1 files changed, 57 insertions, 0 deletions
diff --git a/src/Eval.hs b/src/Eval.hs
index a071770..1828468 100644
--- a/src/Eval.hs
+++ b/src/Eval.hs
@@ -1,18 +1,23 @@
 module Eval (
     EvalInput(..),
     EvalError(..), textEvalError,
+    Eval, runEval,
 
     evalJob,
     evalJobSet,
+    evalJobReference,
 ) where
 
 import Control.Monad
 import Control.Monad.Except
+import Control.Monad.Reader
 
 import Data.Bifunctor
+import Data.List
 import Data.Text (Text)
 import Data.Text qualified as T
 
+import Config
 import Job.Types
 import Repo
 
@@ -27,6 +32,13 @@ data EvalError
 textEvalError :: EvalError -> Text
 textEvalError (OtherEvalError text) = text
 
+
+type Eval a = ReaderT EvalInput (ExceptT EvalError IO) a
+
+runEval :: Eval a -> EvalInput -> IO (Either EvalError a)
+runEval action einput = runExceptT $ flip runReaderT einput action
+
+
 evalJob :: EvalInput -> DeclaredJob -> Except EvalError Job
 evalJob EvalInput {..} decl = do
     otherCheckout <- forM (jobOtherCheckout decl) $ \( DeclaredJobRepo name, revision, checkout ) -> do
@@ -52,3 +64,48 @@ evalJobSet ei decl = do
         }
   where
     runExceptStr = first (T.unpack . textEvalError) . runExcept
+
+
+canonicalJobName :: [ Text ] -> Config -> Eval [ JobIdPart ]
+canonicalJobName (r : rs) config = do
+    einput <- ask
+    let name = JobName r
+    case find ((name ==) . jobName) (configJobs config) of
+        Just djob -> do
+            job <- either throwError return $ runExcept $ evalJob einput djob
+            let repos = nub $ map (\( EvaluatedJobRepo repo, _, _ ) -> repo) $ jobOtherCheckout job
+            (JobIdName name :) <$> canonicalOtherCheckouts rs repos
+        Nothing -> throwError $ OtherEvalError $ "job ‘" <> r <> "’ not found"
+canonicalJobName [] _ = throwError $ OtherEvalError "expected job name"
+
+canonicalOtherCheckouts :: [ Text ] -> [ Repo ] -> Eval [ JobIdPart ]
+canonicalOtherCheckouts (r : rs) (repo : repos) = do
+    tree <- tryReadCommit repo r >>= \case
+        Just commit -> getCommitTree commit
+        Nothing -> tryReadTree repo r >>= \case
+            Just tree -> return tree
+            Nothing -> throwError $ OtherEvalError $ "failed to resolve ‘" <> r <> "’ to a commit or tree in " <> T.pack (show repo)
+    (JobIdTree (treeId tree) :) <$> canonicalOtherCheckouts rs repos
+canonicalOtherCheckouts []       []       = return []
+canonicalOtherCheckouts []       (_ : _ ) = throwError $ OtherEvalError $ "expected commit or tree reference"
+canonicalOtherCheckouts (r : _)  []       = throwError $ OtherEvalError $ "unexpected job ref part ‘" <> r <> "’"
+
+canonicalCommitConfig :: [ Text ] -> Repo -> Eval [ JobIdPart ]
+canonicalCommitConfig (r : rs) repo = do
+    tree <- tryReadCommit repo r >>= \case
+        Just commit -> getCommitTree commit
+        Nothing -> tryReadTree repo r >>= \case
+            Just tree -> return tree
+            Nothing -> throwError $ OtherEvalError $ "failed to resolve ‘" <> r <> "’ to a commit or tree in " <> T.pack (show repo)
+    config <- either fail return =<< loadConfigForCommit tree
+    (JobIdTree (treeId tree) :) <$> canonicalJobName rs config
+canonicalCommitConfig [] _ = throwError $ OtherEvalError "expected commit or tree reference"
+
+evalJobReference :: Config -> JobRef -> Eval JobId
+evalJobReference config (JobRef rs) =
+    fmap JobId $ do
+        asks eiContainingRepo >>= \case
+            Just defRepo -> do
+                canonicalCommitConfig rs defRepo
+            Nothing -> do
+                canonicalJobName rs config