input;

    // The printer itself
    SLAPrinterPtr                           m_printer;

    // Estimated print time, material consumed.
    SLAPrintStatistics                      m_print_statistics;

	friend SLAPrintObject;
};

} // namespace Slic3r

#endif /* slic3r_SLAPrint_hpp_ */