module Database.DuckDB.FFI.ScalarFunctions (
    c_duckdb_create_scalar_function,
    c_duckdb_destroy_scalar_function,
    c_duckdb_scalar_function_set_name,
    c_duckdb_scalar_function_set_varargs,
    c_duckdb_scalar_function_set_special_handling,
    c_duckdb_scalar_function_set_volatile,
    c_duckdb_scalar_function_add_parameter,
    c_duckdb_scalar_function_set_return_type,
    c_duckdb_scalar_function_set_extra_info,
    c_duckdb_scalar_function_set_bind,
    c_duckdb_scalar_function_set_bind_data,
    c_duckdb_scalar_function_set_bind_data_copy,
    c_duckdb_scalar_function_bind_set_error,
    c_duckdb_scalar_function_set_function,
    c_duckdb_register_scalar_function,
    c_duckdb_scalar_function_get_extra_info,
    c_duckdb_scalar_function_bind_get_extra_info,
    c_duckdb_scalar_function_get_bind_data,
    c_duckdb_scalar_function_get_client_context,
    c_duckdb_scalar_function_set_error,
    c_duckdb_create_scalar_function_set,
    c_duckdb_destroy_scalar_function_set,
    c_duckdb_add_scalar_function_to_set,
    c_duckdb_register_scalar_function_set,
    c_duckdb_scalar_function_bind_get_argument_count,
    c_duckdb_scalar_function_bind_get_argument,
) where

import Database.DuckDB.FFI.Types
import Foreign.C.String (CString)
import Foreign.C.Types (CInt (..))
import Foreign.Ptr (Ptr)

{- | Creates a new empty scalar function.

The return value must be destroyed with @duckdb_destroy_scalar_function@.

Returns The scalar function object.
-}
foreign import ccall safe "duckdb_create_scalar_function"
    c_duckdb_create_scalar_function :: IO DuckDBScalarFunction

{- | Destroys the given scalar function object.

Parameters:
* @scalar_function@: The scalar function to destroy
-}
foreign import ccall safe "duckdb_destroy_scalar_function"
    c_duckdb_destroy_scalar_function :: Ptr DuckDBScalarFunction -> IO ()

{- | Sets the name of the given scalar function.

Parameters:
* @scalar_function@: The scalar function
* @name@: The name of the scalar function
-}
foreign import ccall safe "duckdb_scalar_function_set_name"
    c_duckdb_scalar_function_set_name :: DuckDBScalarFunction -> CString -> IO ()

{- | Sets the parameters of the given scalar function to varargs. Does not require
adding parameters with duckdb_scalar_function_add_parameter.

Parameters:
* @scalar_function@: The scalar function.
* @type@: The type of the arguments.

Returns The parameter type. Cannot contain INVALID.
-}
foreign import ccall safe "duckdb_scalar_function_set_varargs"
    c_duckdb_scalar_function_set_varargs :: DuckDBScalarFunction -> DuckDBLogicalType -> IO ()

{- | Sets the scalar function's null-handling behavior to special.

Parameters:
* @scalar_function@: The scalar function.
-}
foreign import ccall safe "duckdb_scalar_function_set_special_handling"
    c_duckdb_scalar_function_set_special_handling :: DuckDBScalarFunction -> IO ()

{- | Sets the Function Stability of the scalar function to VOLATILE, indicating the
function should be re-run for every row. This limits optimization that can be
performed for the function.

Parameters:
* @scalar_function@: The scalar function.
-}
foreign import ccall safe "duckdb_scalar_function_set_volatile"
    c_duckdb_scalar_function_set_volatile :: DuckDBScalarFunction -> IO ()

{- | Adds a parameter to the scalar function.

Parameters:
* @scalar_function@: The scalar function.
* @type@: The parameter type. Cannot contain INVALID.
-}
foreign import ccall safe "duckdb_scalar_function_add_parameter"
    c_duckdb_scalar_function_add_parameter :: DuckDBScalarFunction -> DuckDBLogicalType -> IO ()

{- | Sets the return type of the scalar function.

Parameters:
* @scalar_function@: The scalar function
* @type@: Cannot contain INVALID or ANY.
-}
foreign import ccall safe "duckdb_scalar_function_set_return_type"
    c_duckdb_scalar_function_set_return_type :: DuckDBScalarFunction -> DuckDBLogicalType -> IO ()

{- | Assigns extra information to the scalar function that can be fetched during
binding, etc.

Parameters:
* @scalar_function@: The scalar function
* @extra_info@: The extra information
* @destroy@: The callback that will be called to destroy the extra information
  (if any)
-}
foreign import ccall safe "duckdb_scalar_function_set_extra_info"
    c_duckdb_scalar_function_set_extra_info :: DuckDBScalarFunction -> Ptr () -> DuckDBDeleteCallback -> IO ()

{- | Sets the (optional) bind function of the scalar function.

Parameters:
* @scalar_function@: The scalar function.
* @bind@: The bind function.
-}
foreign import ccall safe "duckdb_scalar_function_set_bind"
    c_duckdb_scalar_function_set_bind :: DuckDBScalarFunction -> DuckDBScalarFunctionBindFun -> IO ()

{- | Sets the user-provided bind data in the bind object of the scalar function.
The bind data object can be retrieved again during execution. In most case,
you also need to set the copy-callback of your bind data via
duckdb_scalar_function_set_bind_data_copy.

Parameters:
* @info@: The bind info of the scalar function.
* @bind_data@: The bind data object.
* @destroy@: The callback to destroy the bind data (if any).
-}
foreign import ccall safe "duckdb_scalar_function_set_bind_data"
    c_duckdb_scalar_function_set_bind_data :: DuckDBBindInfo -> Ptr () -> DuckDBDeleteCallback -> IO ()

{- | Sets the copy-callback for the user-provided bind data in the bind object of
the scalar function.

Parameters:
* @info@: The bind info of the scalar function.
* @copy@: The callback to copy the bind data (if any).
-}
foreign import ccall safe "duckdb_scalar_function_set_bind_data_copy"
    c_duckdb_scalar_function_set_bind_data_copy :: DuckDBBindInfo -> DuckDBCopyCallback -> IO ()

{- | Report that an error has occurred while calling bind on a scalar function.

Parameters:
* @info@: The bind info object.
* @error@: The error message.
-}
foreign import ccall safe "duckdb_scalar_function_bind_set_error"
    c_duckdb_scalar_function_bind_set_error :: DuckDBBindInfo -> CString -> IO ()

{- | Sets the main function of the scalar function.

Parameters:
* @scalar_function@: The scalar function
* @function@: The function
-}
foreign import ccall safe "duckdb_scalar_function_set_function"
    c_duckdb_scalar_function_set_function :: DuckDBScalarFunction -> DuckDBScalarFunctionFun -> IO ()

{- | Register the scalar function object within the given connection.

The function requires at least a name, a function and a return type.

If the function is incomplete or a function with this name already exists
DuckDBError is returned.

Parameters:
* @con@: The connection to register it in.
* @scalar_function@: The function pointer

Returns Whether or not the registration was successful.
-}
foreign import ccall safe "duckdb_register_scalar_function"
    c_duckdb_register_scalar_function :: DuckDBConnection -> DuckDBScalarFunction -> IO DuckDBState

{- | Retrieves the extra info of the function as set in
@duckdb_scalar_function_set_extra_info@.

Parameters:
* @info@: The info object.

Returns The extra info.
-}
foreign import ccall safe "duckdb_scalar_function_get_extra_info"
    c_duckdb_scalar_function_get_extra_info :: DuckDBFunctionInfo -> IO (Ptr ())

{- | Retrieves the extra info of the function as set in the bind info.

Parameters:
* @info@: The info object.

Returns The extra info.
-}
foreign import ccall safe "duckdb_scalar_function_bind_get_extra_info"
    c_duckdb_scalar_function_bind_get_extra_info :: DuckDBBindInfo -> IO (Ptr ())

{- | Gets the scalar function's bind data set by
@duckdb_scalar_function_set_bind_data@. Note that the bind data is read-only.

Parameters:
* @info@: The function info.

Returns The bind data object.
-}
foreign import ccall safe "duckdb_scalar_function_get_bind_data"
    c_duckdb_scalar_function_get_bind_data :: DuckDBFunctionInfo -> IO (Ptr ())

{- | Retrieves the client context of the bind info of a scalar function.

Parameters:
* @info@: The bind info object of the scalar function.
* @out_context@: The client context of the bind info. Must be destroyed with
  @duckdb_destroy_client_context@.
-}
foreign import ccall safe "duckdb_scalar_function_get_client_context"
    c_duckdb_scalar_function_get_client_context :: DuckDBBindInfo -> Ptr DuckDBClientContext -> IO ()

{- | Report that an error has occurred while executing the scalar function.

Parameters:
* @info@: The info object.
* @error@: The error message
-}
foreign import ccall safe "duckdb_scalar_function_set_error"
    c_duckdb_scalar_function_set_error :: DuckDBFunctionInfo -> CString -> IO ()

{- | Creates a new empty scalar function set.

The return value must be destroyed with @duckdb_destroy_scalar_function_set@.

Returns The scalar function set object.
-}
foreign import ccall safe "duckdb_create_scalar_function_set"
    c_duckdb_create_scalar_function_set :: CString -> IO DuckDBScalarFunctionSet

-- | Destroys the given scalar function set object.
foreign import ccall safe "duckdb_destroy_scalar_function_set"
    c_duckdb_destroy_scalar_function_set :: Ptr DuckDBScalarFunctionSet -> IO ()

{- | Adds the scalar function as a new overload to the scalar function set.

Returns DuckDBError if the function could not be added, for example if the
overload already exists.

Parameters:
* @set@: The scalar function set
* @function@: The function to add
-}
foreign import ccall safe "duckdb_add_scalar_function_to_set"
    c_duckdb_add_scalar_function_to_set :: DuckDBScalarFunctionSet -> DuckDBScalarFunction -> IO DuckDBState

{- | Register the scalar function set within the given connection.

The set requires at least a single valid overload.

If the set is incomplete or a function with this name already exists
DuckDBError is returned.

Parameters:
* @con@: The connection to register it in.
* @set@: The function set to register

Returns Whether or not the registration was successful.
-}
foreign import ccall safe "duckdb_register_scalar_function_set"
    c_duckdb_register_scalar_function_set :: DuckDBConnection -> DuckDBScalarFunctionSet -> IO DuckDBState

{- | Returns the number of input arguments of the scalar function.

Parameters:
* @info@: The bind info.

Returns The number of input arguments.
-}
foreign import ccall safe "duckdb_scalar_function_bind_get_argument_count"
    c_duckdb_scalar_function_bind_get_argument_count :: DuckDBBindInfo -> IO DuckDBIdx

{- | Returns the input argument at index of the scalar function.

Parameters:
* @info@: The bind info.
* @index@: The argument index.

Returns The input argument at index. Must be destroyed with
@duckdb_destroy_expression@.
-}
foreign import ccall safe "duckdb_scalar_function_bind_get_argument"
    c_duckdb_scalar_function_bind_get_argument :: DuckDBBindInfo -> DuckDBIdx -> IO DuckDBExpression