#include "HydraMeshManager.h"
#include <GLMIncludes.h>

void HydraMeshManager::Initialise()
{
    m_meshes.resize(MAX_ACTORS);
    for(uint32_t mesh_idx = 0; mesh_idx < MAX_ACTORS; mesh_idx++)
    {
        m_available_mesh_ids.push(mesh_idx);
    }
}

void HydraMeshManager::Shutdown()
{
    for(uint32_t mesh_idx = 0; mesh_idx < MAX_ACTORS; mesh_idx++)
    {
        if(m_meshes[mesh_idx].mesh_id != INVALID_HYDRA_ID)
        {
            DeleteMesh(m_meshes[mesh_idx].mesh_id);
        }
    }
    m_meshes.clear();
}

HydraID HydraMeshManager::CreateMesh()
{
    std::lock_guard<std::mutex> lock(m_mutex);
    if(m_available_mesh_ids.size() > 0)
    {
        HydraID mesh_id = m_available_mesh_ids.front();
        m_available_mesh_ids.pop();
        m_meshes[mesh_id].mesh_id = mesh_id;
        return mesh_id;
    }
    return INVALID_HYDRA_ID;
}

HydraMesh * const HydraMeshManager::GetMesh(HydraID mesh_id)
{
    // TODO: insert return statement here
    if(mesh_id < m_meshes.size())
    {
        return &m_meshes[mesh_id];
    }
    return nullptr;
}

void HydraMeshManager::DeleteMesh(HydraID mesh_id)
{
    std::lock_guard<std::mutex> lock(m_mutex);
    if(mesh_id < m_meshes.size())
    {
        m_meshes[mesh_id].vertexes.clear();
        m_meshes[mesh_id].mesh_id = INVALID_HYDRA_ID;
    }
}

void HydraMeshManager::CalculateNormals(HydraID mesh_id)
{

    HydraMesh mesh = m_meshes[mesh_id];
	for (int i = 0; i < mesh.indexes.size(); i += 3)
	{
        uint32_t idx0 = mesh.indexes[i+0];
        uint32_t idx1 = mesh.indexes[i+1];
        uint32_t idx2 = mesh.indexes[i+2];

        glm::vec3 vec0 = glm::normalize(glm::vec3(mesh.vertexes[idx0].position[0], mesh.vertexes[idx0].position[1], mesh.vertexes[idx0].position[2]));
        glm::vec3 vec1 = glm::normalize(glm::vec3(mesh.vertexes[idx1].position[0], mesh.vertexes[idx1].position[1], mesh.vertexes[idx1].position[2]));
        glm::vec3 vec2 = glm::normalize(glm::vec3(mesh.vertexes[idx2].position[0], mesh.vertexes[idx2].position[1], mesh.vertexes[idx2].position[2]));

        glm::vec3 normal = glm::triangleNormal(vec0, vec1, vec2);

        m_meshes[mesh_id].vertexes[idx0].normal[0] = normal[0];
        m_meshes[mesh_id].vertexes[idx0].normal[1] = normal[1];
        m_meshes[mesh_id].vertexes[idx0].normal[2] = normal[2];

        m_meshes[mesh_id].vertexes[idx1].normal[0] = normal[0];
        m_meshes[mesh_id].vertexes[idx1].normal[1] = normal[1];
        m_meshes[mesh_id].vertexes[idx1].normal[2] = normal[2];

        m_meshes[mesh_id].vertexes[idx2].normal[0] = normal[0];
        m_meshes[mesh_id].vertexes[idx2].normal[1] = normal[1];
        m_meshes[mesh_id].vertexes[idx2].normal[2] = normal[2];
		// glm::vec3 vec0 = glm::vec3(mesh.vertexes[mesh.indexes[i]], mesh.vertexes[mesh.indexes[i] + 1], mesh.vertexes[mesh.indexes[i] + 2]);
		// glm::vec3 vec1 = glm::vec3(Vertexes[Indexes[i+1]], Vertexes[Indexes[i+1] + 1], Vertexes[Indexes[i+1] + 2]);
		// glm::vec3 vec2 = glm::vec3(Vertexes[Indexes[i+2]], Vertexes[Indexes[i+2] + 1], Vertexes[Indexes[i+2] + 2]);

		// glm::vec3 normal = glm::triangleNormal(vec0, vec1, vec2);

		// Normals[Indexes[i]] = normal.x;
		// Normals[Indexes[i]+1] = normal.y; 
		// Normals[Indexes[i]+2] = normal.z;

		// Normals[Indexes[i+1]] = normal.x;
		// Normals[Indexes[i+1] + 1] = normal.y;
		// Normals[Indexes[i+1] + 2] = normal.z;

		// Normals[Indexes[i + 2]] = normal.x;
		// Normals[Indexes[i + 2] + 1] = normal.y;
		// Normals[Indexes[i + 2] + 2] = normal.z;

	}

}