Merge remote-tracking branch 'origin/feature/review'main

1 files changed, 34 insertions, 2 deletions

diff --git a/app/Git.hs b/app/Git.hs
index 6431259..e195d1b 100644
--- a/app/Git.hs
+++ b/app/Git.hs
@@ -8,6 +8,9 @@ module Git
     getCommitOf,
     readTextFileOfText,
     readTextFileOfBS,
+    resolveRef,
+    getCommitsBetween,
+    diffOf,
   )
 where
 
@@ -27,7 +30,8 @@ import Data.Time.Clock (UTCTime, getCurrentTime)
 import Exception qualified as E
 import GHC.Generics (Generic)
 import Git.CommitHash
-import Process (proc, sh)
+import Patch qualified as A
+import Process (proc, sh, sh_)
 import Text.Printf (printf)
 
 getCommitHashes :: IO (NonEmpty T.Text)
@@ -91,7 +95,7 @@ readTextFileOfText :: CommitHash -> FilePath -> IO LT.Text
 readTextFileOfText = readTextFileOf LT.readFile LT.decodeUtf8
 
 readTextFileOfBS :: CommitHash -> FilePath -> IO LB.ByteString
-readTextFileOfBS = readTextFileOf LB.readFile (\x->x)
+readTextFileOfBS = readTextFileOf LB.readFile id
 
 readTextFileOf :: (FilePath -> IO a) -> (LB.ByteString -> a) -> CommitHash -> FilePath -> IO a
 readTextFileOf readFile _ WorkingTree filePath =
@@ -102,3 +106,31 @@ readTextFileOf _ decode (Commit hash) filePath =
   catch
     (decode <$> sh (proc "git show %:%" hash filePath))
     (\(_ :: E.ProcessException) -> throwIO (E.CannotReadFile (printf "%s:%s" hash filePath)))
+
+resolveRef :: T.Text -> IO CommitHash
+resolveRef =
+  fmap (Commit . T.strip . T.decodeUtf8 . LB.toStrict)
+    . sh
+    . proc "git rev-parse %"
+
+-- | `getCommitsBetween prevCommit commit` returns the commits from `prevCommit` to `commit`. The result excludes `prevCommit`, but includes `commit`.
+--
+-- If `prevCommit` is  not an ancestor of `commit`, this functions throws `NoAncestor commit prevCommit`.
+getCommitsBetween :: CommitHash -> CommitHash -> IO [CommitHash]
+getCommitsBetween WorkingTree commit@(Commit _) =
+  throwIO (E.NoAncestor WorkingTree commit)
+getCommitsBetween WorkingTree WorkingTree = pure [WorkingTree]
+getCommitsBetween prevCommit WorkingTree =
+  fmap (++ [WorkingTree]) . getCommitsBetween prevCommit
+    =<< resolveRef "HEAD"
+getCommitsBetween prevCommit@(Commit prevHash) commit@(Commit hash) = do
+  catch
+    (sh_ (proc "git merge-base --is-ancestor % %" prevHash hash))
+    (\(_ :: E.ProcessException) -> throwIO (E.NoAncestor commit prevCommit))
+  map (Commit . T.strip) . T.lines . T.decodeUtf8 . LB.toStrict
+    <$> sh (proc "git log --format=%%H %..%" prevHash hash)
+
+diffOf :: CommitHash -> CommitHash -> IO A.Patch
+diffOf prevHash hash =
+  A.parse . T.decodeUtf8 . LB.toStrict
+    <$> sh (proc "git diff % %" (toTextUnsafe prevHash) (toTextUnsafe hash))