initial work on comparison based filters

This enables filters such as
    -time > 2020-01-01
    -time < 2020-02-03
    ...
for time and duration, and later possibly also for more things (such as
a COUNT(...) construct).

This work tries to integrate them into the existing filter system as
seamless as possible, by providing a Comparator which implements
LogFilter.

The "type checking" is done at parse time, so nonsensical comparisons
like -time > 12s flat out give a parse error. This however might be
changed to a more dynamic system with run-time type checking, in which
case we could do away with the type parameter on Producer and simply
work with a generic Value. The comparator would then return an error if
two non-identical types would be compared.

Note that the system does not support arithmetic expressions, only
simple comparisons to constant values.

6 files changed, 195 insertions, 4 deletions

diff --git a/src/fexpr/grammar.lalrpop b/src/fexpr/grammar.lalrpop
index 45f4fde..c2df097 100644
--- a/src/fexpr/grammar.lalrpop
+++ b/src/fexpr/grammar.lalrpop
@@ -4,12 +4,15 @@ use super::{
     FightOutcome,
     filters,
     PlayerClass,
+
+    DateProducer,
+    DurationProducer,
 };
 use evtclib::Boss;
 use std::collections::HashSet;
 use lalrpop_util::ParseError;
 
-use chrono::{DateTime, Local, TimeZone, Utc, Weekday};
+use chrono::{DateTime, Local, TimeZone, Utc, Weekday, Duration};
 use regex::{Regex, RegexBuilder};
 
 grammar;
@@ -68,6 +71,9 @@ LogPredicate: Box<dyn filters::log::LogFilter> = {
     "any" "(" "player" ":" <PlayerFilter> ")" => filters::player::any(<>),
     "exists" "(" "player" ":" <PlayerFilter> ")" => filters::player::any(<>),
 
+    <Comparison<DateProducer>>,
+    <Comparison<DurationProducer>>,
+
     "(" <LogFilter> ")",
 }
 
@@ -175,6 +181,22 @@ Date: DateTime<Utc> = {
         .map(|d| d.with_timezone(&Utc)),
 }
 
+Duration: Duration = {
+    duration => Duration::seconds(<>[..<>.len() - 1].parse().unwrap()),
+}
+
+CompOp: filters::values::CompOp = {
+    "<" => filters::values::CompOp::Less,
+    "<=" => filters::values::CompOp::LessEqual,
+    "=" => filters::values::CompOp::Equal,
+    ">=" => filters::values::CompOp::GreaterEqual,
+    ">" => filters::values::CompOp::Greater,
+}
+
+Comparison<T>: Box<dyn filters::log::LogFilter> = {
+    <lhs:T> <op:CompOp> <rhs:T> => filters::values::comparison(lhs, op, rhs),
+}
+
 Comma<T>: HashSet<T> = {
     <v:(<T> ",")*> <e:T> => {
         let mut result = v.into_iter().collect::<HashSet<_>>();
@@ -183,6 +205,16 @@ Comma<T>: HashSet<T> = {
     },
 }
 
+DateProducer: Box<dyn DateProducer> = {
+    <Date> => filters::values::constant(<>),
+    "-time" => filters::values::time(),
+}
+
+DurationProducer: Box<dyn DurationProducer> = {
+    <Duration> => filters::values::constant(<>),
+    "-duration" => filters::values::duration(),
+}
+
 match {
     "player" => "player",
     "not" => "not",
@@ -194,7 +226,8 @@ match {
 
     r"\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d" => datetime,
     r"\d\d\d\d-\d\d-\d\d" => date,
-    r"[\w]+" => word,
+    r"\d+s" => duration,
+    r"[[:alpha:]][\w]*" => word,
     r#""[^"]*""# => string,
 
     _
diff --git a/src/fexpr/mod.rs b/src/fexpr/mod.rs
index c6a3a39..1738e44 100644
--- a/src/fexpr/mod.rs
+++ b/src/fexpr/mod.rs
@@ -11,6 +11,9 @@ use itertools::Itertools;
 use lalrpop_util::{lalrpop_mod, lexer::Token, ParseError};
 use thiserror::Error;
 
+trait DateProducer = filters::values::Producer<Output = chrono::DateTime<chrono::Utc>>;
+trait DurationProducer = filters::values::Producer<Output = chrono::Duration>;
+
 lalrpop_mod!(#[allow(clippy::all)] pub grammar, "/fexpr/grammar.rs");
 
 #[derive(Debug)]
diff --git a/src/filters/log.rs b/src/filters/log.rs
index 8cfdcb4..9ca7d3c 100644
--- a/src/filters/log.rs
+++ b/src/filters/log.rs
@@ -137,7 +137,7 @@ fn time_is_between(
 ///
 /// This expects the filename to have the datetime in the pattern `YYYYmmdd-HHMMSS` somewhere in
 /// it.
-fn datetime_from_filename(name: &OsStr) -> Option<DateTime<Utc>> {
+pub(crate) fn datetime_from_filename(name: &OsStr) -> Option<DateTime<Utc>> {
     let date_match = DATE_REGEX.find(name.to_str()?)?;
     let local_time = Local
         .datetime_from_str(date_match.as_str(), "%Y%m%d-%H%M%S")
diff --git a/src/filters/mod.rs b/src/filters/mod.rs
index 162b6f8..e966851 100644
--- a/src/filters/mod.rs
+++ b/src/filters/mod.rs
@@ -5,6 +5,7 @@ use num_traits::FromPrimitive as _;
 
 pub mod log;
 pub mod player;
+pub mod values;
 
 /// Early filtering result.
 ///
diff --git a/src/filters/values.rs b/src/filters/values.rs
new file mode 100644
index 0000000..543b59c
--- /dev/null
+++ b/src/filters/values.rs
@@ -0,0 +1,144 @@
+use std::{
+    cmp::Ordering,
+    fmt::{self, Debug},
+};
+
+use chrono::{DateTime, Duration, Utc};
+
+use super::{log::LogFilter, Filter};
+use crate::{EarlyLogResult, LogResult};
+
+pub trait Producer: Send + Sync + Debug {
+    type Output;
+
+    fn produce_early(&self, _early_log: &EarlyLogResult) -> Option<Self::Output> {
+        None
+    }
+
+    fn produce(&self, log: &LogResult) -> Self::Output;
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub enum CompOp {
+    Less,
+    LessEqual,
+    Equal,
+    GreaterEqual,
+    Greater,
+}
+
+impl fmt::Display for CompOp {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let symbol = match self {
+            CompOp::Less => "<",
+            CompOp::LessEqual => "<=",
+            CompOp::Equal => "=",
+            CompOp::GreaterEqual => ">=",
+            CompOp::Greater => ">",
+        };
+        f.pad(symbol)
+    }
+}
+
+impl CompOp {
+    pub fn matches(self, cmp: Ordering) -> bool {
+        match cmp {
+            Ordering::Less => self == CompOp::Less || self == CompOp::LessEqual,
+            Ordering::Equal => {
+                self == CompOp::LessEqual || self == CompOp::Equal || self == CompOp::GreaterEqual
+            }
+            Ordering::Greater => self == CompOp::Greater || self == CompOp::GreaterEqual,
+        }
+    }
+}
+
+struct Comparator<V>(
+    Box<dyn Producer<Output = V>>,
+    CompOp,
+    Box<dyn Producer<Output = V>>,
+);
+
+impl<V> Debug for Comparator<V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "({:?} {} {:?})", self.0, self.1, self.2)
+    }
+}
+
+impl<V> Filter<EarlyLogResult, LogResult> for Comparator<V>
+where
+    V: Ord,
+{
+    fn filter(&self, log: &LogResult) -> bool {
+        let lhs = self.0.produce(log);
+        let rhs = self.2.produce(log);
+        self.1.matches(lhs.cmp(&rhs))
+    }
+}
+
+pub fn comparison<V: 'static>(
+    lhs: Box<dyn Producer<Output = V>>,
+    op: CompOp,
+    rhs: Box<dyn Producer<Output = V>>,
+) -> Box<dyn LogFilter>
+where
+    V: Ord,
+{
+    Box::new(Comparator(lhs, op, rhs))
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+struct ConstantProducer<V>(V);
+
+impl<V: Send + Sync + Debug + Clone> Producer for ConstantProducer<V> {
+    type Output = V;
+    fn produce_early(&self, _: &EarlyLogResult) -> Option<Self::Output> {
+        Some(self.0.clone())
+    }
+
+    fn produce(&self, _: &LogResult) -> Self::Output {
+        self.0.clone()
+    }
+}
+
+pub fn constant<V: Send + Sync + Debug + Clone + 'static>(
+    value: V,
+) -> Box<dyn Producer<Output = V>> {
+    Box::new(ConstantProducer(value))
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+struct TimeProducer;
+
+impl Producer for TimeProducer {
+    type Output = DateTime<Utc>;
+
+    fn produce_early(&self, early_log: &EarlyLogResult) -> Option<Self::Output> {
+        early_log
+            .log_file
+            .file_name()
+            .and_then(super::log::datetime_from_filename)
+    }
+
+    fn produce(&self, log: &LogResult) -> Self::Output {
+        log.time
+    }
+}
+
+pub fn time() -> Box<dyn Producer<Output = DateTime<Utc>>> {
+    Box::new(TimeProducer)
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+struct DurationProducer;
+
+impl Producer for DurationProducer {
+    type Output = Duration;
+
+    fn produce(&self, log: &LogResult) -> Self::Output {
+        log.duration
+    }
+}
+
+pub fn duration() -> Box<dyn Producer<Output = Duration>> {
+    Box::new(DurationProducer)
+}
diff --git a/src/main.rs b/src/main.rs
index ba834ce..9ed67cf 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,7 +8,7 @@ use std::str::FromStr;
 use std::sync::atomic::{AtomicBool, Ordering};
 
 use anyhow::{anyhow, Context, Error, Result};
-use chrono::{DateTime, TimeZone, Utc};
+use chrono::{DateTime, Duration, TimeZone, Utc};
 use colored::Colorize;
 use log::debug;
 use regex::Regex;
@@ -156,6 +156,8 @@ pub struct LogResult {
     log_file: PathBuf,
     /// The time of the recording.
     time: DateTime<Utc>,
+    /// The duration of the fight.
+    duration: Duration,
     /// The boss.
     boss: Option<Boss>,
     /// A vector of all participating players.
@@ -550,9 +552,17 @@ fn extract_info(path: &Path, log: &Log) -> LogResult {
         .collect::<Vec<Player>>();
     players.sort();
 
+    let duration = log
+        .local_end_timestamp()
+        .and_then(|end| log.local_start_timestamp().map(|start| end - start))
+        .map(|x| x as i64)
+        .map(Duration::seconds)
+        .unwrap_or_else(Duration::zero);
+
     LogResult {
         log_file: path.to_path_buf(),
         time: Utc.timestamp(i64::from(log.local_end_timestamp().unwrap_or(0)), 0),
+        duration,
         boss,
         players,
         outcome: get_fight_outcome(log),