use std::{env, fs::File, io::Write, path::PathBuf, process::Command};

fn main() {
    // Put the linker script somewhere the linker can find it
    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
    File::create(out.join("memory.x"))
        .unwrap()
        .write_all(include_bytes!("memory.x"))
        .unwrap();
    println!("cargo:rustc-link-search={}", out.display());

    // Only re-run the build script when memory.x is changed,
    // instead of when any part of the source code changes.
    println!("cargo:rerun-if-changed=memory.x");

    let revision = env::var("BUILD_REVISION");
    match revision {
        Ok(r) => {
            // Skip if the environment variable is already set
            println!("cargo:rustc-env=BUILD_REVISION={}", r);
        }
        Err(_) => {
            let output = Command::new("git")
                .args(&["rev-parse", "--short=7", "HEAD"])
                .output()
                .expect("Failed to execute git command");
            
            let dirty = !Command::new("git")
                .args(&["status", "-s"])
                .output()
                .expect("Failed to execute git command").stdout.is_empty();
            
            let build_revision: String;
            if dirty {
                build_revision = String::from_utf8(output.stdout)
                    .expect("Invalid UTF-8 sequence") + "-dirty";
            } else {
                build_revision = String::from_utf8(output.stdout)
                    .expect("Invalid UTF-8 sequence");
            }
            
            println!("cargo:rustc-env=BUILD_REVISION={}", build_revision.trim());
        }
    };
}