// Copyright 2021 Jeremy Wall
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::str::FromStr;

use abortable_parser::{
    ascii_digit, consume_all, discard, do_each, either, eoi, make_fn, must, not, optional, peek,
    repeat, separated, text_token, trap, until, Result, StrIter,
};
use num_rational::Ratio;

use crate::{
    unit::{Measure, Measure::*, Quantity, VolumeMeasure::*, WeightMeasure::*},
    Ingredient, Recipe, Step,
};

pub fn as_recipe(i: &str) -> std::result::Result<Recipe, String> {
    match recipe(StrIter::new(i)) {
        Result::Abort(e) | Result::Fail(e) => Err(format!("Parse Failure: {:?}", e)),
        Result::Incomplete(_) => Err(format!("Incomplete recipe can not parse")),
        Result::Complete(_, r) => Ok(r),
    }
}

make_fn!(
    pub recipe<StrIter, Recipe>,
    do_each!(
        title => title,
        _ => optional!(para_separator),
        desc => optional!(do_each!(
            _ => peek!(not!(step_prefix)),
            desc => description,
            (desc)
        )),
        _ => optional!(para_separator),
        steps => step_list,
        (Recipe::new(title, desc).with_steps(steps))
    )
);

make_fn!(
    pub title<StrIter, &str>,
    do_each!(
        _ => text_token!("title:"),
        _ => optional!(ws),
        title => until!(text_token!("\n")),
        _ => text_token!("\n"),
        (title)
    )
);

make_fn!(
    para_separator<StrIter, &str>,
    do_each!(
        _ => text_token!("\n"),
        _ => optional!(ws),
        _ => text_token!("\n"),
        ("")
    )
);

make_fn!(
    pub description<StrIter, &str>,
    until!(either!(
        discard!(para_separator),
        eoi,
    ))
);

make_fn!(
    pub step_prefix<StrIter, &str>,
    do_each!(
        _ => text_token!("step:"),
        _ => optional!(ws),
        _ => para_separator,
        ("")
    )
);

make_fn!(
    pub step<StrIter, Step>,
    do_each!(
        _ => step_prefix,
        ingredients => must!(ingredient_list),
        _ => para_separator,
        desc => description,
        _ => either!(discard!(para_separator), eoi),
        (Step::new(None, desc).with_ingredients(ingredients))
    )
);

make_fn!(
    pub step_list<StrIter, Vec<Step>>,
    do_each!(
        first_step => must!(step),
        rest => repeat!(step),
        ({
            let mut steps = vec![first_step];
            steps.extend(rest);
            steps
        })
    )
);

make_fn!(ws<StrIter, &str>,
    consume_all!(either!(
        text_token!(" "),
        text_token!("\t"),
        text_token!("\r")
    ))
);

make_fn!(nonzero<StrIter, ()>,
    peek!(not!(do_each!(
        n => consume_all!(text_token!("0")),
        _ => ws,
        (n)
    )))
);

make_fn!(num<StrIter, u32>,
    do_each!(
        _ => peek!(ascii_digit),
        n => consume_all!(ascii_digit),
        (u32::from_str(n).unwrap())
    )
);

make_fn!(
    pub ratio<StrIter, Ratio<u32>>,
    do_each!(
        // First we assert non-zero numerator
        //_ => nonzero,
        numer => num,
        _ => text_token!("/"),
        denom => num,
        (Ratio::new(numer, denom))
    )
);

make_fn!(unit<StrIter, &str>,
    do_each!(
        u => either!(
            text_token!("tsp"),
            text_token!("tbsp"),
            text_token!("floz"),
            text_token!("ml"),
            text_token!("ltr"),
            text_token!("lb"),
            text_token!("oz"),
            text_token!("cup"),
            text_token!("qrt"),
            text_token!("pint"),
            text_token!("pnt"),
            text_token!("gal"),
            text_token!("gal"),
            text_token!("cnt"),
            text_token!("g"),
            text_token!("gram")),
        (u))
);

make_fn!(
    pub quantity<StrIter, Quantity>,
     either!(
        do_each!(
            whole => num,
            _ => ws,
            frac => ratio,
            _ => ws,
            (Quantity::Whole(whole) + Quantity::Frac(frac))
        ),
        do_each!(
            frac => ratio,
            _ => ws,
            (Quantity::Frac(frac))
        ),
        do_each!(
            whole => num,
            _ => ws,
            (Quantity::whole(whole))
        )
    )
);

make_fn!(
    pub measure_parts<StrIter, (Quantity, Option<&str>)>,
    do_each!(
        qty => quantity,
        unit => optional!(do_each!(
            _ => ws,
            unit => unit,
            (unit)
        )),
        _ => ws,
        ((qty, unit))
    )
);

pub fn measure(i: StrIter) -> abortable_parser::Result<StrIter, Measure> {
    match measure_parts(i) {
        Result::Complete(i, (qty, unit)) => {
            return Result::Complete(
                i.clone(),
                match unit {
                    Some("tsp") => Volume(Tsp(qty)),
                    Some("tbsp") => Volume(Tbsp(qty)),
                    Some("floz") => Volume(Floz(qty)),
                    Some("ml") => Volume(ML(qty)),
                    Some("ltr") | Some("liter") => Volume(Ltr(qty)),
                    Some("cup") | Some("cp") => Volume(Cup(qty)),
                    Some("qrt") | Some("quart") => Volume(Qrt(qty)),
                    Some("pint") | Some("pnt") => Volume(Pint(qty)),
                    Some("cnt") | Some("count") => Count(qty),
                    Some("lb") => Weight(Pound(qty)),
                    Some("oz") => Weight(Oz(qty)),
                    Some("kg") => Weight(Kilogram(qty)),
                    Some("g") | Some("gram") => Weight(Gram(qty)),
                    Some(u) => {
                        return Result::Abort(abortable_parser::Error::new(
                            format!("Invalid Unit {}", u),
                            Box::new(i),
                        ))
                    }
                    None => Count(qty),
                },
            )
        }
        Result::Fail(e) => {
            return Result::Fail(e);
        }
        Result::Abort(e) => {
            return Result::Abort(e);
        }
        Result::Incomplete(i) => return Result::Incomplete(i),
    }
}

make_fn!(
    pub ingredient_name<StrIter, &str>,
    do_each!(
        name => until!(either!(
            discard!(text_token!("\n")),
            eoi,
            discard!(text_token!("(")))),
        (name.trim())
    )
);

make_fn!(
    ingredient_modifier<StrIter, &str>,
    do_each!(
        _ => text_token!("("),
        modifier => until!(text_token!(")")),
        _ => text_token!(")"),
        (modifier)
    )
);

make_fn!(
    pub ingredient<StrIter, Ingredient>,
    do_each!(
        _ => optional!(ws),
        measure => measure,
        name => ingredient_name,
        modifier => optional!(ingredient_modifier),
        _ => optional!(ws),
        (Ingredient::new(name, modifier.map(|s| s.to_owned()), measure, ""))
    )
);

make_fn!(
    pub ingredient_list<StrIter, Vec<Ingredient>>,
    separated!(text_token!("\n"), ingredient)
);