mod preproc;
mod ast;
mod table;
mod states;

use anyhow::{Result, Context};
use crate::ast::Parseable;

fn read_source(path: &str) -> Result<String> {
    std::fs::read_to_string(path)
    .with_context(||
        format!("Failed to read file at path '{}'", path)
    )
}

pub fn run(path: &str) -> Result<()> {
    let source: String = read_source(path)?;
    
    let mut flat_parser = preproc::tokenize(source);

    let parsers = crate::preproc::Parsers::new(&mut flat_parser).with_context(||
        format!("Could not determine different parts of the expression.")
    )?;

    let mut l_parser = parsers.l_parser;

    let expr = ast::Expr::consume(&mut l_parser)?;

    let table = ast::build_table(expr);

    let mut states_parser = parsers.s_parser;

    let mut states = states::States::parse(&mut states_parser);

    let steps = parsers.steps;

    for _ in 0..steps {
        states.print();
        states.update_using(&table);
    }
    states.print();

    Ok(())
}