{-# LANGUAGE GADTs             #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards   #-}
{-# LANGUAGE ViewPatterns      #-}

module Ide.Plugin.ConfigUtils where

import qualified Data.Aeson            as A
import qualified Data.Aeson.Types      as A
import           Data.Default          (def)
import qualified Data.Dependent.Map    as DMap
import qualified Data.Dependent.Sum    as DSum
import qualified Data.HashMap.Lazy     as HMap
import           Ide.Plugin.Config
import           Ide.Plugin.Properties (toDefaultJSON, toVSCodeExtensionSchema)
import           Ide.Types
import           Language.LSP.Types

-- Attention:
-- 'diagnosticsOn' will never be added into the default config or the schema,
-- since diagnostics emit in arbitrary shake rules -- we don't know
-- whether a plugin is capable of producing diagnostics.

-- | Generates a defalut 'Config', but remains only effective items
pluginsToDefaultConfig :: IdePlugins a -> A.Value
pluginsToDefaultConfig IdePlugins {..} =
  A.Object $
    HMap.adjust
      ( \(unsafeValueToObject -> o) ->
          A.Object $ HMap.insert "plugin" elems o -- inplace the "plugin" section with our 'elems', leaving others unchanged
      )
      "haskell"
      (unsafeValueToObject (A.toJSON defaultConfig))
  where
    defaultConfig@Config {} = def
    unsafeValueToObject (A.Object o) = o
    unsafeValueToObject _            = error "impossible"
    elems = A.object $ mconcat $ singlePlugin <$> map snd ipMap
    -- Splice genericDefaultConfig and dedicatedDefaultConfig
    -- Example:
    --
    -- {
    --  "plugin-id": {
    --    "globalOn": true,
    --    "codeActionsOn": true,
    --    "codeLensOn": true,
    --    "config": {
    --      "property1": "foo"
    --     }
    --   }
    -- }
    singlePlugin PluginDescriptor {..} =
      let x = genericDefaultConfig <> dedicatedDefaultConfig
       in [pId A..= A.object x | not $ null x]
      where
        (PluginHandlers (DMap.toList -> handlers)) = pluginHandlers
        customConfigToDedicatedDefaultConfig (CustomConfig p) = toDefaultJSON p
        -- Example:
        --
        -- {
        --   "globalOn": true,
        --   "codeActionsOn": true,
        --   "codeLensOn": true
        -- }
        --
        -- we don't generate the config section if the plugin doesn't register any of the following six methods,
        -- which avoids producing trivial configuration for formatters:
        --
        -- "stylish-haskell": {
        --    "globalOn": true
        -- }
        genericDefaultConfig =
          let x = mconcat (handlersToGenericDefaultConfig <$> handlers)
           in ["globalOn" A..= True | not $ null x] <> x
        -- Example:
        --
        -- {
        --  "config": {
        --      "property1": "foo"
        --   }
        --}
        dedicatedDefaultConfig =
          let x = customConfigToDedicatedDefaultConfig pluginCustomConfig
           in ["config" A..= A.object x | not $ null x]

        (PluginId pId) = pluginId

        -- This function captures ide methods registered by the plugin, and then converts it to kv pairs
        handlersToGenericDefaultConfig :: DSum.DSum IdeMethod f -> [A.Pair]
        handlersToGenericDefaultConfig (IdeMethod m DSum.:=> _) = case m of
          STextDocumentCodeAction     -> ["codeActionsOn" A..= True]
          STextDocumentCodeLens       -> ["codeLensOn" A..= True]
          STextDocumentRename         -> ["renameOn" A..= True]
          STextDocumentHover          -> ["hoverOn" A..= True]
          STextDocumentDocumentSymbol -> ["symbolsOn" A..= True]
          STextDocumentCompletion     -> ["completionOn" A..= True]
          _                           -> []

-- | Generates json schema used in haskell vscode extension
-- Similar to 'pluginsToDefaultConfig' but simpler, since schema has a flatten structure
pluginsToVSCodeExtensionSchema :: IdePlugins a -> A.Value
pluginsToVSCodeExtensionSchema IdePlugins {..} = A.object $ mconcat $ singlePlugin <$> map snd ipMap
  where
    singlePlugin PluginDescriptor {..} = genericSchema <> dedicatedSchema
      where
        (PluginHandlers (DMap.toList -> handlers)) = pluginHandlers
        customConfigToDedicatedSchema (CustomConfig p) = toVSCodeExtensionSchema (withIdPrefix "config.") p
        (PluginId pId) = pluginId
        genericSchema = withIdPrefix "globalOn" A..= schemaEntry "plugin" : mconcat (handlersToGenericSchema <$> handlers)
        dedicatedSchema = customConfigToDedicatedSchema pluginCustomConfig
        handlersToGenericSchema (IdeMethod m DSum.:=> _) = case m of
          STextDocumentCodeAction -> [withIdPrefix "codeActionsOn" A..= schemaEntry "code actions"]
          STextDocumentCodeLens -> [withIdPrefix "codeLensOn" A..= schemaEntry "code lenses"]
          STextDocumentRename -> [withIdPrefix "renameOn" A..= schemaEntry "rename"]
          STextDocumentHover -> [withIdPrefix "hoverOn" A..= schemaEntry "hover"]
          STextDocumentDocumentSymbol -> [withIdPrefix "symbolsOn" A..= schemaEntry "symbols"]
          STextDocumentCompletion -> [withIdPrefix "completionOn" A..= schemaEntry "completions"]
          _ -> []
        schemaEntry desc =
          A.object
            [ "scope" A..= A.String "resource",
              "type" A..= A.String "boolean",
              "default" A..= True,
              "description" A..= A.String ("Enables " <> pId <> " " <> desc)
            ]
        withIdPrefix x = "haskell.plugin." <> pId <> "." <> x