feat(agent): implement smart base branch selection

Amp-Thread-ID:
https://ampcode.com/threads/T-79499d9e-f4f4-40de-893c-524c32a45483
Co-authored-by: Amp <amp@ampcode.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/Omni/Agent/Git.hs b/Omni/Agent/Git.hs
index cf9a122..7717cee 100644
--- a/Omni/Agent/Git.hs
+++ b/Omni/Agent/Git.hs
@@ -11,6 +11,8 @@ module Omni.Agent.Git
     commit,
     createBranch,
     getCurrentBranch,
+    branchExists,
+    isMerged,
     main,
     test,
   )
@@ -175,3 +177,17 @@ getCurrentBranch repo = do
   case code of
     Exit.ExitSuccess -> pure <| Text.strip (Text.pack out)
     _ -> panic "git branch failed"
+
+branchExists :: FilePath -> Text -> IO Bool
+branchExists repo branch = do
+  let cmd = (Process.proc "git" ["show-ref", "--verify", "refs/heads/" <> Text.unpack branch]) {Process.cwd = Just repo}
+  (code, _, _) <- Process.readCreateProcessWithExitCode cmd ""
+  pure (code == Exit.ExitSuccess)
+
+isMerged :: FilePath -> Text -> Text -> IO Bool
+isMerged repo branch target = do
+  -- Check if 'branch' is merged into 'target'
+  -- git merge-base --is-ancestor <branch> <target>
+  let cmd = (Process.proc "git" ["merge-base", "--is-ancestor", Text.unpack branch, Text.unpack target]) {Process.cwd = Just repo}
+  (code, _, _) <- Process.readCreateProcessWithExitCode cmd ""
+  pure (code == Exit.ExitSuccess)