module Hasura.Server.Migrate.Internal
  ( getCatalogVersion
  , from3To4
  , setCatalogVersion
  ) where

import           Hasura.Prelude

import           Data.Time.Clock                     (UTCTime)

import qualified Data.Aeson                          as A
import qualified Database.PG.Query                   as Q

import           Hasura.Backends.Postgres.Connection
import           Hasura.Base.Error
import           Hasura.RQL.Types.Backend            (Backend)
import           Hasura.RQL.Types.Common             (InputWebhook)
import           Hasura.RQL.Types.EventTrigger
import           Hasura.SQL.Backend


-- | The old 0.8 catalog version is non-integral, so we store it in the database as a
-- string.
getCatalogVersion :: Q.TxE QErr Text
getCatalogVersion = runIdentity . Q.getRow <$> Q.withQE defaultTxErrorHandler
  [Q.sql| SELECT version FROM hdb_catalog.hdb_version |] () False

from3To4 :: forall m. (Backend ('Postgres 'Vanilla), MonadTx m) => m ()
from3To4 = liftTx $ Q.catchE defaultTxErrorHandler $ do
    Q.unitQ [Q.sql|
      ALTER TABLE hdb_catalog.event_triggers
      ADD COLUMN configuration JSON |] () False
    eventTriggers <- map uncurryEventTrigger <$> Q.listQ [Q.sql|
      SELECT e.name, e.definition::json, e.webhook, e.num_retries, e.retry_interval, e.headers::json
      FROM hdb_catalog.event_triggers e |] () False
    forM_ eventTriggers updateEventTrigger3To4
    Q.unitQ [Q.sql|
      ALTER TABLE hdb_catalog.event_triggers
      DROP COLUMN definition,
      DROP COLUMN query,
      DROP COLUMN webhook,
      DROP COLUMN num_retries,
      DROP COLUMN retry_interval,
      DROP COLUMN headers,
      DROP COLUMN metadataTransform|] () False
    where
      uncurryEventTrigger
        :: ( TriggerName
           , Q.AltJ (TriggerOpsDef ('Postgres 'Vanilla))
           , InputWebhook
           , Int
           , Int
           , Q.AltJ (Maybe [HeaderConf]))
        -> EventTriggerConf ('Postgres 'Vanilla)
      uncurryEventTrigger (trn, Q.AltJ tDef, w, nr, rint, Q.AltJ headers) =
        EventTriggerConf trn tDef (Just w) Nothing (RetryConf nr rint Nothing) headers Nothing
      updateEventTrigger3To4 etc@(EventTriggerConf name _ _ _ _ _ _) = Q.unitQ [Q.sql|
                                            UPDATE hdb_catalog.event_triggers
                                            SET
                                            configuration = $1
                                            WHERE name = $2
                                            |] (Q.AltJ $ A.toJSON etc, name) True

setCatalogVersion :: MonadTx m => Text -> UTCTime -> m ()
setCatalogVersion ver time = liftTx $ Q.unitQE defaultTxErrorHandler [Q.sql|
    INSERT INTO hdb_catalog.hdb_version (version, upgraded_on) VALUES ($1, $2)
    ON CONFLICT ((version IS NOT NULL))
    DO UPDATE SET version = $1, upgraded_on = $2
  |] (ver, time) False