ogma-cli: Add CLI argument to standalone command to set target direct…

…ory. Refs nasa#189.

The standalone backend uses a fixed template to generate the Copilot
monitor. That template does not fit all use cases, so we are finding
users heavily modifying the output (which is hard to keep up with when
there are changes), or not using ogma altogether for that reason.

A prior commit introduced, in the standalone command, support for custom
templates. Unlike the prior implementation of the standalone command,
which printed the output to standard output, the new interface puts the
result in a file (or several files) included with the template.  To
implement this new functionality, we have added an argument to specify a
target directory for the generated standalone application, where the
files will be copied to.

This commit exposes that new parameter to set the target directory to
the user in the CLI.

ogma-cli/src/CLI/CommandStandalone.hs

@@ -58,7 +58,8 @@ import qualified Command.Standalone
 
 -- | Options to generate Copilot from specification.
 data CommandOpts = CommandOpts
-  { standaloneFileName   :: FilePath
+  { standaloneTargetDir  :: FilePath
+  , standaloneFileName   :: FilePath
   , standaloneFormat     :: String
   , standalonePropFormat :: String
   , standaloneTypes      :: [String]
@@ -71,7 +72,8 @@ command c = standalone (standaloneFileName c) internalCommandOpts
   where
     internalCommandOpts :: Command.Standalone.StandaloneOptions
     internalCommandOpts = Command.Standalone.StandaloneOptions
-      { Command.Standalone.standaloneFormat      = standaloneFormat c
+      { Command.Standalone.standaloneTargetDir   = standaloneTargetDir c
+      , Command.Standalone.standaloneFormat      = standaloneFormat c
       , Command.Standalone.standalonePropFormat  = standalonePropFormat c
       , Command.Standalone.standaloneTypeMapping = types
       , Command.Standalone.standaloneFilename    = standaloneTarget c
@@ -98,6 +100,13 @@ commandDesc =
 commandOptsParser :: Parser CommandOpts
 commandOptsParser = CommandOpts
   <$> strOption
+        (  long "target-dir"
+        <> metavar "DIR"
+        <> showDefault
+        <> value "copilot"
+        <> help strStandaloneTargetDirDesc
+        )
+  <*> strOption
         (  long "file-name"
         <> metavar "FILENAME"
         <> help strStandaloneFilenameDesc
@@ -133,6 +142,10 @@ commandOptsParser = CommandOpts
         <> value "monitor"
         )
 
+-- | Target dir flag description.
+strStandaloneTargetDirDesc :: String
+strStandaloneTargetDirDesc = "Target directory"
+
 -- | Filename flag description.
 strStandaloneFilenameDesc :: String
 strStandaloneFilenameDesc = "File with properties or requirements"