use schala_repl::{Repl, ProgrammingLanguageInterface, ComputationRequest};

use std::{fs::File, io::Read, path::PathBuf, process::exit, collections::HashSet};
use schala_lang::Schala;

//TODO specify multiple langs, and have a way to switch between them
fn main() {
    let args: Vec<String> = std::env::args().collect();
    let matches = command_line_options()
        .parse(&args[1..])
        .unwrap_or_else(|e| {
            eprintln!("Error parsing options: {}", e);
            exit(1);
        });

    if matches.opt_present("help") {
        println!("{}", command_line_options().usage("Schala metainterpreter"));
        exit(0);
    }

    if matches.free.is_empty() {
        let state = Schala::new();
        let mut repl = Repl::new(state);
        repl.run_repl();
    } else {
        let paths: Vec<PathBuf> = matches.free.iter().map(PathBuf::from).collect();
        //TODO handle more than one file
        let filename = &paths[0];
        let extension = filename.extension().and_then(|e| e.to_str())
          .unwrap_or_else(|| {
            eprintln!("Source file `{}` has no extension.", filename.display());
            exit(1);
          });

        //TODO this proably should be a macro for every supported language
        if extension == Schala::source_file_suffix() {
          run_noninteractive(paths, Schala::new());
        } else {
          eprintln!("Extension .{} not recognized", extension);
          exit(1);
        }
    }
}

pub fn run_noninteractive<L: ProgrammingLanguageInterface>(filenames: Vec<PathBuf>, mut language: L) {
    // for now, ony do something with the first filename

    let filename = &filenames[0];
    let mut source_file = File::open(filename).unwrap();
    let mut buffer = String::new();
    source_file.read_to_string(&mut buffer).unwrap();

    let request = ComputationRequest {
        source: &buffer,
        debug_requests: HashSet::new(),
    };

    let response = language.run_computation(request);
    match response.main_output {
        Ok(s) => println!("{}", s),
        Err(s) => eprintln!("{}", s),
    };
}

fn command_line_options() -> getopts::Options {
    let mut options = getopts::Options::new();
    options.optflag("h", "help", "Show help text");
    //options.optflag("w", "webapp", "Start up web interpreter");
    options
}