use clap::CommandFactory;

#[path = "src/cli.rs"]
mod cli;

/// Writes a manfile to the `target/man` directory. The name of the file
/// is dependent on the package name as set by cargo.
fn main() -> std::io::Result<()> {
    let current_dir = std::env::current_dir().map_err(|_| std::io::ErrorKind::NotFound)?;

    println!("current dir: {:?}", current_dir);
    println!("cargo:rerun-if-changed=src/cli.rs");
    println!("cargo:rerun-if-changed=build.rs");
    let mut out_dir = std::path::PathBuf::from(
        std::env::var("CARGO_MANIFEST_DIR").map_err(|_| std::io::ErrorKind::NotFound)?,
    );

    out_dir.pop();

    let target_dir = out_dir.join("target").join("man");

    let create_dir_res = std::fs::create_dir_all(&target_dir);

    if let Err(create_error) = create_dir_res {
        match create_error.kind() {
            std::io::ErrorKind::AlreadyExists => {
                println!("Manpage dir already exists, continuing")
            }
            _ => {
                print!(
                    "Error creating manpage dir {:?}: {:?}",
                    &target_dir, create_error
                );
                return Err(create_error);
            }
        }
    }

    let cmd = cli::Cli::command();
    let pkg_name = cmd.get_name().to_string();

    let subcommands = cmd.get_subcommands().cloned();

    let all_commands = std::iter::once(cmd.clone()).chain(subcommands);

    for cmd in all_commands {
        let cmd_name = cmd.get_name().to_string();

        let cmd_name = if !cmd_name.starts_with(&pkg_name) {
            format!("{}-{}", &pkg_name, &cmd_name)
        } else {
            cmd_name
        };

        let man = clap_mangen::Man::new(cmd);
        let mut buffer: Vec<u8> = Default::default();
        let res = man.render(&mut buffer);

        if res.is_err() {
            print!("Error rendering manpage: {:?}", res)
        }

        let manfile = format!("{}.1", cmd_name);

        let write_res = std::fs::write(target_dir.join(manfile), &buffer);

        if write_res.is_err() {
            print!("Error writing manpage: {:?}", &write_res);
            return write_res;
        }
    }

    Ok(())
}