///|/ Copyright (c) Prusa Research 2023 Vojtěch Bubník @bubnikv
///|/
///|/ PrusaSlicer is released under the terms of the AGPLv3 or higher
///|/
#ifndef slic3r_SupportCommon_hpp_
#define slic3r_SupportCommon_hpp_

#include "../Layer.hpp"
#include "../Polygon.hpp"
#include "../Print.hpp"
#include "SupportLayer.hpp"
#include "SupportParameters.hpp"

namespace Slic3r {

class PrintObject;
class SupportLayer;

// Turn some of the base layers into base interface layers.
// For soluble interfaces with non-soluble bases, print maximum two first interface layers with the base
// extruder to improve adhesion of the soluble filament to the base.
// For Organic supports, merge top_interface_layers & top_base_interface_layers with the interfaces
// produced by this function.
std::pair<SupportGeneratorLayersPtr, SupportGeneratorLayersPtr> generate_interface_layers(
    const PrintObjectConfig           &config,
    const SupportParameters           &support_params,
    const SupportGeneratorLayersPtr   &bottom_contacts,
    const SupportGeneratorLayersPtr   &top_contacts,
    // Input / output, will be merged with output
    SupportGeneratorLayersPtr         &top_interface_layers,
    SupportGeneratorLayersPtr         &top_base_interface_layers,
    // Input, will be trimmed with the newly created interface layers.
    SupportGeneratorLayersPtr         &intermediate_layers,
    SupportGeneratorLayerStorage      &layer_storage);

// Generate raft layers, also expand the 1st support layer
// in case there is no raft layer to improve support adhesion.
SupportGeneratorLayersPtr generate_raft_base(
	const PrintObject				&object,
	const SupportParameters			&support_params,
	const SlicingParameters			&slicing_params,
	const SupportGeneratorLayersPtr &top_contacts,
	const SupportGeneratorLayersPtr &interface_layers,
	const SupportGeneratorLayersPtr &base_interface_layers,
	const SupportGeneratorLayersPtr &base_layers,
	SupportGeneratorLayerStorage    &layer_storage);

void tree_supports_generate_paths(ExtrusionEntitiesPtr &dst, const Polygons &polygons, const Flow &flow, const SupportParameters &support_params);

void fill_expolygons_with_sheath_generate_paths(
    ExtrusionEntitiesPtr &dst, const Polygons &polygons, Fill *filler, float density, ExtrusionRole role, const Flow &flow, const SupportParameters& support_params, bool with_sheath, bool no_sort);

// returns sorted layers
SupportGeneratorLayersPtr generate_support_layers(
	PrintObject							&object,
    const SupportGeneratorLayersPtr     &raft_layers,
    const SupportGeneratorLayersPtr     &bottom_contacts,
    const SupportGeneratorLayersPtr     &top_contacts,
    const SupportGeneratorLayersPtr     &intermediate_layers,
    const SupportGeneratorLayersPtr     &interface_layers,
    const SupportGeneratorLayersPtr     &base_interface_layers);

// Produce the support G-code.
// Used by both classic and tree supports.
void generate_support_toolpaths(
	SupportLayerPtrs    				&support_layers,
	const PrintObjectConfig 			&config,
	const SupportParameters 			&support_params,
	const SlicingParameters 			&slicing_params,
    const SupportGeneratorLayersPtr 	&raft_layers,
    const SupportGeneratorLayersPtr   	&bottom_contacts,
    const SupportGeneratorLayersPtr   	&top_contacts,
    const SupportGeneratorLayersPtr   	&intermediate_layers,
	const SupportGeneratorLayersPtr   	&interface_layers,
    const SupportGeneratorLayersPtr   	&base_interface_layers);

// FN_HIGHER_EQUAL: the provided object pointer has a Z value >= of an internal threshold.
// Find the first item with Z value >= of an internal threshold of fn_higher_equal.
// If no vec item with Z value >= of an internal threshold of fn_higher_equal is found, return vec.size()
// If the initial idx is size_t(-1), then use binary search.
// Otherwise search linearly upwards.
template<typename IteratorType, typename IndexType, typename FN_HIGHER_EQUAL>
IndexType idx_higher_or_equal(IteratorType begin, IteratorType end, IndexType idx, FN_HIGHER_EQUAL fn_higher_equal)
{
    auto size = int(end - begin);
    if (size == 0) {
        idx = 0;
    } else if (idx == IndexType(-1)) {
        // First of the batch of layers per thread pool invocation. Use binary search.
        int idx_low  = 0;
        int idx_high = std::max(0, size - 1);
        while (idx_low + 1 < idx_high) {
            int idx_mid  = (idx_low + idx_high) / 2;
            if (fn_higher_equal(begin[idx_mid]))
                idx_high = idx_mid;
            else
                idx_low  = idx_mid;
        }
        idx =  fn_higher_equal(begin[idx_low])  ? idx_low  :
              (fn_higher_equal(begin[idx_high]) ? idx_high : size);
    } else {
        // For the other layers of this batch of layers, search incrementally, which is cheaper than the binary search.
        while (int(idx) < size && ! fn_higher_equal(begin[idx]))
            ++ idx;
    }
    return idx;
}
template<typename T, typename IndexType, typename FN_HIGHER_EQUAL>
IndexType idx_higher_or_equal(const std::vector<T>& vec, IndexType idx, FN_HIGHER_EQUAL fn_higher_equal)
{
    return idx_higher_or_equal(vec.begin(), vec.end(), idx, fn_higher_equal);
}

// FN_LOWER_EQUAL: the provided object pointer has a Z value <= of an internal threshold.
// Find the first item with Z value <= of an internal threshold of fn_lower_equal.
// If no vec item with Z value <= of an internal threshold of fn_lower_equal is found, return -1.
// If the initial idx is < -1, then use binary search.
// Otherwise search linearly downwards.
template<typename IT, typename FN_LOWER_EQUAL>
int idx_lower_or_equal(IT begin, IT end, int idx, FN_LOWER_EQUAL fn_lower_equal)
{
    auto size = int(end - begin);
    if (size == 0) {
        idx = -1;
    } else if (idx < -1) {
        // First of the batch of layers per thread pool invocation. Use binary search.
        int idx_low  = 0;
        int idx_high = std::max(0, size - 1);
        while (idx_low + 1 < idx_high) {
            int idx_mid  = (idx_low + idx_high) / 2;
            if (fn_lower_equal(begin[idx_mid]))
                idx_low  = idx_mid;
            else
                idx_high = idx_mid;
        }
        idx =  fn_lower_equal(begin[idx_high]) ? idx_high :
              (fn_lower_equal(begin[idx_low ]) ? idx_low  : -1);
    } else {
        // For the other layers of this batch of layers, search incrementally, which is cheaper than the binary search.
        while (idx >= 0 && ! fn_lower_equal(begin[idx]))
            -- idx;
    }
    return idx;
}
template<typename T, typename FN_LOWER_EQUAL>
int idx_lower_or_equal(const std::vector<T*> &vec, int idx, FN_LOWER_EQUAL fn_lower_equal)
{
    return idx_lower_or_equal(vec.begin(), vec.end(), idx, fn_lower_equal);
}

[[nodiscard]] Polygons safe_union(const Polygons first, const Polygons second = {});

[[nodiscard]] ExPolygons safe_union(const ExPolygons first, const ExPolygons second = {});

[[nodiscard]] Polygons safe_offset_inc(
    const Polygons &me, coord_t distance, const Polygons &collision, coord_t safe_step_size, coord_t last_step_offset_without_check, size_t min_amount_offset);


/*!
 * \brief Offsets (increases the area of) a polygons object in multiple steps to ensure that it does not lag through over a given obstacle.
 * \param me[in] Polygons object that has to be offset.
 * \param distance[in] The distance by which me should be offset. Expects values >=0.
 * \param CollisionPolyType collision[in] The area representing obstacles. CollisionPolyType may be ExPolygons or Polygons.
 * \param last_step_offset_without_check[in] The most it is allowed to offset in one step.
 * \param min_amount_offset[in] How many steps have to be done at least. As this uses round offset this increases the amount of vertices, which may be required if Polygons get
 * very small. Required as arcTolerance is not exposed in offset, which should result with a similar result. \return The resulting Polygons object.
 */
template<typename CollisionPolyType>
[[nodiscard]] ExPolygons safe_offset_inc(
    const ExPolygons &me, coord_t distance, const CollisionPolyType &collision, coord_t safe_step_size, coord_t last_step_offset_without_check, size_t min_amount_offset)
{
    bool     do_final_difference = last_step_offset_without_check == 0;
    ExPolygons ret               = safe_union(me); // ensure sane input

    // Trim the collision polygons with the region of interest for diff() efficiency.
    Polygons collision_trimmed_buffer;
    auto     collision_trimmed = [&collision_trimmed_buffer, &collision, &ret, distance]() -> const Polygons     &{
        if (collision_trimmed_buffer.empty() && !collision.empty())
            collision_trimmed_buffer = ClipperUtils::clip_clipper_polygons_with_subject_bbox(collision, get_extents(ret).inflated(std::max(0, distance) + SCALED_EPSILON));
        return collision_trimmed_buffer;
    };

    if (distance == 0) return do_final_difference ? diff_ex(ret, collision_trimmed()) : union_ex(ret);
    if (safe_step_size < 0 || last_step_offset_without_check < 0) {
        BOOST_LOG_TRIVIAL(error) << "Offset increase got invalid parameter!";
        return do_final_difference ? diff_ex(ret, collision_trimmed()) : union_ex(ret);
    }

    coord_t step_size = safe_step_size;
    int     steps     = distance > last_step_offset_without_check ? (distance - last_step_offset_without_check) / step_size : 0;
    if (distance - steps * step_size > last_step_offset_without_check) {
        if ((steps + 1) * step_size <= distance)
            // This will be the case when last_step_offset_without_check >= safe_step_size
            ++steps;
        else
            do_final_difference = true;
    }
    if (steps + (distance < last_step_offset_without_check || (distance % step_size) != 0) < int(min_amount_offset) && min_amount_offset > 1) {
        // yes one can add a bool as the standard specifies that a result from compare operators has to be 0 or 1
        // reduce the stepsize to ensure it is offset the required amount of times
        step_size = distance / min_amount_offset;
        if (step_size >= safe_step_size) {
            // effectivly reduce last_step_offset_without_check
            step_size = safe_step_size;
            steps     = min_amount_offset;
        } else
            steps = distance / step_size;
    }
    // offset in steps
    for (int i = 0; i < steps; ++i) {
        ret = diff_ex(offset_ex(ret, step_size, ClipperLib::jtRound, scaled<float>(0.01)), collision_trimmed());
        // ensure that if many offsets are done the performance does not suffer extremely by the new vertices of jtRound.
        if (i % 10 == 7) ret = expolygons_simplify(ret, scaled<double>(0.015));
    }
    // offset the remainder
    float last_offset = distance - steps * step_size;
    if (last_offset > SCALED_EPSILON) ret = offset_ex(ret, distance - steps * step_size, ClipperLib::jtRound, scaled<float>(0.01));
    ret = expolygons_simplify(ret, scaled<double>(0.015));

    if (do_final_difference) ret = diff_ex(ret, collision_trimmed());
    return union_ex(ret);
}


} // namespace Slic3r

#endif /* slic3r_SupportCommon_hpp_ */