refactor similar RepostsModel and ReactionsModel into one parent class

Closes: #650

damus/Models/EventsModel.swift

@@ -9,9 +9,63 @@ import Foundation
 
 
 class EventsModel: ObservableObject {
-    var has_event: Set<String> = Set()
+    let state: DamusState
+    let target: String
+    let kind: NostrKind
+    let sub_id = UUID().uuidString
+    let profiles_id = UUID().uuidString
+    
     @Published var events: [NostrEvent] = []
     
-    init() {
+    init(state: DamusState, target: String, kind: NostrKind) {
+        self.state = state
+        self.target = target
+        self.kind = kind
+    }
+    
+    private func get_filter() -> NostrFilter {
+        var filter = NostrFilter.filter_kinds([kind.rawValue])
+        filter.referenced_ids = [target]
+        filter.limit = 500
+        return filter
+    }
+    
+    func subscribe() {
+        state.pool.subscribe(sub_id: sub_id,
+                             filters: [get_filter()],
+                             handler: handle_nostr_event)
+    }
+    
+    func unsubscribe() {
+        state.pool.unsubscribe(sub_id: sub_id)
+    }
+    
+    private func handle_event(relay_id: String, ev: NostrEvent) {
+        guard ev.kind == kind.rawValue else {
+            return
+        }
+        
+        guard last_etag(tags: ev.tags) == target else {
+            return
+        }
+        
+        if insert_uniq_sorted_event(events: &self.events, new_ev: ev, cmp: { a, b in a.created_at < b.created_at } ) {
+            objectWillChange.send()
+        }
+    }
+    
+    func handle_nostr_event(relay_id: String, ev: NostrConnectionEvent) {
+        guard case .nostr_event(let nev) = ev else {
+            return
+        }
+        
+        switch nev {
+        case .event(_, let ev):
+            handle_event(relay_id: relay_id, ev: ev)
+        case .notice(_):
+            break
+        case .eose(_):
+            load_profiles(profiles_subid: profiles_id, relay_id: relay_id, events: events, damus_state: state)
+        }
     }
 }