#define STB_IMAGE_IMPLEMENTATION
#include "HydraTextureBufferManager.h"
#include "../scheduler/HydraTaskScheduler.h"
#include "../task/buffer/HydraCreateTextureTask.hpp"

void HydraTextureBufferManager::Intialise()
{
    m_textures.resize(MAX_TEXTURES);
    m_bindless_texture_ids.resize(MAX_TEXTURES);
    for (uint32_t tex_idx = 0; tex_idx < MAX_TEXTURES; tex_idx++)
    {
        m_available_texture_ids.push(tex_idx);
        m_bindless_texture_ids[tex_idx] = 0;
    }
}

void HydraTextureBufferManager::Shutdown()
{
    for (uint32_t tex_idx = 0; tex_idx < MAX_TEXTURES; tex_idx++)
    {
        if (m_textures[tex_idx].texture_id != INVALID_HYDRA_ID)
        {
            DeleteTexture(tex_idx);
        }
    }
}

HydraID HydraTextureBufferManager::LoadTexture(std::string texture_filename)
{
    HydraID texture_id = FindTexture(texture_filename);
    if (texture_id != INVALID_HYDRA_ID)
    {
        return texture_id;
    }

    void *data = nullptr;
    int width = 0;
    int height = 0;
    int channels = 0;

    //stbi_set_flip_vertically_on_load(true);
    data = stbi_load(texture_filename.c_str(), &width, &height, &channels, 0);

    if (data == nullptr)
    {
        return INVALID_HYDRA_ID;
    }

    uint32_t format = GL_RGBA;

    if (channels == 3)
    {
        format = GL_RGB;
    }

    HydraTaskScheduler *scheduler = GetEngine()->TaskScheduler();
    HydraID create_tex_id = scheduler->CreateTask<HydraCreateTextureTask>(HydraThreadAffinity::Render);
    HydraCreateTextureTask *create_tex_task = static_cast<HydraCreateTextureTask *>(scheduler->GetTask(create_tex_id));
    HydraID tex_id = INVALID_HYDRA_ID;
    create_tex_task->Initialise(texture_filename,                                
                                width,
                                height,
                                GL_RGBA8,
                                format,
                                GL_NEAREST_MIPMAP_NEAREST,
                                GL_LINEAR,                                
                                GL_UNSIGNED_BYTE,
                                5,
                                data,
                                &tex_id);
    scheduler->WaitForTask(create_tex_id);
    return tex_id;
}

HydraID HydraTextureBufferManager::FindTexture(std::string texture_name)
{
    if (m_texture_lookup.find(texture_name) == m_texture_lookup.end())
    {
        return INVALID_HYDRA_ID;
    }
    return m_texture_lookup.find(texture_name)->second;
}

void *HydraTextureBufferManager::GetTextureBuffer()
{
    return &m_bindless_texture_ids[0];
}

const HydraTextureBuffer &HydraTextureBufferManager::GetTexture(HydraID texture_id)
{
    return m_textures[texture_id];
}

HydraID HydraTextureBufferManager::_GetTextureID()
{
    std::lock_guard<std::mutex> lock(m_mutex);

    if (m_available_texture_ids.size() == 0)
    {
        return INVALID_HYDRA_ID;
    }

    HydraID id = m_available_texture_ids.front();
    m_available_texture_ids.pop();

    return id;
}

HydraID HydraTextureBufferManager::CreateTextureArray(std::string texture_name,                                                 
                                                 uint32_t width,
                                                 uint32_t height,
                                                 uint32_t internal_format,
                                                 uint32_t min_filter,
                                                 uint32_t mag_filter,
                                                 uint32_t levels                                                 
                                                 )
{
    uint32_t gl_tex_id = 0;
    glCreateTextures(GL_TEXTURE_2D_ARRAY, 1, &gl_tex_id);
    glBindTexture(GL_TEXTURE_2D_ARRAY, gl_tex_id);

    
    glTextureStorage3D(gl_tex_id, 1, internal_format, width, height, levels);

    
    glTextureParameteri(gl_tex_id, GL_TEXTURE_MIN_FILTER, min_filter);
    glTextureParameteri(gl_tex_id, GL_TEXTURE_MAG_FILTER, mag_filter);

    glBindTexture(GL_TEXTURE_2D_ARRAY, 0);
    HydraTextureBuffer texture_buffer = {};
    HydraID texture_id = _GetTextureID();
    texture_buffer.texture_id = texture_id;
    texture_buffer.format = 0;
    texture_buffer.internal_format = internal_format;
    texture_buffer.width = width;
    texture_buffer.height = height;
    texture_buffer.gl_tex_id = gl_tex_id;
    texture_buffer.mag_filter = mag_filter;
    texture_buffer.min_filter = min_filter;

    m_textures[texture_id] = texture_buffer;
    m_texture_lookup.insert(std::pair<std::string, HydraID>(texture_name, texture_id));

    return texture_id;
}

HydraID HydraTextureBufferManager::CreateTexture(std::string texture_name,                                                 
                                                 uint32_t width,
                                                 uint32_t height,
                                                 uint32_t internal_format,
                                                 uint32_t min_filter,
                                                 uint32_t mag_filter,                                                 
                                                 uint32_t format,
                                                 uint32_t data_type,
                                                 uint32_t mip_levels,
                                                 void *data)
{
    uint32_t gl_tex_id = 0;
    glCreateTextures(GL_TEXTURE_2D, 1, &gl_tex_id);
    glBindTexture(GL_TEXTURE_2D, gl_tex_id);
    
    glTextureStorage2D(gl_tex_id,1+ mip_levels, internal_format, width, height);

    if (data != nullptr)
    {
        glTextureSubImage2D(
            gl_tex_id,
            // level, xoffset, yoffset, width, height
            0, 0, 0, width, height,
            format, data_type,
            data);

        if (mip_levels > 0)
        {
            glGenerateTextureMipmap(gl_tex_id);
        }
    }
    
    glTextureParameteri(gl_tex_id, GL_TEXTURE_MIN_FILTER, min_filter);
    glTextureParameteri(gl_tex_id, GL_TEXTURE_MAG_FILTER, mag_filter);

    glBindTexture(GL_TEXTURE_2D, 0);
    HydraTextureBuffer texture_buffer = {};
    HydraID texture_id = _GetTextureID();
    texture_buffer.texture_id = texture_id;
    texture_buffer.format = format;
    texture_buffer.internal_format = internal_format;
    texture_buffer.width = width;
    texture_buffer.height = height;
    texture_buffer.gl_tex_id = gl_tex_id;
    texture_buffer.mag_filter = mag_filter;
    texture_buffer.min_filter = min_filter;

    m_textures[texture_id] = texture_buffer;
    m_texture_lookup.insert(std::pair<std::string, HydraID>(texture_name, texture_id));

    return texture_id;
}

void HydraTextureBufferManager::BindTexture(HydraID texture_id, uint32_t target)
{

    if (texture_id >= MAX_TEXTURES)
    {
        return;
    }
    HydraTextureBuffer texture = m_textures[texture_id];
    glBindTexture(target, texture.gl_tex_id);
    glTextureParameteri(texture.gl_tex_id, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTextureParameteri(texture.gl_tex_id, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTextureParameteri(texture.gl_tex_id, GL_TEXTURE_MIN_FILTER, texture.min_filter);
    glTextureParameteri(texture.gl_tex_id, GL_TEXTURE_MAG_FILTER, texture.mag_filter);

    texture.texture_binding = glGetTextureHandleARB(texture.gl_tex_id);
    glMakeTextureHandleResidentARB(texture.texture_binding);
    m_bindless_texture_ids[texture_id] = texture.texture_binding;
}

void HydraTextureBufferManager::UnbindTexture(HydraID texture_id)
{
    glMakeTextureHandleNonResidentARB(texture_id);
}

void HydraTextureBufferManager::DeleteTexture(HydraID texture_id)
{
    if (m_bindless_texture_ids[texture_id] != 0)
    {
        UnbindTexture(m_bindless_texture_ids[texture_id]);
    }
}