/*
 * This file is part of Datafu
 * Copyright (C) 2021  Soni L.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

use std::borrow::Borrow;
use std::collections::BTreeMap;

use crate::PatternTypes;
use crate::RefOwn;
use crate::Predicate;
use crate::errors::PatternError;
use crate::parser::parse;
use crate::vm::Matcher;
use crate::vm::PatternConstants;
use crate::vm::MAX_CALLS;

pub struct Pattern<T: PatternTypes> {
    consts: PatternConstants<T>,
}

impl<T: PatternTypes> Pattern<T> {
    /// Compiles the input into a pattern.
    pub fn compile<'s, P, O>(
        input: &'s str,
        preds: Option<BTreeMap<P, Box<Predicate<T>>>>,
        objs: Option<BTreeMap<O, T::Own>>
    ) -> Result<Self, PatternError<'s>>
        where
            P: Borrow<str> + Ord,
            O: Borrow<str> + Ord,
    {
        Ok(Self {
            consts: parse(input, preds, objs)?
        })
    }

    pub fn attempt_match<'a, 'b>(
        &'a self,
        value: impl Into<RefOwn<'b, T::Ref, T::Own>>
    ) -> Matcher<'a, 'b, T> {
        Matcher::new(value.into(), &self.consts, self.consts.protos.len() - 1, MAX_CALLS).ok().expect("datafu internal error: MAX_CALLS must not be 0")
    }
}