use nom::branch::alt;
use nom::bytes::complete::is_not;
use nom::bytes::complete::tag;
use nom::character::complete::line_ending;
use nom::character::complete::space0;
use nom::character::complete::space1;
use nom::combinator::eof;
use nom::combinator::not;
use nom::combinator::opt;
use nom::multi::many0;
use nom::sequence::preceded;
use nom::sequence::tuple;

use super::Context;
use crate::error::Res;
use crate::parser::parser_with_context::parser_with_context;
use crate::parser::util::exit_matcher_parser;
use crate::parser::util::get_consumed;
use crate::parser::util::start_of_line;
use crate::parser::FixedWidthArea;

#[tracing::instrument(ret, level = "debug")]
pub fn fixed_width_area<'r, 's>(
    context: Context<'r, 's>,
    input: &'s str,
) -> Res<&'s str, FixedWidthArea<'s>> {
    let fixed_width_area_line_matcher = parser_with_context!(fixed_width_area_line)(context);
    let exit_matcher = parser_with_context!(exit_matcher_parser)(context);
    let (remaining, _first_line) = fixed_width_area_line_matcher(input)?;
    let (remaining, _remaining_lines) =
        many0(preceded(not(exit_matcher), fixed_width_area_line_matcher))(remaining)?;

    let source = get_consumed(input, remaining);
    Ok((remaining, FixedWidthArea { source }))
}

#[tracing::instrument(ret, level = "debug")]
fn fixed_width_area_line<'r, 's>(
    context: Context<'r, 's>,
    input: &'s str,
) -> Res<&'s str, &'s str> {
    start_of_line(context, input)?;
    let (remaining, _indent) = space0(input)?;
    let (remaining, (_hash, _leading_whitespace_and_content, _line_ending)) = tuple((
        tag(":"),
        opt(tuple((space1, is_not("\r\n")))),
        alt((line_ending, eof)),
    ))(remaining)?;
    let source = get_consumed(input, remaining);
    Ok((remaining, source))
}