//! ----------------------------------------------------
//! `🗲` Vulkan Device `🗲`
//! ----------------------------------------------------

const gtl = @import("gtl");
const std = @import("std");
const vk = @import("vulkan");
const Instance = @import("instance.zig");
const Self = @This();

//
// FIELDS
//

raw: *vk.VkDevice_T,

/// ----------------------------------------------------
/// ----------------------------------------------------
pub fn init(
    instance: *Instance,
    alloc: std.mem.Allocator,
) !Self {
    var physical: vk.VkPhysicalDevice = null;
    var count: u32 = 0;

    if (vk.vkEnumeratePhysicalDevices(instance.raw, &count, null) != vk.VK_SUCCESS) {
        return error.FailedToEnumeratePhysicalDevices;
    }

    if (count == 0) {
        return error.FailedToFindGPUWithVKSupport;
    }

    const devices = try alloc.alloc(vk.VkPhysicalDevice, count);
    defer alloc.free(devices);

    if (vk.vkEnumeratePhysicalDevices(instance.raw, &count, devices.ptr) != vk.VK_SUCCESS) {
        return error.FailedToEnumeratePhysicalDevices;
    }

    for (devices) |device| {
        if (try isDeviceSuitable(device)) {
            physical = device;
            break;
        }
    }

    var features: vk.VkPhysicalDeviceFeatures = .{};
    var queue_create_info: vk.VkDeviceQueueCreateInfo = .{
        .sType = vk.VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,
    };

    var create_info: vk.VkDeviceCreateInfo = .{
        .sType = vk.VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO,
        .pQueueCreateInfos = &queue_create_info,
        .queueCreateInfoCount = 1,
        .pEnabledFeatures = &features,
    };

    var device: vk.VkDevice = null;
    if (vk.vkCreateDevice(physical, &create_info, null, &device) != vk.VK_SUCCESS) {
        return error.FailedToCreateVulkanDevice;
    }

    return .{
        .raw = device.?,
    };
}

/// ----------------------------------------------------
/// ----------------------------------------------------
pub fn deinit(self: *Self) void {
    vk.vkDestroyDevice(self.raw, null);
}

/// ----------------------------------------------------
/// ----------------------------------------------------
fn isDeviceSuitable(device: vk.VkPhysicalDevice) !bool {
    var properties: vk.VkPhysicalDeviceProperties = .{};
    vk.vkGetPhysicalDeviceProperties(device, &properties);

    var features: vk.VkPhysicalDeviceFeatures = .{};
    vk.vkGetPhysicalDeviceFeatures(device, &features);

    if (gtl.log.print(.debug, "DEVICE", gtl.ansi.blue)) |v| {
        defer v.end();

        v.write("Name: {s}", .{properties.deviceName});
        v.write("Type: {s}", .{
            switch (properties.deviceType) {
                vk.VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU => "discrete",
                else => "idk",
            },
        });
    }

    return properties.deviceType == vk.VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU and features.geometryShader == 1;
}