tui: Add module providing access to patch cob

Signed-off-by: Erik Kundt <erik@zirkular.io>

radicle-tui/src/cob.rs

@@ -0,0 +1 @@
+pub mod patch;

radicle-tui/src/cob/patch.rs

@@ -0,0 +1,51 @@
+use anyhow::Result;
+
+use radicle::git::raw::Oid;
+
+use radicle::cob::patch::{MergeTarget, Patch, PatchId, Patches};
+use radicle::prelude::*;
+use radicle::storage::git::Repository;
+
+pub fn load_all(profile: &Profile, id: Id) -> Vec<(PatchId, Patch)> {
+    if let Ok(repository) = &profile.storage.repository(id) {
+        if let Ok(proposed) = load_proposed(repository) {
+            return proposed;
+        }
+    }
+    vec![]
+}
+
+pub fn load_proposed(repository: &Repository) -> Result<Vec<(PatchId, Patch)>> {
+    let proposed = Patches::open(repository)?
+        .proposed()?
+        .into_iter()
+        .map(|(id, patch, _)| (id, patch))
+        .collect();
+
+    Ok(proposed)
+}
+
+pub fn sync_status(repository: &Repository, patch: &Patch) -> Result<(usize, usize)> {
+    let (_, revision) = patch.latest().unwrap();
+    let target_oid = merge_target_oid(patch.target(), repository)?;
+    let (ahead, behind) = repository
+        .raw()
+        .graph_ahead_behind(*revision.head(), target_oid)?;
+
+    Ok((ahead, behind))
+}
+
+pub fn merge_target_oid(target: MergeTarget, repository: &Repository) -> Result<Oid> {
+    match target {
+        MergeTarget::Delegates => {
+            if let Ok((_, target)) = repository.head() {
+                Ok(*target)
+            } else {
+                anyhow::bail!(
+                    "failed to determine default branch head for project {}",
+                    repository.id,
+                );
+            }
+        }
+    }
+}