#include "HydraPointShadowSourceSystem.h"
#include "../../engine/HydraEngine.h"
#include "../../camera/HydraCamera.h"
#include "../HydraECS.h"
#include "../components/HydraPointShadowSourceComponent.h"
#include "../components/HydraPositionComponent.h"
#include "../components/HydraLightComponent.h"

#include "../../buffer/HydraShadowBuffer.h"
#include "../../buffer/HydraTextureBufferManager.h"
#include "../../buffer/HydraShadowBufferManager.h"

#include "../../scheduler/HydraTaskScheduler.h"
#include "../../task/buffer/HydraCreateGPUBufferTask.hpp"
#include "../../task/buffer/HydraUpdateWholeGPUBufferTask.hpp"
#include "../../task/buffer/HydraUpdatePartialGPUBufferTask.hpp"
#include "../../task/buffer/HydraCreateUnBoundTextureTask.hpp"
#include "../../task/renderer/HydraCreateCubemapShadowFrameBuffer.hpp"
#include "../../task/renderer/HydraCreateShadowFrameBuffer.hpp"
#include "../../actor/HydraActorManager.h"

void HydraPointShadowSourceSystem::Initialise()
{

}

void HydraPointShadowSourceSystem::InitialiseComponent(HydraID entity_id)
{
    HydraEngine *engine = GetEngine();
    HydraECS *ecs = engine->ECS();
    HydraLightComponent &light_comp = ecs->GetComponent<HydraLightComponent>(entity_id);

    HydraPointShadowSourceComponent& shadow_comp = ecs->GetComponent<HydraPointShadowSourceComponent>(entity_id);

    HydraID shadow_id = GetEngine()->ShadowBufferManager()->AddPointShadow(shadow_comp);
    assert(shadow_id != INVALID_HYDRA_ID && "Add point Shadow - out of shadows!");

    light_comp.shadow_map_id = shadow_id;
    light_comp.shadow_caster = 1;
    shadow_comp.entity_id = entity_id;
    //shadow_comp.shadow_id = shadow_id;
    //_InitialiseShadowMap(entity_id);
}

void HydraPointShadowSourceSystem::UpdateSystem(float delta_t_seconds)
{
    for (HydraID entity_id : Entities)
    {
        _UpdateShadowMap(entity_id);
    }
}

void HydraPointShadowSourceSystem::DestroyComponent(HydraID entity_id)
{
    HydraEngine *engine = GetEngine();
    HydraECS *ecs = engine->ECS();
    HydraPointShadowSourceComponent& shadow_comp = ecs->GetComponent<HydraPointShadowSourceComponent>(entity_id);
    GetEngine()->ShadowBufferManager()->DeletePointShadow(shadow_comp.shadow_id);
}

void HydraPointShadowSourceSystem::_UpdateShadowMap(HydraID entity_id)
{
    HydraEngine *engine = GetEngine();
    HydraECS *ecs = engine->ECS();
    HydraPositionComponent pos_comp = ecs->GetComponent<HydraPositionComponent>(entity_id);
    HydraPointShadowSourceComponent &shad_comp = ecs->GetComponent<HydraPointShadowSourceComponent>(entity_id);

    float view_size = 4.0f;
    float view_near = 0.1f;
    float view_far = 100.0f;
    

    glm::vec3 camera_pos = GetEngine()->Camera()->GetPosition();

    float aspect = (float)POINT_SHADOW_MAP_SIZE/(float)POINT_SHADOW_MAP_SIZE;
    float width = POINT_SHADOW_MAP_SIZE;
    float fov = glm::radians(90.0f);

    glm::mat4 shadow_proj = glm::perspectiveFovLH<float>(fov, width, width, view_near, view_far); 
    //glm::mat4 shadow_proj = glm::perspective<float>(fov, 1.0f, view_near, view_far); 

    glm::vec3 light_pos = pos_comp.position;
    
	//GL_TEXTURE_CUBE_MAP_POSITIVE_X - left
    shad_comp.light_space_view[0] = glm::lookAt(light_pos, light_pos + glm::vec3(1.0, 0.0, 0.0), glm::vec3(0.0, 1.0, 0.0));
    //GL_TEXTURE_CUBE_MAP_NEGATIVE_X - right
    shad_comp.light_space_view[1] = glm::lookAt(light_pos, light_pos + glm::vec3(-1.0, 0.0, 0.0), glm::vec3(0.0, 1.0, 0.0));
    //GL_TEXTURE_CUBE_MAP_POSITIVE_Y - Up
    shad_comp.light_space_view[2] = glm::lookAt(light_pos, light_pos + glm::vec3(0.0, 1.0, 0.0), glm::vec3(0.0, 0.0, -1.0));
    //GL_TEXTURE_CUBE_MAP_NEGATIVE_Y - down
    shad_comp.light_space_view[3] = glm::lookAt(light_pos, light_pos + glm::vec3(0.0, -1.0, 0.0), glm::vec3(0.0, 0.0, 1.0));
    //GL_TEXTURE_CUBE_MAP_POSITIVE_Z - back
    shad_comp.light_space_view[4] = glm::lookAt(light_pos, light_pos + glm::vec3(0.0, 0.0, 1.0), glm::vec3(0.0, 1.0, 0.0));
    //GL_TEXTURE_CUBE_MAP_NEGATIVE_Z - forward
    shad_comp.light_space_view[5] = glm::lookAt(light_pos, light_pos + glm::vec3(0.0, 0.0, -1.0), glm::vec3(0.0, 1.0, 0.0));

    shad_comp.light_space_proj = shadow_proj;
    shad_comp.far_plane = view_far;
    GetEngine()->ShadowBufferManager()->UpdatePointShadow(shad_comp.shadow_id, shad_comp);
}


void HydraPointShadowSourceSystem::_InitialiseShadowMap(HydraID entity_id)
{
    // HydraEngine *engine = GetEngine();
    // HydraECS *ecs = engine->ECS();
    // HydraTextureBufferManager *tex_man = engine->TextureBufferManager();
    // HydraPointShadowSourceComponent &shad_comp = ecs->GetComponent<HydraPointShadowSourceComponent>(entity_id);
    // HydraLightComponent &light_comp = ecs->GetComponent<HydraLightComponent>(entity_id);

    // shad_comp.entity_id = entity_id;   
    
    // HydraTaskScheduler *task_scheduler = GetEngine()->TaskScheduler();

    // uint32_t depth_texture_id = 0;
    // HydraID create_framebuffer_task_id = task_scheduler->CreateTask<HydraCreateCubemapShadowFrameBuffer>(HydraThreadAffinity::Render);
    // HydraCreateCubemapShadowFrameBuffer *fb_task = static_cast<HydraCreateCubemapShadowFrameBuffer *>(task_scheduler->GetTask(create_framebuffer_task_id));
    // fb_task->Initialise(&shad_comp.shadow_texture_id, &depth_texture_id, &shad_comp.frame_buffer_id);
    
    // task_scheduler->WaitForTask(create_framebuffer_task_id);
    // shad_comp.shadow_texture_id = depth_texture_id;
}