use std::env;
use std::path::PathBuf;

fn main() {
    #[cfg(unix)]
    let builder;

    #[cfg(windows)]
    let mut builder;

    builder = bindgen::Builder::default().header("wrapper.h");

    #[cfg(windows)]
    let modify_builder = |nvtt_path: PathBuf| -> bindgen::Builder {
        let nvtt_path = nvtt_path.into_os_string().into_string().unwrap();
        let path = format!("-I{nvtt_path}\\include\\nvtt");
        println!("{}", &path);
        builder.clang_arg(path).clang_arg("-v")
    };

    if let Some(nvtt_path) = std::env::var_os("NVTT_PATH") {
        let nvtt_path = PathBuf::from(nvtt_path);
        cfg_if::cfg_if! {
            if #[cfg(unix)] {
                println!("cargo:rustc-link-search={}", nvtt_path.to_str().unwrap());
            }
            else if #[cfg(windows)] {
                println!("cargo:rustc-link-search={}", nvtt_path.to_str().unwrap());
                println!("cargo:rustc-link-search={}", nvtt_path.join(r"lib\x64-v142").to_str().unwrap());
                println!("cargo:rustc-link-search={}", nvtt_path.join(r"include\nvtt").to_str().unwrap());
                builder = modify_builder(nvtt_path);
            }
        }
    } else {
        #[cfg(windows)]
        {
            unsafe {
                let path_pw = windows::Win32::UI::Shell::SHGetKnownFolderPath(
                    &windows::Win32::UI::Shell::FOLDERID_ProgramFiles,
                    windows::Win32::UI::Shell::KNOWN_FOLDER_FLAG(0),
                    windows::Win32::Foundation::HANDLE(0),
                )
                .expect("Failed to find Program Files");
                let pf = PathBuf::from(
                    path_pw
                        .to_string()
                        .expect("Failed to make Program Files path into String"),
                );
                let nvtt_path = pf.join(r"NVIDIA Corporation\NVIDIA Texture Tools");

                println!("cargo:rustc-link-search={}", nvtt_path.to_str().unwrap());
                println!(
                    "cargo:rustc-link-search={}",
                    nvtt_path.join(r"lib\x64-v142").to_str().unwrap()
                );
                println!(
                    "cargo:rustc-link-search={}",
                    nvtt_path.join(r"include\nvtt").to_str().unwrap()
                );

                builder = modify_builder(nvtt_path);
            }
        }
    };

    cfg_if::cfg_if! {
        if #[cfg(windows)] {
            println!("cargo:rustc-link-lib=nvtt30106");
        } else if #[cfg(unix)] {
            println!("cargo:rustc-link-lib=nvtt");
        }
    }

    println!("cargo:rerun-if-changed=wrapper.h");

    let bindings = builder
        // Tell cargo to invalidate the built crate whenever any of the
        // included header files changed.
        .parse_callbacks(Box::new(bindgen::CargoCallbacks))
        // Enums
        .rustified_enum("NvttBoolean")
        .rustified_enum("NvttValueType")
        .rustified_enum("NvttChannelOrder")
        .rustified_enum("NvttFormat")
        .rustified_enum("NvttPixelType")
        .rustified_enum("NvttQuality")
        .rustified_enum("NvttWrapMode")
        .rustified_enum("NvttTextureType")
        .rustified_enum("NvttInputFormat")
        .rustified_enum("NvttMipmapFilter")
        .rustified_enum("NvttResizeFilter")
        .rustified_enum("NvttRoundMode")
        .rustified_enum("NvttAlphaMode")
        .rustified_enum("NvttError")
        .rustified_enum("NvttContainer")
        .rustified_enum("NvttNormalTransform")
        .rustified_enum("NvttToneMapper")
        .rustified_enum("NvttCubeLayout")
        .rustified_enum("EdgeFixup")
        // Finish the builder and generate the bindings.
        .generate()
        // Unwrap the Result and panic on failure.
        .expect("Unable to generate bindings");

    // Write the bindings to the $OUT_DIR/bindings.rs file.
    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
    bindings
        .write_to_file(out_path.join("bindings.rs"))
        .expect("Couldn't write bindings!");
}