chore: and reconcile pushes with server only refs

CHANGELOG.md

@@ -13,6 +13,7 @@
 - Allow choosing the default branch when publishing a repository
 - Detect when local commits are not on Nostr yet, showing an unsynced count badge on sidebar repository rows and a Sync now banner on the repository view
 - Add a step-by-step push checklist while publishing and syncing a repository
+- Add a `Reset remote to local` action that republishes the mirror and deletes grasp refs the mirror does not have
 
 ### Changed
 
@@ -35,6 +36,8 @@
 - Fix opening a repository failing with a `destination already exists` error when two loads raced to clone its mirror, clones are now serialized and later loads reuse the finished clone
 - Fix a repository never opening again after an interrupted clone left an unusable mirror directory behind, which is now removed and re-cloned
 - Fix signing in with a `bunker://` URI silently generating a new identity instead of erroring when its master key cannot be parsed
+- Fix repository sync failing with `state event in purgatory ... doesn't match push` when grasp servers hold branches or tags the local repository lacks
+- Fix sync failing with `could not fetch refs/tags/...^{}` on repositories with annotated tags, where the peel entries `git ls-remote` reports for annotated tags were mistaken for missing refs
 
 ### Removed
 

crates/signed_git/src/repo.rs

@@ -1222,22 +1222,25 @@ impl Repo {
             base_url,
             owner,
             repo_id,
-            &["refs/heads/main:refs/heads/main"],
+            &["+refs/heads/main:refs/heads/main"],
         )
     }
 
     /// Mirrors all branches and tags to the grasp repository at `base_url`.
+    ///
+    /// Force refspecs keep the server ref map following the local repository,
+    /// grasp authorizes pushes by ref map equality, not fast-forwards.
     pub fn push_all(&self, base_url: &str, owner: &str, repo_id: &str) -> Result<()> {
         self.push_refspecs(
             base_url,
             owner,
             repo_id,
-            &["refs/heads/*:refs/heads/*", "refs/tags/*:refs/tags/*"],
+            &["+refs/heads/*:refs/heads/*", "+refs/tags/*:refs/tags/*"],
         )
     }
 
     /// Pushes explicit refspecs to the grasp repository at `base_url`.
-    fn push_refspecs(
+    pub fn push_refspecs(
         &self,
         base_url: &str,
         owner: &str,
@@ -1262,6 +1265,33 @@ impl Repo {
         Ok(())
     }
 
+    /// Lists branches and tags advertised by the remote at `url`.
+    pub fn ls_remote(&self, url: &str) -> Result<Vec<(String, String)>> {
+        let url = Self::transport_url(url);
+        let output = Self::run_git(self.workdir_or_dot(), &["ls-remote", &url], "git ls-remote")?;
+
+        if !output.status.success() {
+            bail!(
+                "git ls-remote on {url} failed: {}",
+                String::from_utf8_lossy(&output.stderr).trim()
+            );
+        }
+
+        let refs = String::from_utf8_lossy(&output.stdout)
+            .lines()
+            .filter_map(|line| {
+                let (oid, name) = line.split_once('\t')?;
+                let name = name.trim();
+
+                (name.starts_with("refs/heads/") || name.starts_with("refs/tags/"))
+                    .then(|| (name.to_owned(), oid.to_owned()))
+                    .filter(|(name, _)| !name.ends_with("^{}"))
+            })
+            .collect();
+
+        Ok(refs)
+    }
+
     /// Sets the `origin` URL when the repository has no remote yet.
     pub fn ensure_origin(&self, url: &str) -> Result<()> {
         if self.inner.find_remote("origin").is_ok() {

crates/signed_git/src/tests.rs

@@ -122,6 +122,166 @@ fn push_all_mirrors_branches_and_tags() {
     assert!(refs.contains("refs/tags/v1.0"));
 }
 
+#[test]
+fn ls_remote_lists_branches_and_tags_only() {
+    let server = tempfile::tempdir().unwrap();
+    let server_repo = bare_server(server.path(), "npub1test", "my-repo");
+
+    let (dir, repo) = fixture(&[("a.txt", b"one")]);
+    commit_all(&repo, "initial");
+    let dir = dir.path();
+
+    git_run(dir, &["branch", "feature"]);
+    git_run(dir, &["tag", "v1"]);
+    git_run(dir, &["tag", "-a", "v2", "-m", "annotated"]);
+
+    let base_url = format!("file://{}", server.path().display());
+    let local = Repo::open(dir).expect("open");
+    local
+        .push_all(&base_url, "npub1test", "my-repo")
+        .expect("push");
+
+    // Refs outside heads and tags, and the HEAD symref line, are not listed.
+    let main = git_in(dir, &["rev-parse", "refs/heads/main"]).expect("main oid");
+    git_run(&server_repo, &["update-ref", "refs/nostr/abc", &main]);
+
+    let remote = local
+        .ls_remote(&format!("file://{}", server_repo.display()))
+        .expect("ls-remote");
+    let names: Vec<String> = remote.iter().map(|(name, _)| name.clone()).collect();
+
+    assert_eq!(
+        names,
+        vec![
+            "refs/heads/feature".to_owned(),
+            "refs/heads/main".to_owned(),
+            "refs/tags/v1".to_owned(),
+            "refs/tags/v2".to_owned(),
+        ]
+    );
+    assert_eq!(
+        remote
+            .iter()
+            .find(|(name, _)| name == "refs/heads/main")
+            .map(|(_, oid)| oid.as_str()),
+        Some(main.as_str())
+    );
+    // The annotated tag lists the tag object, matching the local ref state,
+    // without a peeled `^{}` duplicate.
+    let v2 = git_in(dir, &["rev-parse", "refs/tags/v2"]).expect("v2 oid");
+    assert_eq!(
+        remote
+            .iter()
+            .find(|(name, _)| name == "refs/tags/v2")
+            .map(|(_, oid)| oid.as_str()),
+        Some(v2.as_str())
+    );
+}
+
+#[test]
+fn push_all_force_updates_diverged_remote_branches() {
+    let server = tempfile::tempdir().unwrap();
+    let server_repo = bare_server(server.path(), "npub1test", "my-repo");
+
+    let (dir, repo) = fixture(&[("a.txt", b"one")]);
+    commit_all(&repo, "initial");
+    std::fs::write(dir.path().join("b.txt"), b"two").expect("write");
+    commit_all(&repo, "second");
+    let dir = dir.path();
+
+    let base_url = format!("file://{}", server.path().display());
+    let local = Repo::open(dir).expect("open");
+    local
+        .push_all(&base_url, "npub1test", "my-repo")
+        .expect("initial push");
+
+    // Diverge local main from the pushed state.
+    git_run(dir, &["reset", "-q", "--hard", "HEAD~1"]);
+    std::fs::write(dir.join("c.txt"), b"three").expect("write");
+    commit_all(&repo, "diverged");
+
+    local
+        .push_all(&base_url, "npub1test", "my-repo")
+        .expect("force push");
+
+    assert_eq!(
+        git_in(dir, &["rev-parse", "refs/heads/main"]).expect("local main"),
+        git_in(&server_repo, &["rev-parse", "refs/heads/main"]).expect("server main")
+    );
+}
+
+#[test]
+fn push_refspecs_deletes_server_refs_missing_locally() {
+    let server = tempfile::tempdir().unwrap();
+    let server_repo = bare_server(server.path(), "npub1test", "my-repo");
+
+    let (dir, repo) = fixture(&[("a.txt", b"one")]);
+    commit_all(&repo, "initial");
+    let dir = dir.path();
+
+    git_run(dir, &["branch", "feature"]);
+    git_run(dir, &["tag", "v1"]);
+
+    let base_url = format!("file://{}", server.path().display());
+    let local = Repo::open(dir).expect("open");
+    local
+        .push_all(&base_url, "npub1test", "my-repo")
+        .expect("initial push");
+
+    git_run(dir, &["branch", "-D", "feature"]);
+    git_run(dir, &["tag", "-d", "v1"]);
+
+    local
+        .push_refspecs(
+            &base_url,
+            "npub1test",
+            "my-repo",
+            &[
+                "+refs/heads/*:refs/heads/*",
+                "+refs/tags/*:refs/tags/*",
+                ":refs/heads/feature",
+                ":refs/tags/v1",
+            ],
+        )
+        .expect("push with deletions");
+
+    let refs = git_in(&server_repo, &["show-ref"]).expect("server refs");
+    assert!(refs.contains("refs/heads/main"));
+    assert!(!refs.contains("refs/heads/feature"));
+    assert!(!refs.contains("refs/tags/v1"));
+}
+
+#[test]
+fn fetch_refs_brings_server_only_branches_into_local() {
+    let server = tempfile::tempdir().unwrap();
+    bare_server(server.path(), "npub1test", "my-repo");
+
+    let (dir, repo) = fixture(&[("a.txt", b"one")]);
+    commit_all(&repo, "initial");
+    let dir = dir.path();
+    git_run(dir, &["branch", "feature"]);
+
+    let base_url = format!("file://{}", server.path().display());
+    Repo::open(dir)
+        .expect("open")
+        .push_all(&base_url, "npub1test", "my-repo")
+        .expect("push");
+    let feature = git_in(dir, &["rev-parse", "refs/heads/feature"]).expect("feature oid");
+
+    // A repository that never had the branch fetches it by name.
+    let (other_dir, _other_repo) = fixture(&[("unrelated.txt", b"x")]);
+    let other = Repo::open(other_dir.path()).expect("open other");
+    let server_url = format!("file://{}/npub1test/my-repo.git", server.path().display());
+    other
+        .fetch_refs(&[&server_url], "+refs/heads/feature:refs/heads/feature")
+        .expect("fetch ref");
+
+    assert_eq!(
+        git_in(other_dir.path(), &["rev-parse", "refs/heads/feature"]).expect("fetched feature"),
+        feature
+    );
+}
+
 #[test]
 fn ref_state_matches_the_git_cli_ref_listing() {
     let (dir, repo) = fixture(&[("a.txt", b"one")]);

crates/signed_state/src/backend.rs

@@ -21,7 +21,7 @@ use crate::git_store::Mirrors;
 use crate::inbox::Inbox;
 use crate::push::{PushOutcome, grasp_base_url, grasp_clone_url};
 use crate::repos::RepoListStore;
-use crate::state::{GitPushMode, GitRef, PushStepStatus, SyncState};
+use crate::state::{GitPushMode, GitPushPolicy, GitRef, PushStepStatus, SyncState};
 
 pub const USER_KEYRING: &str = "Signed Safe Storage";
 pub const NOSTR_CONNECT_TIMEOUT: u64 = 60;
@@ -588,6 +588,7 @@ impl Backend {
                 head: Some("main".to_owned()),
                 path: Some(destination.clone()),
                 mode: GitPushMode::Main,
+                policy: GitPushPolicy::default(),
             };
 
             let on_step = &mut |status: PushStepStatus, cx: &mut AsyncApp| {
@@ -735,7 +736,17 @@ impl Backend {
         cx: &mut Context<Self>,
     ) -> Task<Result<PushOutcome, Error>> {
         let path = Mirrors::path(&announcement.addr());
-        self.push_repo_from(announcement, path, None, cx)
+        self.push_repo_from(announcement, path, None, GitPushPolicy::Reconcile, cx)
+    }
+
+    /// Republishes the mirror and deletes grasp refs the mirror does not have.
+    pub fn reset_repository(
+        &mut self,
+        announcement: Announcement,
+        cx: &mut Context<Self>,
+    ) -> Task<Result<PushOutcome, Error>> {
+        let path = Mirrors::path(&announcement.addr());
+        self.push_repo_from(announcement, path, None, GitPushPolicy::ResetRemote, cx)
     }
 
     pub fn push_checkout(
@@ -745,7 +756,13 @@ impl Backend {
         announced_head: Option<String>,
         cx: &mut Context<Self>,
     ) -> Task<Result<PushOutcome, Error>> {
-        self.push_repo_from(announcement, checkout, announced_head, cx)
+        self.push_repo_from(
+            announcement,
+            checkout,
+            announced_head,
+            GitPushPolicy::Reconcile,
+            cx,
+        )
     }
 
     fn push_repo_from(
@@ -753,6 +770,7 @@ impl Backend {
         announcement: Announcement,
         path: PathBuf,
         announced_head: Option<String>,
+        policy: GitPushPolicy,
         cx: &mut Context<Self>,
     ) -> Task<Result<PushOutcome, Error>> {
         let addr = announcement.addr();
@@ -789,6 +807,11 @@ impl Backend {
                 });
                 work.await?
             };
+            state.policy = policy;
+
+            // Fetch grasp refs the local repository lacks before the state event is signed,
+            // so the servers' full ref map is declared.
+            state.reconcile(&announcement, cx).await?;
 
             // Keep the announced default branch in `HEAD` when it is among the pushed refs.
             if let Some(head) = announced_head

crates/signed_state/src/lib.rs

@@ -28,7 +28,7 @@ pub use repo::RepoStore;
 pub use repos::RepoListStore;
 pub use signed_git::{Nip34Binding, Nip34Kind};
 use signed_nostr::NostrBackend;
-pub use state::{GitPushMode, GitRef, PushStep, PushStepStatus, SyncState};
+pub use state::{GitPushMode, GitPushPolicy, GitRef, PushStep, PushStepStatus, SyncState};
 pub use sync_status::{CheckoutSyncStatus, SyncEvent, SyncStatusDirectory, SyncStatusStore};
 
 pub fn init(

crates/signed_state/src/repo.rs

@@ -1172,6 +1172,24 @@ impl RepoStore {
         self.run_push(push, None, cx)
     }
 
+    /// Republishes the mirror and deletes grasp refs the mirror does not have.
+    pub fn reset_repository(&mut self, cx: &mut Context<Self>) -> Task<Result<(), Error>> {
+        if self.pushing {
+            return Task::ready(Err(anyhow::anyhow!(
+                "A push to this repository is already in progress"
+            )));
+        }
+
+        let Some(announcement) = self.action_announcement(cx) else {
+            return self.action_error("Repository announcement is not loaded yet", cx);
+        };
+
+        let backend = Backend::global(cx);
+        let push = backend.update(cx, |backend, cx| backend.reset_repository(announcement, cx));
+
+        self.run_push(push, None, cx)
+    }
+
     pub fn push_checkout(
         &mut self,
         path: PathBuf,

crates/signed_state/src/state.rs

@@ -40,6 +40,17 @@ pub enum GitPushMode {
     Main,
 }
 
+/// How to handle server-only refs when pushing.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub enum GitPushPolicy {
+    /// Reconcile the local refs with the grasp servers,
+    /// fetching missing refs before pushing.
+    #[default]
+    Reconcile,
+    /// Declare the local refs only and delete server-only refs while pushing.
+    ResetRemote,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct SyncState {
     pub refs: Vec<GitRef>,
@@ -47,6 +58,7 @@ pub struct SyncState {
     /// Local repository to push from; `None` for states parsed from events.
     pub path: Option<PathBuf>,
     pub mode: GitPushMode,
+    pub policy: GitPushPolicy,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -135,6 +147,7 @@ impl SyncState {
             head,
             path: None,
             mode: GitPushMode::default(),
+            policy: GitPushPolicy::default(),
         }
     }
 
@@ -154,6 +167,7 @@ impl SyncState {
             head: state.head,
             path: Some(path.to_path_buf()),
             mode: GitPushMode::default(),
+            policy: GitPushPolicy::default(),
         })
     }
 
@@ -162,13 +176,127 @@ impl SyncState {
         self
     }
 
+    pub fn with_policy(mut self, policy: GitPushPolicy) -> Self {
+        self.policy = policy;
+        self
+    }
+
+    /// Reconciles the local repository with the grasp servers, fetching missing refs.
+    pub async fn reconcile(
+        &mut self,
+        announcement: &Announcement,
+        cx: &mut AsyncApp,
+    ) -> Result<(), Error> {
+        if self.policy == GitPushPolicy::ResetRemote || self.refs.is_empty() {
+            return Ok(());
+        }
+
+        let Some(path) = self.path.clone() else {
+            return Ok(());
+        };
+
+        let local: Vec<(String, String)> = self
+            .refs
+            .iter()
+            .map(|git_ref| (git_ref.name.clone(), git_ref.commit.to_string()))
+            .collect();
+
+        let urls: Vec<String> = announcement
+            .clone
+            .iter()
+            .map(|url| url.to_string())
+            .collect();
+
+        let snapshot_path = path.clone();
+
+        let missing = cx
+            .background_spawn(async move {
+                let repo = Repo::open(&path)?;
+
+                // Refs the servers advertise that the local repository lacks
+                let mut missing: Vec<(String, Vec<String>)> = Vec::new();
+                // Diverged server tips that exist only on the servers
+                let mut backups: Vec<(String, String, Vec<String>)> = Vec::new();
+
+                for url in &urls {
+                    let Ok(remote_refs) = repo.ls_remote(url) else {
+                        continue;
+                    };
+
+                    for (name, oid) in remote_refs {
+                        let Some((_, local_oid)) =
+                            local.iter().find(|(local_name, _)| local_name == &name)
+                        else {
+                            match missing.iter_mut().find(|(known, _)| known == &name) {
+                                Some((_, sources)) => sources.push(url.clone()),
+                                None => missing.push((name, vec![url.clone()])),
+                            }
+                            continue;
+                        };
+
+                        if local_oid == &oid {
+                            continue;
+                        }
+
+                        if repo.merge_base(local_oid, &oid).is_err() {
+                            match backups.iter_mut().find(|(known, _, _)| known == &name) {
+                                Some((_, _, sources)) => sources.push(url.clone()),
+                                None => {
+                                    backups.push((name.clone(), oid.clone(), vec![url.clone()]))
+                                }
+                            }
+                        }
+                    }
+                }
+
+                let mut failures = Vec::new();
+
+                for (name, sources) in &missing {
+                    let refspec = format!("+{name}:{name}");
+                    if let Err(error) = repo.fetch_refs(sources, &refspec) {
+                        log::warn!("failed to fetch {name} from grasp servers: {error}");
+                        failures.push(name.clone());
+                    }
+                }
+
+                for (name, oid, sources) in &backups {
+                    let refspec = format!("+{name}:refs/nostr/backup/{oid}");
+                    if let Err(error) = repo.fetch_refs(sources, &refspec) {
+                        log::warn!("failed to back up {name} from grasp servers: {error}");
+                    }
+                }
+
+                match failures.is_empty() {
+                    true => Ok(missing
+                        .into_iter()
+                        .map(|(name, _)| name)
+                        .collect::<Vec<_>>()),
+                    false => bail!(
+                        "could not fetch {} from any grasp server",
+                        failures.join(", ")
+                    ),
+                }
+            })
+            .await?;
+
+        if !missing.is_empty() {
+            let (mode, policy) = (self.mode, self.policy);
+            *self = Self::from_repo(&snapshot_path)?;
+            self.mode = mode;
+            self.policy = policy;
+        }
+
+        Ok(())
+    }
+
     /// State event for these refs; the caller signs it.
     pub fn state_event(&self, repo_id: &str) -> EventBuilder {
         Self::build(repo_id, &self.refs, self.head.as_deref())
     }
 
-    /// Push the state event and objects to the grasp servers,
-    /// calling `on_step` for each step.
+    /// Push the state event and objects to the grasp servers.
+    ///
+    /// Calling `on_step` for each step.
     pub async fn push_to_grasps<P>(
         &self,
         client: &Client,
@@ -191,6 +319,12 @@ impl SyncState {
             .map_err(|error| anyhow!("could not encode the repository owner: {error}"))?;
 
         let mut outcome = PushOutcome::default();
+        let policy = self.policy;
+        let declared: Vec<String> = self
+            .refs
+            .iter()
+            .map(|git_ref| git_ref.name.clone())
+            .collect();
 
         for relay in &announcement.relays {
             let step = PushStep::StageStateEvent(relay.clone());
@@ -241,12 +375,24 @@ impl SyncState {
                 let owner = owner.clone();
                 let repo_id = announcement.id.clone();
                 let mode = self.mode;
+                let declared = declared.clone();
 
                 async move {
                     let repo = Repo::open(&path)?;
+
                     match mode {
                         GitPushMode::Main => repo.push_main(&base, &owner, &repo_id),
-                        GitPushMode::All => repo.push_all(&base, &owner, &repo_id),
+                        GitPushMode::All => {
+                            let mut refspecs = force_refspecs();
+                            if policy == GitPushPolicy::ResetRemote {
+                                let url = format!("{base}/{owner}/{repo_id}.git");
+                                let server_refs = repo.ls_remote(&url)?;
+                                refspecs.extend(deletion_refspecs(&declared, &server_refs));
+                            }
+
+                            let refspecs = refspecs.iter().map(String::as_str).collect::<Vec<_>>();
+                            repo.push_refspecs(&base, &owner, &repo_id, &refspecs)
+                        }
                     }
                 }
             });
@@ -370,75 +516,19 @@ impl SyncState {
     }
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    const COMMIT_A: &str = "aa231c4c6a5777dc89b42207b499891a344add5c";
-    const COMMIT_B: &str = "59429cfc6cb35b0a1ddace73b5a5c5ed57b8f5ca";
-
-    fn git_ref(name: &str, commit: &str) -> GitRef {
-        GitRef::new(name, commit).expect("valid ref")
-    }
-
-    fn keys() -> Keys {
-        Keys::new(
-            SecretKey::from_hex("0000000000000000000000000000000000000000000000000000000000000001")
-                .expect("valid secret key"),
-        )
-    }
-
-    fn state_event(tags: &[&[&str]]) -> Event {
-        let tags: Vec<Tag> = tags
-            .iter()
-            .map(|t| Tag::parse(t.to_vec()).expect("valid tag"))
-            .collect();
-
-        EventBuilder::new(Kind::RepoState, "")
-            .tags(tags)
-            .finalize(&keys())
-            .expect("signed event")
-    }
-
-    #[test]
-    fn parses_heads_and_tags() {
-        let event = state_event(&[
-            &["HEAD", "ref: refs/heads/main"],
-            &["refs/heads/main", COMMIT_A],
-            &["refs/heads/dev", COMMIT_B],
-            &["refs/tags/v1.0", COMMIT_A],
-        ]);
-
-        let state = SyncState::parse(&event);
-
-        assert_eq!(state.head.as_deref(), Some("main"));
-        assert_eq!(
-            state.refs,
-            vec![
-                git_ref("refs/heads/main", COMMIT_A),
-                git_ref("refs/heads/dev", COMMIT_B),
-                git_ref("refs/tags/v1.0", COMMIT_A),
-            ]
-        );
-    }
-
-    #[test]
-    fn build_round_trips_through_parse() {
-        let refs = vec![
-            git_ref("refs/heads/main", COMMIT_A),
-            git_ref("refs/heads/dev", COMMIT_B),
-            git_ref("refs/tags/v1.0", COMMIT_A),
-        ];
-
-        let event = SyncState::build("my-repo", &refs, Some("main"))
-            .finalize(&keys())
-            .expect("signed event");
-
-        assert_eq!(event.kind, Kind::RepoState);
-        assert_eq!(event.tags.identifier().as_deref(), Some("my-repo"));
-
-        let state = SyncState::parse(&event);
-        assert_eq!(state.refs, refs);
-        assert_eq!(state.head.as_deref(), Some("main"));
-    }
+/// Refspecs to force push all heads and tags to the grasp servers.
+fn force_refspecs() -> Vec<String> {
+    vec![
+        "+refs/heads/*:refs/heads/*".to_owned(),
+        "+refs/tags/*:refs/tags/*".to_owned(),
+    ]
+}
+
+/// Refspecs to delete server-only refs from the grasp servers.
+fn deletion_refspecs(declared: &[String], server_refs: &[(String, String)]) -> Vec<String> {
+    server_refs
+        .iter()
+        .filter(|(name, _)| !declared.contains(name))
+        .map(|(name, _)| format!(":{name}"))
+        .collect()
 }

crates/workspace/src/views/repo/mod.rs

@@ -15,10 +15,12 @@ use gpui_base::{Button as BaseButton, Disableable, Popover};
 use gpui_component::alert::Alert;
 use gpui_component::button::{Button, ButtonVariants};
 use gpui_component::combobox::{Combobox, ComboboxEvent};
+use gpui_component::dialog::{DialogDescription, DialogFooter, DialogHeader, DialogTitle};
 use gpui_component::menu::{DropdownMenu, PopupMenu};
 use gpui_component::spinner::Spinner;
 use gpui_component::{
-    ActiveTheme, Colorize, Icon, IconName, Sizable, StyledExt, ThemeStyled, h_flex, v_flex,
+    ActiveTheme, Colorize, Icon, IconName, Sizable, StyledExt, ThemeStyled, WindowExt, h_flex,
+    v_flex,
 };
 use metadata::ProfileDirectory;
 use nostr::nips::nip19::Nip19Coordinate;
@@ -72,6 +74,7 @@ pub(crate) enum RepoAction {
     SendPatch,
     About,
     Push,
+    ResetRemote,
     Delete,
 }
 
@@ -841,6 +844,63 @@ impl RepoDetailView {
         self.tasks.push(task);
     }
 
+    pub(super) fn reset_remote(&mut self, window: &mut Window, cx: &mut Context<Self>) {
+        let Some(announcement) = self.announcement(cx).cloned() else {
+            return;
+        };
+
+        let store = self.store.clone();
+        let mirror = Mirrors::path(&announcement.addr());
+
+        let urls: Vec<String> = announcement
+            .clone
+            .iter()
+            .map(|url| url.to_string())
+            .collect();
+
+        let probe = cx.background_spawn(async move {
+            let mut deleted: Vec<String> = Vec::new();
+            let repo = Repo::open(&mirror)?;
+
+            let local: HashSet<String> = repo
+                .ref_state()?
+                .refs
+                .into_iter()
+                .map(|(name, _)| name)
+                .collect();
+
+            for url in &urls {
+                let Ok(remote_refs) = repo.ls_remote(url) else {
+                    continue;
+                };
+                for (name, _) in remote_refs {
+                    if !local.contains(&name) && !deleted.contains(&name) {
+                        deleted.push(name);
+                    }
+                }
+            }
+
+            deleted.sort();
+
+            Ok::<_, Error>(deleted)
+        });
+
+        cx.spawn_in(window, async move |this, cx| {
+            let deleted = probe.await;
+
+            this.update_in(cx, |this, window, cx| match deleted {
+                Ok(deleted) => open_reset_remote_dialog(store, deleted, window, cx),
+                Err(error) => {
+                    this.error = Some(error.to_string().into());
+                    cx.notify();
+                }
+            })?;
+
+            Ok::<(), Error>(())
+        })
+        .detach();
+    }
+
     /// Delete the repository from nostr, announcement, state and activity.
     pub(super) fn delete_repository(&mut self, _window: &mut Window, cx: &mut Context<Self>) {
         let task = self
@@ -971,6 +1031,7 @@ impl RepoDetailView {
                         }
                     }
                     RepoAction::Push => this.push_repository(window, cx),
+                    RepoAction::ResetRemote => this.reset_remote(window, cx),
                     RepoAction::Delete => this.delete_repository(window, cx),
                 }),
             )
@@ -1173,6 +1234,16 @@ impl RepoDetailView {
                                                     .child(Icon::new(CustomIconName::Init))
                                                     .child("Republish")
                                             })
+                                            .menu_element(
+                                                Box::new(RepoAction::ResetRemote),
+                                                |_, _| {
+                                                    h_flex()
+                                                        .gap_2()
+                                                        .text_sm()
+                                                        .child(Icon::new(IconName::RefreshCw))
+                                                        .child("Reset remote to local")
+                                                },
+                                            )
                                             .separator()
                                             .menu_element(Box::new(RepoAction::Delete), |_, cx| {
                                                 h_flex()
@@ -2043,6 +2114,75 @@ impl RepoDetailView {
     }
 }
 
+/// Confirmation for the remote reset, listing the server refs it deletes.
+fn open_reset_remote_dialog(
+    store: Entity<RepoStore>,
+    deleted: Vec<String>,
+    window: &mut Window,
+    cx: &mut App,
+) {
+    const DESC: &str = "Grasp servers are overwritten to match the local mirror. \
+         Refs that do not exist locally are deleted from the servers. \
+         This cannot be undone.";
+
+    window.open_dialog(cx, move |dialog, _window, _cx| {
+        let deleted = deleted.clone();
+        let store = store.clone();
+
+        dialog
+            .w(px(480.))
+            .keyboard(true)
+            .close_button(true)
+            .content(move |body, _window, cx| {
+                let deleted = deleted.clone();
+                let store = store.clone();
+
+                body.child(
+                    DialogHeader::new()
+                        .child(DialogTitle::new().child("Reset remote to local"))
+                        .child(DialogDescription::new().child(DESC)),
+                )
+                .child(if deleted.is_empty() {
+                    div()
+                        .text_sm()
+                        .text_color(cx.theme().muted_foreground)
+                        .child("No server refs will be deleted.")
+                        .into_any_element()
+                } else {
+                    v_flex()
+                        .gap_1()
+                        .children(deleted.iter().map(|name| {
+                            div()
+                                .text_sm()
+                                .font_family(cx.theme().mono_font_family.clone())
+                                .child(name.clone())
+                        }))
+                        .into_any_element()
+                })
+                .child(
+                    DialogFooter::new()
+                        .justify_end()
+                        .child(Button::new("cancel-reset-remote").label("Cancel").on_click(
+                            |_, window, cx| {
+                                window.close_dialog(cx);
+                            },
+                        ))
+                        .child(
+                            Button::new("confirm-reset-remote")
+                                .danger()
+                                .label("Reset remote")
+                                .on_click(move |_, window, cx| {
+                                    store.update(cx, |store, cx| {
+                                        store.reset_repository(cx).detach_and_log_err(cx);
+                                    });
+                                    window.close_dialog(cx);
+                                }),
+                        ),
+                )
+            })
+    });
+}
+
 fn nostr_clone_url(announcement: &Announcement, nip05: Option<&str>) -> SharedString {
     let owner = announcement.owner;
     let user = nip05