//!
//! The zkEVM LLVM builder utilities.
//!

use std::path::Path;
use std::path::PathBuf;
use std::process::Command;

use path_slash::PathBufExt;

const DRY_RUN: bool = false;
/// Enable verbose output.
pub const VERBOSE: bool = false;

///
/// The subprocess runner.
///
/// Checks the status and prints `stderr`.
///
pub fn command(command: &mut Command, description: &str) -> anyhow::Result<()> {
    if VERBOSE {
        println!("\ndescription: {}; command: {:?}", description, command);
    }
    if DRY_RUN {
        println!("\tOnly a dry run; not executing the command.");
    } else {
        let status = command
            .status()
            .map_err(|error| anyhow::anyhow!("{} process: {}", description, error))?;
        if !status.success() {
            anyhow::bail!("{} failed", description);
        }
    }
    Ok(())
}

/// Call ninja to build the LLVM.
pub fn ninja(build_dir: &Path) -> anyhow::Result<()> {
    let mut ninja = Command::new("ninja");
    ninja.args(["-C", build_dir.to_string_lossy().as_ref()]);
    if std::env::var("DRY_RUN").is_ok() {
        ninja.arg("-n");
    }
    command(ninja.arg("install"), "Running ninja install")?;
    Ok(())
}

///
/// Create an absolute path, appending it to the current working directory.
///
pub fn absolute_path<P: AsRef<Path>>(path: P) -> anyhow::Result<PathBuf> {
    let mut full_path = std::env::current_dir()?;
    full_path.push(path);
    Ok(full_path)
}

///
/// Converts a Windows path into a Unix path.
///
pub fn path_windows_to_unix<P: AsRef<Path> + PathBufExt>(path: P) -> anyhow::Result<PathBuf> {
    path.to_slash()
        .map(|pathbuf| PathBuf::from(pathbuf.to_string()))
        .ok_or_else(|| anyhow::anyhow!("Windows-to-Unix path conversion error"))
}

///
/// Checks if the tool exists in the system.
///
pub fn check_presence(name: &str) -> anyhow::Result<()> {
    let status = Command::new("which")
        .arg(name)
        .status()
        .map_err(|error| anyhow::anyhow!("`which {}` process: {}", name, error))?;
    if !status.success() {
        anyhow::bail!("Tool `{}` is missing. Please install", name);
    }
    Ok(())
}