// SPDX-FileCopyrightText: 2023 Aravinth Manivannan <realaravinth@batsense.net>
//
// SPDX-License-Identifier: AGPL-3.0-or-later

use std::collections::HashMap;
use std::rc::Rc;

use rust_decimal::prelude::*;
use rust_decimal_macros::dec;

use crate::actor::*;
use crate::purchase::*;

// key is a string for getting Eq and PartialEq w object safety
pub type ShareHashMap = HashMap<String, (Rc<dyn Actor>, Decimal)>;

/*
 * SPLITTING STRATEGIES:
 *  Unequal: Each actor's split is specified in specific amounts
 *  Shares: Each actor's split is specified in specific percentage
 *  Equal: Each actor's split is computed by splitting total expense among all participating actors
 */
#[derive(Clone)]
pub enum SplitStrategy {
    Unequal(ShareHashMap),
    Shares(ShareHashMap),
    Equal,
}

impl SplitStrategy {
    pub(crate) fn validate(&self, purchase: &dyn Purchasable) -> bool {
        match self {
            SplitStrategy::Unequal(shares) => {
                let mut total = dec!(0.00);
                for (_actor_str, (_actor_obj, share)) in shares.iter() {
                    total += share;
                }

                let cost = purchase.cost();
                println!("Unequal sharing: expected {cost} got {total}");
                total == cost
            }
            SplitStrategy::Shares(shares) => {
                let mut total = dec!(0.00);
                let cost = purchase.cost();
                let mut total_shares = dec!(0.00);
                for (_actor_str, (_actor_obj, share)) in shares.iter() {
                    total_shares += share;
                    total += cost * share;
                    println!("Shares: {:?}, total: {total_shares}", share);
                }

                println!("Unequal sharing: expected shares 1 got {total_shares}");
                println!("Unequal sharing: expected {cost} got {total}");
                total_shares == dec!(1.00) && total == cost
            }
            SplitStrategy::Equal => true,
        }
    }
}