use super::GeneralName;

use crate::error::{X509Error, X509Result};

use crate::extensions::parse_generalname;

use asn1_rs::FromDer;

use der_parser::der::*;

use der_parser::error::BerError;

use nom::combinator::{all_consuming, complete, map, opt};

use nom::multi::many1;

use nom::{Err, IResult};

#[derive(Clone, Debug, PartialEq)]

pub struct NameConstraints<'a> {

    pub permitted_subtrees: Option<Vec<GeneralSubtree<'a>>>,

    pub excluded_subtrees: Option<Vec<GeneralSubtree<'a>>>,

}

impl<'a> FromDer<'a, X509Error> for NameConstraints<'a> {

    fn from_der(i: &'a [u8]) -> X509Result<'a, Self> {

        parse_nameconstraints(i).map_err(Err::convert)

    }

}

#[derive(Clone, Debug, PartialEq)]

/// Represents the structure used in the name constraints extensions.

/// The fields minimum and maximum are not supported (openssl also has no support).

pub struct GeneralSubtree<'a> {

    pub base: GeneralName<'a>,

    // minimum: u32,

    // maximum: Option<u32>,

}

pub(crate) fn parse_nameconstraints(i: &[u8]) -> IResult<&[u8], NameConstraints, BerError> {

    fn parse_subtree(i: &[u8]) -> IResult<&[u8], GeneralSubtree, BerError> {

        parse_der_sequence_defined_g(|input, _| {

            map(parse_generalname, |base| GeneralSubtree { base })(input)

        })(i)

    }

    fn parse_subtrees(i: &[u8]) -> IResult<&[u8], Vec<GeneralSubtree>, BerError> {

        all_consuming(many1(complete(parse_subtree)))(i)

    }

    let (ret, named_constraints) = parse_der_sequence_defined_g(|input, _| {

        let (rem, permitted_subtrees) =

            opt(complete(parse_der_tagged_explicit_g(0, |input, _| {

                parse_subtrees(input)

            })))(input)?;

        let (rem, excluded_subtrees) =

            opt(complete(parse_der_tagged_explicit_g(1, |input, _| {

                parse_subtrees(input)

            })))(rem)?;

        let named_constraints = NameConstraints {

            permitted_subtrees,

            excluded_subtrees,

        };

        Ok((rem, named_constraints))

    })(i)?;

    Ok((ret, named_constraints))

}