use std::io;
use std::path::Path;
use std::str::FromStr;
use std::sync::LazyLock;

use crate::java::{JAVA_VM, VMFlag};

use anyhow::Context;

static JAVA_VERSION: LazyLock<String> = LazyLock::new(|| {
    crate::io::run_process(&[JAVA_VM, VMFlag::Version.to_string().as_str()])
        .expect("Failed to call java")
        .0
        .expect("Failed to read java version from stdout")
});

pub fn get_javac_ver() -> anyhow::Result<semver::Version> {
    /*
     * $ java --version
     *      openjdk 21.0.9 2025-10-21
     *      OpenJDK Runtime Environment (build 21.0.9+10)
     *      OpenJDK 64-Bit Server VM (build 21.0.9+10, mixed mode, sharing)
     */

    semver::Version::from_str(
        JAVA_VERSION
            .lines()
            .nth(0)
            .context("stdout from Java is all f-cked up")?
            .split_ascii_whitespace()
            .nth(1)
            .context("Java version position is all f-cked up")?,
    )
    .context("Failed to produce a version struct from string")
}

pub fn set_cwd<P: AsRef<Path>>(path: P) -> io::Result<()> {
    let mut cwd = crate::PROJECT_ROOT.clone();
    cwd.push(path.as_ref());
    std::env::set_current_dir(cwd.as_path())
}