1 files changed, 86 insertions, 0 deletions
diff --git a/src/power/mod.rs b/src/power/mod.rs
new file mode 100644
index 0000000..afe5194
--- /dev/null
+++ b/src/power/mod.rs
@@ -0,0 +1,86 @@
+use std;
+
+use std::io::Read;
+
+mod sys;
+
+// XXX maybe extract this out into a separate crate?
+
+#[derive(Debug)]
+pub struct PowerInfo {
+    power_supplies: Vec<sys::PowerSupplyInfo>,
+}
+
+impl PowerInfo {
+    pub fn new() -> PowerInfo {
+        let power_supplies = sys::power_supplies();
+
+        PowerInfo {
+            power_supplies,
+        }
+    }
+
+    pub fn battery_usage(&self) -> Option<f64> {
+        let mut total_now = 0;
+        let mut total_full = 0;
+        for battery in self.batteries() {
+            if let Some(now) = battery.energy_now {
+                total_now += now;
+            }
+            else {
+                return None;
+            }
+            if let Some(full) = battery.energy_full {
+                total_full += full;
+            }
+            else {
+                return None;
+            }
+        }
+
+        if total_full > 0 {
+            Some((total_now as f64) / (total_full as f64))
+        }
+        else {
+            None
+        }
+    }
+
+    pub fn charging(&self) -> bool {
+        for mains in self.mains() {
+            if mains.online == Some(true) {
+                return true;
+            }
+        }
+        false
+    }
+
+    pub fn has_batteries(&self) -> bool {
+        self.batteries().count() > 0
+    }
+
+    fn batteries(&self) -> impl Iterator<Item=&sys::PowerSupplyInfo> {
+        self.power_supplies
+            .iter()
+            .filter(|p| p.ty == sys::PowerSupplyType::Battery)
+    }
+
+    fn mains(&self) -> impl Iterator<Item=&sys::PowerSupplyInfo> {
+        self.power_supplies
+            .iter()
+            .filter(|p| p.ty == sys::PowerSupplyType::AC)
+    }
+}
+
+fn slurp<T, U>(path: U) -> Option<T>
+where
+    T: std::str::FromStr,
+    U: AsRef<std::path::Path>,
+{
+    let mut contents = String::new();
+    std::fs::File::open(path).ok().and_then(|mut fh| {
+        fh.read_to_string(&mut contents)
+            .ok()
+            .and_then(|_| contents.trim().parse().ok())
+    })
+}