-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Haskell bindings to ExifTool
--   
--   Haskell bindings to the <a>ExifTool</a> command-line application that
--   enable reading, writing and deleting metadata in various file formats.
@package exiftool
@version 0.2.0.4


-- | This module contains bindings to the <a>ExifTool</a> command-line
--   application that enable reading, writing and deleting metadata in
--   various file formats. Here's a short code example, the details are
--   explained below.
--   
--   <pre>
--   {-# LANGUAGE OverloadedStrings #-}
--   
--   import Data.Text (Text)
--   import ExifTool
--   
--   data Foo = Foo
--     { description :: Text,
--       resolution :: Int
--     }
--     deriving (Show)
--   
--   main :: IO ()
--   main = withExifTool $ \et -&gt; do
--     m &lt;- readMeta et [] "a.jpg"
--     print $ Foo &lt;$&gt; get (Tag "Description") m &lt;*&gt; get (Tag "XResolution") m
--     let m' = del (Tag "Description") . set (Tag "XResolution") (42 :: Int) $ m
--     writeMeta et m' "a.jpg"
--   </pre>
--   
--   Note that this module expects the <tt>exiftool</tt> binary to be in
--   your PATH.
module ExifTool

-- | An ExifTool instance, initialized with <a>startExifTool</a> and
--   terminated with <a>stopExifTool</a>.
data ExifTool

-- | Start an ExifTool instance. Use <a>stopExifTool</a> when done, or
--   <a>withExifTool</a> to combine both steps.
startExifTool :: IO ExifTool

-- | Stop a running ExifTool instance.
stopExifTool :: ExifTool -> IO ()

-- | Start an ExifTool instance, do something with it, then stop it.
withExifTool :: (ExifTool -> IO a) -> IO a

-- | Read the given tags from a file. Use an empty tag list to return all
--   metadata. Tag names are returned in "simple" form without any leading
--   group prefixes, independent of how they are specified in the given tag
--   list.
readMeta :: ExifTool -> [Tag] -> FilePath -> IO Metadata

-- | Like <a>readMeta</a>, but ExifTool errors are returned as Left values
--   instead of leading to runtime errors.
readMetaEither :: ExifTool -> [Tag] -> FilePath -> IO (Either Text Metadata)

-- | Write metadata to a file. The file is modified in place, make sure you
--   have the necessary backups!
writeMeta :: ExifTool -> Metadata -> FilePath -> IO ()

-- | Like <a>writeMeta</a>, but ExifTool errors are returned as Left values
--   instead of leading to runtime errors.
writeMetaEither :: ExifTool -> Metadata -> FilePath -> IO (Either Text ())

-- | A set of ExifTool tag/value pairs. Use <a>get</a>, <a>set</a> and
--   <a>del</a> to query and manipulate this set.
data Metadata

-- | An ExifTool tag name like <tt>Tag <a>Description</a></tt> or <tt>Tag
--   "EXIF:IFD0:XResolution"</tt>.
newtype Tag
Tag :: Text -> Tag
[tagName] :: Tag -> Text

-- | Remove group prefixes from a tag name e.g., <tt>stripGroups (Tag
--   "XMP:XMP-dc:Description") == Tag <a>Description</a></tt>.
stripGroups :: Tag -> Tag

-- | An ExifTool tag value, enclosed in a type wrapper. The type wrapper
--   can usually be ignored when using the <a>FromValue</a> and
--   <a>ToValue</a> instances.
data Value
String :: !Text -> Value
Binary :: !ByteString -> Value
Number :: !Scientific -> Value
Bool :: !Bool -> Value
List :: ![Value] -> Value

-- | Data types that a <a>Value</a> can be turned into.
class FromValue a
fromValue :: FromValue a => Value -> Maybe a

-- | Data types that can be turned into a <a>Value</a>.
class ToValue a
toValue :: ToValue a => a -> Value

-- | Retrieve the value of a tag. Tag case is ignored i.e., <tt>get (Tag
--   "Description)" m == get (Tag "description") m</tt>.
get :: FromValue a => Tag -> Metadata -> Maybe a

-- | Set a tag to a (new) value. Tag case is ignored.
set :: ToValue a => Tag -> a -> Metadata -> Metadata

-- | Delete a tag (i.e., set its value to a marker that will make ExifTool
--   delete it when <a>writeMeta</a> is called). Tag case is ignored.
del :: Tag -> Metadata -> Metadata
instance Data.Aeson.Types.ToJSON.ToJSONKey ExifTool.Tag
instance Data.Aeson.Types.ToJSON.ToJSON ExifTool.Tag
instance Data.Aeson.Types.FromJSON.FromJSONKey ExifTool.Tag
instance Data.Aeson.Types.FromJSON.FromJSON ExifTool.Tag
instance Data.Hashable.Class.Hashable ExifTool.Tag
instance GHC.Classes.Eq ExifTool.Tag
instance GHC.Show.Show ExifTool.Tag
instance GHC.Classes.Eq ExifTool.Value
instance GHC.Show.Show ExifTool.Value
instance GHC.Base.Monoid ExifTool.Metadata
instance GHC.Base.Semigroup ExifTool.Metadata
instance GHC.Classes.Eq ExifTool.Metadata
instance GHC.Show.Show ExifTool.Metadata
instance ExifTool.ToValue ExifTool.Value
instance ExifTool.ToValue Data.Text.Internal.Text
instance ExifTool.ToValue Data.ByteString.Internal.ByteString
instance ExifTool.ToValue GHC.Types.Int
instance ExifTool.ToValue GHC.Num.Integer.Integer
instance ExifTool.ToValue GHC.Types.Float
instance ExifTool.ToValue GHC.Types.Double
instance ExifTool.ToValue GHC.Types.Bool
instance ExifTool.ToValue a => ExifTool.ToValue [a]
instance ExifTool.FromValue ExifTool.Value
instance ExifTool.FromValue Data.Text.Internal.Text
instance ExifTool.FromValue Data.ByteString.Internal.ByteString
instance ExifTool.FromValue GHC.Types.Int
instance ExifTool.FromValue GHC.Num.Integer.Integer
instance ExifTool.FromValue GHC.Types.Float
instance ExifTool.FromValue GHC.Types.Double
instance ExifTool.FromValue GHC.Types.Bool
instance ExifTool.FromValue a => ExifTool.FromValue [a]
instance Data.Aeson.Types.FromJSON.FromJSON ExifTool.Value
instance Data.Aeson.Types.ToJSON.ToJSON ExifTool.Value