use crate::filter_chain::Vulkan;
use crate::vulkan_primitives::{VulkanBuffer, VulkanImageMemory};
use crate::{error, util};
use ash::vk;
use ash::vk::ImageSubresourceLayers;
use glfw::Key::P;
use librashader_common::{FilterMode, WrapMode};
use librashader_presets::TextureConfig;
use librashader_runtime::image::{Image, BGRA8};
use librashader_runtime::scaling::MipmapSize;
use crate::texture::Texture;

pub struct LutTexture {
    pub memory: VulkanImageMemory,
    pub staging: VulkanBuffer,
    pub image: Texture
}

impl LutTexture {
    pub fn new(
        vulkan: &Vulkan,
        cmd: &vk::CommandBuffer,
        image: Image<BGRA8>,
        config: &TextureConfig,
    ) -> error::Result<LutTexture> {
        // todo: might need to use bgra8
        let image_info = vk::ImageCreateInfo::builder()
            .image_type(vk::ImageType::TYPE_2D)
            .format(vk::Format::B8G8R8A8_UNORM)
            .extent(image.size.into())
            .mip_levels(if config.mipmap {
                image.size.calculate_miplevels()
            } else {
                1
            })
            .array_layers(1)
            .samples(vk::SampleCountFlags::TYPE_1)
            .tiling(vk::ImageTiling::OPTIMAL)
            .usage(
                vk::ImageUsageFlags::SAMPLED
                    | vk::ImageUsageFlags::TRANSFER_SRC
                    | vk::ImageUsageFlags::TRANSFER_DST,
            )
            .initial_layout(vk::ImageLayout::UNDEFINED)
            .build();

        let texture = unsafe { vulkan.device.create_image(&image_info, None)? };

        let memory = unsafe {
            let mem_reqs = vulkan.device.get_image_memory_requirements(texture.clone());
            let mem_type = util::find_vulkan_memory_type(
                &vulkan.memory_properties,
                mem_reqs.memory_type_bits,
                vk::MemoryPropertyFlags::DEVICE_LOCAL,
            );
            crate::vulkan_primitives::VulkanImageMemory::new(
                &vulkan.device,
                &vk::MemoryAllocateInfo::builder()
                    .memory_type_index(mem_type)
                    .allocation_size(mem_reqs.size),
            )?
        };

        memory.bind(&texture)?;

        let image_subresource = vk::ImageSubresourceRange::builder()
            .level_count(image_info.mip_levels)
            .layer_count(1)
            .aspect_mask(vk::ImageAspectFlags::COLOR)
            .build();

        let swizzle_components = vk::ComponentMapping::builder()
            .r(vk::ComponentSwizzle::R)
            .g(vk::ComponentSwizzle::G)
            .b(vk::ComponentSwizzle::B)
            .a(vk::ComponentSwizzle::A)
            .build();

        let mut view_info = vk::ImageViewCreateInfo::builder()
            .view_type(vk::ImageViewType::TYPE_2D)
            .format(vk::Format::B8G8R8A8_UNORM)
            .image(texture.clone())
            .subresource_range(image_subresource)
            .components(swizzle_components)
            .build();

        let texture_view = unsafe { vulkan.device.create_image_view(&view_info, None)? };

        let mut staging = VulkanBuffer::new(
            &vulkan.device,
            &vulkan.memory_properties,
            vk::BufferUsageFlags::TRANSFER_SRC,
            image.bytes.len(),
        )?;
        unsafe {
            let mut handle = staging.map()?;
            handle.copy_from(&image.bytes)
        }

        unsafe {
            util::vulkan_image_layout_transition_levels(
                &vulkan.device,
                *cmd,
                texture,
                vk::REMAINING_MIP_LEVELS,
                vk::ImageLayout::UNDEFINED,
                if config.mipmap {
                    vk::ImageLayout::GENERAL
                } else {
                    vk::ImageLayout::TRANSFER_DST_OPTIMAL
                },
                vk::AccessFlags::empty(),
                vk::AccessFlags::TRANSFER_WRITE,
                vk::PipelineStageFlags::TOP_OF_PIPE,
                vk::PipelineStageFlags::TRANSFER,
                vk::QUEUE_FAMILY_IGNORED,
                vk::QUEUE_FAMILY_IGNORED,
            );

            vulkan.device.cmd_copy_buffer_to_image(
                *cmd,
                staging.handle,
                texture,
                if config.mipmap {
                    vk::ImageLayout::GENERAL
                } else {
                    vk::ImageLayout::TRANSFER_DST_OPTIMAL
                },
                &[vk::BufferImageCopy::builder()
                    .image_subresource(
                        vk::ImageSubresourceLayers::builder()
                            .aspect_mask(vk::ImageAspectFlags::COLOR)
                            .mip_level(0)
                            .base_array_layer(0)
                            .layer_count(1)
                            .build(),
                    )
                    .image_extent(image.size.into())
                    .build()],
            )
        }

        // generate mipmaps
        for level in 1..image_info.mip_levels {
            let source_size = image.size.scale_mipmap(level - 1);
            let target_size = image.size.scale_mipmap(level);

            let src_offsets = [
                vk::Offset3D { x: 0, y: 0, z: 0 },
                vk::Offset3D {
                    x: source_size.width as i32,
                    y: source_size.height as i32,
                    z: 1,
                },
            ];

            let dst_offsets = [
                vk::Offset3D { x: 0, y: 0, z: 0 },
                vk::Offset3D {
                    x: target_size.width as i32,
                    y: target_size.height as i32,
                    z: 1,
                },
            ];
            let src_subresource = ImageSubresourceLayers::builder()
                .aspect_mask(vk::ImageAspectFlags::COLOR)
                .mip_level(level - 1)
                .base_array_layer(0)
                .layer_count(1)
                .build();

            let dst_subresource = ImageSubresourceLayers::builder()
                .aspect_mask(vk::ImageAspectFlags::COLOR)
                .mip_level(level)
                .base_array_layer(0)
                .layer_count(1)
                .build();

            let image_blit = [vk::ImageBlit::builder()
                .src_subresource(src_subresource)
                .src_offsets(src_offsets)
                .dst_subresource(dst_subresource)
                .dst_offsets(dst_offsets)
                .build()];

            unsafe {
                util::vulkan_image_layout_transition_levels(
                    &vulkan.device,
                    *cmd,
                    texture,
                    vk::REMAINING_MIP_LEVELS,
                    vk::ImageLayout::GENERAL,
                    vk::ImageLayout::GENERAL,
                    vk::AccessFlags::TRANSFER_WRITE,
                    vk::AccessFlags::TRANSFER_READ,
                    vk::PipelineStageFlags::TRANSFER,
                    vk::PipelineStageFlags::TRANSFER,
                    vk::QUEUE_FAMILY_IGNORED,
                    vk::QUEUE_FAMILY_IGNORED,
                );

                // todo: respect mipmap filter?
                vulkan.device.cmd_blit_image(
                    *cmd,
                    texture,
                    vk::ImageLayout::GENERAL,
                    texture,
                    vk::ImageLayout::GENERAL,
                    &image_blit,
                    vk::Filter::LINEAR,
                );
            }
        }

        unsafe {
            util::vulkan_image_layout_transition_levels(
                &vulkan.device,
                *cmd,
                texture,
                vk::REMAINING_MIP_LEVELS,
                if config.mipmap {
                    vk::ImageLayout::GENERAL
                } else {
                    vk::ImageLayout::TRANSFER_DST_OPTIMAL
                },
                vk::ImageLayout::SHADER_READ_ONLY_OPTIMAL,
                vk::AccessFlags::TRANSFER_WRITE,
                vk::AccessFlags::SHADER_READ,
                vk::PipelineStageFlags::TRANSFER,
                vk::PipelineStageFlags::FRAGMENT_SHADER,
                vk::QUEUE_FAMILY_IGNORED,
                vk::QUEUE_FAMILY_IGNORED,
            );
        }

        Ok(LutTexture {
            memory,
            staging,
            image: Texture {
                size: image.size,
                image_view: texture_view,
                image: texture,
                filter_mode: config.filter_mode,
                wrap_mode: config.wrap_mode,
                mip_filter: config.filter_mode,
                format: vk::Format::B8G8R8A8_UNORM
            }
        })
    }
}