//! this module interprets the domain specific language as a text adventure.

use crate::dsl::FreeSausageRoll;

pub fn run<'a, 's:'a>(mut game : FreeSausageRoll<'a, 's, ()>) -> std::io::Result<()>{
    //this function doesn't know who it is, or why it is here. It only knows it must deal.
    //Deal with the few commands in the eDSL and nothing more.

    //This would be easier to write recursively. However, in an actual project this might run for quite some time.
    //Since we operate on the stack, let's rather be safe than sorry, and use a loop instead of recursion therefore.
    while let FreeSausageRoll::Free(command) = game { 
        game = match *command {
            crate::dsl::SausageRoll::SayDialogueLine { speaker, text, mood, next } => {
                println!("{} says: \"{text}\" with {} on their face.", speaker.text_description(), mood.text_description());
                next
            },
            crate::dsl::SausageRoll::GivePlayerOptions { options, next } => 
            {
                println!("Your options are:");
                for (id, option) in options.iter().enumerate().map(|(i,o)| (i+1,o)){
                    println!("{id}: {option}");
                }

                let mut input = String::new();
                let mut chosen;
                while {
                    input.clear();
                    std::io::stdin().read_line(&mut input)?;
                    chosen = input.trim().parse().ok().filter(|o : &usize| *o > 0 && *o <= options.len());
                    chosen.is_none()
                } {
                    println!("Invalid choice. Please select one of the options given above.");
                }
                println!();
                next(chosen.unwrap()-1)
            },
            crate::dsl::SausageRoll::PresentLocation { location, next } => {
                println!("{}", location.get_text_description());
                next
            },
            crate::dsl::SausageRoll::Exposition { text, next } => {
                println!("{text}");
                next
            },
        };
    };
    std::io::Result::Ok(())
}