//! Completed, same-session minute events. These bars never become execution quotes.
use crate::{
    daily_patterns::{PatternResult, PatternSpec},
    factor_events::{Expr, Frame},
};
use chrono::{FixedOffset, NaiveDateTime, NaiveTime, TimeZone, Timelike};
use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use std::collections::BTreeMap;
use std::sync::Arc;

pub const CONTRACT: &str = "fidc_completed_session_events_v1";
pub const EVENTS: &[&str] = &[
    "PRICE_CROSS_VWAP_UP",
    "PRICE_CROSS_VWAP_DOWN",
    "INTRADAY_HIGH_BREAKOUT",
    "INTRADAY_LOW_BREAKDOWN",
    "OPENING_RANGE_BREAKOUT_UP",
    "OPENING_RANGE_BREAKOUT_DOWN",
    "INTRADAY_VOLUME_SPIKE",
    "MORNING_HIGH_BREAKOUT",
    "MORNING_LOW_BREAKDOWN",
    "AFTERNOON_MOMENTUM_UP",
    "AFTERNOON_MOMENTUM_DOWN",
    "LATE_SESSION_STRENGTH",
    "LATE_SESSION_WEAKNESS",
];

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct MinuteBar {
    pub symbol: String,
    pub timestamp: NaiveDateTime,
    pub available_at: NaiveDateTime,
    pub open: f64,
    pub high: f64,
    pub low: f64,
    pub close: f64,
    pub volume: f64,
    pub amount: f64,
}
pub type BarStore = Arc<BTreeMap<(chrono::NaiveDate, String), Vec<MinuteBar>>>;
pub fn bar_store(bars: Vec<MinuteBar>) -> Result<BarStore, String> {
    let mut groups = BTreeMap::<(chrono::NaiveDate, String), Vec<MinuteBar>>::new();
    for bar in bars {
        groups
            .entry((bar.timestamp.date(), bar.symbol.clone()))
            .or_default()
            .push(bar);
    }
    for rows in groups.values_mut() {
        rows.sort_by_key(|r| r.timestamp);
        if rows
            .windows(2)
            .any(|pair| pair[0].timestamp == pair[1].timestamp)
        {
            return Err("duplicate_completed_minute_bar".into());
        }
    }
    Ok(Arc::new(groups))
}
fn f(name: &str) -> Expr {
    Expr::Field { name: name.into() }
}
fn n(value: f64) -> Expr {
    Expr::Number { value }
}
fn op(name: &str, args: Vec<Expr>, window: Option<usize>) -> Expr {
    Expr::Operator {
        name: name.into(),
        args,
        window,
    }
}
fn time(minutes: u32) -> NaiveTime {
    NaiveTime::from_hms_opt(minutes / 60, minutes % 60, 0).unwrap()
}

pub fn is_regular_label(t: NaiveTime) -> bool {
    t.second() == 0 && (time(570) <= t && t <= time(690) || time(780) < t && t <= time(900))
}

pub fn expression(event: &str, p: &BTreeMap<String, Value>) -> Result<Expr, String> {
    let cross = |up: bool, a: Expr, b: Expr| {
        op(
            if up { "CROSS_ABOVE" } else { "CROSS_BELOW" },
            vec![a, b],
            None,
        )
    };
    Ok(match event {
        "PRICE_CROSS_VWAP_UP" => cross(true, f("close"), f("session_vwap")),
        "PRICE_CROSS_VWAP_DOWN" => cross(false, f("close"), f("session_vwap")),
        "INTRADAY_HIGH_BREAKOUT" => op(
            "GT",
            vec![
                f("close"),
                op("LAG", vec![op("CUMMAX", vec![f("high")], None)], Some(1)),
            ],
            None,
        ),
        "INTRADAY_LOW_BREAKDOWN" => op(
            "LT",
            vec![
                f("close"),
                op("LAG", vec![op("CUMMIN", vec![f("low")], None)], Some(1)),
            ],
            None,
        ),
        "OPENING_RANGE_BREAKOUT_UP" => cross(true, f("close"), f("opening_high")),
        "OPENING_RANGE_BREAKOUT_DOWN" => cross(false, f("close"), f("opening_low")),
        "MORNING_HIGH_BREAKOUT" => cross(true, f("close"), f("morning_high")),
        "MORNING_LOW_BREAKDOWN" => cross(false, f("close"), f("morning_low")),
        "AFTERNOON_MOMENTUM_UP" => cross(true, f("afternoon_return"), n(0.)),
        "AFTERNOON_MOMENTUM_DOWN" => cross(false, f("afternoon_return"), n(0.)),
        "LATE_SESSION_STRENGTH" => cross(true, f("late_return"), n(0.)),
        "LATE_SESSION_WEAKNESS" => cross(false, f("late_return"), n(0.)),
        "INTRADAY_VOLUME_SPIKE" => op(
            "GTE",
            vec![
                f("volume"),
                op(
                    "MUL",
                    vec![
                        op(
                            "LAG",
                            vec![op(
                                "ROLLING_MEAN",
                                vec![f("volume")],
                                Some(p["volume_window"].as_u64().unwrap() as usize),
                            )],
                            Some(1),
                        ),
                        n(p["volume_multiple"].as_f64().unwrap()),
                    ],
                    None,
                ),
            ],
            None,
        ),
        _ => return Err("session_event_not_registered".into()),
    })
}

pub fn evaluate(
    spec: &PatternSpec,
    symbol: &str,
    bars: &[MinuteBar],
    decision: NaiveDateTime,
) -> Result<PatternResult, String> {
    let mut result = PatternResult {
        symbol: symbol.into(),
        name: None,
        matched: false,
        score: None,
        checks: vec![],
        values: json!({}),
        anchor: Value::Null,
        exclusion: None,
    };
    if bars.is_empty() {
        return Err(format!(
            "session_source_missing: {symbol} {}",
            decision.date()
        ));
    }
    let visible = bars
        .iter()
        .filter(|b| {
            b.timestamp.date() == decision.date()
                && b.timestamp < decision
                && b.available_at <= decision
        })
        .collect::<Vec<_>>();
    if visible.is_empty() {
        result.exclusion = Some(json!({"reason":"session_before_first_completed_bar"}));
        return Ok(result);
    }
    let last = visible.last().unwrap().timestamp;
    let expected = (570..=690)
        .chain(781..=900)
        .map(|m| decision.date().and_time(time(m)))
        .filter(|t| *t < decision)
        .last();
    if expected != Some(last) {
        return Err(format!(
            "session_latest_bar_missing: {symbol} expected={expected:?} actual={last}"
        ));
    }
    let mut indexed = BTreeMap::new();
    for b in &visible {
        if b.symbol != symbol
            || !is_regular_label(b.timestamp.time())
            || b.available_at < b.timestamp
            || [b.open, b.high, b.low, b.close, b.volume, b.amount]
                .iter()
                .any(|v| !v.is_finite())
            || b.low <= 0.
            || b.open <= 0.
            || b.close <= 0.
            || b.high < b.open.max(b.close)
            || b.low > b.open.min(b.close)
            || b.volume < 0.
            || b.amount < 0.
            || indexed.insert(b.timestamp, b).is_some()
        {
            return Err(format!("session_bar_invalid: {symbol} {}", b.timestamp));
        }
    }
    for minute in (571..=690).chain(781..=900) {
        let stamp = decision.date().and_time(time(minute));
        if stamp <= last && !indexed.contains_key(&stamp) {
            return Err(format!(
                "session_bar_gap: {symbol} {stamp}; no filling or calendar compression"
            ));
        }
    }
    let opening_end = time(570 + spec.n("opening_minutes") as u32);
    let (mut volume, mut amount) = (0., 0.);
    let (mut opening_high, mut opening_low) = (f64::NEG_INFINITY, f64::INFINITY);
    let (mut morning_high, mut morning_low) = (f64::NEG_INFINITY, f64::INFINITY);
    let (mut morning_close, mut late_close) = (None, None);
    let mut fields: BTreeMap<String, Vec<Option<f64>>> = [
        "open",
        "high",
        "low",
        "close",
        "volume",
        "amount",
        "session_vwap",
        "opening_high",
        "opening_low",
        "morning_high",
        "morning_low",
        "afternoon_return",
        "late_return",
    ]
    .into_iter()
    .map(|s| (s.into(), vec![]))
    .collect();
    let mut timestamps = vec![];
    let mut available_at = vec![];
    let zone = FixedOffset::east_opt(8 * 3600).unwrap();
    for b in indexed.values() {
        let t = b.timestamp.time();
        volume += b.volume;
        amount += b.amount;
        if t <= opening_end {
            opening_high = opening_high.max(b.high);
            opening_low = opening_low.min(b.low);
        }
        if t <= time(690) {
            morning_high = morning_high.max(b.high);
            morning_low = morning_low.min(b.low);
        }
        if t == time(690) {
            morning_close = Some(b.close);
        }
        if t == time(870) {
            late_close = Some(b.close);
        }
        for (name, value) in [
            ("open", Some(b.open)),
            ("high", Some(b.high)),
            ("low", Some(b.low)),
            ("close", Some(b.close)),
            ("volume", Some(b.volume)),
            ("amount", Some(b.amount)),
            ("session_vwap", (volume > 0.).then_some(amount / volume)),
            ("opening_high", (t >= opening_end).then_some(opening_high)),
            ("opening_low", (t >= opening_end).then_some(opening_low)),
            ("morning_high", (t >= time(690)).then_some(morning_high)),
            ("morning_low", (t >= time(690)).then_some(morning_low)),
            ("afternoon_return", morning_close.map(|v| b.close / v - 1.)),
            ("late_return", late_close.map(|v| b.close / v - 1.)),
        ] {
            fields.get_mut(name).unwrap().push(value);
        }
        timestamps.push(zone.from_local_datetime(&b.timestamp).single().unwrap());
        available_at.push(zone.from_local_datetime(&b.available_at).single().unwrap());
    }
    let frame = Frame {
        symbol: symbol.into(),
        frequency: "1m".into(),
        decision_at: zone.from_local_datetime(&decision).single().unwrap(),
        timestamps,
        available_at,
        fields,
    };
    let event = spec
        .session_event
        .as_deref()
        .ok_or("session_event_id_required")?;
    let values = crate::factor_events::evaluate(&expression(event, &spec.parameters)?, &frame)?;
    let latest = values.values.last().copied().flatten();
    result.score = latest;
    result.matched = latest == Some(1.);
    result.values = json!({"session_event":event,"session_contract":CONTRACT,"expression":values,"signal_bar_end":last,"decision_at":decision,"bars":visible.len(),"bar_times":frame.timestamps.iter().map(|t|t.format("%Y-%m-%dT%H:%M:%S").to_string()).collect::<Vec<_>>(),"close":visible.last().unwrap().close,"session_return":visible.last().unwrap().close/visible.first().unwrap().open-1.,"price_policy":"same_session_raw_ohlcv"});
    if latest.is_none() {
        result.exclusion = Some(json!({"reason":"session_warmup_or_undefined"}));
    } else {
        result.checks.push(json!({"label":"分钟事件","actual":latest,"operator":"==","threshold":1,"passed":result.matched}));
    }
    Ok(result)
}

#[cfg(test)]
mod tests {
    use super::*;
    fn spec(event: &str) -> PatternSpec {
        serde_json::from_value::<PatternSpec>(
            json!({"template":"session_event","session_event":event,"parameters":{}}),
        )
        .unwrap()
        .validate()
        .unwrap()
    }
    fn bars() -> Vec<MinuteBar> {
        let date = chrono::NaiveDate::from_ymd_opt(2026, 9, 8).unwrap();
        (570..=690)
            .chain(781..=900)
            .enumerate()
            .map(|(i, m)| {
                let timestamp = date.and_time(time(m));
                let price = 100. + (i % 17) as f64 / 10.;
                let volume = if i % 39 == 0 { 1000. } else { 100. };
                MinuteBar {
                    symbol: "300395.SZ".into(),
                    timestamp,
                    available_at: timestamp,
                    open: price,
                    high: price + 0.1,
                    low: price - 0.1,
                    close: price,
                    volume,
                    amount: volume * price,
                }
            })
            .collect()
    }
    #[test]
    fn all_thirteen_events_return_native_boolean_series() {
        let bars = bars();
        let decision = "2026-09-08T15:00:01".parse().unwrap();
        for event in EVENTS {
            let value = evaluate(&spec(event), "300395.SZ", &bars, decision).unwrap();
            assert!(value.score.is_some(), "{event}");
            assert_eq!(value.values["expression"]["value_type"], "boolean");
        }
    }
    #[test]
    fn decision_uses_the_previous_completed_label_and_future_prices_do_not_rewrite() {
        let mut bars = bars();
        let decision = "2026-09-08T10:02:00".parse().unwrap();
        for event in EVENTS {
            let before = evaluate(&spec(event), "300395.SZ", &bars, decision).unwrap();
            for bar in &mut bars {
                if bar.timestamp >= decision {
                    bar.open = 1000.;
                    bar.close = 1000.;
                    bar.high = 1001.;
                    bar.low = 999.;
                }
            }
            let after = evaluate(&spec(event), "300395.SZ", &bars, decision).unwrap();
            assert_eq!(before.values, after.values);
            assert_eq!(after.values["signal_bar_end"], "2026-09-08T10:01:00");
        }
    }
    #[test]
    fn gaps_and_stale_last_bars_do_not_become_false_or_repeated_signals() {
        let mut values = bars();
        let decision = "2026-09-08T10:02:00".parse().unwrap();
        values.retain(|r| r.timestamp.time() != time(600));
        assert!(evaluate(&spec(EVENTS[0]), "300395.SZ", &values, decision)
            .unwrap_err()
            .contains("session_bar_gap"));
        let stale = bars()
            .into_iter()
            .filter(|r| r.timestamp.time() < time(601))
            .collect::<Vec<_>>();
        assert!(evaluate(&spec(EVENTS[0]), "300395.SZ", &stale, decision)
            .unwrap_err()
            .contains("latest_bar_missing"));
    }
    #[test]
    fn opening_range_is_unavailable_before_the_range_has_completed() {
        let value = evaluate(
            &spec("OPENING_RANGE_BREAKOUT_UP"),
            "300395.SZ",
            &bars(),
            "2026-09-08T09:59:01".parse().unwrap(),
        )
        .unwrap();
        assert_eq!(value.score, None);
        assert!(!value.matched);
    }
}