Comment on diff lines in the Changes view

mac/Sources/Byre/Drafts.swift

@@ -11,6 +11,19 @@ private struct Saved: Codable {
     var composer: [String: Composer] = [:]
     var checked: [String: [String]] = [:]
     var texts: [String: String] = [:]
+    var comments: [String: [LineComment]]? = nil
+}
+
+struct LineAnchor: Codable, Hashable {
+    let path: String
+    let line: Int
+    let old: Bool
+    let quote: String
+}
+
+struct LineComment: Codable {
+    let anchor: LineAnchor
+    var text: String
 }
 
 final class DraftSend {
@@ -40,6 +53,7 @@ final class Drafts {
     private var lostImages: [String: Int] = [:]
     private var checked: [String: [String]] = [:]
     private var texts: [String: String] = [:]
+    private var comments: [String: [LineComment]] = [:]
     @ObservationIgnored private let scope: String
     @ObservationIgnored private var timer: Task<Void, Never>?
     @ObservationIgnored private var dirty = false
@@ -59,6 +73,7 @@ final class Drafts {
         }
         checked = saved.checked
         texts = saved.texts
+        comments = saved.comments ?? [:]
     }
 
     func reload() {
@@ -94,6 +109,10 @@ final class Drafts {
                 changed = true
             }
         }
+        for taskId in comments.keys where store.findTask(taskId)?.status != .active {
+            comments[taskId] = nil
+            changed = true
+        }
         for id in Set(checked.keys).union(texts.keys) where !store.inbox.contains(where: { $0.id == id }) {
             checked[id] = nil
             texts[id] = nil
@@ -122,7 +141,7 @@ final class Drafts {
             return
         }
         dirty = false
-        var out = Saved(checked: checked, texts: texts)
+        var out = Saved(checked: checked, texts: texts, comments: comments)
         let keys = Set(composerTexts.keys).union(composerImages.keys).union(sending.map(\.key)).union(lostImages.keys)
         for key in keys {
             let inFlight = sending.filter { $0.key == key }
@@ -233,6 +252,67 @@ final class Drafts {
         save()
     }
 
+    func lineComments(_ taskId: String) -> [LineComment] {
+        comments[taskId] ?? []
+    }
+
+    func lineComment(_ taskId: String, _ anchor: LineAnchor) -> LineComment? {
+        comments[taskId]?.first { $0.anchor == anchor }
+    }
+
+    func toggleLineComment(_ taskId: String, _ anchor: LineAnchor) {
+        var list = comments[taskId] ?? []
+        if let i = list.firstIndex(where: { $0.anchor == anchor }) {
+            if !trimmed(list[i].text).isEmpty {
+                return
+            }
+            list.remove(at: i)
+        } else {
+            list.append(LineComment(anchor: anchor, text: ""))
+        }
+        comments[taskId] = list.isEmpty ? nil : list
+        save()
+    }
+
+    func setLineComment(_ taskId: String, _ anchor: LineAnchor, _ text: String) {
+        guard let i = comments[taskId]?.firstIndex(where: { $0.anchor == anchor }), comments[taskId]![i].text != text else {
+            return
+        }
+        comments[taskId]![i].text = text
+        save()
+    }
+
+    func dropLineComment(_ taskId: String, _ anchor: LineAnchor) {
+        comments[taskId]?.removeAll { $0.anchor == anchor }
+        if comments[taskId]?.isEmpty == true {
+            comments[taskId] = nil
+        }
+        save()
+    }
+
+    func takeLineComments(_ taskId: String) -> [LineComment] {
+        let all = comments[taskId] ?? []
+        let ready = all.filter { !trimmed($0.text).isEmpty }
+        let rest = all.filter { trimmed($0.text).isEmpty }
+        comments[taskId] = rest.isEmpty ? nil : rest
+        dirty = true
+        flush()
+        return ready
+    }
+
+    func restoreLineComments(_ taskId: String, _ back: [LineComment]) {
+        var list = back
+        for c in comments[taskId] ?? [] {
+            if let i = list.firstIndex(where: { $0.anchor == c.anchor }) {
+                list[i].text = [list[i].text, c.text].filter { !trimmed($0).isEmpty }.joined(separator: "\n\n")
+            } else {
+                list.append(c)
+            }
+        }
+        comments[taskId] = list
+        save()
+    }
+
     func clearAnswer(_ id: String) {
         checked[id] = nil
         texts[id] = nil