deduce initial provenance from commit history

1 files changed, 26 insertions, 4 deletions

diff --git a/app/History.hs b/app/History.hs
index c3b3699..fad911a 100644
--- a/app/History.hs
+++ b/app/History.hs
@@ -7,11 +7,11 @@ import Control.Exception (Exception, catch, handle, throw)
 import Data.Aeson (eitherDecode)
 import Data.ByteString.Lazy.Char8 qualified as L8
 import Data.List (intercalate)
-import Data.Maybe (catMaybes)
+import Data.Maybe (catMaybes, mapMaybe)
 import Data.String (fromString)
 import Data.Text (Text, lines, unpack)
 import Data.Text.Encoding (decodeUtf8)
-import Issue (Issue (..), fromMatch)
+import Issue (Issue (..), fromMatch, id)
 import Issue.Filter (Filter, applyFilter)
 import Process (quote, sh, sh_)
 import System.Directory (getCurrentDirectory, setCurrentDirectory)
@@ -21,7 +21,7 @@ import System.IO.Temp (withSystemTempDirectory)
 import Text.Printf (printf)
 import TreeGrepper.Match qualified as G
 import TreeGrepper.Result qualified as G
-import Prelude hiding (lines)
+import Prelude hiding (id, lines)
 import Prelude qualified as Prelude
 
 data UnknownFileExtension = UnknownFileExtension
@@ -41,7 +41,29 @@ instance Exception InvalidTreeGrepperResult
 listIssues :: [Filter] -> [FilePath] -> IO [Issue]
 listIssues filters files = do
   commits <- fmap (lines . decodeUtf8 . L8.toStrict) $ sh ("git log --format=%H")
-  fmap head $ mapM (\commit -> listIssuesOf commit filters files) commits
+  issueses <- mapM (\commit -> listIssuesOf commit filters files) commits
+  (currentIssues, historicalIssues) <-
+    case issueses of
+      currentIssues : historicalIssueses ->
+        pure (currentIssues, concat historicalIssueses)
+      [] ->
+        die "no commits"
+  pure (map (merge . pick historicalIssues) currentIssues)
+
+pick :: [Issue] -> Issue -> (Issue, [Issue])
+pick issues issue =
+  (issue, filter (isSameIssue) issues)
+  where
+    isSameIssue otherIssue =
+      id otherIssue == id issue
+
+merge :: (Issue, [Issue]) -> Issue
+merge (issue, issues) =
+  case (mapMaybe provenance (reverse issues)) of
+    [] ->
+      issue
+    provenance : _ ->
+      issue {provenance = Just provenance}
 
 listIssuesOf :: Text -> [Filter] -> [FilePath] -> IO [Issue]
 listIssuesOf commit filters files = do