#include "HydraForwardPipeline.h"
#include "HydraRenderStage.h"
#include "../engine/HydraEngine.h"
#include "../buffer/HydraBufferManager.h"
#include "PerFrameUBO.hpp"
#include "../camera/HydraCamera.h"
#include "../renderer/HydraRenderer.h"
#include "../ecs/HydraECS.h"
#include "../ecs/systems/HydraRenderSystem.h"
#include "../mesh/StandardVertex.h"

void HydraForwardPipeline::Initialise()
{
    _EnableVertexAttributes();
    HydraRenderStage* render_stage = new HydraRenderStage();
    std::string shader_path = std::string(shader_base);
    HydraBufferManager* buffer_manager = GetEngine()->BufferManager();

    HydraID pos_buffer_id = buffer_manager->FindBuffer("PositionsBuffer");
    HydraID mat_buffer_id = buffer_manager->FindBuffer("MaterialBuffer");
    HydraID tex_buffer_id = buffer_manager->FindBuffer("TextureBuffer");

    HydraShaderBinding shader_binding = {};
    
    shader_binding.block_name.push_back("PositionsBuffer");
    shader_binding.binding_point.push_back(1);
    shader_binding.buffer_id.push_back(pos_buffer_id);

    shader_binding.block_name.push_back("MaterialBuffer");
    shader_binding.binding_point.push_back(2);
    shader_binding.buffer_id.push_back(mat_buffer_id);

    shader_binding.block_name.push_back("TextureBuffer");
    shader_binding.binding_point.push_back(3);
    shader_binding.buffer_id.push_back(tex_buffer_id);
    std::vector<uint32_t> textures;
    std::vector<uint32_t> rb_attachments;
    
    render_stage->Initialise(shader_path + "forward_shader.vert", shader_path + "forward_shader.frag", "", shader_binding, 0, textures, true, GL_BACK, true, HYDRA_RENDERABLE_TYPE::HYDRA_COLOUR);
    m_render_stages.push_back(render_stage);

    m_per_frame_ubo = buffer_manager->CreateGPUBuffer("PerFrameUBO", 
    sizeof(PerFrameUBO), 0, HYDRA_BUFFER_TYPE::HYDRA_UBO_BUFFER);
    
}

void HydraForwardPipeline::Shutdown()
{
    for(uint32_t rs_idx =0; rs_idx <m_render_stages.size(); rs_idx++)
    {
        m_render_stages[rs_idx]->ShutDown();
        delete m_render_stages[rs_idx];
    }
}

void HydraForwardPipeline::Render()
{
    _UpdateUBO();
    
    HydraECS* ecs = GetEngine()->ECS();
    std::shared_ptr<HydraRenderSystem> render_system = ecs->GetSystem<HydraRenderSystem>();
    
    float depth_value = 1;
    float screen_colour[4] = {0, 0.2, 0.7, 1};
    
    glClearNamedFramebufferfv(0, GL_COLOR, 0, screen_colour);
    glClearNamedFramebufferfv(0, GL_DEPTH, 0, &depth_value);
    
    for(uint32_t rs_idx = 0; rs_idx <m_render_stages.size(); rs_idx++)
    {
        m_render_stages[rs_idx]->Render(render_system->Entities);
    }
}

void HydraForwardPipeline::_UpdateUBO()
{
    HydraCamera* camera = GetEngine()->Camera();
    PerFrameUBO ubo = {};

    ubo.view = camera->GetView();
    ubo.proj = camera->GetProjection();

    HydraBufferManager* buffer_manager = GetEngine()->BufferManager();
    buffer_manager->UpdateWholeBuffer(m_per_frame_ubo, &ubo);
    glBindBuffer(GL_UNIFORM_BUFFER, m_per_frame_ubo);
}

void HydraForwardPipeline::_EnableVertexAttributes()
{

        //already on the render thread so dont neet another job
    // position
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(StandardVertex), (void *)0);
    glEnableVertexAttribArray(0);
    // texcoord01
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(StandardVertex), (void *)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);
    // chunkID
    glVertexAttribIPointer(2, 3, GL_UNSIGNED_INT, sizeof(StandardVertex), (void *)(5 * sizeof(float)));
    glEnableVertexAttribArray(2);
}