//! cassiopeia file format

mod gen;
pub(crate) mod ir;
mod lexer;
mod parser;

pub(crate) use lexer::{LineLexer, LineToken, Token};
pub(crate) use parser::LineCfg;

use crate::TimeFile;
use ir::{IrItem, IrStream};
use std::{
    fs::{File, OpenOptions},
    io::{Read, Write},
};

#[derive(Default)]
pub(crate) struct ParseOutput {
    pub(crate) ir: IrStream,
    pub(crate) tf: TimeFile,
}

impl ParseOutput {
    fn append(mut self, ir: IrItem) -> Self {
        self.tf.append(ir.clone());
        self.ir.push(ir);
        self
    }
}

/// Load a file from disk and parse it into a
/// [`TimeFile`](crate::TimeFile)
pub(crate) fn load_file(path: &str) -> Option<ParseOutput> {
    let mut f = File::open(path).ok()?;
    let mut content = String::new();
    f.read_to_string(&mut content).ok()?;

    let mut lines: Vec<String> = content.split("\n").map(|l| l.to_owned()).collect();

    Some(
        ir::generate_ir(
            lines
                .iter_mut()
                .map(|line| lexer::lex(line))
                .map(|lex| parser::parse(lex)),
        )
        .into_iter()
        .fold(ParseOutput::default(), |output, ir| output.append(ir)),
    )
}

/// Write a file with the updated IR stream
pub(crate) fn write_file(path: &str, ir: &mut IrStream) -> Option<()> {
    ir::update_header(ir);
    let mut lines = ir.into_iter().map(|ir| gen::line(ir)).collect::<Vec<_>>();
    lines.insert(0, gen::head_comment());

    let mut f = OpenOptions::new()
        .write(true)
        .create(true)
        .truncate(true)
        .open(path)
        .ok()?;
    f.write_all(lines.join("\n").as_bytes()).ok()?;
    Some(())
}