Skip to main content

diffler_core/
session.rs

1//! Review session: comments and per-file viewed marks, reconciled against
2//! fresh diff models. Persistence lives in `store`.
3
4use std::collections::BTreeMap;
5use std::time::{SystemTime, UNIX_EPOCH};
6
7use serde::{Deserialize, Serialize};
8
9use crate::model::DiffModel;
10
11#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
12#[serde(rename_all = "snake_case")]
13pub enum CommentStatus {
14    Open,
15    Replied,
16    Resolved,
17}
18
19#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
20pub struct Reply {
21    pub author: String,
22    pub body: String,
23    pub at: u64,
24    /// Forge-side id once synced/posted; `None` for purely local replies.
25    #[serde(default, skip_serializing_if = "Option::is_none")]
26    pub remote_id: Option<String>,
27}
28
29/// Where a comment is anchored. `line` (and `line_end` for visual ranges)
30/// is the new-side line number unless the line is a deletion, then it is
31/// the old-side number with `on_old_side`.
32#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
33pub struct Anchor {
34    pub file: String,
35    #[serde(default)]
36    pub line: Option<u32>,
37    #[serde(default)]
38    pub line_end: Option<u32>,
39    #[serde(default)]
40    pub on_old_side: bool,
41    /// Snapshot of the anchored line's text, so the UI can mark the
42    /// comment outdated when the agent rewrites the line.
43    #[serde(default)]
44    pub line_text: Option<String>,
45}
46
47impl Anchor {
48    /// Whether the anchor no longer matches the model. Range comments
49    /// anchor to their end line: that is the line whose disappearance or
50    /// `line_text` drift marks them outdated. A line-less anchor is
51    /// outdated only once the whole file leaves the diff.
52    pub fn is_outdated(&self, model: &DiffModel) -> bool {
53        match self.line_end.or(self.line) {
54            Some(line) => match model.find_line(&self.file, line, self.on_old_side) {
55                Some(found) => self
56                    .line_text
57                    .as_deref()
58                    .is_some_and(|snap| snap != found.text),
59                None => true,
60            },
61            None => !model.files.iter().any(|f| f.path == self.file),
62        }
63    }
64}
65
66#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
67pub struct Comment {
68    pub id: String,
69    pub author: String,
70    /// Forge-side id once synced/posted; `None` for purely local comments.
71    #[serde(default, skip_serializing_if = "Option::is_none")]
72    pub remote_id: Option<String>,
73    /// The forge's review-thread handle, where the forge has one — what
74    /// thread resolution posts against.
75    #[serde(default, skip_serializing_if = "Option::is_none")]
76    pub thread_id: Option<String>,
77    pub anchor: Anchor,
78    pub body: String,
79    pub status: CommentStatus,
80    #[serde(default)]
81    pub replies: Vec<Reply>,
82    pub at: u64,
83}
84
85#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
86pub struct Session {
87    #[serde(default)]
88    pub comments: Vec<Comment>,
89    /// Per-file viewed marks: path -> content hash of the new side at the
90    /// time of marking. A changed hash means the file needs re-review.
91    #[serde(default)]
92    pub viewed: BTreeMap<String, String>,
93}
94
95pub fn now_unix() -> u64 {
96    SystemTime::now()
97        .duration_since(UNIX_EPOCH)
98        .map_or(0, |d| d.as_secs())
99}
100
101impl Session {
102    pub fn add_comment(&mut self, anchor: Anchor, author: &str, body: &str) -> &Comment {
103        self.comments.push(Comment {
104            remote_id: None,
105            thread_id: None,
106            id: uuid::Uuid::new_v4().to_string(),
107            author: author.to_owned(),
108            anchor,
109            body: body.to_owned(),
110            status: CommentStatus::Open,
111            replies: Vec::new(),
112            at: now_unix(),
113        });
114        // just pushed, so the vec is non-empty
115        #[allow(clippy::expect_used)]
116        self.comments.last().expect("just pushed")
117    }
118
119    fn comment_mut(&mut self, comment_id: &str) -> Option<&mut Comment> {
120        self.comments.iter_mut().find(|c| c.id == comment_id)
121    }
122
123    /// Remove the comment with `id`; `true` when something was deleted.
124    pub fn delete_comment(&mut self, id: &str) -> bool {
125        let before = self.comments.len();
126        self.comments.retain(|c| c.id != id);
127        self.comments.len() != before
128    }
129
130    pub fn reply(&mut self, comment_id: &str, author: &str, body: &str) -> bool {
131        let Some(comment) = self.comment_mut(comment_id) else {
132            return false;
133        };
134        comment.replies.push(Reply {
135            remote_id: None,
136            author: author.to_owned(),
137            body: body.to_owned(),
138            at: now_unix(),
139        });
140        if comment.status == CommentStatus::Open {
141            comment.status = CommentStatus::Replied;
142        }
143        true
144    }
145
146    pub fn resolve(&mut self, comment_id: &str) -> bool {
147        let Some(comment) = self.comment_mut(comment_id) else {
148            return false;
149        };
150        comment.status = CommentStatus::Resolved;
151        true
152    }
153
154    /// Replace a comment's body in place (status, replies, and anchor are
155    /// kept). No author: an edit corrects the existing comment, it doesn't
156    /// attribute a new one.
157    pub fn edit_comment(&mut self, comment_id: &str, body: &str) -> bool {
158        let Some(comment) = self.comment_mut(comment_id) else {
159            return false;
160        };
161        body.clone_into(&mut comment.body);
162        true
163    }
164
165    pub fn mark_viewed(&mut self, path: &str, hash: &str) {
166        self.viewed.insert(path.to_owned(), hash.to_owned());
167    }
168
169    pub fn unmark_viewed(&mut self, path: &str) {
170        self.viewed.remove(path);
171    }
172
173    /// A stale hash means the file changed since it was marked: not viewed
174    /// anymore (auto-reset semantics).
175    pub fn is_viewed(&self, path: &str, current_hash: &str) -> bool {
176        self.viewed.get(path).is_some_and(|h| h == current_hash)
177    }
178
179    /// Drop viewed marks for files that left the diff or whose content
180    /// changed since marking. Comments are kept: they stay useful (possibly
181    /// flagged outdated) even when their file moves on.
182    pub fn reconcile(&mut self, model: &DiffModel) {
183        let live: BTreeMap<&str, String> = model
184            .files
185            .iter()
186            .map(|f| (f.path.as_str(), f.content_hash()))
187            .collect();
188        self.viewed
189            .retain(|path, hash| live.get(path.as_str()).is_some_and(|h| h == hash));
190    }
191}
192
193#[cfg(test)]
194mod tests {
195    use crate::model::{DiffLine, FileDiff, FileStatus, Hunk, HunkId, LineKind};
196    use crate::test_support::{anchor, file_diff};
197
198    use super::*;
199
200    fn model(files: Vec<FileDiff>) -> DiffModel {
201        DiffModel { files }
202    }
203
204    #[test]
205    fn comment_lifecycle_open_replied_resolved() {
206        let mut s = Session::default();
207        let id = s
208            .add_comment(anchor("a.txt", Some(3)), "reviewer", "why?")
209            .id
210            .clone();
211        assert_eq!(s.comments[0].status, CommentStatus::Open);
212        assert!(s.reply(&id, "agent", "because"));
213        assert_eq!(s.comments[0].status, CommentStatus::Replied);
214        assert!(s.resolve(&id));
215        assert_eq!(s.comments[0].status, CommentStatus::Resolved);
216        assert!(
217            s.comments
218                .iter()
219                .all(|c| c.status == CommentStatus::Resolved)
220        );
221    }
222
223    #[test]
224    fn reply_to_missing_comment_returns_false() {
225        let mut s = Session::default();
226        assert!(!s.reply("nope", "agent", "hi"));
227    }
228
229    #[test]
230    fn resolve_missing_comment_returns_false() {
231        let mut s = Session::default();
232        assert!(!s.resolve("nope"));
233    }
234
235    #[test]
236    fn edit_comment_replaces_body_and_keeps_status() {
237        let mut s = Session::default();
238        let id = s
239            .add_comment(anchor("a.txt", Some(3)), "reviewer", "old body")
240            .id
241            .clone();
242        assert!(s.reply(&id, "agent", "ack"));
243        assert!(s.edit_comment(&id, "new body"));
244        let c = s.comments.iter().find(|c| c.id == id).expect("comment");
245        assert_eq!(c.body, "new body");
246        assert_eq!(c.status, CommentStatus::Replied, "status is untouched");
247        assert_eq!(c.replies.len(), 1, "replies are untouched");
248        assert!(!s.edit_comment("nope", "x"));
249    }
250
251    #[test]
252    fn unresolved_comments_filters_resolved_only() {
253        let mut s = Session::default();
254        let keep = s
255            .add_comment(anchor("a.txt", Some(3)), "reviewer", "open")
256            .id
257            .clone();
258        let done = s
259            .add_comment(anchor("a.txt", Some(3)), "reviewer", "done")
260            .id
261            .clone();
262        assert!(s.resolve(&done));
263        let unresolved: Vec<_> = s
264            .comments
265            .iter()
266            .filter(|c| c.status != CommentStatus::Resolved)
267            .map(|c| c.id.clone())
268            .collect();
269        assert_eq!(unresolved, vec![keep]);
270    }
271
272    #[test]
273    fn session_serializes_round_trip_with_range_anchor() {
274        let mut s = Session::default();
275        let mut range = anchor("a.txt", Some(3));
276        range.line_end = Some(7);
277        s.add_comment(range, "reviewer", "this whole block");
278        s.mark_viewed("b.txt", "hash-b");
279        let json = serde_json::to_string(&s).expect("serialize");
280        let back: Session = serde_json::from_str(&json).expect("deserialize");
281        assert_eq!(s, back);
282        assert_eq!(back.comments[0].anchor.line_end, Some(7));
283    }
284
285    #[test]
286    fn is_viewed_true_for_same_hash_false_after_change() {
287        let mut s = Session::default();
288        s.mark_viewed("a.txt", "hash-1");
289        assert!(s.is_viewed("a.txt", "hash-1"));
290        assert!(!s.is_viewed("a.txt", "hash-2"));
291        assert!(!s.is_viewed("other.txt", "hash-1"));
292    }
293
294    #[test]
295    fn unmark_viewed_removes_entry() {
296        let mut s = Session::default();
297        s.mark_viewed("a.txt", "hash-1");
298        s.unmark_viewed("a.txt");
299        assert!(!s.is_viewed("a.txt", "hash-1"));
300    }
301
302    /// One file, one hunk: context(1/1), deleted(2), added(2), context(3/3).
303    fn hunked_model() -> DiffModel {
304        DiffModel {
305            files: vec![FileDiff {
306                path: "src/auth.py".into(),
307                old_path: None,
308                status: FileStatus::Modified,
309                binary: false,
310                old_text: None,
311                new_text: None,
312                hunks: vec![Hunk {
313                    id: HunkId("h1".into()),
314                    old_start: 1,
315                    old_lines: 3,
316                    new_start: 1,
317                    new_lines: 3,
318                    context: String::new(),
319                    lines: vec![
320                        DiffLine::new(LineKind::Context, Some(1), Some(1), "one".into()),
321                        DiffLine::new(LineKind::Deleted, Some(2), None, "two".into()),
322                        DiffLine::new(LineKind::Added, None, Some(2), "TWO".into()),
323                        DiffLine::new(LineKind::Context, Some(3), Some(3), "three".into()),
324                    ],
325                }],
326                hashes: crate::model::HashCache::default(),
327            }],
328        }
329    }
330
331    #[test]
332    fn anchor_with_matching_line_text_is_current() {
333        let mut a = anchor("src/auth.py", Some(2));
334        a.line_text = Some("TWO".to_owned());
335        assert!(!a.is_outdated(&hunked_model()));
336        // without a snapshot, a present line counts as current
337        a.line_text = None;
338        assert!(!a.is_outdated(&hunked_model()));
339    }
340
341    #[test]
342    fn anchor_with_drifted_line_text_is_outdated() {
343        let mut a = anchor("src/auth.py", Some(2));
344        a.line_text = Some("old text".to_owned());
345        assert!(a.is_outdated(&hunked_model()));
346    }
347
348    #[test]
349    fn anchor_to_a_departed_line_is_outdated() {
350        let a = anchor("src/auth.py", Some(99));
351        assert!(a.is_outdated(&hunked_model()));
352    }
353
354    #[test]
355    fn old_side_anchor_checks_the_old_line() {
356        let mut a = anchor("src/auth.py", Some(2));
357        a.on_old_side = true;
358        a.line_text = Some("two".to_owned());
359        assert!(!a.is_outdated(&hunked_model()));
360        a.line_text = Some("TWO".to_owned());
361        assert!(a.is_outdated(&hunked_model()), "old side carries 'two'");
362    }
363
364    #[test]
365    fn range_anchor_judges_drift_on_its_end_line() {
366        let mut a = anchor("src/auth.py", Some(1));
367        a.line_end = Some(3);
368        a.line_text = Some("three".to_owned());
369        assert!(!a.is_outdated(&hunked_model()), "end line still matches");
370        a.line_text = Some("changed".to_owned());
371        assert!(a.is_outdated(&hunked_model()), "end line drifted");
372    }
373
374    #[test]
375    fn file_level_anchor_is_outdated_only_when_the_file_departs() {
376        assert!(!anchor("src/auth.py", None).is_outdated(&hunked_model()));
377        assert!(anchor("gone.py", None).is_outdated(&hunked_model()));
378    }
379
380    #[test]
381    fn reconcile_drops_departed_and_changed_keeps_matching() {
382        let kept = file_diff("kept.txt", "stable content\n");
383        let changed = file_diff("changed.txt", "rewritten content\n");
384
385        let mut s = Session::default();
386        s.mark_viewed("kept.txt", &kept.content_hash());
387        s.mark_viewed("changed.txt", "hash-of-old-content");
388        s.mark_viewed("departed.txt", "whatever");
389        s.add_comment(
390            anchor("departed.txt", Some(3)),
391            "reviewer",
392            "still relevant",
393        );
394
395        s.reconcile(&model(vec![kept, changed]));
396
397        assert!(s.viewed.contains_key("kept.txt"));
398        assert!(!s.viewed.contains_key("changed.txt"));
399        assert!(!s.viewed.contains_key("departed.txt"));
400        // comments survive reconciliation untouched
401        assert_eq!(s.comments.len(), 1);
402    }
403}