#include "ExtrusionEntityCollection.hpp"
#include <algorithm>
#include <cmath>
#include <map>

namespace Slic3r {

ExtrusionEntityCollection::ExtrusionEntityCollection(const ExtrusionPaths &paths)
    : no_sort(false)
{
    this->append(paths);
}

ExtrusionEntityCollection& ExtrusionEntityCollection::operator=(const ExtrusionEntityCollection &other)
{
    this->entities      = other.entities;
    for (size_t i = 0; i < this->entities.size(); ++i)
        this->entities[i] = this->entities[i]->clone();
    this->orig_indices  = other.orig_indices;
    this->no_sort       = other.no_sort;
    return *this;
}

void ExtrusionEntityCollection::swap(ExtrusionEntityCollection &c)
{
    std::swap(this->entities, c.entities);
    std::swap(this->orig_indices, c.orig_indices);
    std::swap(this->no_sort, c.no_sort);
}

void ExtrusionEntityCollection::clear()
{
	for (size_t i = 0; i < this->entities.size(); ++i)
		delete this->entities[i];
    this->entities.clear();
}

ExtrusionEntityCollection::operator ExtrusionPaths() const
{
    ExtrusionPaths paths;
    for (const ExtrusionEntity *ptr : this->entities) {
        if (const ExtrusionPath *path = dynamic_cast<const ExtrusionPath*>(ptr))
            paths.push_back(*path);
    }
    return paths;
}

ExtrusionEntity* ExtrusionEntityCollection::clone() const
{
    ExtrusionEntityCollection* coll = new ExtrusionEntityCollection(*this);
    for (size_t i = 0; i < coll->entities.size(); ++i)
        coll->entities[i] = this->entities[i]->clone();
    return coll;
}

void ExtrusionEntityCollection::reverse()
{
    for (ExtrusionEntity *ptr : this->entities)
        // Don't reverse it if it's a loop, as it doesn't change anything in terms of elements ordering
        // and caller might rely on winding order
        if (! ptr->is_loop())
        	ptr->reverse();
    std::reverse(this->entities.begin(), this->entities.end());
}

void ExtrusionEntityCollection::replace(size_t i, const ExtrusionEntity &entity)
{
    delete this->entities[i];
    this->entities[i] = entity.clone();
}

void ExtrusionEntityCollection::remove(size_t i)
{
    delete this->entities[i];
    this->entities.erase(this->entities.begin() + i);
}

ExtrusionEntityCollection ExtrusionEntityCollection::chained_path(bool no_reverse, ExtrusionRole role) const
{
    ExtrusionEntityCollection coll;
    this->chained_path(&coll, no_reverse, role);
    return coll;
}

void ExtrusionEntityCollection::chained_path(ExtrusionEntityCollection* retval, bool no_reverse, ExtrusionRole role, std::vector<size_t>* orig_indices) const
{
    if (this->entities.empty()) return;
    this->chained_path_from(this->entities.front()->first_point(), retval, no_reverse, role, orig_indices);
}

ExtrusionEntityCollection ExtrusionEntityCollection::chained_path_from(Point start_near, bool no_reverse, ExtrusionRole role) const
{
    ExtrusionEntityCollection coll;
    this->chained_path_from(start_near, &coll, no_reverse, role);
    return coll;
}

void ExtrusionEntityCollection::chained_path_from(Point start_near, ExtrusionEntityCollection* retval, bool no_reverse, ExtrusionRole role, std::vector<size_t>* orig_indices) const
{
    if (this->no_sort) {
        *retval = *this;
        return;
    }

    retval->entities.reserve(this->entities.size());
    retval->orig_indices.reserve(this->entities.size());
    
    // if we're asked to return the original indices, build a map
    std::map<ExtrusionEntity*,size_t> indices_map;
    
    ExtrusionEntitiesPtr my_paths;
    for (ExtrusionEntity * const &entity_src : this->entities) {
        if (role != erMixed) {
            // The caller wants only paths with a specific extrusion role.
            auto role2 = entity_src->role();
            if (role != role2) {
                // This extrusion entity does not match the role asked.
                assert(role2 != erMixed);
                continue;
            }
        }

        ExtrusionEntity *entity = entity_src->clone();
        my_paths.push_back(entity);
        if (orig_indices != nullptr)
        	indices_map[entity] = &entity_src - &this->entities.front();
    }
    
    Points endpoints;
    for (const ExtrusionEntity *entity : my_paths) {
        endpoints.push_back(entity->first_point());
        endpoints.push_back((no_reverse || ! entity->can_reverse()) ?
        	entity->first_point() : entity->last_point());
    }
    
    while (! my_paths.empty()) {
        // find nearest point
        int start_index = start_near.nearest_point_index(endpoints);
        int path_index = start_index/2;
        ExtrusionEntity* entity = my_paths.at(path_index);
        // never reverse loops, since it's pointless for chained path and callers might depend on orientation
        if (start_index % 2 && !no_reverse && entity->can_reverse())
            entity->reverse();
        retval->entities.push_back(my_paths.at(path_index));
        if (orig_indices != nullptr)
        	orig_indices->push_back(indices_map[entity]);
        my_paths.erase(my_paths.begin() + path_index);
        endpoints.erase(endpoints.begin() + 2*path_index, endpoints.begin() + 2*path_index + 2);
        start_near = retval->entities.back()->last_point();
    }
}

void ExtrusionEntityCollection::polygons_covered_by_width(Polygons &out, const float scaled_epsilon) const
{
    for (const ExtrusionEntity *entity : this->entities)
        entity->polygons_covered_by_width(out, scaled_epsilon);
}

void ExtrusionEntityCollection::polygons_covered_by_spacing(Polygons &out, const float scaled_epsilon) const
{
    for (const ExtrusionEntity *entity : this->entities)
        entity->polygons_covered_by_spacing(out, scaled_epsilon);
}

// Recursively count paths and loops contained in this collection.
size_t ExtrusionEntityCollection::items_count() const
{
    size_t count = 0;
    for (const ExtrusionEntity *entity : this->entities)
        if (entity->is_collection())
            count += static_cast<const ExtrusionEntityCollection*>(entity)->items_count();
        else
            ++ count;
    return count;
}

// Returns a single vector of pointers to all non-collection items contained in this one.
ExtrusionEntityCollection ExtrusionEntityCollection::flatten() const
{
	struct Flatten {
		ExtrusionEntityCollection out;
		void recursive_do(const ExtrusionEntityCollection &collection) {
			for (const ExtrusionEntity* entity : collection.entities)
				if (entity->is_collection())
					this->recursive_do(*static_cast<const ExtrusionEntityCollection*>(entity));
				else
					out.append(*entity);
		}
	} flatten;
	flatten.recursive_do(*this);
    return flatten.out;
}

double ExtrusionEntityCollection::min_mm3_per_mm() const
{
    double min_mm3_per_mm = std::numeric_limits<double>::max();
    for (const ExtrusionEntity *entity : this->entities)
    	min_mm3_per_mm = std::min(min_mm3_per_mm, entity->min_mm3_per_mm());
    return min_mm3_per_mm;
}

}