use nom::branch::alt;
use nom::combinator::map;

use super::clock::clock;
use super::comment::comment;
use super::comment::detect_comment;
use super::diary_sexp::detect_diary_sexp;
use super::diary_sexp::diary_sexp;
use super::drawer::drawer;
use super::dynamic_block::dynamic_block;
use super::fixed_width_area::detect_fixed_width_area;
use super::fixed_width_area::fixed_width_area;
use super::footnote_definition::detect_footnote_definition;
use super::footnote_definition::footnote_definition;
use super::greater_block::greater_block;
use super::horizontal_rule::horizontal_rule;
use super::keyword::affiliated_keyword;
use super::keyword::babel_call_keyword;
use super::keyword::keyword;
use super::latex_environment::latex_environment;
use super::lesser_block::comment_block;
use super::lesser_block::example_block;
use super::lesser_block::export_block;
use super::lesser_block::src_block;
use super::lesser_block::verse_block;
use super::org_source::OrgSource;
use super::paragraph::paragraph;
use super::plain_list::detect_plain_list;
use super::plain_list::plain_list;
use super::table::detect_table;
use super::util::get_consumed;
use super::util::maybe_consume_trailing_whitespace_if_not_exiting;
use crate::context::parser_with_context;
use crate::context::RefContext;
use crate::error::CustomError;
use crate::error::MyError;
use crate::error::Res;
use crate::parser::table::org_mode_table;
use crate::types::Element;
use crate::types::SetSource;

pub(crate) const fn element(
    can_be_paragraph: bool,
) -> impl for<'b, 'g, 'r, 's> Fn(
    RefContext<'b, 'g, 'r, 's>,
    OrgSource<'s>,
) -> Res<OrgSource<'s>, Element<'s>> {
    move |context, input: OrgSource<'_>| _element(context, input, can_be_paragraph)
}

#[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
fn _element<'b, 'g, 'r, 's>(
    context: RefContext<'b, 'g, 'r, 's>,
    input: OrgSource<'s>,
    can_be_paragraph: bool,
) -> Res<OrgSource<'s>, Element<'s>> {
    let plain_list_matcher = parser_with_context!(plain_list)(context);
    let greater_block_matcher = parser_with_context!(greater_block)(context);
    let dynamic_block_matcher = parser_with_context!(dynamic_block)(context);
    let footnote_definition_matcher = parser_with_context!(footnote_definition)(context);
    let comment_matcher = parser_with_context!(comment)(context);
    let drawer_matcher = parser_with_context!(drawer)(context);
    let table_matcher = parser_with_context!(org_mode_table)(context);
    let verse_block_matcher = parser_with_context!(verse_block)(context);
    let comment_block_matcher = parser_with_context!(comment_block)(context);
    let example_block_matcher = parser_with_context!(example_block)(context);
    let export_block_matcher = parser_with_context!(export_block)(context);
    let src_block_matcher = parser_with_context!(src_block)(context);
    let clock_matcher = parser_with_context!(clock)(context);
    let diary_sexp_matcher = parser_with_context!(diary_sexp)(context);
    let fixed_width_area_matcher = parser_with_context!(fixed_width_area)(context);
    let horizontal_rule_matcher = parser_with_context!(horizontal_rule)(context);
    let keyword_matcher = parser_with_context!(keyword)(context);
    let babel_keyword_matcher = parser_with_context!(babel_call_keyword)(context);
    let paragraph_matcher = parser_with_context!(paragraph)(context);
    let latex_environment_matcher = parser_with_context!(latex_environment)(context);

    let (remaining, mut element) = match alt((
        map(plain_list_matcher, Element::PlainList),
        greater_block_matcher,
        map(dynamic_block_matcher, Element::DynamicBlock),
        map(footnote_definition_matcher, Element::FootnoteDefinition),
        map(comment_matcher, Element::Comment),
        map(drawer_matcher, Element::Drawer),
        map(table_matcher, Element::Table),
        map(verse_block_matcher, Element::VerseBlock),
        map(comment_block_matcher, Element::CommentBlock),
        map(example_block_matcher, Element::ExampleBlock),
        map(export_block_matcher, Element::ExportBlock),
        map(src_block_matcher, Element::SrcBlock),
        map(clock_matcher, Element::Clock),
        map(diary_sexp_matcher, Element::DiarySexp),
        map(fixed_width_area_matcher, Element::FixedWidthArea),
        map(horizontal_rule_matcher, Element::HorizontalRule),
        map(latex_environment_matcher, Element::LatexEnvironment),
        map(babel_keyword_matcher, Element::BabelCall),
        map(keyword_matcher, Element::Keyword),
    ))(input)
    {
        the_ok @ Ok(_) => the_ok,
        Err(_) => {
            if can_be_paragraph {
                match map(paragraph_matcher, Element::Paragraph)(input) {
                    the_ok @ Ok(_) => the_ok,
                    Err(_) => {
                        // TODO: Because this function expects a single element, if there are multiple affiliated keywords before an element that cannot have affiliated keywords, we end up re-parsing the affiliated keywords many times.
                        map(affiliated_keyword, Element::Keyword)(input)
                    }
                }
            } else {
                map(affiliated_keyword, Element::Keyword)(input)
            }
        }
    }?;

    let (remaining, _trailing_ws) =
        maybe_consume_trailing_whitespace_if_not_exiting(context, remaining)?;

    let source = get_consumed(input, remaining);
    element.set_source(source.into());

    Ok((remaining, element))
}

pub(crate) const fn detect_element(
    can_be_paragraph: bool,
) -> impl for<'b, 'g, 'r, 's> Fn(RefContext<'b, 'g, 'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, ()>
{
    move |context, input: OrgSource<'_>| _detect_element(context, input, can_be_paragraph)
}

#[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
fn _detect_element<'b, 'g, 'r, 's>(
    context: RefContext<'b, 'g, 'r, 's>,
    input: OrgSource<'s>,
    can_be_paragraph: bool,
) -> Res<OrgSource<'s>, ()> {
    // TODO: What about affiliated keywords in the detect_* functions?
    if alt((
        parser_with_context!(detect_plain_list)(context),
        detect_footnote_definition,
        detect_diary_sexp,
        detect_comment,
        detect_fixed_width_area,
        detect_table,
    ))(input)
    .is_ok()
    {
        return Ok((input, ()));
    }
    if _element(context, input, can_be_paragraph).is_ok() {
        return Ok((input, ()));
    }
    return Err(nom::Err::Error(CustomError::MyError(MyError(
        "No element detected.".into(),
    ))));
}