mod git;
mod parser;

use clap::Parser;
use parser::*;
use rustyline::{error::ReadlineError, DefaultEditor};
use std::{io, ops::ControlFlow};
use thiserror::Error;

/// Shackle Shell - A replacement for git-shell with repo management commands built in.
#[derive(Parser, Debug)]
#[command(author, version, about, long_about = None)]
struct Args {
    /// Run a single shell command and exit
    #[arg(short, long)]
    command: Option<String>,
}

fn main() -> Result<(), ShackleError> {
    let args = Args::parse();
    match args.command {
        Some(user_input) => {
            run_command(user_input)?;
        }
        None => {
            run_interactive_loop()?;
        }
    }

    Ok(())
}

fn run_command(user_input: String) -> Result<ControlFlow<(), ()>, ShackleError> {
    match user_input.parse::<ShackleCommand>() {
        Err(parse_error) => {
            println!("{}", parse_error);
        }
        Ok(ShackleCommand::Whitespace) => {}
        Ok(ShackleCommand::Exit) => {
            return Ok(ControlFlow::Break(()));
        }
        Ok(ShackleCommand::GitInit(GitInitArgs { repo_name })) => {
            git::init(&repo_name)?;
            println!("Successfully created \"{}.git\"", repo_name);
        }
        Ok(ShackleCommand::GitUploadPack(upload_pack_args)) => {
            git::upload_pack(&upload_pack_args)?;
        }
        Ok(ShackleCommand::GitReceivePack(receive_pack_args)) => {
            git::receive_pack(&receive_pack_args)?;
        }
    }
    Ok(ControlFlow::Continue(()))
}

fn run_interactive_loop() -> Result<(), ShackleError> {
    let mut rl = DefaultEditor::new()?;
    loop {
        let readline = rl.readline("> ");
        match readline {
            Ok(user_input) => {
                rl.add_history_entry(user_input.as_str())?;
                match run_command(user_input) {
                    Ok(control_flow) => {
                        if control_flow.is_break() {
                            break;
                        }
                    }
                    Err(e) => {
                        println!("{:?}", e);
                    }
                }
            }
            Err(ReadlineError::Interrupted) => {
                println!("Interrupted");
                break;
            }
            Err(ReadlineError::Eof) => {
                break;
            }
            Err(err) => {
                println!("Error: {:?}", err);
                break;
            }
        }
    }
    Ok(())
}

pub enum FlowControl {}

#[derive(Error, Debug)]
pub enum ShackleError {
    #[error(transparent)]
    IoError(#[from] io::Error),
    #[error(transparent)]
    GitError(#[from] git2::Error),
    #[error(transparent)]
    ReadlineError(#[from] ReadlineError),
}