Version 0.1.0

[tattlekey] / server / src / main.rs

diff --git a/server/src/main.rs b/server/src/main.rs
index 0d4377a88ae6242bf2808666a1f7d5c12e1934e7..ddf5217c41d67a1db956178de083f2d7f0fac753 100644 (file)
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -14,23 +14,140 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
 use std::net::UdpSocket;
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
 const MESSAGE_SIZE: usize = 12;
+const LOGFILENAME: &str = "log.csv";
+
+#[derive(Eq, Debug, Hash, PartialEq)]
+struct MessageKey {
+    epoch: u32,
+    device: u16,
+    seq: u16,
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+struct Message {
+    epoch: u32,
+    device: u16,
+    seq: u16,
+    t: u64,
+}
+impl Message {
+    fn key(&self) -> MessageKey {
+        MessageKey {
+            epoch: self.epoch,
+            device: self.device,
+            seq: self.seq,
+        }
+    }
+}
+
+impl From<&[u8; MESSAGE_SIZE]> for Message {
+    fn from(value: &[u8; MESSAGE_SIZE]) -> Self {
+        let ago = u32::from_be_bytes(value[8..=11].try_into().expect("I can't count"));
+        let press_time = SystemTime::now() - Duration::new(ago.into(), 0);
+        Self {
+            epoch: u32::from_be_bytes(value[0..=3].try_into().expect("I can't count")),
+            device: u16::from_be_bytes(value[4..=5].try_into().expect("I can't count")),
+            seq: u16::from_be_bytes(value[6..=7].try_into().expect("I can't count")),
+            t: press_time
+                .duration_since(UNIX_EPOCH)
+                .expect("Bad time?")
+                .as_secs(),
+        }
+    }
+}
+impl TryFrom<&[u8]> for Message {
+    type Error = std::array::TryFromSliceError;
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        match <[u8; MESSAGE_SIZE]>::try_from(value) {
+            Ok(correct_size) => Ok(Message::from(&correct_size)),
+            Err(e) => Err(e),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct Range {
+    start: u64,
+    end: u64,
+}
+impl Range {
+    fn new(t: &u64) -> Self {
+        Self { start: *t, end: *t }
+    }
+    fn contains(&self, t: &u64) -> bool {
+        t > &self.start && t < &self.end
+    }
+    fn extend(&mut self, t: &u64) {
+        if t < &self.start {
+            self.start = *t;
+        }
+        if t > &self.end {
+            self.end = *t;
+        }
+    }
+}
+
+fn merge_message(presses: &mut HashMap<MessageKey, Range>, message: Message) {
+    let key = message.key();
+    if let Some(r) = presses.get_mut(&key) {
+        if !r.contains(&message.t) {
+            r.extend(&message.t);
+        }
+    } else {
+        presses.insert(key, Range::new(&message.t));
+    }
+}
+
+fn replay_log() -> HashMap<MessageKey, Range> {
+    let mut presses = HashMap::new();
+    if std::path::Path::new(LOGFILENAME).exists() {
+        let mut log = csv::Reader::from_path(LOGFILENAME).expect("Couldn't open log for replay");
+        for message in log.deserialize() {
+            merge_message(
+                &mut presses,
+                message.expect("Error reading log during replay"),
+            );
+        }
+    }
+    presses
+}
+
+fn open_log_for_writing() -> csv::Writer<std::fs::File> {
+    let log_file_exists = std::path::Path::new(LOGFILENAME).exists();
+    let logfile = std::fs::OpenOptions::new()
+        .create_new(!log_file_exists)
+        .append(true)
+        .open(LOGFILENAME)
+        .expect("Coudln't open log file");
+    csv::WriterBuilder::new()
+        .has_headers(!log_file_exists)
+        .from_writer(logfile)
+}
 
 fn main() {
     let socket = UdpSocket::bind("0.0.0.0:29803").expect("couldn't bind to address");
+    let mut presses = replay_log();
+    let mut log = open_log_for_writing();
     loop {
         let mut buf = [0; MESSAGE_SIZE];
         match socket.recv_from(&mut buf) {
             Err(e) => eprintln!("Didn't receive data: {e}"),
             Ok((number_of_bytes, src_addr)) => {
-                let filled_buf = &mut buf[..number_of_bytes];
+                let filled_buf = &buf[..number_of_bytes];
                 if number_of_bytes != MESSAGE_SIZE {
                     eprintln!("Ignoring short message ({number_of_bytes}) from {src_addr}");
                     continue;
                 }
-                println!("Got packet from {src_addr}: {filled_buf:?}");
+                let message = Message::try_from(filled_buf).expect("I can't count");
+                log.serialize(&message).expect("Couldn't write log");
+                log.flush().expect("Couldn't flush log");
+                merge_message(&mut presses, message);
             }
         }
     }