1 files changed, 67 insertions, 3 deletions

diff --git a/src/bin/day_1.rs b/src/bin/day_1.rs
index 3b80d88..68a570c 100644
--- a/src/bin/day_1.rs
+++ b/src/bin/day_1.rs
@@ -1,4 +1,6 @@
 use bevy::prelude::*;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
 
 fn main() {
     App::build()
@@ -9,11 +11,73 @@ fn main() {
             ..Default::default()
         })
         .add_resource(ClearColor(Color::rgb(0., 0., 0.)))
-        .add_startup_system(setup.system())
-        .add_plugins(DefaultPlugins)
+        .add_startup_system(setup_camera.system())
+        .add_startup_system(read_input_file.system())
+        .add_stage("mark")
+        .add_system_to_stage("mark", mark_sum_pair.system())
+        .add_system_to_stage("mark", mark_sum_triple.system())
+        .add_stage("report")
+        .add_system_to_stage("report", print_product_pair.system())
+        .add_system_to_stage("report", print_product_triple.system())
+        //.add_plugins(DefaultPlugins)
         .run();
 }
 
-fn setup(mut commands: Commands) {
+fn setup_camera(mut commands: Commands) {
     commands.spawn(Camera2dComponents::default());
 }
+
+struct Expense(i32);
+struct FlaggedPair;
+struct FlaggedTriple;
+
+fn read_input_file(mut commands: Commands) {
+    let f = File::open("./inputs/day_1.txt").unwrap(); // TODO: Error handling on systems?
+    for line in BufReader::new(f).lines() {
+        let expense = line.unwrap().trim().parse().unwrap();
+        commands.spawn((Expense(expense),));
+    }
+}
+
+fn mark_sum_pair(mut commands: Commands, expenses: Query<(Entity, &Expense)>) {
+    for (entity_1, expense_1) in expenses.iter() {
+        for (entity_2, expense_2) in expenses.iter() {
+            if expense_1.0 + expense_2.0 == 2020 {
+                commands.insert_one(entity_1, FlaggedPair);
+                commands.insert_one(entity_2, FlaggedPair);
+            }
+        }
+    }
+}
+
+fn mark_sum_triple(mut commands: Commands, expenses: Query<(Entity, &Expense)>) {
+    for (entity_1, expense_1) in expenses.iter() {
+        for (entity_2, expense_2) in expenses.iter() {
+            for (entity_3, expense_3) in expenses.iter() {
+                if expense_1.0 + expense_2.0 + expense_3.0 == 2020 {
+                    commands.insert_one(entity_1, FlaggedTriple);
+                    commands.insert_one(entity_2, FlaggedTriple);
+                    commands.insert_one(entity_3, FlaggedTriple);
+                }
+            }
+        }
+    }
+}
+
+fn print_product_pair(flagged_expenses: Query<With<FlaggedPair, &Expense>>) {
+    let mut product = 1;
+    for expense in flagged_expenses.iter() {
+        product *= expense.0;
+    }
+    // TODO: Put it on the screen!
+    println!("Product Pair: {}", product);
+}
+
+fn print_product_triple(flagged_expenses: Query<With<FlaggedTriple, &Expense>>) {
+    let mut product = 1;
+    for expense in flagged_expenses.iter() {
+        product *= expense.0;
+    }
+    // TODO: Put it on the screen!
+    println!("Product Triple: {}", product);
+}