extern crate hyper;

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

/// 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 = match Command::new(command)
        .current_dir(path)
        .args(args)
        .spawn() {
            Err(x) => return Err(x),
            Ok(child) => child,
        };

    child.wait()
}

/// Tries to build a certain directory using the specified builders.
pub fn build(path: &PathBuf, builders: &Vec<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.
#[derive(Clone)]
pub struct GeneralBuilder {
    /// The builders contained.
    builders: Vec<Builder>,
}

impl GeneralBuilder {
    /// Creates a new general builder with the defaults builders.
    pub fn new() -> GeneralBuilder {
        GeneralBuilder {
            builders: vec![
                Builder::make(),
                Builder::cargo(),
            ],
        }
    }

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

/// The builder that looks for makefiles.
#[derive(Clone)]
pub struct Builder {
    /// The file to lookup to check build.
    file: String,

    /// The command to launch to build.
    command: String,

    /// The arguments to the command.
    args: Vec<String>,
}

impl Builder {
    /// Creates a new make builder.
    pub fn make() -> Builder {
        Builder {
            file: "Makefile".to_string(),
            command: "make".to_string(),
            args: vec![],
        }
    }

    /// Creates a new cargo builder.
    pub fn cargo() -> Builder {
        Builder {
            file: "Cargo.toml".to_string(),
            command: "cargo".to_string(),
            args: vec!["build".to_string()],
        }
    }

    /// 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 {
        contains_file(path, &self.file)
    }

    /// Trigger all the commands to build the project.
    fn build(&self, path: &str) -> Result<(), ()> {
        match run_command_with_args(&self.command, path, &self.args) {
            Ok(_) => Ok(()),
            Err(_) => Err(()),
        }
    }
}