mars/src/lib.rs

extern crate hyper;

use std::io;
use std::process::{Command, ExitStatus};
use std::path::PathBuf;
use std::ffi::OsStr;
use std::fs::create_dir_all;

macro_rules! destroy {
    ($e: expr) => {
        match $e {
            Err(_) => {
                let err: Result<(), ()> = Err(());
                return err;
            },
            _ => (),
        }
    }
}

/// Tests if a file is in a directory.
pub fn contains_file(path: &str, file: &str) -> bool {
    let mut path = PathBuf::from(path);
    path.push(file);
    path.exists()
}

/// Tries to build a certain directory using the specified builders.
pub fn run_command(command: &str, path: &str) -> Result<ExitStatus, io::Error> {
    let mut child = match Command::new(command)
        .current_dir(path)
        .spawn() {
            Err(x) => return Err(x),
            Ok(child) => child,
        };

    child.wait()
}

/// Run a build commands, and wait untils its finished, returning its result.
pub fn run_command_with_args<I, S>(command: &str, path: &str, args: I) -> Result<ExitStatus, io::Error> where
    I: IntoIterator<Item=S>,
    S: AsRef<OsStr> {

    let mut child = Command::new(command)
        .current_dir(path)
        .args(args)
        .spawn()?;

    child.wait()
}

/// Tries to build a certain directory using the specified builders.
pub fn build(path: &PathBuf, builders: &Vec<Box<Builder>>) -> Result<(), ()> {

    let mut path = path.clone();

    loop {

        if path.to_str().unwrap() == "/" {
            // Couldn't find a buildable directory
            return Err(());
        }

        for builder in builders {

            if builder.is_buildable(path.to_str().unwrap()) {
                builder.build(path.to_str().unwrap())?;
                return Ok(());
            }

        }

        path.pop();
    };

}

/// Destucture a Result to return a Result<(), ()>
pub fn destroy<T, E>(result: Result<T, E>) -> Result<(), ()> {
    match result {
        Err(_) => Err(()),
        Ok(_) => Ok(()),
    }
}

/// A general builders that contains many builders and can build any type of code.
pub struct GeneralBuilder {
    /// The builders contained.
    builders: Vec<Box<Builder>>,
}

impl GeneralBuilder {
    /// Creates a new general builder with the defaults builders.
    pub fn new() -> GeneralBuilder {
        GeneralBuilder {
            builders: vec![
                Box::new(MakeBuilder::new()),
                Box::new(CMakeBuilder::new()),
                Box::new(CargoBuilder::new()),
            ],
        }
    }

    /// Triggers a build.
    pub fn build(&self, path: &str) -> Result<(), ()> {
        build(&PathBuf::from(path), &self.builders)
    }
}

/// A generic builder. It can build some projects.
pub trait Builder {
    /// Checks if a directory has corresponding files so it can build it.
    /// e.g.: if there is a Makefile
    fn is_buildable(&self, path: &str) -> bool;

    /// Trigger all the commands to build the project.
    fn build(&self, path: &str) -> Result<(), ()>;
}

/// The builder that looks for makefiles.
pub struct MakeBuilder;

impl MakeBuilder {
    /// Creates a new make builder.
    pub fn new() -> MakeBuilder {
        MakeBuilder
    }
}

impl Builder for MakeBuilder {
    fn is_buildable(&self, path: &str) -> bool {
        contains_file(path, "Makefile")
    }

    fn build(&self, path: &str) -> Result<(), ()> {
        destroy!(run_command("make", path));
        Ok(())
    }
}

/// The builder that builds cmake projects.
pub struct CMakeBuilder;

impl CMakeBuilder {
    /// Creates a new cmake builder.
    pub fn new() -> CMakeBuilder {
        CMakeBuilder
    }
}

impl Builder for CMakeBuilder {
    fn is_buildable(&self, path: &str) -> bool {
        contains_file(path, "CMakeLists.txt")
    }

    fn build(&self, path: &str) -> Result<(), ()> {

        let mut build = PathBuf::from(path);
        build.push("build");

        // If there's a build/Makefile, we'll only make
        if ! contains_file(path, "build/Makefile") {

            // Create build directory
            destroy!(create_dir_all(&build));

            // Run cmake .. in build directory
            destroy!(run_command_with_args("cmake", build.to_str().unwrap(), [".."].iter()));
        }

        // Run make in build directory
        destroy!(run_command("make", build.to_str().unwrap()));
        Ok(())
    }

}

/// The builder that looks for Cargo.toml.
pub struct CargoBuilder;

impl CargoBuilder {
    /// Creates a new cargo builder.
    pub fn new() -> CargoBuilder {
        CargoBuilder
    }
}

impl Builder for CargoBuilder {
    fn is_buildable(&self, path: &str) -> bool {
        contains_file(path, "Cargo.toml")
    }

    fn build(&self, path: &str) -> Result<(), ()> {
        destroy(run_command_with_args("cargo", path, ["build"].iter()))
    }
}