add event type filter capability to watcher

README.md

@@ -47,6 +47,7 @@ Create a configuration file in either JSON, ZON, or YAML format. Example (in JSO
 - `watchers`: Array of event watchers with the following properties:
   - `folder`: Syncthing folder ID to watch
   - `path_pattern`: Regular expression to match file paths
+  - `event_type`: [Event type](https://docs.syncthing.net/dev/events.html#event-types) to match on. Defaults to ItemFinished
   - `command`: Command to execute when a match is found. Supports variables:
     - `${path}`: Full path to the changed file
     - `${folder}`: Folder ID where the change occurred

src/main.zig

@@ -6,6 +6,11 @@ const EventPoller = lib.EventPoller;
 const Args = struct {
     config_path: []const u8 = "config.json",
     syncthing_url: ?[]const u8 = null,
+
+    pub fn deinit(self: Args, allocator: std.mem.Allocator) void {
+        allocator.free(self.config_path);
+        if (self.syncthing_url) |url| allocator.free(url);
+    }
 };
 
 pub const std_options: std.Options = .{
@@ -32,6 +37,7 @@ pub fn main() !u8 {
     const allocator = gpa.allocator();
 
     const args = try parseArgs(allocator);
+    defer args.deinit(allocator);
 
     const file = try std.fs.cwd().openFile(args.config_path, .{});
     defer file.close();
@@ -61,7 +67,6 @@ pub fn main() !u8 {
     }
 
     const stdout = std.io.getStdOut().writer();
-    try stdout.print("Monitoring Syncthing events at {s}\n", .{config.syncthing_url});
 
     var last_id: ?i64 = null;
     const connection_pool = std.http.Client.ConnectionPool{};
@@ -76,6 +81,8 @@ pub fn main() !u8 {
             config,
             connection_pool,
         );
+        if (last_id == null) // first run
+            try stdout.print("Monitoring Syncthing events at {s}\n", .{try poller.url()});
         defer last_id = poller.last_id;
         poller.last_id = last_id;
         const events = poller.poll() catch |err| switch (err) {

src/root.zig

@@ -13,6 +13,7 @@ pub const Watcher = struct {
     folder: []const u8,
     path_pattern: []const u8,
     action: []const u8,
+    event_type: []const u8 = "ItemFinished",
     command: []const u8,
     compiled_pattern: ?mvzr.Regex = null,
 
@@ -43,6 +44,7 @@ pub const Watcher = struct {
 
 pub const SyncthingEvent = struct {
     id: i64,
+    event_type: []const u8,
     data_type: []const u8,
     folder: []const u8,
     path: []const u8,
@@ -54,6 +56,7 @@ pub const SyncthingEvent = struct {
         return SyncthingEvent{
             .id = value.object.get("id").?.integer,
             .time = try allocator.dupe(u8, value.object.get("time").?.string),
+            .event_type = try allocator.dupe(u8, value.object.get("type").?.string),
             .data_type = try allocator.dupe(u8, data.get("type").?.string),
             .folder = try allocator.dupe(u8, data.get("folder").?.string),
             .action = try allocator.dupe(u8, data.get("action").?.string),
@@ -87,6 +90,28 @@ pub const EventPoller = struct {
         };
     }
 
+    pub fn url(self: EventPoller) ![]const u8 {
+        const watched_events = blk: {
+            var type_set = std.StringArrayHashMap(void).init(self.allocator);
+            try type_set.ensureTotalCapacity(self.config.watchers.len);
+            for (self.config.watchers) |watcher|
+                type_set.putAssumeCapacity(watcher.event_type, {});
+            break :blk try std.mem.join(self.allocator, ",", type_set.keys());
+        };
+        var since_buf: [100]u8 = undefined;
+        const since = if (self.last_id) |id|
+            try std.fmt.bufPrint(&since_buf, "&since={d}", .{id})
+        else
+            "";
+        return try std.fmt.allocPrint(
+            self.allocator,
+            "{s}/rest/events?events={s}{s}",
+            .{
+                self.config.syncthing_url, watched_events, since,
+            },
+        );
+    }
+
     pub fn poll(self: *EventPoller) ![]SyncthingEvent {
         var client = std.http.Client{ .allocator = self.allocator, .connection_pool = self.connection_pool };
         var arena = std.heap.ArenaAllocator.init(self.allocator);
@@ -101,22 +126,13 @@ pub const EventPoller = struct {
         const MAX_UCF_RETRIES: usize = 20;
         var retry_count: usize = 0;
         const first_run = self.last_id == null;
+        const poll_url = try self.url();
         while (retry_count < self.config.max_retries) : (retry_count += 1) {
-            var url_buf: [1024]u8 = undefined;
-            var since_buf: [100]u8 = undefined;
-            const since = if (self.last_id) |id|
-                try std.fmt.bufPrint(&since_buf, "&since={d}", .{id})
-            else
-                "";
-            const url = try std.fmt.bufPrint(&url_buf, "{s}/rest/events?events=ItemFinished{s}", .{
-                self.config.syncthing_url, since,
-            });
-
             var al = std.ArrayList(u8).init(self.allocator);
             defer al.deinit();
 
             const response = client.fetch(.{
-                .location = .{ .url = url },
+                .location = .{ .url = poll_url },
                 .response_storage = .{ .dynamic = &al },
                 .headers = .{
                     .authorization = .{ .override = auth },