Builder.hs

{-# OPTIONS_GHC -fno-warn-orphans #-}
{-# LANGUAGE CPP #-}

-- | DDL syntax instances for 'SqlSyntaxBuilder'
module Database.Beam.Migrate.SQL.Builder where

import           Database.Beam.Backend.SQL
import           Database.Beam.Backend.SQL.Builder
import           Database.Beam.Migrate.SQL
import           Database.Beam.Migrate.Serialization

import           Control.Applicative

import           Data.ByteString.Builder (Builder, byteString, toLazyByteString)
import qualified Data.ByteString.Lazy.Char8 as BCL

import qualified Data.List.NonEmpty as NE



-- | Options for @CREATE TABLE@. Given as a separate ADT because the options may
-- go in different places syntactically.
--
-- You never really need to use this type directly.
data SqlSyntaxBuilderCreateTableOptions
    = SqlSyntaxBuilderCreateTableOptions
        SqlSyntaxBuilder
        SqlSyntaxBuilder
    deriving Eq

instance IsSql92DdlSchemaCommandSyntax SqlSyntaxBuilder where
  type Sql92DdlCommandCreateSchemaSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92DdlCommandDropSchemaSyntax SqlSyntaxBuilder = SqlSyntaxBuilder

  createSchemaCmd = id
  dropSchemaCmd = id

instance IsSql92DdlCommandSyntax SqlSyntaxBuilder where
  type Sql92DdlCommandCreateTableSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92DdlCommandDropTableSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92DdlCommandAlterTableSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  createTableCmd = id
  alterTableCmd = id
  dropTableCmd = id

instance IsSql92DropTableSyntax SqlSyntaxBuilder where
  type Sql92DropTableTableNameSyntax SqlSyntaxBuilder = SqlSyntaxBuilder

  dropTableSyntax tblNm =
    SqlSyntaxBuilder $
    byteString "DROP TABLE " <> buildSql tblNm

instance IsSql92AlterTableSyntax SqlSyntaxBuilder where
  type Sql92AlterTableTableNameSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92AlterTableAlterTableActionSyntax SqlSyntaxBuilder = SqlSyntaxBuilder

  alterTableSyntax tblNm action =
    SqlSyntaxBuilder $
    byteString "ALTER TABLE " <> buildSql tblNm <> byteString " " <> buildSql action

instance IsSql92AlterTableActionSyntax SqlSyntaxBuilder where
  type Sql92AlterTableAlterColumnActionSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92AlterTableColumnSchemaSyntax SqlSyntaxBuilder = SqlSyntaxBuilder

  alterColumnSyntax colNm action =
    SqlSyntaxBuilder $
    byteString "ALTER COLUMN " <> quoteSql colNm <> byteString " " <> buildSql action

  addColumnSyntax colNm colSchema =
    SqlSyntaxBuilder $
    byteString "ADD COLUMN " <> quoteSql colNm <> byteString " " <> buildSql colSchema
  dropColumnSyntax colNm =
    SqlSyntaxBuilder $
    byteString "DROP COLUMN " <> quoteSql colNm

  renameColumnToSyntax oldNm newNm =
    SqlSyntaxBuilder $
    byteString "RENAME COLUMN " <> quoteSql oldNm <> " TO " <> quoteSql newNm
  renameTableToSyntax newNm =
    SqlSyntaxBuilder $
    byteString "RENAME TO " <> quoteSql newNm

instance IsSql92AlterColumnActionSyntax SqlSyntaxBuilder where
  setNotNullSyntax = SqlSyntaxBuilder (byteString "SET NOT NULL")
  setNullSyntax = SqlSyntaxBuilder (byteString "DROP NOT NULL")

instance IsSql92CreateSchemaSyntax SqlSyntaxBuilder where
  type Sql92CreateSchemaSchemaNameSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  createSchemaSyntax schName = 
      SqlSyntaxBuilder $
        byteString "CREATE SCHEMA " <> buildSql schName

instance IsSql92DropSchemaSyntax SqlSyntaxBuilder where
  type Sql92DropSchemaSchemaNameSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  dropSchemaSyntax schName = 
      SqlSyntaxBuilder $
        byteString "DROP SCHEMA " <> buildSql schName

instance IsSql92CreateTableSyntax SqlSyntaxBuilder where
  type Sql92CreateTableTableNameSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92CreateTableColumnSchemaSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92CreateTableTableConstraintSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92CreateTableOptionsSyntax SqlSyntaxBuilder = SqlSyntaxBuilderCreateTableOptions

  createTableSyntax tableOptions tblName fieldSchemas constraints =
      SqlSyntaxBuilder $
      byteString "CREATE " <>
      maybe mempty (\b -> buildSql b <> byteString " ") beforeOptions <>
      byteString " TABLE " <>

      buildSql tblName <>

      byteString "(" <>
      buildSepBy (byteString ", ")
                 (map (\(nm, schema) -> quoteSql nm <> byteString " " <> buildSql schema) fieldSchemas <>
                  map buildSql constraints) <>
      byteString ")" <>

      maybe mempty (\a -> buildSql a <> byteString " ") afterOptions

    where
      (beforeOptions, afterOptions) =
          case tableOptions of
            Just (SqlSyntaxBuilderCreateTableOptions b a) -> (Just b, Just a)
            Nothing -> (Nothing, Nothing)

instance IsSql92TableConstraintSyntax SqlSyntaxBuilder where
  primaryKeyConstraintSyntax fs =
    SqlSyntaxBuilder $
    byteString "PRIMARY KEY(" <> buildSepBy (byteString ", ") (map quoteSql $ NE.toList fs) <> byteString ")"

-- | Some backends use this to represent their constraint attributes. Does not
-- need to be used in practice.
data ConstraintAttributeTiming = InitiallyDeferred | InitiallyImmediate
  deriving (Show, Eq, Ord, Enum, Bounded)

-- | Valid 'IsSql92ConstraintAttributesSyntax' shared among some backends.
data SqlConstraintAttributesBuilder
  = SqlConstraintAttributesBuilder
  { _sqlConstraintAttributeTiming :: Maybe ConstraintAttributeTiming
  , _sqlConstraintAttributeDeferrable :: Maybe Bool }
  deriving (Show, Eq)

instance Semigroup SqlConstraintAttributesBuilder where
  a <> b =
    SqlConstraintAttributesBuilder
      (_sqlConstraintAttributeTiming b <|> _sqlConstraintAttributeTiming a)
      (_sqlConstraintAttributeDeferrable b <|> _sqlConstraintAttributeDeferrable a)

instance Monoid SqlConstraintAttributesBuilder where
  mempty = SqlConstraintAttributesBuilder Nothing Nothing

-- | Convert a 'SqlConstraintAttributesBuilder' to its @SQL92@ representation in
-- the returned 'ByteString' 'Builder'.
fromSqlConstraintAttributes :: SqlConstraintAttributesBuilder -> Builder
fromSqlConstraintAttributes (SqlConstraintAttributesBuilder timing deferrable) =
  maybe mempty timingBuilder timing <> maybe mempty deferrableBuilder deferrable
  where timingBuilder InitiallyDeferred = byteString "INITIALLY DEFERRED"
        timingBuilder InitiallyImmediate = byteString "INITIALLY IMMEDIATE"
        deferrableBuilder False = byteString "NOT DEFERRABLE"
        deferrableBuilder True = byteString "DEFERRABLE"

-- | Serialize a 'SqlConstraintAttributesBuilder'
sqlConstraintAttributesSerialized :: SqlConstraintAttributesBuilder -> BeamSerializedConstraintAttributes
sqlConstraintAttributesSerialized (SqlConstraintAttributesBuilder timing deferrable) =
  mconcat [ maybe mempty serializeTiming timing
          , maybe mempty serializeDeferrable deferrable ]

  where
    serializeTiming InitiallyDeferred = initiallyDeferredAttributeSyntax
    serializeTiming InitiallyImmediate = initiallyImmediateAttributeSyntax

    serializeDeferrable True = deferrableAttributeSyntax
    serializeDeferrable False = notDeferrableAttributeSyntax

instance IsSql92ConstraintAttributesSyntax SqlConstraintAttributesBuilder where
  initiallyDeferredAttributeSyntax = SqlConstraintAttributesBuilder (Just InitiallyDeferred) Nothing
  initiallyImmediateAttributeSyntax = SqlConstraintAttributesBuilder (Just InitiallyImmediate) Nothing
  deferrableAttributeSyntax = SqlConstraintAttributesBuilder Nothing (Just True)
  notDeferrableAttributeSyntax = SqlConstraintAttributesBuilder Nothing (Just False)

instance IsSql92ColumnSchemaSyntax SqlSyntaxBuilder where
  type Sql92ColumnSchemaColumnConstraintDefinitionSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92ColumnSchemaColumnTypeSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92ColumnSchemaExpressionSyntax SqlSyntaxBuilder = SqlSyntaxBuilder

  columnSchemaSyntax type_ default_ constraints collation =
    SqlSyntaxBuilder $
    buildSql type_ <>
    maybe mempty (\d -> byteString " DEFAULT " <> buildSql d) default_ <>
    (case constraints of
       [] -> mempty
       _ -> foldMap (\c -> byteString " " <> buildSql c) constraints) <>
    maybe mempty (\nm -> byteString " COLLATE " <> quoteSql nm) collation

instance IsSql92ColumnConstraintDefinitionSyntax SqlSyntaxBuilder where
  type Sql92ColumnConstraintDefinitionConstraintSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92ColumnConstraintDefinitionAttributesSyntax SqlSyntaxBuilder = SqlConstraintAttributesBuilder

  constraintDefinitionSyntax nm c attrs =
    SqlSyntaxBuilder $
    maybe mempty (\nm' -> byteString "CONSTRAINT " <> quoteSql nm' <> byteString " ") nm <>
    buildSql c <>
    maybe mempty fromSqlConstraintAttributes attrs

instance IsSql92ColumnConstraintSyntax SqlSyntaxBuilder where
  type Sql92ColumnConstraintMatchTypeSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92ColumnConstraintReferentialActionSyntax SqlSyntaxBuilder = SqlSyntaxBuilder
  type Sql92ColumnConstraintExpressionSyntax SqlSyntaxBuilder = SqlSyntaxBuilder

  notNullConstraintSyntax = SqlSyntaxBuilder (byteString "NOT NULL")
  uniqueColumnConstraintSyntax = SqlSyntaxBuilder (byteString "UNIQUE")
  primaryKeyColumnConstraintSyntax = SqlSyntaxBuilder (byteString "PRIMARY KEY")
  checkColumnConstraintSyntax e = SqlSyntaxBuilder ("CHECK (" <> buildSql e <> ")")
  referencesConstraintSyntax tbl fields match onUpdate onDelete =
    SqlSyntaxBuilder $
    "REFERENCES " <> quoteSql tbl <> "(" <>
    buildSepBy ", " (map quoteSql fields) <> ")" <>
    maybe mempty (\m -> " " <> buildSql m) match <>
    maybe mempty (\a -> " ON UPDATE " <> buildSql a) onUpdate <>
    maybe mempty (\a -> " ON DELETE " <> buildSql a) onDelete

instance IsSql92MatchTypeSyntax SqlSyntaxBuilder where
  fullMatchSyntax = SqlSyntaxBuilder "FULL"
  partialMatchSyntax = SqlSyntaxBuilder "PARTIAL"

instance IsSql92ReferentialActionSyntax SqlSyntaxBuilder where
  referentialActionCascadeSyntax = SqlSyntaxBuilder "CASCADE"
  referentialActionNoActionSyntax = SqlSyntaxBuilder "NO ACTION"
  referentialActionSetDefaultSyntax = SqlSyntaxBuilder "SET DEFAULT"
  referentialActionSetNullSyntax = SqlSyntaxBuilder "SET NULL"

instance Sql92DisplaySyntax SqlSyntaxBuilder where
  displaySyntax = BCL.unpack . toLazyByteString . buildSql