build.rs

use std::env;
use std::fs::File;
use std::io::Write;
use std::path::Path;

fn main() {
    let out_dir = env::var("OUT_DIR").unwrap();
    let dest_path = Path::new(&out_dir).join("cmake_versions.rs");
    let mut f = File::create(&dest_path).unwrap();

    // Generate the enum.
    writeln!(f, "#[derive(Debug, Clone, ValueEnum)]").unwrap();
    writeln!(f, "pub enum CMakeVersion {{").unwrap();

    let versions = vec![
        (4, 0..=2), // 4.0 to 4.2
        (3, 0..=31), // 3.0 to 3.31
    ];

    for (major, minor_range) in &versions {
        for minor in minor_range.clone() {
            writeln!(f, "    #[value(name = \"{}.{}\")]", major, minor).unwrap();
            writeln!(f, "    CMake{}_{},\n", major, minor).unwrap();
        }
    }

    writeln!(f, "}}\n").unwrap();

    // Generate the as_str method.
    writeln!(f, "impl CMakeVersion {{").unwrap();
    writeln!(f, "    pub fn as_str(&self) -> &'static str {{").unwrap();
    writeln!(f, "        match self {{").unwrap();
    
    for (major, minor_range) in &versions {
        for minor in minor_range.clone() {
            writeln!(
                f,
                "            CMakeVersion::CMake{}_{} => \"{}.{}\",",
                major, minor, major, minor
            ).unwrap();
        }
    }
    
    writeln!(f, "        }}").unwrap();
    writeln!(f, "    }}").unwrap();
    writeln!(f, "}}").unwrap();
}