import enum
import tokens
from prompt_toolkit.formatted_text import FormattedText


class RunStatus:
	"""
	Base class for run status.
	These are returned whenever the runner does something.
	"""
	pass

class MacroStatus(RunStatus):
	"""
	Returned when a macro is defined.

	Values:
	`was_rewritten`:	If true, an old macro was replaced.
	`macro_label`:		The name of the macro we just made.
	`macro_expr`:		The expr of the macro we just made.
	"""

	def __init__(
		self,
		*,
		was_rewritten: bool,
		macro_label: str,
		macro_expr
	):
		self.was_rewritten = was_rewritten
		self.macro_label = macro_label
		self.macro_expr = macro_expr


class StopReason(enum.Enum):
	BETA_NORMAL		= ("#FFFFFF", "β-normal form")
	LOOP_DETECTED	= ("#FFFF00", "loop detected")
	MAX_EXCEEDED	= ("#FFFF00", "too many reductions")
	INTERRUPT		= ("#FF0000", "user interrupt")


class ReduceStatus(RunStatus):
	"""
	Returned when an expression is reduced.

	Values:
	`reduction_count`:	How many reductions were made.
	`stop_reason`:		Why we stopped. See `StopReason`.
	"""

	def __init__(
		self,
		*,
		reduction_count: int,
		stop_reason: StopReason,
		result: tokens.LambdaToken
	):
		self.reduction_count = reduction_count
		self.stop_reason = stop_reason
		self.result = result


class CommandStatus(RunStatus):
	"""
	Returned when a command is executed.

	Values:
	`formatted_text`: What to print after this command is executed
	"""

	def __init__(
		self,
		*,
		formatted_text: FormattedText
	):
		self.formatted_text = formatted_text