{-# LANGUAGE Arrows #-}

module Hasura.RQL.DDL.Schema.Cache.Fields (addNonColumnFields) where

import Control.Arrow.Extended
import Control.Lens ((^.), _3, _4)
import Data.Aeson
import Data.Align (align)
import Data.HashMap.Strict.Extended qualified as M
import Data.HashSet qualified as HS
import Data.Sequence qualified as Seq
import Data.Text.Extended
import Data.These (These (..))
import Hasura.Base.Error
import Hasura.Incremental qualified as Inc
import Hasura.Prelude
import Hasura.RQL.DDL.ComputedField
import Hasura.RQL.DDL.Relationship
import Hasura.RQL.DDL.RemoteRelationship
import Hasura.RQL.DDL.Schema.Cache.Common
import Hasura.RQL.DDL.Schema.Function
import Hasura.RQL.Types
import Hasura.SQL.AnyBackend qualified as AB
import Language.GraphQL.Draft.Syntax qualified as G

addNonColumnFields ::
  forall b arr m.
  ( ArrowChoice arr,
    Inc.ArrowDistribute arr,
    ArrowWriter (Seq CollectedInfo) arr,
    ArrowKleisli m arr,
    MonadError QErr m,
    BackendMetadata b
  ) =>
  ( HashMap SourceName (AB.AnyBackend PartiallyResolvedSource),
    SourceName,
    HashMap (TableName b) (TableCoreInfoG b (ColumnInfo b) (ColumnInfo b)),
    FieldInfoMap (ColumnInfo b),
    RemoteSchemaMap,
    DBFunctionsMetadata b,
    NonColumnTableInputs b
  )
    `arr` FieldInfoMap (FieldInfo b)
addNonColumnFields =
  proc
    ( allSources,
      source,
      rawTableInfo,
      columns,
      remoteSchemaMap,
      pgFunctions,
      NonColumnTableInputs {..}
      )
  -> do
    objectRelationshipInfos <-
      buildInfoMapPreservingMetadata
        (_rdName . (^. _3))
        (\(s, t, c) -> mkRelationshipMetadataObject @b ObjRel (s, t, c))
        buildObjectRelationship
        -<
          (_tciForeignKeys <$> rawTableInfo, map (source,_nctiTable,) _nctiObjectRelationships)

    arrayRelationshipInfos <-
      buildInfoMapPreservingMetadata
        (_rdName . (^. _3))
        (mkRelationshipMetadataObject @b ArrRel)
        buildArrayRelationship
        -<
          (_tciForeignKeys <$> rawTableInfo, map (source,_nctiTable,) _nctiArrayRelationships)

    let relationshipInfos = objectRelationshipInfos <> arrayRelationshipInfos

    computedFieldInfos <-
      buildInfoMapPreservingMetadata
        (_cfmName . (^. _4))
        (\(s, _, t, c) -> mkComputedFieldMetadataObject (s, t, c))
        buildComputedField
        -<
          (HS.fromList $ M.keys rawTableInfo, map (source,pgFunctions,_nctiTable,) _nctiComputedFields)

    let columnsAndComputedFields =
          let columnFields = columns <&> FIColumn
              computedFields = M.fromList $
                flip map (M.toList computedFieldInfos) $
                  \(cfName, (cfInfo, _)) -> (fromComputedField cfName, FIComputedField cfInfo)
           in M.union columnFields computedFields

    rawRemoteRelationshipInfos <-
      buildInfoMapPreservingMetadata
        (_rrmName . (^. _3))
        (mkRemoteRelationshipMetadataObject @b)
        buildRemoteRelationship
        -<
          ((allSources, columnsAndComputedFields, remoteSchemaMap), map (source,_nctiTable,) _nctiRemoteRelationships)

    let relationshipFields = mapKeys fromRel relationshipInfos
        computedFieldFields = mapKeys fromComputedField computedFieldInfos
        remoteRelationshipFields = mapKeys fromRemoteRelationship rawRemoteRelationshipInfos

    -- First, check for conflicts between non-column fields, since we can raise a better error
    -- message in terms of the two metadata objects that define them.
    (align relationshipFields computedFieldFields >- returnA)
      >-> (| Inc.keyed (\fieldName fields -> (fieldName, fields) >- noFieldConflicts FIRelationship FIComputedField) |)
      -- Second, align with remote relationship fields
      >-> (\fields -> align (M.catMaybes fields) remoteRelationshipFields >- returnA)
      >-> (| Inc.keyed (\fieldName fields -> (fieldName, fields) >- noFieldConflicts id FIRemoteRelationship) |)
      -- Next, check for conflicts with custom field names. This is easiest to do before merging with
      -- the column info itself because we have access to the information separately, and custom field
      -- names are not currently stored as a separate map (but maybe should be!).
      >-> (\fields -> (columns, M.catMaybes fields) >- noCustomFieldConflicts)
      -- Finally, check for conflicts with the columns themselves.
      >-> (\fields -> align columns (M.catMaybes fields) >- returnA)
      >-> (| Inc.keyed (\_ fields -> fields >- noColumnConflicts) |)
  where
    noFieldConflicts this that = proc (fieldName, fields) -> case fields of
      This (thisField, metadata) -> returnA -< Just (this thisField, metadata)
      That (thatField, metadata) -> returnA -< Just (that thatField, metadata)
      These (_, thisMetadata) (_, thatMetadata) -> do
        tellA
          -<
            Seq.singleton $
              CIInconsistency $
                ConflictingObjects
                  ("conflicting definitions for field " <>> fieldName)
                  [thisMetadata, thatMetadata]
        returnA -< Nothing

    noCustomFieldConflicts = proc (columns, nonColumnFields) -> do
      let columnsByGQLName = mapFromL pgiName $ M.elems columns
      (|
        Inc.keyed
          ( \_ (fieldInfo, metadata) ->
              (|
                withRecordInconsistency
                  ( do
                      (|
                        traverseA_
                          ( \fieldGQLName -> case M.lookup fieldGQLName columnsByGQLName of
                              -- Only raise an error if the GQL name isn’t the same as the Postgres column name.
                              -- If they are the same, `noColumnConflicts` will catch it, and it will produce a
                              -- more useful error message.
                              Just columnInfo
                                | toTxt (pgiColumn columnInfo) /= G.unName fieldGQLName ->
                                  throwA
                                    -<
                                      err400 AlreadyExists $
                                        "field definition conflicts with custom field name for postgres column "
                                          <>> pgiColumn columnInfo
                              _ -> returnA -< ()
                          )
                        |) (fieldInfoGraphQLNames fieldInfo)
                      returnA -< (fieldInfo, metadata)
                  )
              |) metadata
          )
        |) nonColumnFields

    noColumnConflicts = proc fields -> case fields of
      This columnInfo -> returnA -< FIColumn columnInfo
      That (fieldInfo, _) -> returnA -< fieldInfo
      These columnInfo (_, fieldMetadata) -> do
        recordInconsistency -< ((Nothing, fieldMetadata), "field definition conflicts with postgres column")
        returnA -< FIColumn columnInfo

mkRelationshipMetadataObject ::
  forall b a.
  (ToJSON a, Backend b) =>
  RelType ->
  (SourceName, TableName b, RelDef a) ->
  MetadataObject
mkRelationshipMetadataObject relType (source, table, relDef) =
  let objectId =
        MOSourceObjId source $
          AB.mkAnyBackend $
            SMOTableObj @b table $
              MTORel (_rdName relDef) relType
   in MetadataObject objectId $ toJSON $ WithTable @b source table relDef

buildObjectRelationship ::
  ( ArrowChoice arr,
    ArrowWriter (Seq CollectedInfo) arr,
    Backend b
  ) =>
  ( HashMap (TableName b) (HashSet (ForeignKey b)),
    ( SourceName,
      TableName b,
      ObjRelDef b
    )
  )
    `arr` Maybe (RelInfo b)
buildObjectRelationship = proc (fkeysMap, (source, table, relDef)) -> do
  let buildRelInfo def = objRelP2Setup source table fkeysMap def
  buildRelationship -< (source, table, buildRelInfo, ObjRel, relDef)

buildArrayRelationship ::
  ( ArrowChoice arr,
    ArrowWriter (Seq CollectedInfo) arr,
    Backend b
  ) =>
  ( HashMap (TableName b) (HashSet (ForeignKey b)),
    ( SourceName,
      TableName b,
      ArrRelDef b
    )
  )
    `arr` Maybe (RelInfo b)
buildArrayRelationship = proc (fkeysMap, (source, table, relDef)) -> do
  let buildRelInfo def = arrRelP2Setup fkeysMap source table def
  buildRelationship -< (source, table, buildRelInfo, ArrRel, relDef)

buildRelationship ::
  forall b arr a.
  ( ArrowChoice arr,
    ArrowWriter (Seq CollectedInfo) arr,
    ToJSON a,
    Backend b
  ) =>
  ( SourceName,
    TableName b,
    RelDef a -> Either QErr (RelInfo b, [SchemaDependency]),
    RelType,
    RelDef a
  )
    `arr` Maybe (RelInfo b)
buildRelationship = proc (source, table, buildRelInfo, relType, relDef) -> do
  let relName = _rdName relDef
      metadataObject = mkRelationshipMetadataObject @b relType (source, table, relDef)
      schemaObject =
        SOSourceObj source $
          AB.mkAnyBackend $
            SOITableObj @b table $
              TORel relName
      addRelationshipContext e = "in relationship " <> relName <<> ": " <> e
  (|
    withRecordInconsistency
      ( (|
          modifyErrA
            ( do
                (info, dependencies) <- liftEitherA -< buildRelInfo relDef
                recordDependencies -< (metadataObject, schemaObject, dependencies)
                returnA -< info
            )
        |) (addTableContext @b table . addRelationshipContext)
      )
    |) metadataObject

mkComputedFieldMetadataObject ::
  forall b.
  (Backend b) =>
  (SourceName, TableName b, ComputedFieldMetadata b) ->
  MetadataObject
mkComputedFieldMetadataObject (source, table, ComputedFieldMetadata {..}) =
  let objectId =
        MOSourceObjId source $
          AB.mkAnyBackend $
            SMOTableObj @b table $
              MTOComputedField _cfmName
      definition = AddComputedField source table _cfmName _cfmDefinition _cfmComment
   in MetadataObject objectId (toJSON definition)

buildComputedField ::
  forall b arr m.
  ( ArrowChoice arr,
    ArrowWriter (Seq CollectedInfo) arr,
    ArrowKleisli m arr,
    MonadError QErr m,
    BackendMetadata b
  ) =>
  ( HashSet (TableName b),
    (SourceName, DBFunctionsMetadata b, TableName b, ComputedFieldMetadata b)
  )
    `arr` Maybe (ComputedFieldInfo b)
buildComputedField = proc (trackedTableNames, (source, pgFunctions, table, cf@ComputedFieldMetadata {..})) -> do
  let addComputedFieldContext e = "in computed field " <> _cfmName <<> ": " <> e
      function = _cfdFunction _cfmDefinition
      funcDefs = fromMaybe [] $ M.lookup function pgFunctions
  (|
    withRecordInconsistency
      ( (|
          modifyErrA
            ( do
                rawfi <- bindErrorA -< handleMultipleFunctions @b (_cfdFunction _cfmDefinition) funcDefs
                bindErrorA -< buildComputedFieldInfo trackedTableNames table _cfmName _cfmDefinition rawfi _cfmComment
            )
        |) (addTableContext @b table . addComputedFieldContext)
      )
    |) (mkComputedFieldMetadataObject (source, table, cf))

mkRemoteRelationshipMetadataObject ::
  forall b.
  Backend b =>
  (SourceName, TableName b, RemoteRelationshipMetadata) ->
  MetadataObject
mkRemoteRelationshipMetadataObject (source, table, RemoteRelationshipMetadata {..}) =
  let objectId =
        MOSourceObjId source $
          AB.mkAnyBackend $
            SMOTableObj @b table $
              MTORemoteRelationship _rrmName
   in MetadataObject objectId $
        toJSON $
          RemoteRelationship @b _rrmName source table _rrmDefinition

buildRemoteRelationship ::
  forall b arr m.
  ( ArrowChoice arr,
    ArrowWriter (Seq CollectedInfo) arr,
    ArrowKleisli m arr,
    MonadError QErr m,
    BackendMetadata b
  ) =>
  ( (HashMap SourceName (AB.AnyBackend PartiallyResolvedSource), FieldInfoMap (FieldInfo b), RemoteSchemaMap),
    (SourceName, TableName b, RemoteRelationshipMetadata)
  )
    `arr` Maybe (RemoteFieldInfo b)
buildRemoteRelationship =
  proc
    ( (allSources, allColumns, remoteSchemaMap),
      (source, table, rrm@RemoteRelationshipMetadata {..})
      )
  -> do
    let metadataObject = mkRemoteRelationshipMetadataObject @b (source, table, rrm)
        schemaObj =
          SOSourceObj source $
            AB.mkAnyBackend $
              SOITableObj @b table $
                TORemoteRel _rrmName
        addRemoteRelationshipContext e = "in remote relationship" <> _rrmName <<> ": " <> e
        def = _rrmDefinition
        remoteRelationship =
          RemoteRelationship
            @b
            _rrmName
            source
            table
            def
    (|
      withRecordInconsistency
        ( (|
            modifyErrA
              ( do
                  (remoteField, dependencies) <- bindErrorA -< buildRemoteFieldInfo source table allColumns remoteRelationship allSources remoteSchemaMap
                  recordDependencies -< (metadataObject, schemaObj, dependencies)
                  returnA -< remoteField
              )
          |) (addTableContext @b table . addRemoteRelationshipContext)
        )
      |) metadataObject