added special functions for decoding StyleDefinitions

3 files changed, 143 insertions, 9 deletions

diff --git a/src/Mapbox/Layer.elm b/src/Mapbox/Layer.elm
index dea484c..8d9cb63 100644
--- a/src/Mapbox/Layer.elm
+++ b/src/Mapbox/Layer.elm
@@ -1,6 +1,6 @@
 module Mapbox.Layer exposing
     ( Layer, SourceId, encode
-    , background, fill, symbol, line, raster, circle, fillExtrusion, heatmap, hillshade
+    , background, fill, json, jsonList, symbol, line, raster, circle, fillExtrusion, heatmap, hillshade
     , Background, Fill, Symbol, Line, Raster, Circle, FillExtrusion, Heatmap, Hillshade
     , LayerAttr
     , metadata, sourceLayer, minzoom, maxzoom, filter, visible
@@ -13,6 +13,7 @@ module Mapbox.Layer exposing
     , rasterBrightnessMax, rasterBrightnessMin, rasterContrast, rasterFadeDuration, rasterHueRotate, rasterOpacity, rasterResampling, rasterSaturation
     , hillshadeAccentColor, hillshadeExaggeration, hillshadeHighlightColor, hillshadeIlluminationAnchor, hillshadeIlluminationDirection, hillshadeShadowColor
     , backgroundColor, backgroundOpacity, backgroundPattern
+    , decode
     )
 
 {-| Layers specify what is actually rendered on the map and are rendered in order.
@@ -46,8 +47,8 @@ Paint properties are applied later in the rendering process. Changes to a paint
 
 ### Layer Types
 
-@docs background, fill, symbol, line, raster, circle, fillExtrusion, heatmap, hillshade
-@docs Background, Fill, Symbol, Line, Raster, Circle, FillExtrusion, Heatmap, Hillshade
+@docs background, fill, json, jsonList, symbol, line, raster, circle, fillExtrusion, heatmap, hillshade
+@docs Background, Fill, Json, Symbol, Line, Raster, Circle, FillExtrusion, Heatmap, Hillshade
 
 
 ### General Attributes
@@ -100,10 +101,16 @@ Paint properties are applied later in the rendering process. Changes to a paint
 
 @docs backgroundColor, backgroundOpacity, backgroundPattern
 
+
+### List Decoder
+
+@docs decode
+
 -}
 
 import Array exposing (Array)
 import Internal exposing (Supported)
+import Json.Decode as Decode exposing (Decoder)
 import Json.Encode as Encode exposing (Value)
 import Mapbox.Expression as Expression exposing (CameraExpression, Color, DataExpression, Expression, FormattedText)
 
@@ -165,6 +172,11 @@ type Hillshade
     = HillshadeLayer
 
 
+{-| -}
+type Json
+    = JsonLayer
+
+
 {-| Turns a layer into JSON
 -}
 encode : Layer -> Value
@@ -173,8 +185,8 @@ encode (Layer value) =
 
 
 layerImpl tipe id source attrs =
-    [ ( "type", Encode.string tipe )
-    , ( "id", Encode.string id )
+    [ ( "id", Encode.string id )
+    , ( "type", Encode.string tipe )
     , ( "source", Encode.string source )
     ]
         ++ encodeAttrs attrs
@@ -271,6 +283,29 @@ hillshade =
     layerImpl "hillshade"
 
 
+{-| Directly aass a json value layer
+-}
+json : Value -> Layer
+json =
+    Layer
+
+
+{-| Directly aass a json value layer
+-}
+jsonList : String -> List Layer
+jsonList =
+    Decode.decodeString (Decode.list Decode.value)
+        >> Result.withDefault []
+        >> List.map json
+
+
+{-| Directly aass a json value layer
+-}
+decode : Decoder (List Layer)
+decode =
+    Decode.list (Decode.value |> Decode.map json)
+
+
 {-| -}
 type LayerAttr tipe
     = Top String Value
diff --git a/src/Mapbox/Source.elm b/src/Mapbox/Source.elm
index 68d1862..5ca38ea 100644
--- a/src/Mapbox/Source.elm
+++ b/src/Mapbox/Source.elm
@@ -1,6 +1,6 @@
 module Mapbox.Source exposing
     ( Source, SourceOption
-    , Id, Url
+    , Id, Url, decode
     , vector, vectorFromUrl, VectorSource
     , raster, tileSize, rasterFromUrl, RasterSource
     , rasterDEMMapbox, rasterDEMTerrarium
@@ -17,7 +17,7 @@ module Mapbox.Source exposing
 
 @docs Source, SourceOption
 
-@docs Id, Url
+@docs Id, Url, decode
 
 
 ### Vector
@@ -58,7 +58,9 @@ Tiled sources can also take the following attributes:
 
 -}
 
+import Dict
 import Internal
+import Json.Decode as Decode exposing (Decoder)
 import Json.Encode exposing (Value)
 import LngLat exposing (LngLat)
 import Mapbox.Expression as Expression exposing (DataExpression, Expression)
@@ -123,6 +125,18 @@ encode (Source _ value) =
 
 
 {-| -}
+decode : Decoder (List Source)
+decode =
+    Decode.dict Decode.value
+        |> Decode.map (Dict.toList >> List.map tupleToSource)
+
+
+tupleToSource : ( String, Value ) -> Source
+tupleToSource ( id, value ) =
+    Source id value
+
+
+{-| -}
 getId : Source -> String
 getId (Source k _) =
     k
diff --git a/src/Mapbox/Style.elm b/src/Mapbox/Style.elm
index c33de45..20a91c1 100644
--- a/src/Mapbox/Style.elm
+++ b/src/Mapbox/Style.elm
@@ -1,5 +1,5 @@
 module Mapbox.Style exposing
-    ( Style(..), encode, StyleDef
+    ( Style(..), encode, StyleDef, decode, MiscDef, decodeMiscDef, miscDefToList
     , Light, defaultLight
     , Transition, defaultTransition
     , MiscAttr, sprite, glyphs, name, defaultCenter, defaultZoomLevel, defaultBearing, defaultPitch, metadata
@@ -8,7 +8,7 @@ module Mapbox.Style exposing
 
 {-| A Mapbox style is a document that defines the visual appearance of a map: what data to draw, the order to draw it in, and how to style the data when drawing it. A style document is a JSON object with specific root level and nested properties. This specification defines and describes these properties.
 
-@docs Style, encode, StyleDef
+@docs Style, encode, StyleDef, decode, MiscDef, decodeMiscDef, miscDefToList
 
 
 ### Light
@@ -35,7 +35,9 @@ You can also use one of these predefined styles.
 -}
 
 import Array exposing (Array)
+import Dict
 import Internal exposing (Supported)
+import Json.Decode as Decode exposing (Decoder)
 import Json.Encode as Encode exposing (Value)
 import LngLat exposing (LngLat)
 import Mapbox.Expression exposing (CameraExpression, Color, Expression, float, floats, rgba, viewport)
@@ -154,6 +156,18 @@ type alias StyleDef =
     }
 
 
+type alias MiscDef =
+    { sprite : Maybe MiscAttr
+    , glyphs : Maybe MiscAttr
+    , name : Maybe MiscAttr
+    , center : Maybe MiscAttr
+    , zoom : Maybe MiscAttr
+    , bearing : Maybe MiscAttr
+    , pitch : Maybe MiscAttr
+    , meta : Maybe MiscAttr
+    }
+
+
 {-| -}
 type MiscAttr
     = MiscAttr String Value
@@ -285,3 +299,74 @@ defaultTransition =
     { duration = 300
     , delay = 0
     }
+
+
+{-| -}
+decode : Decoder StyleDef
+decode =
+    Decode.map5 StyleDef
+        (Decode.maybe decTransition
+            |> Decode.map (Maybe.withDefault defaultTransition)
+        )
+        (Decode.succeed defaultLight)
+        (Decode.field "layers" Mapbox.Layer.decode)
+        (Decode.field "sources" Mapbox.Source.decode)
+        (Decode.succeed [])
+
+
+decTransition : Decoder Transition
+decTransition =
+    Decode.map2 Transition
+        (Decode.field "duration" Decode.int)
+        (Decode.field "delay" Decode.int)
+
+
+maybeDecode : String -> Decoder a -> (a -> b) -> Decoder (Maybe b)
+maybeDecode id dec fn =
+    Decode.field id (dec |> Decode.map fn)
+        |> Decode.maybe
+
+
+{-| -}
+decodeMiscDef : Decoder MiscDef
+decodeMiscDef =
+    Decode.map8 MiscDef
+        (maybeDecode "sprite" Decode.string sprite)
+        (maybeDecode "glyphs" Decode.string glyphs)
+        (maybeDecode "name" Decode.string name)
+        (maybeDecode "center"
+            (Decode.float
+                |> Decode.list
+                |> Decode.andThen
+                    (\list ->
+                        case list of
+                            [ lng, lat ] ->
+                                Decode.succeed <| LngLat lng lat
+
+                            _ ->
+                                Decode.fail "not a valid position"
+                    )
+            )
+            defaultCenter
+        )
+        (maybeDecode "zoom" Decode.float defaultZoomLevel)
+        (maybeDecode "pitch" Decode.float defaultPitch)
+        (maybeDecode "bearing" Decode.float defaultBearing)
+        (maybeDecode "metadata" (Decode.dict Decode.value) (Dict.toList >> metadata))
+
+
+maybeSingleton : Maybe MiscAttr -> List MiscAttr
+maybeSingleton =
+    Maybe.map List.singleton >> Maybe.withDefault []
+
+
+{-| -}
+miscDefToList : MiscDef -> List MiscAttr
+miscDefToList miscDef =
+    maybeSingleton miscDef.sprite
+        ++ maybeSingleton miscDef.glyphs
+        ++ maybeSingleton miscDef.name
+        ++ maybeSingleton miscDef.center
+        ++ maybeSingleton miscDef.zoom
+        ++ maybeSingleton miscDef.bearing
+        ++ maybeSingleton miscDef.pitch