use nom::branch::alt;
use nom::bytes::complete::escaped;
use nom::bytes::complete::tag;
use nom::bytes::complete::take_till1;
use nom::character::complete::line_ending;
use nom::character::complete::one_of;
use nom::character::complete::space0;
use nom::combinator::opt;
use nom::combinator::verify;
use nom::multi::many_till;
use nom::sequence::tuple;

use super::parser_with_context::parser_with_context;
use super::util::get_consumed;
use super::Context;
use super::Object;
use super::RegularLink;
use crate::error::Res;
use crate::parser::exiting::ExitClass;
use crate::parser::object_parser::regular_link_description_object_set;
use crate::parser::parser_context::ContextElement;
use crate::parser::parser_context::ExitMatcherNode;
use crate::parser::util::exit_matcher_parser;

#[tracing::instrument(ret, level = "debug")]
pub fn regular_link<'r, 's>(
    context: Context<'r, 's>,
    input: &'s str,
) -> Res<&'s str, RegularLink<'s>> {
    alt((
        parser_with_context!(regular_link_without_description)(context),
        parser_with_context!(regular_link_with_description)(context),
    ))(input)
}

#[tracing::instrument(ret, level = "debug")]
pub fn regular_link_without_description<'r, 's>(
    context: Context<'r, 's>,
    input: &'s str,
) -> Res<&'s str, RegularLink<'s>> {
    let (remaining, _opening_bracket) = tag("[[")(input)?;
    let (remaining, _path) = pathreg(context, remaining)?;
    let (remaining, _closing_bracket) = tag("]]")(remaining)?;
    let source = get_consumed(input, remaining);
    Ok((remaining, RegularLink { source }))
}

#[tracing::instrument(ret, level = "debug")]
pub fn regular_link_with_description<'r, 's>(
    context: Context<'r, 's>,
    input: &'s str,
) -> Res<&'s str, RegularLink<'s>> {
    let (remaining, _opening_bracket) = tag("[[")(input)?;
    let (remaining, _path) = pathreg(context, remaining)?;
    let (remaining, _closing_bracket) = tag("][")(remaining)?;
    let (remaining, _description) = description(context, remaining)?;
    let (remaining, _closing_bracket) = tag("]]")(remaining)?;
    let source = get_consumed(input, remaining);
    Ok((remaining, RegularLink { source }))
}

#[tracing::instrument(ret, level = "debug")]
pub fn pathreg<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
    let (remaining, path) = escaped(
        take_till1(|c| match c {
            '\\' | ']' => true,
            _ => false,
        }),
        '\\',
        one_of(r#"]"#),
    )(input)?;
    Ok((remaining, path))
}

#[tracing::instrument(ret, level = "debug")]
pub fn description<'r, 's>(
    context: Context<'r, 's>,
    input: &'s str,
) -> Res<&'s str, Vec<Object<'s>>> {
    let parser_context =
        context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
            class: ExitClass::Beta,
            exit_matcher: &description_end,
        }));
    let (remaining, (children, _exit_contents)) = verify(
        many_till(
            parser_with_context!(regular_link_description_object_set)(&parser_context),
            parser_with_context!(exit_matcher_parser)(&parser_context),
        ),
        |(children, _exit_contents)| !children.is_empty(),
    )(input)?;

    Ok((remaining, children))
}

#[tracing::instrument(ret, level = "debug")]
fn description_end<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
    tag("]]")(input)
}