Parse the input for 2023 day5 part 1

2023/day5/src/main.rs

@@ -1,10 +1,13 @@
+use std::collections::{HashMap, VecDeque};
 use std::ops::Range;
-use std::collections::HashMap;
-const FILE_STR: &'static str = include_str!("input.txt");
+use crate::DataType::Soil;
 
-#[derive(Debug)]
+const FILE_STR: &'static str = include_str!("input.txt");
+const EXAMPLE_FILE_STR: &'static str = include_str!("example-input.txt");
+
+#[derive(Debug, PartialEq, Eq, Hash, Copy, Clone)]
 enum DataType {
-    Seeds,
+    Seed,
     Soil,
     Fertilizer,
     Water,
@@ -14,6 +17,22 @@ enum DataType {
     Location,
 }
 
+impl DataType {
+    fn try_from(s: &str) -> Option<Self> {
+        match s {
+            "seed" => Some(Self::Seed),
+            "soil" => Some(Self::Soil),
+            "fertilizer" => Some(Self::Fertilizer),
+            "water" => Some(Self::Water),
+            "light" => Some(Self::Light),
+            "temperature" => Some(Self::Temperature),
+            "humidity" => Some(Self::Humidity),
+            "location" => Some(Self::Location),
+            _ => None,
+        }
+    }
+}
+
 #[derive(Debug, Default)]
 struct DataMap {
     from_range: Range<u64>,
@@ -27,7 +46,7 @@ impl DataMap {
 
         DataMap {
             from_range,
-            to_range
+            to_range,
         }
     }
 
@@ -41,7 +60,7 @@ impl DataMap {
 
         match dest_index {
             Some(n) => n,
-            None => src_value
+            None => src_value,
         }
     }
 
@@ -55,28 +74,85 @@ impl DataMap {
 
         match src_index {
             Some(n) => n,
-            None => dest_value
+            None => dest_value,
         }
     }
 }
 
+type MapMap = HashMap<(DataType, DataType), Vec<DataMap>>;
+
 #[derive(Debug, Default)]
 struct Almanac {
     seeds: Vec<u64>,
-    maps: HashMap<(DataType, DataType), Vec<DataMap>>,
+    maps: MapMap,
 }
 
 impl Almanac {
     fn parse(input: &str) -> Self {
+        let mut data_chunks: VecDeque<_> = input.split("\n\n").collect();
+        let seeds: Vec<u64> = data_chunks
+            .pop_front()
+            .unwrap()
+            .split(':')
+            .collect::<Vec<&str>>()
+            .pop()
+            .unwrap()
+            .split_whitespace()
+            .map(|s| s.trim())
+            .map(|s| s.parse::<u64>().unwrap())
+            .collect();
+
+        let maps = data_chunks
+            .into_iter()
+            .map(|chunk| {
+                let mut lines: VecDeque<_> = chunk.split("\n").collect();
+                let type_line_parts: Vec<_> =
+                    lines.pop_front().unwrap().split_whitespace().collect();
+                let types: Vec<_> = type_line_parts[0]
+                    .split("-to-")
+                    .map(|s| DataType::try_from(s.trim()).unwrap())
+                    .collect();
+                let (from, to) = (types[0], types[1]);
+                let mappings: Vec<DataMap> = lines
+                    .into_iter()
+                    .map(|line| {
+                        line.split_whitespace()
+                            .map(|s| s.trim())
+                            .filter(|s| s.len() > 0)
+                            .map(|s| s.parse::<u64>().unwrap())
+                            .collect::<Vec<u64>>()
+                    })
+                    .map(|m| DataMap::new(m[0], m[1], m[2]))
+                    .collect();
+
+                ((from, to), mappings)
+            })
+            .collect();
+
+        Almanac { seeds, maps }
+    }
+
+    fn x_from_y(&self, x: DataType, y: DataType, search: u64) -> u64 {
+        let maps = self.maps.get(&(y, x)).expect(&format!("Missing mapping from {:?} to {:?}", x, y));
         todo!();
     }
+
+    fn soil_from_seed(&self, seed: u64) -> u64 {
+        use DataType::*;
+
+        self.x_from_y(Soil, Seed, seed)
+    }
 }
 
 fn main() {
-    println!("Hello, world!");
+    let almanac = Almanac::parse(EXAMPLE_FILE_STR);
+    let soil = almanac.soil_from_seed(79);
 }
 
 #[cfg(test)]
 mod tests {
     const EXAMPLE_FILE_STR: &'static str = include_str!("example-input.txt");
-}
+
+    #[test]
+    fn test_parse() {}
+}