{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE ViewPatterns #-}

{-# OPTIONS -Wno-redundant-constraints #-}

-- | BigQuery helpers. This module contains BigQuery specific schema
-- setup/teardown functions because BigQuery API has a different API
-- (dataset field, manual_configuration field etc)
module Harness.Backend.BigQuery
  ( run_,
    runSql_,
    getServiceAccount,
    getProjectId,
    createTable,
    defaultSourceMetadata,
    insertTable,
    trackTable,
    dropTable,
    untrackTable,
    setup,
    setupWithAdditionalRelationship,
    teardown,
    teardownWithAdditionalRelationship,
  )
where

import Control.Monad (void)
import Data.Aeson
  ( Value (..),
    object,
    (.=),
  )
import Data.Foldable (for_)
import Data.String
import Data.Text (Text, pack, replace)
import Data.Text qualified as T
import Data.Text.Extended (commaSeparated)
import Data.Time (defaultTimeLocale, formatTime)
import GHC.Stack
import Harness.Constants as Constants
import Harness.Env
import Harness.Exceptions
import Harness.GraphqlEngine qualified as GraphqlEngine
import Harness.Quoter.Yaml (yaml)
import Harness.Test.Context
  ( BackendType (BigQuery),
    defaultBackendTypeString,
    defaultSource,
  )
import Harness.Test.Schema
  ( BackendScalarType (..),
    BackendScalarValue (..),
    ManualRelationship (..),
    Reference (..),
    ScalarValue (..),
    Table (..),
  )
import Harness.Test.Schema qualified as Schema
import Harness.TestEnvironment (TestEnvironment)
import Hasura.Backends.BigQuery.Connection (initConnection)
import Hasura.Backends.BigQuery.Execute qualified as Execute
import Hasura.Backends.BigQuery.Source (ServiceAccount)
import Hasura.Prelude (onLeft, tshow)
import Prelude

getServiceAccount :: HasCallStack => IO ServiceAccount
getServiceAccount = getEnvJson Constants.bigqueryServiceKeyVar

getProjectId :: (HasCallStack) => IO Text
getProjectId = getEnvString Constants.bigqueryProjectIdVar

-- | Run a plain Standard SQL string against the server, ignore the
-- result. Just checks for errors.
run_ :: (HasCallStack) => ServiceAccount -> Text -> String -> IO ()
run_ serviceAccount projectId query = do
  conn <- initConnection serviceAccount projectId Nothing
  res <- Execute.executeBigQuery conn Execute.BigQuery {Execute.query = fromString query, Execute.parameters = mempty}
  res `onLeft` (`bigQueryError` query)

runSql_ :: HasCallStack => String -> IO ()
runSql_ query = do
  serviceAccount <- getServiceAccount
  projectId <- getProjectId
  catch
    ( bracket
        (initConnection serviceAccount projectId Nothing)
        (const (pure ()))
        (\conn -> void $ handleResult <$> (Execute.executeBigQuery conn Execute.BigQuery {Execute.query = fromString query, Execute.parameters = mempty}))
    )
    ( \(e :: SomeException) ->
        error
          ( unlines
              [ "BigQuery error:",
                show e,
                "SQL was:",
                query
              ]
          )
    )
  where
    handleResult :: Either Execute.ExecuteProblem () -> IO ()
    handleResult (Left _) = throwString "Error handling bigquery"
    handleResult (Right ()) = pure ()

bigQueryError :: HasCallStack => Execute.ExecuteProblem -> String -> IO ()
bigQueryError e query =
  error
    ( unlines
        [ "BigQuery query error:",
          T.unpack (Execute.executeProblemMessage e),
          "SQL was:",
          query
        ]
    )

-- | Serialize Table into a SQL statement, as needed, and execute it on the BigQuery backend
createTable :: Schema.Table -> IO ()
createTable Schema.Table {tableName, tableColumns} = do
  serviceAccount <- getServiceAccount
  projectId <- getProjectId
  run_
    serviceAccount
    projectId
    $ T.unpack $
      T.unwords
        [ "CREATE TABLE",
          T.pack Constants.bigqueryDataset <> "." <> tableName,
          "(",
          commaSeparated $
            (mkColumn <$> tableColumns),
          -- Primary keys are not supported by BigQuery
          -- Foreign keys are not support by BigQuery
          ");"
        ]

scalarType :: HasCallStack => Schema.ScalarType -> Text
scalarType = \case
  Schema.TInt -> "INT64"
  Schema.TStr -> "STRING"
  Schema.TUTCTime -> "DATETIME"
  Schema.TBool -> "BIT"
  Schema.TCustomType txt -> Schema.getBackendScalarType txt bstBigQuery

-- | Create column. BigQuery doesn't support default values. Also,
-- currently we don't support specifying NOT NULL constraint.
mkColumn :: Schema.Column -> Text
mkColumn Schema.Column {columnName, columnType} =
  T.unwords
    [ columnName,
      scalarType columnType
    ]

-- | Serialize tableData into an SQL insert statement and execute it.
insertTable :: Schema.Table -> IO ()
insertTable Schema.Table {tableName, tableColumns, tableData}
  | null tableData = pure ()
  | otherwise = do
    serviceAccount <- getServiceAccount
    projectId <- getProjectId
    run_
      serviceAccount
      projectId
      $ T.unpack $
        T.unwords
          [ "INSERT INTO",
            T.pack Constants.bigqueryDataset <> "." <> tableName,
            "(",
            commaSeparated (Schema.columnName <$> tableColumns),
            ")",
            "VALUES",
            commaSeparated $ mkRow <$> tableData,
            ";"
          ]

-- | 'ScalarValue' serializer for BigQuery
serialize :: ScalarValue -> Text
serialize = \case
  VInt i -> tshow i
  VStr s -> "'" <> replace "'" "\'" s <> "'"
  VUTCTime t -> pack $ formatTime defaultTimeLocale "'%F %T'" t
  VBool b -> tshow @Int $ if b then 1 else 0
  VNull -> "NULL"
  VCustomValue bsv -> Schema.formatBackendScalarValueType $ Schema.backendScalarValue bsv bsvBigQuery

mkRow :: [Schema.ScalarValue] -> Text
mkRow row =
  T.unwords
    [ "(",
      commaSeparated $ serialize <$> row,
      ")"
    ]

-- | Serialize Table into an SQL DROP statement and execute it
dropTable :: Schema.Table -> IO ()
dropTable Schema.Table {tableName} = do
  serviceAccount <- getServiceAccount
  projectId <- getProjectId
  run_
    serviceAccount
    projectId
    $ T.unpack $
      T.unwords
        [ "DROP TABLE", -- we don't want @IF EXISTS@ here, because we don't want this to fail silently
          T.pack Constants.bigqueryDataset <> "." <> tableName,
          ";"
        ]

-- | Post an http request to start tracking
-- Overriding here because bigquery's API is uncommon
trackTable :: TestEnvironment -> Schema.Table -> IO ()
trackTable testEnvironment Schema.Table {tableName} = do
  let datasetName = T.pack Constants.bigqueryDataset
      source = defaultSource BigQuery
  GraphqlEngine.postMetadata_
    testEnvironment
    [yaml|
type: bigquery_track_table
args:
  source: *source
  table:
    dataset: *datasetName
    name: *tableName
|]

-- | Post an http request to stop tracking the table
-- Overriding `Schema.trackTable` here because bigquery's API expects a `dataset` key
untrackTable :: TestEnvironment -> Schema.Table -> IO ()
untrackTable testEnvironment Schema.Table {tableName} = do
  let datasetName = T.pack Constants.bigqueryDataset
      source = defaultSource BigQuery
  GraphqlEngine.postMetadata_
    testEnvironment
    [yaml|
type: bigquery_untrack_table
args:
  source: *source
  table:
    dataset: *datasetName
    name: *tableName
|]

-- | Metadata source information for the default BigQuery instance
defaultSourceMetadata :: IO Value
defaultSourceMetadata = do
  let dataset = Constants.bigqueryDataset
      source = defaultSource BigQuery
      backendType = defaultBackendTypeString BigQuery
  serviceAccount <- getServiceAccount
  projectId <- getProjectId
  pure $
    [yaml|
type: replace_metadata
args:
  version: 3
  sources:
  - name: *source
    kind: *backendType
    tables: []
    configuration:
      service_account: *serviceAccount
      project_id: *projectId
      datasets: [*dataset]
|]

-- | Converts 'ManualRelationship' to 'Table'. Should be only used for
-- building the relationship.
relationshipToTable :: ManualRelationship -> Schema.Table
relationshipToTable ManualRelationship {..} =
  Table
    { tableName = relSourceTable,
      tablePrimaryKey = [],
      tableColumns = [],
      tableData = [],
      tableReferences =
        [ Reference
            { referenceLocalColumn = relSourceColumn,
              referenceTargetTable = relTargetTable,
              referenceTargetColumn = relTargetColumn
            }
        ]
    }

-- | Same as 'setup' but also additional sets up the manual
-- relationship that might be required for some cases.
setupWithAdditionalRelationship :: [Schema.Table] -> [ManualRelationship] -> (TestEnvironment, ()) -> IO ()
setupWithAdditionalRelationship tables rels (testEnvironment, _) = do
  setup tables (testEnvironment, ())
  let relTables = map relationshipToTable rels
  for_ relTables $ \table -> do
    trackObjectRelationships BigQuery table testEnvironment
    trackArrayRelationships BigQuery table testEnvironment

-- | Setup the schema in the most expected way.
-- NOTE: Certain test modules may warrant having their own local version.
setup :: [Schema.Table] -> (TestEnvironment, ()) -> IO ()
setup tables (testEnvironment, _) = do
  let dataset = Constants.bigqueryDataset
      source = defaultSource BigQuery
      backendType = defaultBackendTypeString BigQuery
  -- Clear and reconfigure the metadata
  serviceAccount <- getServiceAccount
  projectId <- getProjectId
  GraphqlEngine.postMetadata_
    testEnvironment
    [yaml|
type: replace_metadata
args:
  version: 3
  sources:
  - name: *source
    kind: *backendType
    tables: []
    configuration:
      service_account: *serviceAccount
      project_id: *projectId
      datasets: [*dataset]
|]
  -- Setup and track tables
  for_ tables $ \table -> do
    createTable table
    insertTable table
    trackTable testEnvironment table
  -- Setup relationships
  for_ tables $ \table -> do
    trackObjectRelationships BigQuery table testEnvironment
    trackArrayRelationships BigQuery table testEnvironment

-- | Teardown the schema and tracking in the most expected way.
-- NOTE: Certain test modules may warrant having their own version.
teardown :: [Schema.Table] -> (TestEnvironment, ()) -> IO ()
teardown (reverse -> tables) (testEnvironment, _) = do
  -- Teardown relationships first
  forFinally_ tables $ \table ->
    untrackRelationships BigQuery table testEnvironment
  -- Then teardown tables
  forFinally_ tables $ \table -> do
    untrackTable testEnvironment table
    dropTable table

-- | Same as 'teardown' but also tears the manual relationship that
-- was setup.
teardownWithAdditionalRelationship :: [Schema.Table] -> [ManualRelationship] -> (TestEnvironment, ()) -> IO ()
teardownWithAdditionalRelationship tables rels (testEnvironment, _) = do
  let relTables = map relationshipToTable rels
  for_ relTables $ \table -> do
    untrackRelationships BigQuery table testEnvironment
  -- We do teardown in the reverse order to ensure that the tables
  -- that have dependency are removed first. This has to be only done
  -- for BigQuery backend since the metadata tracks the relationship
  -- between them.
  teardown (reverse tables) (testEnvironment, ())

-- | Bigquery specific function for tracking array relationships
trackArrayRelationships :: HasCallStack => BackendType -> Table -> TestEnvironment -> IO ()
trackArrayRelationships backend Table {tableName, tableReferences} testEnvironment = do
  let source = defaultSource backend
      dataset = Constants.bigqueryDataset
      requestType = source <> "_create_array_relationship"
  for_ tableReferences $ \Reference {referenceLocalColumn, referenceTargetTable, referenceTargetColumn} -> do
    let relationshipName = Schema.mkArrayRelationshipName referenceTargetTable referenceTargetColumn
        manualConfiguration :: Value
        manualConfiguration =
          object
            [ "remote_table"
                .= object
                  [ "dataset" .= String (T.pack dataset),
                    "name" .= String referenceTargetTable
                  ],
              "column_mapping"
                .= object [referenceLocalColumn .= referenceTargetColumn]
            ]
        payload =
          [yaml|
type: *requestType
args:
  source: *source
  table:
    dataset: *dataset
    name: *tableName
  name: *relationshipName
  using:
    manual_configuration: *manualConfiguration
|]
    GraphqlEngine.postMetadata_
      testEnvironment
      payload

-- | Bigquery specific function for tracking object relationships
trackObjectRelationships :: HasCallStack => BackendType -> Table -> TestEnvironment -> IO ()
trackObjectRelationships backend Table {tableName, tableReferences} testEnvironment = do
  let source = defaultSource backend
      dataset = Constants.bigqueryDataset
      requestType = source <> "_create_object_relationship"
  for_ tableReferences $ \ref@Reference {referenceLocalColumn, referenceTargetTable, referenceTargetColumn} -> do
    let relationshipName = Schema.mkObjectRelationshipName ref
        manualConfiguration :: Value
        manualConfiguration =
          object
            [ "remote_table"
                .= object
                  [ "dataset" .= String (T.pack dataset),
                    "name" .= String referenceTargetTable
                  ],
              "column_mapping"
                .= object [referenceLocalColumn .= referenceTargetColumn]
            ]
        payload =
          [yaml|
type: *requestType
args:
  source: *source
  table:
    dataset: *dataset
    name: *tableName
  name: *relationshipName
  using:
    manual_configuration: *manualConfiguration
|]

    GraphqlEngine.postMetadata_
      testEnvironment
      payload

-- | Bigquery specific function for untracking relationships
-- Overriding `Schema.untrackRelationships` here because bigquery's API expects a `dataset` key
untrackRelationships :: HasCallStack => BackendType -> Table -> TestEnvironment -> IO ()
untrackRelationships backend Table {tableName, tableReferences} testEnvironment = do
  let source = defaultSource backend
      dataset = Constants.bigqueryDataset
      requestType = source <> "_drop_relationship"
  for_ tableReferences $ \ref@Reference {referenceTargetTable, referenceTargetColumn} -> do
    let arrayRelationshipName = Schema.mkArrayRelationshipName referenceTargetTable referenceTargetColumn
        objectRelationshipName = Schema.mkObjectRelationshipName ref
    -- drop array relationships
    GraphqlEngine.postMetadata_
      testEnvironment
      [yaml|
type: *requestType
args:
  source: *source
  table:
    dataset: *dataset
    name: *tableName
  relationship: *arrayRelationshipName
|]
    -- drop object relationships
    GraphqlEngine.postMetadata_
      testEnvironment
      [yaml|
type: *requestType
args:
  source: *source
  table:
    dataset: *dataset
    name: *tableName
  relationship: *objectRelationshipName
|]