From 2b714b646b23cc0721e70314000b66a86a68a2c7 Mon Sep 17 00:00:00 2001
From: Stefan Schwarz <stefan@f2o.io>
Date: Sat, 23 May 2020 10:49:59 +0200
Subject: [PATCH] wip

---
 input14           |   6 ++
 src/day14/main.rs | 159 +++++++++++++++++++++++++++++++++++-----------
 2 files changed, 128 insertions(+), 37 deletions(-)
 create mode 100644 input14

diff --git a/input14 b/input14
new file mode 100644
index 0000000..65ad5cc
--- /dev/null
+++ b/input14
@@ -0,0 +1,6 @@
+10 ORE => 10 A
+1 ORE => 1 B
+7 A, 1 B => 1 C
+7 A, 1 C => 1 D
+7 A, 1 D => 1 E
+7 A, 1 E => 1 FUEL
diff --git a/src/day14/main.rs b/src/day14/main.rs
index 5ba72da..a393f67 100644
--- a/src/day14/main.rs
+++ b/src/day14/main.rs
@@ -1,78 +1,163 @@
 use std::collections::HashMap;
 use std::fs::File;
 use std::io::{BufRead, BufReader};
-use std::iter::Peekable;
 
 type Resource = String;
-type Requirements = HashMap<Resource, Vec<Resource>>;
+type Pipeline = HashMap<Resource, ResourceBuilder>;
 
-#[derive(Default)]
-struct NanoFactory {
-    requirements: Requirements,
+#[derive(Debug)]
+struct ResourceBuilder {
+    requirements: Vec<Resource>,
+    out_count: usize,
 }
 
+impl From<(Vec<Resource>, usize)> for ResourceBuilder {
+    fn from(build: (Vec<Resource>, usize)) -> Self {
+        ResourceBuilder {
+            requirements: build.0,
+            out_count: build.1,
+        }
+    }
+}
+
+#[derive(Default, Debug)]
+struct NanoFactory {
+    pipeline: Pipeline,
+    storage: HashMap<Resource, usize>,
+}
+
+#[derive(Debug)]
 enum NanoFactoryBuildState {
     InputCount,
     InputResource,
-    InputDivider,
     OutputArrow,
     OutputCount,
     OutputResource,
 }
 
+impl NanoFactory {
+    fn generate_fuel(&mut self) -> usize {
+        return self.lookup_resource("FUEL");
+    }
+
+    fn lookup_resource(&mut self, resource: &str) -> usize {
+        if resource == "ORE" {
+            return 1;
+        }
+        if let Some(count) = self.storage.get_mut(resource.into()) {
+            *count -= 1
+        }
+        let pipeline = self.pipeline.as_mut_ref();
+        let required = self
+            .pipeline
+            .get(resource.into())
+            .expect("unable to find resource");
+        required.requirements.iter().fold(0, |mut acc, c| {
+            acc += self.lookup_resource(c);
+            acc
+        })
+    }
+}
+
 impl<T> From<T> for NanoFactory
 where
     T: BufRead,
 {
     fn from(bufreader: T) -> Self {
-        let f = NanoFactory::default();
+        let mut f = NanoFactory::default();
         let mut state = NanoFactoryBuildState::InputCount;
-        bufreader.split(b'\n').for_each(|line| {
+        bufreader.split(b'\n').enumerate().for_each(|(nr, line)| {
             let line = line.unwrap();
             let mut line = line.into_iter().peekable();
             let mut count_var = 0;
-            match state {
-                NanoFactoryBuildState::InputCount => {
-                    let test = next_if_in_range(&mut line, 48..84);
-                    println!("{:?}", test);
-                    while let Some(_) = line.peek().and_then(|c| match c {
-                        48..=57 => Some(c),
-                        _ => None,
-                    }) {
-                        count_var = count_var * 10 + line.next().unwrap() as usize;
+            let mut cur_requirements = Vec::new();
+            loop {
+                match state {
+                    NanoFactoryBuildState::InputCount | NanoFactoryBuildState::OutputCount => {
+                        while let Some(c) = next_if_in_range(&mut line, 48..=57) {
+                            count_var = count_var * 10 + (c as usize) - 48;
+                        }
+                        assert_eq!(line.next().unwrap(), b' ');
+                        state = match state {
+                            NanoFactoryBuildState::InputCount => {
+                                NanoFactoryBuildState::InputResource
+                            }
+                            NanoFactoryBuildState::OutputCount => {
+                                NanoFactoryBuildState::OutputResource
+                            }
+                            _ => unreachable!(),
+                        }
                     }
-                    assert_eq!(line.next().unwrap(), b' ');
-                    state = NanoFactoryBuildState::InputResource;
-                }
-                NanoFactoryBuildState::InputResource => {}
-                _ => (),
-            };
-            line.for_each(|c| match c {
-                b'0'..=b'9' => println!("test:{}", c),
-                _ => (),
-            })
+                    NanoFactoryBuildState::InputResource => {
+                        let mut r = Resource::new();
+                        while let Some(c) = next_if_in_range(&mut line, 65..=90) {
+                            r.push(c.into());
+                        }
+                        for _ in 0..count_var {
+                            cur_requirements.push(r.clone());
+                        }
+                        r.truncate(0);
+                        count_var = 0;
+                        let next = line.next();
+                        match next {
+                            Some(b',') => {
+                                assert_eq!(line.next().unwrap(), b' ');
+                                state = NanoFactoryBuildState::InputCount;
+                            }
+                            Some(b' ') => state = NanoFactoryBuildState::OutputArrow,
+                            _ => panic!(
+                                "invalid format in line {}, expected ' ' or ',', got '{:?}'",
+                                nr, next
+                            ),
+                        }
+                    }
+                    NanoFactoryBuildState::OutputResource => {
+                        let mut r = Resource::new();
+                        while let Some(c) = next_if_in_range(&mut line, 65..=90) {
+                            r.push(c.into());
+                        }
+                        f.pipeline
+                            .insert(r, ResourceBuilder::from((cur_requirements, count_var)));
+                        state = NanoFactoryBuildState::InputCount;
+                        return;
+                    }
+                    NanoFactoryBuildState::OutputArrow => {
+                        assert_eq!(line.next().unwrap(), b'=');
+                        assert_eq!(line.next().unwrap(), b'>');
+                        assert_eq!(line.next().unwrap(), b' ');
+                        state = NanoFactoryBuildState::OutputCount
+                    }
+                };
+            }
         });
-        NanoFactory {
-            requirements: Default::default(),
-        }
+        println! {"{:?}", f};
+        f
     }
 }
 
 fn next_if_in_range<I, T>(
     peekable: &mut std::iter::Peekable<I>,
-    range: std::ops::Range<T>,
-) -> Option<&T>
+    range: std::ops::RangeInclusive<T>,
+) -> Option<T>
 where
     I: std::iter::Iterator<Item = T>,
+    T: Copy + std::cmp::PartialOrd,
 {
-    peekable.peek().and_then(|peeked| match peeked {
-        range => Some(peeked),
-        _ => None,
-    })
+    if let Some(peeked) = peekable.peek() {
+        if range.contains(peeked) {
+            peekable.next()
+        } else {
+            None
+        }
+    } else {
+        None
+    }
 }
 
 fn main() {
     let f = File::open("input14").unwrap();
     let bufreader = BufReader::new(f);
-    let factory = NanoFactory::from(bufreader);
+    let mut factory = NanoFactory::from(bufreader);
+    let ores = factory.generate_fuel();
+    println!("ores: {}", ores)
 }