use chrono::NaiveDate;

use crate::data::{CandidateEligibility, DailyMarketSnapshot, PriceField};
use crate::portfolio::Position;
use crate::risk_control::ChinaAShareRiskControl;

#[derive(Debug, Clone)]
pub struct RuleCheck {
    pub allowed: bool,
    pub reason: Option<String>,
}

impl RuleCheck {
    pub fn allow() -> Self {
        Self {
            allowed: true,
            reason: None,
        }
    }

    pub fn reject(reason: impl Into<String>) -> Self {
        Self {
            allowed: false,
            reason: Some(reason.into()),
        }
    }
}

pub trait EquityRuleHooks {
    fn can_buy(
        &self,
        execution_date: NaiveDate,
        snapshot: &DailyMarketSnapshot,
        candidate: &CandidateEligibility,
        price_field: PriceField,
    ) -> RuleCheck;

    fn can_sell(
        &self,
        execution_date: NaiveDate,
        snapshot: &DailyMarketSnapshot,
        candidate: &CandidateEligibility,
        position: &Position,
        price_field: PriceField,
    ) -> RuleCheck;
}

#[derive(Debug, Clone, Default)]
pub struct ChinaEquityRuleHooks;

impl EquityRuleHooks for ChinaEquityRuleHooks {
    fn can_buy(
        &self,
        _execution_date: NaiveDate,
        snapshot: &DailyMarketSnapshot,
        candidate: &CandidateEligibility,
        price_field: PriceField,
    ) -> RuleCheck {
        if let Some(reason) = ChinaAShareRiskControl::buy_rejection_reason(
            _execution_date,
            candidate,
            snapshot,
            None,
            ChinaAShareRiskControl::buy_check_price(snapshot, price_field),
        ) {
            return RuleCheck::reject(reason);
        }

        RuleCheck::allow()
    }

    fn can_sell(
        &self,
        execution_date: NaiveDate,
        snapshot: &DailyMarketSnapshot,
        candidate: &CandidateEligibility,
        position: &Position,
        price_field: PriceField,
    ) -> RuleCheck {
        if let Some(reason) = ChinaAShareRiskControl::sell_rejection_reason(
            execution_date,
            candidate,
            snapshot,
            None,
            Some(position),
            ChinaAShareRiskControl::sell_check_price(snapshot, price_field),
        ) {
            return RuleCheck::reject(reason);
        }

        RuleCheck::allow()
    }
}