From 428d9fcfaf80b47b24de8fb71c06f14a337beece Mon Sep 17 00:00:00 2001
From: jorgecardleitao <149073281+jorgecardleitao@users.noreply.github.com>
Date: Tue, 23 Jan 2024 18:44:07 +0100
Subject: [PATCH] Made legs contain positions (#17)

This allows deriving leg properties directly, as well as identifying if
a leg passed through a location (e.g. to track airports).
---
 examples/dk_jets.rs    |  2 +-
 examples/period.rs     | 20 ++++++-------
 examples/single_day.rs |  6 ++--
 src/legs.rs            | 68 ++++++++++++++++++++----------------------
 4 files changed, 47 insertions(+), 49 deletions(-)

diff --git a/examples/dk_jets.rs b/examples/dk_jets.rs
index e19644f..905c674 100644
--- a/examples/dk_jets.rs
+++ b/examples/dk_jets.rs
@@ -159,7 +159,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
         .iter()
         .map(|(_, legs)| {
             legs.iter()
-                .map(|leg| emissions(leg.from.pos(), leg.to.pos(), Class::First) / 1000.0)
+                .map(|leg| emissions(leg.from().pos(), leg.to().pos(), Class::First) / 1000.0)
                 .sum::<f64>()
         })
         .sum::<f64>();
diff --git a/examples/period.rs b/examples/period.rs
index 03a8d00..75b985c 100644
--- a/examples/period.rs
+++ b/examples/period.rs
@@ -136,22 +136,22 @@ async fn main() -> Result<(), Box<dyn Error>> {
     for leg in &legs {
         log::info!(
             "{},{},{},{},{},{},{},{},{}",
-            leg.from.datetime(),
-            leg.from.latitude(),
-            leg.from.longitude(),
-            leg.from.altitude(),
-            leg.to.datetime(),
-            leg.to.latitude(),
-            leg.to.longitude(),
-            leg.to.altitude(),
-            leg.maximum_altitude
+            leg.from().datetime(),
+            leg.from().latitude(),
+            leg.from().longitude(),
+            leg.from().altitude(),
+            leg.to().datetime(),
+            leg.to().latitude(),
+            leg.to().longitude(),
+            leg.to().altitude(),
+            leg.maximum_altitude(),
         );
     }
 
     let commercial_to_private_ratio = 10.0;
     let commercial_emissions_tons = legs
         .iter()
-        .map(|leg| emissions(leg.from.pos(), leg.to.pos(), Class::First) / 1000.0)
+        .map(|leg| emissions(leg.from().pos(), leg.to().pos(), Class::First) / 1000.0)
         .sum::<f64>();
     let emissions_tons = Fact {
         claim: (commercial_emissions_tons * commercial_to_private_ratio) as usize,
diff --git a/examples/single_day.rs b/examples/single_day.rs
index 240b1f9..9a7455d 100644
--- a/examples/single_day.rs
+++ b/examples/single_day.rs
@@ -104,11 +104,11 @@ async fn flight_date(
     log::info!("Number of legs: {}", legs.len());
 
     Ok(legs.into_iter().filter_map(|leg| {
-        let is_leg = matches!(leg.from, Position::Grounded{..}) & matches!(leg.to, Position::Grounded{..});
+        let is_leg = matches!(leg.from(), Position::Grounded{..}) & matches!(leg.to(), Position::Grounded{..});
         if !is_leg {
-            log::info!("{:?} -> {:?} skipped", leg.from, leg.to);
+            log::info!("{:?} -> {:?} skipped", leg.from(), leg.to());
         }
-        is_leg.then_some((leg.from, leg.to))
+        is_leg.then_some((leg.from().clone(), leg.to().clone()))
     }).map(|(from, to)| {
         let emissions = emissions(from.pos(), to.pos(), Class::First);
 
diff --git a/src/legs.rs b/src/legs.rs
index b76d1ca..9b76ca6 100644
--- a/src/legs.rs
+++ b/src/legs.rs
@@ -4,60 +4,58 @@ use crate::Position;
 /// between two positions.
 #[derive(Debug, Clone)]
 pub struct Leg {
-    pub from: Position,
-    pub to: Position,
-    /// in feet
-    pub maximum_altitude: f64,
+    /// Sequence of positions defining the leg. Ends may start Flying, when the first/last observed
+    /// position was flying. Otherwise, first and last are Grounded.
+    positions: Vec<Position>,
 }
 
 impl Leg {
+    /// Positions of the leg
+    pub fn positions(&self) -> &[Position] {
+        &self.positions
+    }
+
     /// Leg geo distance in km
     pub fn distance(&self) -> f64 {
-        self.from.distace(&self.to)
+        self.from().distace(&self.to())
     }
 
     /// Leg duration
     pub fn duration(&self) -> time::Duration {
-        self.to.datetime() - self.from.datetime()
+        self.to().datetime() - self.from().datetime()
+    }
+
+    pub fn maximum_altitude(&self) -> f64 {
+        self.positions
+            .iter()
+            .map(|p| p.altitude() as u32)
+            .max()
+            .unwrap() as f64
+    }
+
+    pub fn from(&self) -> &Position {
+        self.positions.first().unwrap()
+    }
+
+    pub fn to(&self) -> &Position {
+        self.positions.last().unwrap()
     }
 }
 
 /// Returns a set of [`Leg`]s from a sequence of [`Position`]s.
-fn all_legs(mut positions: impl Iterator<Item = Position>) -> Vec<Leg> {
+pub fn all_legs(mut positions: impl Iterator<Item = Position>) -> Vec<Leg> {
     let Some(mut prev_position) = positions.next() else {
         return vec![];
     };
 
-    let first = prev_position.clone();
+    let mut sequence: Vec<Position> = vec![];
     let mut legs: Vec<Leg> = vec![];
-    let mut maximum_altitude = first.altitude();
     positions.for_each(|position| {
-        maximum_altitude = position.altitude().max(maximum_altitude);
-        match (&prev_position, &position) {
-            (Position::Grounded { .. }, Position::Flying { .. }) => {
-                // departed, still do not know to where
-                legs.push(Leg {
-                    from: prev_position.clone(),
-                    to: prev_position.clone(),
-                    maximum_altitude,
-                });
-            }
-            (Position::Flying { .. }, Position::Grounded { .. }) => {
-                // arrived
-                if let Some(leg) = legs.last_mut() {
-                    // there is a leg - set its arrival position
-                    leg.to = position.clone();
-                } else {
-                    // if it was initially flying, need to push to the leg
-                    legs.push(Leg {
-                        from: first.clone(),
-                        to: position.clone(),
-                        maximum_altitude,
-                    });
-                    maximum_altitude = 0.0
-                }
-            }
-            _ => {}
+        sequence.push(position.clone());
+        if let (Position::Flying { .. }, Position::Grounded { .. }) = (&prev_position, &position) {
+            legs.push(Leg {
+                positions: std::mem::take(&mut sequence),
+            });
         };
         prev_position = position;
     });