From 8325ffaa1d5c19fb4e76ee82902c1eddfb5a7462 Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Tue, 10 Oct 2023 18:41:36 -0700
Subject: [PATCH] server: Replay log

---
 server/src/main.rs | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/server/src/main.rs b/server/src/main.rs
index 9406811..ddf5217 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -14,7 +14,7 @@
 // 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::Serialize;
+use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::net::UdpSocket;
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
@@ -29,7 +29,7 @@ struct MessageKey {
     seq: u16,
 }
 
-#[derive(Debug, Serialize)]
+#[derive(Debug, Deserialize, Serialize)]
 struct Message {
     epoch: u32,
     device: u16,
@@ -104,6 +104,20 @@ fn merge_message(presses: &mut HashMap<MessageKey, Range>, message: Message) {
     }
 }
 
+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()
@@ -118,7 +132,7 @@ fn open_log_for_writing() -> csv::Writer<std::fs::File> {
 
 fn main() {
     let socket = UdpSocket::bind("0.0.0.0:29803").expect("couldn't bind to address");
-    let mut presses = HashMap::<MessageKey, Range>::new();
+    let mut presses = replay_log();
     let mut log = open_log_for_writing();
     loop {
         let mut buf = [0; MESSAGE_SIZE];
-- 
2.44.1