refactored todo file into todo module

src/todo/file.rs

@@ -0,0 +1,68 @@
+use chrono::naive::NaiveDate;
+use regex::Regex;
+use std::convert::TryFrom;
+use std::fs::DirEntry;
+use std::str::FromStr;
+
+#[derive(Debug)]
+pub struct TodoFile {
+    pub file: DirEntry,
+    pub date: NaiveDate,
+}
+
+impl TodoFile {
+    fn capture_as_number<T: FromStr>(capture: &regex::Captures, name: &str) -> Result<T, String> {
+        Ok(capture
+            .name(name)
+            .unwrap()
+            .as_str()
+            .parse::<T>()
+            .ok()
+            .ok_or("Something went wrong".to_owned())?)
+    }
+
+    pub fn latest_file(a: TodoFile, b: TodoFile) -> TodoFile {
+        if a.date > b.date {
+            a
+        } else {
+            b
+        }
+    }
+
+    fn get_file_regex() -> Regex {
+        //TODO This would ideally be configurable
+        Regex::new(r"(?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2}).md")
+            .expect("could not create regex")
+    }
+}
+
+impl TryFrom<DirEntry> for TodoFile {
+    type Error = String;
+
+    fn try_from(direntry: DirEntry) -> Result<Self, Self::Error> {
+        let re = TodoFile::get_file_regex();
+//        println!("{:?}", re);
+        let file_name = direntry.file_name();
+        let file_name_str = match file_name.to_str() {
+            Some(name) => name,
+            _ => "",
+        };
+//        println!("{:?}", file_name_str);
+
+        if let Some(caps) = re.captures(file_name_str) {
+            let year: i32 = Self::capture_as_number(&caps, "year").unwrap();
+            let month: u32 = Self::capture_as_number(&caps, "month").unwrap();
+            let day: u32 = Self::capture_as_number(&caps, "day").unwrap();
+
+            return Ok(Self {
+                file: direntry,
+                date: NaiveDate::from_ymd_opt(year, month, day).unwrap(),
+            });
+        };
+        Err(format!(
+            "Could not parse file name => {{ name: {:?}, re: {:?} }}",
+            file_name, re
+        )
+        .to_string())
+    }
+}