{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE NoImplicitPrelude #-}

module Data.Morpheus.Validation.Document.Validation
  ( ValidateSchema (..),
  )
where

import Control.Monad.Except (MonadError (..))
import Data.Morpheus.Ext.Result
  ( GQLResult,
  )
import Data.Morpheus.Internal.Utils ((<:>))
import Data.Morpheus.Schema.Schema
  ( internalSchema,
  )
import Data.Morpheus.Types.Internal.AST
  ( ArgumentDefinition (..),
    CONST,
    DataEnumValue (..),
    DirectiveDefinition (..),
    DirectiveLocation (..),
    FieldContent (..),
    FieldDefinition (..),
    FieldName,
    IN,
    Msg (..),
    OUT,
    Schema (..),
    TRUE,
    TypeCategory,
    TypeContent (..),
    TypeDefinition (..),
    TypeRef (..),
    Typed (..),
    UnionMember (..),
    VALID,
    Value,
  )
import Data.Morpheus.Types.Internal.AST.Error (GQLError)
import Data.Morpheus.Types.Internal.AST.Name (Name, isValidName)
import Data.Morpheus.Types.Internal.Config (Config (..))
import Data.Morpheus.Types.Internal.Validation
  ( InputSource (..),
    ValidatorContext (localContext),
    startInput,
  )
import Data.Morpheus.Types.Internal.Validation.SchemaValidator
  ( Field (..),
    ON_TYPE,
    SchemaValidator,
    TypeEntity (..),
    TypeSystemContext (..),
    inField,
    inType,
    runSchemaValidator,
  )
import Data.Morpheus.Validation.Document.Interface (validateImplements)
import Data.Morpheus.Validation.Internal.Directive
  ( validateDirectives,
  )
import Data.Morpheus.Validation.Internal.Value
  ( validateInputByTypeRef,
  )
import Relude hiding (empty, local)

class ValidateSchema s where
  validateSchema :: Bool -> Config -> Schema s -> GQLResult (Schema VALID)

instance ValidateSchema CONST where
  validateSchema withSystem config schema = do
    sysSchema <-
      if withSystem
        then internalSchema <:> schema
        else pure schema
    runSchemaValidator (typeCheck schema) config sysSchema

instance ValidateSchema VALID where
  validateSchema _ _ = pure

----- TypeCheck -------------------------------
---
---
---
class TypeCheck a where
  type TypeContext a :: Type
  type TypeContext a = ()
  typeCheck :: a CONST -> SchemaValidator (TypeContext a) (a VALID)

instance TypeCheck Schema where
  typeCheck
    Schema
      { types,
        query,
        mutation,
        subscription,
        directiveDefinitions
      } =
      Schema
        <$> traverse typeCheck types
        <*> typeCheck query
        <*> traverse typeCheck mutation
        <*> traverse typeCheck subscription
        <*> traverse typeCheck directiveDefinitions

instance TypeCheck (TypeDefinition cat) where
  typeCheck
    TypeDefinition
      { typeName,
        typeDescription,
        typeDirectives,
        typeContent
      } =
      inType typeName $
        TypeDefinition
          typeDescription
          <$> checkName typeName
          <*> validateDirectives (typeDirectiveLocation typeContent) typeDirectives
          <*> typeCheck typeContent

checkName :: MonadError GQLError f => Name t -> f (Name t)
checkName name
  | isValidName name = pure name
  | otherwise = throwError ("Invalid Name:" <> msg name)

typeDirectiveLocation :: TypeContent a b c -> DirectiveLocation
typeDirectiveLocation DataObject {} = LOCATION_OBJECT
typeDirectiveLocation DataInputObject {} = LOCATION_INPUT_OBJECT
typeDirectiveLocation DataScalar {} = LOCATION_SCALAR
typeDirectiveLocation DataEnum {} = LOCATION_ENUM
typeDirectiveLocation DataInputUnion {} = LOCATION_OBJECT
typeDirectiveLocation DataUnion {} = LOCATION_UNION
typeDirectiveLocation DataInterface {} = LOCATION_INTERFACE

instance TypeCheck (TypeContent TRUE cat) where
  type TypeContext (TypeContent TRUE cat) = TypeEntity ON_TYPE
  typeCheck DataObject {objectImplements, objectFields} =
    DataObject
      <$> validateImplements objectImplements objectFields
      <*> traverse typeCheck objectFields
  typeCheck DataInputObject {inputObjectFields} =
    DataInputObject <$> traverse typeCheck inputObjectFields
  typeCheck DataScalar {..} = pure DataScalar {..}
  typeCheck DataEnum {enumMembers} = DataEnum <$> traverse typeCheck enumMembers
  typeCheck DataInputUnion {inputUnionMembers} =
    DataInputUnion <$> traverse typeCheck inputUnionMembers
  typeCheck DataUnion {unionMembers} = DataUnion <$> traverse typeCheck unionMembers
  typeCheck (DataInterface fields) = DataInterface <$> traverse typeCheck fields

instance FieldDirectiveLocation cat => TypeCheck (FieldDefinition cat) where
  type TypeContext (FieldDefinition cat) = TypeEntity ON_TYPE
  typeCheck FieldDefinition {..} =
    inField
      fieldName
      ( FieldDefinition
          fieldDescription
          fieldName
          fieldType
          <$> traverse checkFieldContent fieldContent
          <*> validateDirectives (directiveLocation (Proxy @cat)) fieldDirectives
      )
    where
      checkFieldContent :: FieldContent TRUE cat CONST -> SchemaValidator (Field ON_TYPE) (FieldContent TRUE cat VALID)
      checkFieldContent (FieldArgs args) = FieldArgs <$> traverse typeCheck args
      checkFieldContent (DefaultInputValue value) = DefaultInputValue <$> validateDefaultValue fieldType Nothing value

class FieldDirectiveLocation (cat :: TypeCategory) where
  directiveLocation :: Proxy cat -> DirectiveLocation

instance FieldDirectiveLocation OUT where
  directiveLocation _ = LOCATION_FIELD_DEFINITION

instance FieldDirectiveLocation IN where
  directiveLocation _ = LOCATION_INPUT_FIELD_DEFINITION

instance TypeCheck DirectiveDefinition where
  typeCheck DirectiveDefinition {directiveDefinitionArgs = arguments, ..} =
    inType "Directive" $
      inField directiveDefinitionName $ do
        directiveDefinitionArgs <- traverse typeCheck arguments
        pure DirectiveDefinition {..}

instance TypeCheck ArgumentDefinition where
  type TypeContext ArgumentDefinition = Field ON_TYPE
  typeCheck (ArgumentDefinition FieldDefinition {..}) =
    ArgumentDefinition
      <$> ( FieldDefinition
              fieldDescription
              fieldName
              fieldType
              <$> traverse checkArgumentDefaultValue fieldContent
              <*> validateDirectives LOCATION_ARGUMENT_DEFINITION fieldDirectives
          )
    where
      checkArgumentDefaultValue (DefaultInputValue value) =
        DefaultInputValue
          <$> validateDefaultValue fieldType (Just fieldName) value

validateDefaultValue ::
  TypeRef ->
  Maybe FieldName ->
  Value CONST ->
  SchemaValidator (Field ON_TYPE) (Value VALID)
validateDefaultValue typeRef argName value = do
  Field fName _ (TypeEntity _ typeName) <- asks (local . localContext)
  startInput (SourceInputField typeName fName argName) (validateInputByTypeRef (Typed typeRef) value)

instance TypeCheck DataEnumValue where
  type TypeContext DataEnumValue = TypeEntity ON_TYPE
  typeCheck DataEnumValue {enumDirectives = directives, ..} =
    DataEnumValue enumDescription enumName
      <$> validateDirectives LOCATION_ENUM_VALUE directives

instance TypeCheck (UnionMember cat) where
  type TypeContext (UnionMember cat) = TypeEntity ON_TYPE
  typeCheck UnionMember {..} = pure UnionMember {..}