use std::{fs::File, io::Write, path::Path, process::Command, str::from_utf8};

const VK_INCLUDE: &str = "/usr/include/vulkan";
const VK_HEADER: &[&str] = &[
    "vulkan_core.h",
    "vulkan_xcb.h",
    "vulkan_xlib.h",
    "vulkan_wayland.h",
];
const FN_PREFIX: &str = "PFN_";

const SHADER: &[&str] = &[
    "src/overlay/elements/pedals/single_color.vert",
    "src/overlay/elements/pedals/single_color.frag",
];

fn query_vulkan_function_typedefs() {
    let mut fns = Vec::new();

    for header in VK_HEADER {
        Command::new("ctags")
            .arg("--help")
            .output()
            .expect("Failed to execute ctags. Maybe you need to install it first?");

        let output = Command::new("ctags")
            .arg("-x")
            .arg("--c-types=t")
            .arg(format!("{}/{}", VK_INCLUDE, header))
            .output()
            .expect(&format!("failed to open file {}/{}", VK_INCLUDE, header));

        let output_splits = from_utf8(&output.stdout).unwrap().split_whitespace();

        for split in output_splits {
            if split.starts_with(FN_PREFIX) {
                fns.push(split.trim_start_matches(FN_PREFIX).to_string())
            }
        }
    }

    let path = Path::new("vk_functions");
    let mut file = File::create(path).unwrap();

    for func in fns {
        file.write_all(format!("{}\n", func).as_bytes()).unwrap();
    }
}

fn compile_shader() {
    Command::new("glslangValidator")
        .arg("--help")
        .output()
        .expect("Failed to execute glslangValidator. Maybe you need to install it first?");

    for shader in SHADER {
        Command::new("glslangValidator")
            .arg("-V")
            .arg(shader)
            .arg("-o")
            .arg(&format!("{}.spv", shader))
            .output()
            .expect(&format!("Failed to compile {}", shader));
    }
}

fn main() {
    query_vulkan_function_typedefs();
    compile_shader();
}