// an implementation of Ludus

// curently left undone (and not adding for a while yet):
// * sets
// * interpolated strings & string patterns
// * pkgs, namespaces, imports, `use` forms
// * with forms
// * test forms
// * ignored words

// todo:
// * [x] rewrite fn parser to use chumsky::Recursive::declare/define
//   - [x] do this to extract/simplify/DRY things like tuple patterns, fn clauses, etc.
// * [x] Work around chumsky::Stream::from_iter().spanned disappearing in most recent version
// * [x] investigate using labels (which is behind a compiler flag, somehow)
// * [ ] wire up Ariadne parsing errors
// * [ ] validation
// * [x] break this out into multiple files
// * [x] write a tree-walk VM
//   - [x] learn how to deal with lifetimes
//   - [x] with stack mechanics and refcounting
//   - [ ] with tail-call optimization (nb: this may not be possible w/ a TW-VM)
//   - [ ] with all the necessary forms for current Ludus
//     * [ ] guards in match clauses
//     * [ ] `as` patterns
//     * [ ] splat patterns in tuples, lists, dicts
//     * [ ] splats in list and dict literals
//     * [ ] `loop` and `recur`
// * [ ] write `base` in Rust
// * [ ] turn this into a library function
// * [ ] compile this into WASM
// * [ ] perf testing

use chumsky::{input::Stream, prelude::*};
use std::rc::Rc;

mod spans;

mod lexer;
use crate::lexer::*;

mod value;
use crate::value::*;

mod parser;
use crate::parser::*;

mod vm;
use crate::vm::*;

mod base;
use crate::base::*;

pub fn main() {
    let src = "
eq
    ";
    let (tokens, lex_errs) = lexer().parse(src).into_output_errors();
    if lex_errs.len() > 0 {
        println!("{:?}", lex_errs);
        return ();
    }
    let tokens = tokens.unwrap();
    let to_parse = tokens.clone();
    // for (token, _) in tokens {
    //     println!("{}", token)
    // }
    let (ast, _) = parser()
        .parse(Stream::from_iter(to_parse).map((0..src.len()).into(), |(t, s)| (t, s)))
        .unwrap();
    // println!("{}", ast);

    let mut ctx = base();

    let result = eval(&ast, &mut ctx).unwrap();

    println!("{}", result);
}

// #[cfg(test)]
// mod tests {
//     use crate::lexer;
//     use crate::Token;
//     use chumsky::prelude::*;

//     #[test]
//     fn it_lexes_positive_ints() {
//         let (mytoken, _) = lexer().parse("42").unwrap()[0].clone();
//         assert_eq!(mytoken, Token::Number(42.0))
//     }

//     #[test]
//     fn it_lexes_negative_ints() {
//         let (mytoken, _) = lexer().parse("-42").unwrap()[0].clone();
//         assert_eq!(mytoken, Token::Number(-42.0))
//     }

//     #[test]
//     fn it_lexes_positive_floats() {
//         let (mytoken, _) = lexer().parse("42.032").unwrap()[0].clone();
//         assert_eq!(mytoken, Token::Number(42.032))
//     }

//     #[test]
//     fn it_lexes_positive_decimals() {
//         let (mytoken, _) = lexer().parse("0.123").unwrap()[0].clone();
//         assert_eq!(mytoken, Token::Number(0.123))
//     }

//     #[test]
//     fn it_lexes_negative_floats() {
//         let mytoken = lexer().parse("-42.123").unwrap()[0].clone().0;
//         assert_eq!(mytoken, Token::Number(-42.123))
//     }

//     #[test]
//     fn it_lexes_negative_decimals() {
//         let mytoken = lexer().parse("-0.123").unwrap()[0].clone().0;
//         assert_eq!(mytoken, Token::Number(-0.123))
//     }

//     #[test]
//     fn it_lexes_bools() {
//         let tt = lexer().parse("true").unwrap()[0].clone().0;
//         assert_eq!(tt, Token::Boolean(true));
//         let ff = lexer().parse("false").unwrap()[0].clone().0;
//         assert_eq!(ff, Token::Boolean(false))
//     }

//     #[test]
//     fn it_lexes_words() {
//         let mytoken = lexer().parse("foo").unwrap()[0].clone().0;
//         assert_eq!(mytoken, Token::Word("foo"))
//     }

//     #[test]
//     fn it_lexes_keywords() {
//         let kw = lexer().parse(":foo").unwrap()[0].clone().0;
//         assert_eq!(kw, Token::Keyword("foo"))
//     }

//     #[test]
//     fn it_lexes_strings() {
//         let s = lexer().parse("\"foo bar baz\"").unwrap()[0].clone().0;
//         assert_eq!(s, Token::String("foo bar baz"))
//     }

//     #[test]
//     fn it_ignores_comments() {
//         let e = lexer().parse("foo &bar\nbaz").unwrap();
//         assert_eq!(e[0].0, Token::Word("foo"));
//         assert_eq!(e[1].0, Token::Punctuation("\n"));
//         assert_eq!(e[2].0, Token::Word("baz"))
//     }

//     #[test]
//     fn it_lexes_multiple_tokens() {
//         let toks = lexer().parse("foo;bar\nbaz").unwrap();
//         assert_eq!(toks[0].0, Token::Word("foo"));
//         assert_eq!(toks[2].0, Token::Word("bar"));
//         assert_eq!(toks[4].0, Token::Word("baz"))
//     }

//     #[test]
//     fn it_lexes_collections() {
//         let toks = lexer().parse("(1, 2)").unwrap();
//         assert_eq!(toks[0].0, Token::Punctuation("("));
//         assert_eq!(toks[1].0, Token::Number(1.0));
//         assert_eq!(toks[2].0, Token::Punctuation(","));
//         assert_eq!(toks[3].0, Token::Number(2.0));
//         assert_eq!(toks[4].0, Token::Punctuation(")"))
//     }
// }