#include "World.hpp"

#include "../contouring/SurrondingFlatBox.hpp"
#include "../render/buffer/ShortIndexedBuffer.hpp"
#include <Remotery.h>

World::World(const World::options& options) {
    setOptions(options);
}
World::~World() { }

void World::update(const camera_pos& pos, World::report& rep) {
    const chunk_pos newPos = glm::divide(pos, chunk_voxel_pos(CHUNK_LENGTH));
    const auto chunkChange = newPos != last_pos;
    last_pos = newPos;
    rmt_ScopedCPUSample(World, 0);

    // Update alive chunks
    {
        rmt_ScopedCPUSample(Update, 0);
        for(auto [chunkPos, chunk]: chunks) {
            const glm::ivec3 dist = last_pos - chunkPos;
            if (dist.x * dist.x + dist.y * dist.y + dist.z * dist.z > keepDistance * keepDistance
                    && unloadQueue.push(chunkPos)) {
                //TODO: unloadCount++;
                continue;
            }

            if (chunk->update()) { // MAYBE: update joints
                //TODO: extract in contouring
                contouring::surrounding::chunks surrounding;
                surrounding[contouring::surrounding::CENTER] = chunk;
                bool all_found = true;
                for (size_t i = 0; all_found && i < contouring::surrounding::CENTER; i++) {
                    const auto it = chunks.find(chunkPos + g_face_offsets[i]);
                    if (it != chunks.end())
                        surrounding[i] = it->second;
                    else
                        all_found = false;
                }
                if(all_found) {
                    rmt_ScopedCPUSample(Render, 0);
                    if (chunk->buffer != NULL)
                        delete chunk->buffer;

                    std::vector<VertexData> vertices;
                    {
                        rmt_ScopedCPUSample(Contouring, 0);
                        SurrondingFlatBox::render(surrounding, vertices);
                    }
                    ShortIndexedBuffer::Data data(vertices); // NOTE: indexing is really slow
                    {
                        rmt_ScopedCPUSample(Uploading, 0);
                        chunk->buffer = new ShortIndexedBuffer(GL_TRIANGLES, data);
                    }
                }
            }
        }
    }

    rep.chunk_unload.push(unloadQueue.size());
    // Unload dead chunks
    {
        rmt_ScopedCPUSample(Unload, 0);
        for (size_t i = 0; i < 8 && !unloadQueue.empty(); i++) {
            chunks.extract(unloadQueue.pop());
            //TODO: save to file
        }
    }

    // Find missing chunks (~240ms from max loadDistance)
    if(chunkChange) {
        rmt_ScopedCPUSample(ToLoad, 0);
        std::vector<chunk_pos> to_load;
        for (int x = -loadDistance; x <= loadDistance; x++) {
        for (int y = -loadDistance; y <= loadDistance; y++) {
        for (int z = -loadDistance; z <= loadDistance; z++) {
            if (x * x + y * y + z * z <= loadDistance * loadDistance) {
                const chunk_pos p = last_pos + glm::ivec3(x, y, z);
                if (chunks.find(p) == chunks.end()) {
                    to_load.push_back(p);
                }
            }
        }}}
        std::sort(to_load.begin(), to_load.end(), [](const chunk_pos &a, const chunk_pos &b) {
            return glm::length2(a) < glm::length2(b);
        });
        for(auto p: to_load) {
            loadQueue.push(p);
        }
    }

    rep.chunk_load.push(loadQueue.size());
    // Load chunks
    {
        rmt_ScopedCPUSample(Load, 0);
        for (size_t i = 0; i < 8 && !loadQueue.empty(); i++) {
            const auto pos = loadQueue.pop();
            const auto chunk = std::make_shared<Chunk>(pos, generator);
            chunks.insert({pos, chunk});
            //trigger surronding render
            for (size_t i = 0; i < contouring::surrounding::CENTER; i++) {
                const auto it = chunks.find(pos + g_face_offsets[i]);
                if (it != chunks.end())
                    it->second->invalidate();
            }
        }
    }
    rep.chunk_count.push(chunks.size());
}
void World::setOptions(const World::options& options) {
    loadDistance = options.loadDistance;
    keepDistance = options.keepDistance;
}

void World::getModels(std::vector<std::pair<glm::mat4, Buffer*>> &out, float scale) const {
    const auto scaling = glm::scale(glm::mat4(1), glm::vec3(scale));
    for(const auto [pos, chunk]: chunks) {
        if(chunk->buffer != NULL)
            out.push_back({glm::translate(scaling, glm::vec3(pos) * glm::vec3(CHUNK_LENGTH)), chunk->buffer});
    }
}
void World::getModels(std::vector<std::pair<glm::mat4, Buffer*>> &out, float scale, const Frustum& frustum) const {
    const auto scaling = glm::scale(glm::mat4(1), glm::vec3(scale));
    for(const auto [pos, chunk]: chunks) {
        if(chunk->buffer != NULL && frustum.contains(Box::fromMin(scale * glm::vec3(pos) * glm::vec3(CHUNK_LENGTH), scale * glm::vec3(CHUNK_LENGTH))))
            out.push_back({glm::translate(scaling, glm::vec3(pos) * glm::vec3(CHUNK_LENGTH)), chunk->buffer});
    }
}