//! This module contains specific filters that operate on log files.
//!
//! This is the "base unit", as each file corresponds to one log. Filters on other items (such as
//! players) have to be lifted into log filters first.
use super::{
    super::{EarlyLogResult, FightOutcome, LogResult},
    Filter, Inclusion,
};

use std::collections::HashSet;

use evtclib::{Encounter, GameMode};

use chrono::{DateTime, Datelike, Utc, Weekday};

/// Filter trait used for filters that operate on complete logs.
pub trait LogFilter = Filter<EarlyLogResult, LogResult>;

#[derive(Debug, Clone)]
struct BossFilter(HashSet<Encounter>);

impl Filter<EarlyLogResult, LogResult> for BossFilter {
    fn filter_early(&self, early_log: &EarlyLogResult) -> Inclusion {
        let boss = Encounter::from_header_id(early_log.evtc.header.combat_id);
        boss.map(|b| self.0.contains(&b).into())
            .unwrap_or(Inclusion::Exclude)
    }

    fn filter(&self, log: &LogResult) -> bool {
        log.encounter.map(|b| self.0.contains(&b)).unwrap_or(false)
    }
}

/// A `LogFilter` that only accepts logs with one of the given bosses.
pub fn encounter(bosses: HashSet<Encounter>) -> Box<dyn LogFilter> {
    Box::new(BossFilter(bosses))
}

#[derive(Debug, Clone)]
struct GameModeFilter(HashSet<GameMode>);

impl Filter<EarlyLogResult, LogResult> for GameModeFilter {
    fn filter_early(&self, early_log: &EarlyLogResult) -> Inclusion {
        let encounter_id = early_log.evtc.header.combat_id;
        // Special WvW encounter
        const GENERIC_ENCOUNTER_ID: u16 = 1;
        let mode = if encounter_id == GENERIC_ENCOUNTER_ID {
            Some(GameMode::WvW)
        } else {
            Encounter::from_header_id(encounter_id).map(Encounter::game_mode)
        };
        mode.map(|m| self.0.contains(&m).into())
            .unwrap_or(Inclusion::Exclude)
    }

    fn filter(&self, log: &LogResult) -> bool {
        log.game_mode.map(|m| self.0.contains(&m)).unwrap_or(false)
    }
}

/// A [`LogFilter`] that only accepts logs with the given game mode.
pub fn game_mode(game_modes: HashSet<GameMode>) -> Box<dyn LogFilter> {
    Box::new(GameModeFilter(game_modes))
}

#[derive(Debug, Clone)]
struct OutcomeFilter(HashSet<FightOutcome>);

impl Filter<EarlyLogResult, LogResult> for OutcomeFilter {
    fn filter(&self, log: &LogResult) -> bool {
        self.0.contains(&log.outcome)
    }
}

/// A `LogFilter` that only accepts logs with one of the given outcomes.
///
/// See also [`success`][success] and [`wipe`][wipe].
pub fn outcome(outcomes: HashSet<FightOutcome>) -> Box<dyn LogFilter> {
    Box::new(OutcomeFilter(outcomes))
}

/// A `LogFilter` that only accepts successful logs.
///
/// See also [`outcome`][outcome] and [`wipe`][wipe].
pub fn success() -> Box<dyn LogFilter> {
    let mut outcomes = HashSet::new();
    outcomes.insert(FightOutcome::Success);
    outcome(outcomes)
}

/// A `LogFilter` that only accepts failed logs.
///
/// See also [`outcome`][outcome] and [`success`][wipe].
pub fn wipe() -> Box<dyn LogFilter> {
    let mut outcomes = HashSet::new();
    outcomes.insert(FightOutcome::Wipe);
    outcome(outcomes)
}

#[derive(Debug, Clone)]
struct WeekdayFilter(HashSet<Weekday>);

impl Filter<EarlyLogResult, LogResult> for WeekdayFilter {
    fn filter(&self, log: &LogResult) -> bool {
        self.0.contains(&log.time.weekday())
    }
}

/// A `LogFilter` that only accepts logs if they were done on one of the given weekdays.
pub fn weekday(weekdays: HashSet<Weekday>) -> Box<dyn LogFilter> {
    Box::new(WeekdayFilter(weekdays))
}

#[derive(Debug, Clone)]
struct TimeFilter(Option<DateTime<Utc>>, Option<DateTime<Utc>>);

impl Filter<EarlyLogResult, LogResult> for TimeFilter {
    fn filter(&self, log: &LogResult) -> bool {
        time_is_between(log.time, self.0, self.1)
    }
}

/// Check if the given time is after `after` but before `before`.
///
/// If one of the bounds is `None`, the time is always in bounds w.r.t. that bound.
fn time_is_between(
    time: DateTime<Utc>,
    after: Option<DateTime<Utc>>,
    before: Option<DateTime<Utc>>,
) -> bool {
    let after_ok = match after {
        Some(after) => after <= time,
        None => true,
    };
    let before_ok = match before {
        Some(before) => before >= time,
        None => true,
    };

    after_ok && before_ok
}

/// A `LogFilter` that only accepts logs in the given time frame.
///
/// Compared to [`-time`][super::values::time], this filter ignores the file name. This can result
/// in more accurate results if you renamed logs, but if also leads to a worse runtime.
pub fn log_time(lower: Option<DateTime<Utc>>, upper: Option<DateTime<Utc>>) -> Box<dyn LogFilter> {
    Box::new(TimeFilter(lower, upper))
}

/// Only include logs after the given date, but ignore the file name for date calculations.
pub fn log_after(when: DateTime<Utc>) -> Box<dyn LogFilter> {
    log_time(Some(when), None)
}

/// Only include logs before the given date, but ignore the file name for date calculations.
pub fn log_before(when: DateTime<Utc>) -> Box<dyn LogFilter> {
    log_time(None, Some(when))
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
struct CmFilter;

impl Filter<EarlyLogResult, LogResult> for CmFilter {
    fn filter(&self, log: &LogResult) -> bool {
        log.is_cm
    }
}

/// A filter that only includes logs that had the Challenge Mote turned on.
pub fn challenge_mote() -> Box<dyn LogFilter> {
    Box::new(CmFilter)
}

#[cfg(test)]
mod tests {
    use super::*;
    use chrono::TimeZone;

    #[test]
    fn test_time_is_between() {
        assert!(time_is_between(
            Utc.ymd(1955, 11, 5).and_hms(6, 15, 0),
            None,
            None,
        ));
        assert!(time_is_between(
            Utc.ymd(1955, 11, 5).and_hms(6, 15, 0),
            Some(Utc.ymd(1955, 11, 5).and_hms(5, 0, 0)),
            None,
        ));
        assert!(time_is_between(
            Utc.ymd(1955, 11, 5).and_hms(6, 15, 0),
            None,
            Some(Utc.ymd(1955, 11, 5).and_hms(7, 0, 0)),
        ));
        assert!(time_is_between(
            Utc.ymd(1955, 11, 5).and_hms(6, 15, 0),
            Some(Utc.ymd(1955, 11, 5).and_hms(5, 0, 0)),
            Some(Utc.ymd(1955, 11, 5).and_hms(7, 0, 0)),
        ));

        assert!(!time_is_between(
            Utc.ymd(1955, 11, 5).and_hms(6, 15, 0),
            Some(Utc.ymd(1955, 11, 5).and_hms(7, 0, 0)),
            None,
        ));
        assert!(!time_is_between(
            Utc.ymd(1955, 11, 5).and_hms(6, 15, 0),
            None,
            Some(Utc.ymd(1955, 11, 5).and_hms(5, 0, 0)),
        ));
        assert!(!time_is_between(
            Utc.ymd(1955, 11, 5).and_hms(6, 15, 0),
            Some(Utc.ymd(1955, 11, 5).and_hms(5, 0, 0)),
            Some(Utc.ymd(1955, 11, 5).and_hms(6, 0, 0)),
        ));
    }
}