use super::*;

use ::anyhow::{anyhow, Result};
use ::std::collections::HashSet;
use ::vulkanalia::prelude::v1_0::*;
use ::winit::window::Window;

pub unsafe fn check_physical_device_extensions(
    instance: &Instance,
    physical_device: vk::PhysicalDevice,
) -> Result<()> {
    let extensions = instance
        .enumerate_device_extension_properties(physical_device, None)?
        .iter()
        .map(|e| e.extension_name)
        .collect::<HashSet<_>>();

    if DEVICE_EXTENSIONS.iter().all(|e| extensions.contains(e)) {
        Ok(())
    } else {
        Err(anyhow!(SuitabilityError(
            "Missing required device extensions."
        )))
    }
}

//================================================
// Swapchain
//================================================

pub fn get_swapchain_surface_format(formats: &[vk::SurfaceFormatKHR]) -> vk::SurfaceFormatKHR {
    formats
        .iter()
        .cloned()
        .find(|f| {
            f.format == vk::Format::B8G8R8A8_SRGB
                && f.color_space == vk::ColorSpaceKHR::SRGB_NONLINEAR
        })
        .unwrap_or_else(|| formats[0])
}

pub fn get_swapchain_present_mode(present_modes: &[vk::PresentModeKHR]) -> vk::PresentModeKHR {
    present_modes
        .iter()
        .cloned()
        .find(|m| *m == vk::PresentModeKHR::MAILBOX)
        .unwrap_or(vk::PresentModeKHR::FIFO)
}

pub fn get_swapchain_extent(
    window: &Window,
    capabilities: vk::SurfaceCapabilitiesKHR,
) -> vk::Extent2D {
    if capabilities.current_extent.width != u32::MAX {
        capabilities.current_extent
    } else {
        let size = window.inner_size();
        let clamp = |min: u32, max: u32, v: u32| min.max(max.min(v));
        vk::Extent2D::builder()
            .width(clamp(
                capabilities.min_image_extent.width,
                capabilities.max_image_extent.width,
                size.width,
            ))
            .height(clamp(
                capabilities.min_image_extent.height,
                capabilities.max_image_extent.height,
                size.height,
            ))
            .build()
    }
}

//================================================
// Pipeline
//================================================

pub unsafe fn create_shader_module(device: &Device, bytecode: &[u8]) -> Result<vk::ShaderModule> {
    let bytecode = Vec::<u8>::from(bytecode);
    let (prefix, code, suffix) = bytecode.align_to::<u32>();
    if !prefix.is_empty() || !suffix.is_empty() {
        return Err(anyhow!("Shader bytecode is not properly aligned."));
    }

    let info = vk::ShaderModuleCreateInfo::builder()
        .code_size(bytecode.len())
        .code(code);

    Ok(device.create_shader_module(&info, None)?)
}