From 5f2b74d4e17d8b95a49dd091385d75797d669480 Mon Sep 17 00:00:00 2001
From: Michael Snoyman <michael@snoyman.com>
Date: Tue, 9 Jun 2015 18:36:23 +0300
Subject: [PATCH] Basic init command #229

---
 src/Stack/Config.hs       |  1 +
 src/Stack/Types/Config.hs |  5 +++++
 src/main/Main.hs          | 21 +++++++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/src/Stack/Config.hs b/src/Stack/Config.hs
index 60a2df2d07..16d4a15bd7 100644
--- a/src/Stack/Config.hs
+++ b/src/Stack/Config.hs
@@ -222,6 +222,7 @@ loadConfig configArgs = do
         { lcConfig          = config
         , lcLoadBuildConfig = loadBuildConfig mproject config
         , lcProjectRoot     = fmap (\(_, fp, _) -> parent fp) mproject
+        , lcStackYaml       = fmap (\(_, fp, _) -> fp) mproject
         }
 
 -- | Load the build configuration, adds build-specific values to config loaded by @loadConfig@.
diff --git a/src/Stack/Types/Config.hs b/src/Stack/Types/Config.hs
index 6b1f21b471..f452d17fa5 100644
--- a/src/Stack/Types/Config.hs
+++ b/src/Stack/Types/Config.hs
@@ -176,6 +176,11 @@ data LoadConfig m = LoadConfig
         -- ^ Action to load the remaining 'BuildConfig'.
     , lcProjectRoot     :: !(Maybe (Path Abs Dir))
         -- ^ The project root directory, if in a project.
+
+    , lcStackYaml       :: !(Maybe (Path Abs File))
+        -- ^ The project config file, if in a project.  Note: If the STACK_YAML
+        -- environment variable is used, this may not simply be lcProjectRoot
+        -- with stack.yaml appended.
     }
 
 data NoBuildConfigStrategy
diff --git a/src/main/Main.hs b/src/main/Main.hs
index 824e864a35..ac0a727b2d 100644
--- a/src/main/Main.hs
+++ b/src/main/Main.hs
@@ -72,6 +72,10 @@ main =
                         "Build the project(s) in this directory/configuration"
                         (buildCmd DoNothing)
                         buildOpts
+             addCommand "init"
+                        "Create a missing stack.yaml file"
+                        initCmd
+                        (pure ())
              addCommand "test"
                         "Build and test the project(s) in this directory/configuration"
                         (buildCmd DoTests)
@@ -323,6 +327,23 @@ buildCmd :: FinalAction -> BuildOpts -> GlobalOpts -> IO ()
 buildCmd finalAction opts go@GlobalOpts{..} = withBuildConfig go CreateConfig $
     Stack.Build.build opts { boptsFinalAction = finalAction }
 
+-- | Create a stack.yaml file, if missing
+initCmd :: () -> GlobalOpts -> IO ()
+initCmd () go@GlobalOpts{..} = do
+    (manager,lc) <- loadConfigWithOpts go
+    runStackLoggingT manager globalLogLevel $
+        Docker.rerunWithOptionalContainer (lcConfig lc) (lcProjectRoot lc) $
+        runStackLoggingT manager globalLogLevel $
+            case lcStackYaml lc of
+                Just file -> $logInfo $
+                    "stack.yaml already exists at: " <>
+                    T.pack (toFilePath file)
+                Nothing -> do
+                    bconfig <- lcLoadBuildConfig lc CreateConfig
+                    $logInfo $
+                        "Project configuration file created at: " <>
+                        T.pack (toFilePath $ bcStackYaml bconfig)
+
 -- | Unpack packages to the filesystem
 unpackCmd :: [String] -> GlobalOpts -> IO ()
 unpackCmd names go@GlobalOpts{..} = do