use mon::{Parser, r#if, not, numeric1, one_of, opt, tag, take_while};

use crate::{
    atom::{
        Atom, Blocker, Category, Name, Slot, SlotName, SlotOperator, UseDep, UseDepCondition,
        UseDepNegate, UseDepSign, Version, VersionNumber, VersionOperator, VersionSuffix,
        VersionSuffixKind,
    },
    useflag::parsers::useflag,
};

pub fn blocker<'a>() -> impl Parser<&'a str, Output = Blocker> {
    tag("!!")
        .map(|_| Blocker::Strong)
        .or(tag("!").map(|_| Blocker::Weak))
}

pub fn version_operator<'a>() -> impl Parser<&'a str, Output = VersionOperator> {
    tag("<=")
        .map(|_| VersionOperator::LtEq)
        .or(tag(">=").map(|_| VersionOperator::GtEq))
        .or(tag("<").map(|_| VersionOperator::Lt))
        .or(tag(">").map(|_| VersionOperator::Gt))
        .or(tag("~").map(|_| VersionOperator::Roughly))
}

pub fn version_number<'a>() -> impl Parser<&'a str, Output = VersionNumber> {
    numeric1().map(|output: &str| VersionNumber(output.to_string()))
}

pub fn version_suffix_kind<'a>() -> impl Parser<&'a str, Output = VersionSuffixKind> {
    tag("alpha")
        .map(|_| VersionSuffixKind::Alpha)
        .or(tag("beta").map(|_| VersionSuffixKind::Beta))
        .or(tag("pre").map(|_| VersionSuffixKind::Pre))
        .or(tag("rc").map(|_| VersionSuffixKind::Rc))
        .or(tag("p").map(|_| VersionSuffixKind::P))
}

pub fn version_suffix<'a>() -> impl Parser<&'a str, Output = VersionSuffix> {
    version_suffix_kind()
        .and(opt(version_number()))
        .map(|(kind, number)| VersionSuffix { kind, number })
}

pub fn version<'a>() -> impl Parser<&'a str, Output = Version> {
    let numbers = version_number().separated_list1(tag("."));
    let suffixes = version_suffix().separated_list(tag("_"));
    let rev = version_number().preceded_by(tag("-r"));

    numbers
        .and(opt(r#if(|c: &char| c.is_ascii_alphabetic())))
        .and(opt(suffixes.preceded_by(tag("_"))))
        .and(opt(rev))
        .map(|(((numbers, letter), suffixes), rev)| Version {
            numbers,
            letter,
            suffixes: suffixes.unwrap_or(Vec::new()),
            rev,
        })
}

pub fn category<'a>() -> impl Parser<&'a str, Output = Category> {
    let start = r#if(|c: &char| c.is_ascii_alphanumeric() || *c == '_');
    let rest = take_while(r#if(|c: &char| {
        c.is_ascii_alphanumeric() || "+_.-".contains(*c)
    }));

    start
        .and(rest)
        .recognize()
        .map(|output: &str| Category(output.to_string()))
}

pub fn name<'a>() -> impl Parser<&'a str, Output = Name> {
    let start = r#if(|c: &char| c.is_ascii_alphanumeric() || *c == '_');
    let rest = take_while(
        r#if(|c: &char| c.is_ascii_alphanumeric() || "_+".contains(*c)).or(one_of("-".chars())
            .and_not(
                version()
                    .preceded_by(tag("-"))
                    .followed_by(not(r#if(|c: &char| {
                        c.is_ascii_alphanumeric() || "_+-".contains(*c)
                    }))),
            )),
    );

    start
        .and(rest)
        .recognize()
        .map(|output: &str| Name(output.to_string()))
}

pub fn slot_operator<'a>() -> impl Parser<&'a str, Output = SlotOperator> {
    tag("=")
        .map(|_| SlotOperator::Eq)
        .or(tag("*").map(|_| SlotOperator::Star))
}

pub fn slotname<'a>() -> impl Parser<&'a str, Output = SlotName> {
    let start = r#if(|c: &char| c.is_ascii_alphanumeric() || *c == '_');
    let rest = take_while(r#if(|c: &char| {
        c.is_ascii_alphanumeric() || "+_.-".contains(*c)
    }));

    start
        .and(rest)
        .recognize()
        .map(|output: &str| SlotName(output.to_string()))
}

pub fn slot<'a>() -> impl Parser<&'a str, Output = Slot> {
    slotname()
        .and(opt(slotname().preceded_by(tag("/"))))
        .and(opt(slot_operator()))
        .map(|((slot, sub), operator)| Slot {
            slot,
            sub,
            operator,
        })
}

pub fn usedep_negate<'a>() -> impl Parser<&'a str, Output = UseDepNegate> {
    tag("-")
        .map(|_| UseDepNegate::Minus)
        .or(tag("!").map(|_| UseDepNegate::Exclamation))
}

pub fn usedep_sign<'a>() -> impl Parser<&'a str, Output = UseDepSign> {
    tag("(-)")
        .map(|_| UseDepSign::Disabled)
        .or(tag("(+)").map(|_| UseDepSign::Enabled))
}

pub fn usedep_condition<'a>() -> impl Parser<&'a str, Output = UseDepCondition> {
    tag("=")
        .map(|_| UseDepCondition::Eq)
        .or(tag("?").map(|_| UseDepCondition::Question))
}

pub fn usedep<'a>() -> impl Parser<&'a str, Output = UseDep> {
    opt(usedep_negate())
        .and(useflag())
        .and(opt(usedep_sign()))
        .and(opt(usedep_condition()))
        .map(|(((negate, flag), sign), condition)| UseDep {
            negate,
            flag,
            sign,
            condition,
        })
}

pub fn atom<'a>() -> impl Parser<&'a str, Output = Atom> {
    opt(blocker())
        .and(opt(version_operator()))
        .and(category())
        .and(name().preceded_by(tag("/")))
        .and(opt(version().preceded_by(tag("-"))))
        .and(opt(slot().preceded_by(tag(":"))))
        .and(opt(usedep()
            .separated_list(tag(","))
            .delimited_by(tag("["), tag("]"))))
        .map(
            |((((((blocker, version_operator), category), name), version), slot), usedeps)| Atom {
                blocker,
                version_operator,
                category,
                name,
                version,
                slot,
                usedeps: usedeps.unwrap_or(Vec::new()),
            },
        )
}

#[cfg(test)]
mod test {

    use mon::input::InputIter;

    use super::*;

    #[test]
    fn test_version() {
        let it = InputIter::new("1.0.0v_alpha1_beta1-r1");

        version().check_finished(it).unwrap();
    }

    #[test]
    fn test_name() {
        let it = InputIter::new("foo-1-bar-1.0.0");

        match name().parse(it) {
            Ok((_, output)) => {
                assert_eq!(output.0.as_str(), "foo-1-bar");
            }
            _ => unreachable!(),
        }
    }

    #[test]
    fn test_atom() {
        let it = InputIter::new(
            "!!>=cat/pkg-1-foo-1.0.0v_alpha1_p20250326-r1:primary/sub=[!a(+),-b(-)=,c?]",
        );

        atom().check_finished(it).unwrap();
    }

    #[test]
    fn test_cursed_atom() {
        let it = InputIter::new(
            "!!>=_.+-0-/_-test-T-123_beta1_-4a-6+-_p--1.00.02b_alpha3_pre_p4-r5:slot/_-+6-9=[test(+),test(-)]",
        );

        atom().check_finished(it).unwrap();
    }

    #[test]
    fn test_atom_with_star_in_non_empty_slot() {
        let it = InputIter::new("foo/bar-1.0.0:*/subslot");

        assert!(atom().check_finished(it).is_err());
    }
}