// Copyright (C) 2026 Elias Wendland <eliaswendland@pm.me>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 3 exclusively.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

use clap::CommandFactory;
use std::{env, fs, path::Path, process::Command};

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

fn command_output(command: &str, args: &[&str]) -> String {
    Command::new(command)
        .args(args)
        .output()
        .ok()
        .filter(|output| output.status.success())
        .map(|output| String::from_utf8_lossy(&output.stdout).trim().to_owned())
        .filter(|output| !output.is_empty())
        .unwrap_or_else(|| "unknown".to_owned())
}

fn main() {
    let out_dir = env::var_os("OUT_DIR").expect("OUT_DIR is set by Cargo");
    let version = env::var("CARGO_PKG_VERSION").unwrap_or_else(|_| "unknown".to_owned());
    let rustc_version = command_output(
        &env::var("RUSTC").unwrap_or_else(|_| "rustc".to_owned()),
        &["--version"],
    );
    let target = env::var("TARGET").unwrap_or_else(|_| "unknown".to_owned());
    println!("cargo:rustc-env=CONVERTIS_RUSTC_VERSION={rustc_version}");
    println!("cargo:rustc-env=CONVERTIS_TARGET={target}");
    let version_text = format!(
        "{}\nbuild-time: {}\ncommit: {}\ntarget: {}\nrustc: {}",
        version,
        command_output("date", &["-u", "+%Y-%m-%d %H:%M:%S UTC"]),
        command_output("git", &["rev-parse", "--short", "HEAD"]),
        target,
        rustc_version,
    );
    fs::write(Path::new(&out_dir).join("version.txt"), version_text).unwrap();

    let man_dir = Path::new("target/man");
    fs::create_dir_all(man_dir).unwrap();
    let command = args::Args::command()
        .name("convertis")
        .version(env!("CARGO_PKG_VERSION"));
    let mut buffer = Vec::new();
    clap_mangen::Man::new(command).render(&mut buffer).unwrap();
    fs::write(man_dir.join("convertis.1"), buffer).unwrap();
}