changed Day implementation

src/store/day.rs

@@ -0,0 +1,63 @@
+use core::fmt::Write;
+
+use embedded_sdmmc::ShortFileName;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Copy, Serialize, Deserialize, Debug, PartialEq, Eq)]
+pub struct Day(u32);
+
+impl Day {
+    const SECONDS_PER_DAY: u64 = 86_400;
+
+    pub fn new(daystamp: u32) -> Self {
+        Day(daystamp)
+    }
+
+    pub fn new_from_timestamp(time: u64) -> Self {
+        let day = time / Self::SECONDS_PER_DAY;
+
+        if day > u32::MAX as u64 {
+            // TBH this would only happen if about 11 million years have passed
+            // I sure hope i don't have to work on this project any more then
+            // So we just cap it at this
+            Day(u32::MAX)
+        } else {
+            Day(day as u32)
+        }
+    }
+
+    pub fn to_timestamp(self) -> u64 {
+        (self.0 as u64) * Self::SECONDS_PER_DAY
+    }
+
+    pub fn to_string(self) -> heapless::String<8> {
+        let mut s: heapless::String<8> = heapless::String::new();
+        write!(s, "{:08X}", self.0).unwrap();
+        s
+    }
+
+    pub fn from_hex_str(s: &str) -> Result<Self, &'static str> {
+        if s.len() > 8 {
+            return Err("hex string too long");
+        }
+
+        u32::from_str_radix(s, 16)
+            .map_err(|_| "invalid hex string")
+            .map(Day)
+    }
+}
+
+impl From<u64> for Day {
+    fn from(value: u64) -> Self {
+        Self::new_from_timestamp(value)
+    }
+}
+
+impl TryFrom<ShortFileName> for Day {
+    type Error = ();
+
+    fn try_from(value: ShortFileName) -> Result<Self, Self::Error> {
+        let name = core::str::from_utf8(value.base_name()).map_err(|_| ())?;
+        Self::from_hex_str(name).map_err(|_| ())
+    }
+}