import asyncio
import functools
import inspect
import logging
import re
from collections.abc import Callable
from inspect import Parameter, iscoroutinefunction, signature
from types import UnionType
from typing import Any, Generic, Optional, TypeVar, Union, get_args, get_origin

import pyotp
from pydantic import BaseModel, Field, RootModel, create_model

from browser_use.browser import BrowserSession
from browser_use.filesystem.file_system import FileSystem
from browser_use.llm.base import BaseChatModel
from browser_use.observability import observe_debug
from browser_use.telemetry.service import ProductTelemetry
from browser_use.tools.registry.views import (
	ActionModel,
	ActionRegistry,
	RegisteredAction,
	SpecialActionParameters,
)
from browser_use.utils import is_new_tab_page, match_url_with_domain_pattern, time_execution_async

Context = TypeVar('Context')

logger = logging.getLogger(__name__)


class Registry(Generic[Context]):
	"""Service for registering and managing actions"""

	def __init__(self, exclude_actions: list[str] | None = None):
		self.registry = ActionRegistry()
		self.telemetry = ProductTelemetry()
		self.exclude_actions = exclude_actions if exclude_actions is not None else []

	def _get_special_param_types(self) -> dict[str, type | UnionType | None]:
		"""Get the expected types for special parameters from SpecialActionParameters"""
		# Manually define the expected types to avoid issues with Optional handling.
		# we should try to reduce this list to 0 if possible, give as few standardized objects to all the actions
		# but each driver should decide what is relevant to expose the action methods,
		# e.g. CDP client, 2fa code getters, sensitive_data wrappers, other context, etc.
		return {
			'context': None,  # Context is a TypeVar, so we can't validate type
			'browser_session': BrowserSession,
			'page_url': str,
			'cdp_client': None,  # CDPClient type from cdp_use, but we don't import it here
			'page_extraction_llm': BaseChatModel,
			'available_file_paths': list,
			'has_sensitive_data': bool,
			'file_system': FileSystem,
		}

	def _normalize_action_function_signature(
		self,
		func: Callable,
		description: str,
		param_model: type[BaseModel] | None = None,
	) -> tuple[Callable, type[BaseModel]]:
		"""
		Normalize action function to accept only kwargs.

		Returns:
			- Normalized function that accepts (*_, params: ParamModel, **special_params)
			- The param model to use for registration
		"""
		sig = signature(func)
		parameters = list(sig.parameters.values())
		special_param_types = self._get_special_param_types()
		special_param_names = set(special_param_types.keys())

		# Step 1: Validate no **kwargs in original function signature
		# if it needs default values it must use a dedicated param_model: BaseModel instead
		for param in parameters:
			if param.kind == Parameter.VAR_KEYWORD:
				raise ValueError(
					f"Action '{func.__name__}' has **{param.name} which is not allowed. "
					f'Actions must have explicit positional parameters only.'
				)

		# Step 2: Separate special and action parameters
		action_params = []
		special_params = []
		param_model_provided = param_model is not None

		for i, param in enumerate(parameters):
			# Check if this is a Type 1 pattern (first param is BaseModel)
			if i == 0 and param_model_provided and param.name not in special_param_names:
				# This is Type 1 pattern - skip the params argument
				continue

			if param.name in special_param_names:
				# Validate special parameter type
				expected_type = special_param_types.get(param.name)
				if param.annotation != Parameter.empty and expected_type is not None:
					# Handle Optional types - normalize both sides
					param_type = param.annotation
					origin = get_origin(param_type)
					if origin is Union:
						args = get_args(param_type)
						# Find non-None type
						param_type = next((arg for arg in args if arg is not type(None)), param_type)

					# Check if types are compatible (exact match, subclass, or generic list)
					types_compatible = (
						param_type == expected_type
						or (
							inspect.isclass(param_type)
							and inspect.isclass(expected_type)
							and issubclass(param_type, expected_type)
						)
						or
						# Handle list[T] vs list comparison
						(expected_type is list and (param_type is list or get_origin(param_type) is list))
					)

					if not types_compatible:
						expected_type_name = getattr(expected_type, '__name__', str(expected_type))
						param_type_name = getattr(param_type, '__name__', str(param_type))
						raise ValueError(
							f"Action '{func.__name__}' parameter '{param.name}: {param_type_name}' "
							f"conflicts with special argument injected by tools: '{param.name}: {expected_type_name}'"
						)
				special_params.append(param)
			else:
				action_params.append(param)

		# Step 3: Create or validate param model
		if not param_model_provided:
			# Type 2: Generate param model from action params
			if action_params:
				params_dict = {}
				for param in action_params:
					annotation = param.annotation if param.annotation != Parameter.empty else str
					default = ... if param.default == Parameter.empty else param.default
					params_dict[param.name] = (annotation, default)

				param_model = create_model(f'{func.__name__}_Params', __base__=ActionModel, **params_dict)
			else:
				# No action params, create empty model
				param_model = create_model(
					f'{func.__name__}_Params',
					__base__=ActionModel,
				)
		assert param_model is not None, f'param_model is None for {func.__name__}'

		# Step 4: Create normalized wrapper function
		@functools.wraps(func)
		async def normalized_wrapper(*args, params: BaseModel | None = None, **kwargs):
			"""Normalized action that only accepts kwargs"""
			# Validate no positional args
			if args:
				raise TypeError(f'{func.__name__}() does not accept positional arguments, only keyword arguments are allowed')

			# Prepare arguments for original function
			call_args = []
			call_kwargs = {}

			# Handle Type 1 pattern (first arg is the param model)
			if param_model_provided and parameters and parameters[0].name not in special_param_names:
				if params is None:
					raise ValueError(f"{func.__name__}() missing required 'params' argument")
				# For Type 1, we'll use the params object as first argument
				pass
			else:
				# Type 2 pattern - need to unpack params
				# If params is None, try to create it from kwargs
				if params is None and action_params:
					# Extract action params from kwargs
					action_kwargs = {}
					for param in action_params:
						if param.name in kwargs:
							action_kwargs[param.name] = kwargs[param.name]
					if action_kwargs:
						# Use the param_model which has the correct types defined
						params = param_model(**action_kwargs)

			# Build call_args by iterating through original function parameters in order
			params_dict = params.model_dump() if params is not None else {}

			for i, param in enumerate(parameters):
				# Skip first param for Type 1 pattern (it's the model itself)
				if param_model_provided and i == 0 and param.name not in special_param_names:
					call_args.append(params)
				elif param.name in special_param_names:
					# This is a special parameter
					if param.name in kwargs:
						value = kwargs[param.name]
						# Check if required special param is None
						if value is None and param.default == Parameter.empty:
							if param.name == 'browser_session':
								raise ValueError(f'Action {func.__name__} requires browser_session but none provided.')
							elif param.name == 'page_extraction_llm':
								raise ValueError(f'Action {func.__name__} requires page_extraction_llm but none provided.')
							elif param.name == 'file_system':
								raise ValueError(f'Action {func.__name__} requires file_system but none provided.')
							elif param.name == 'page':
								raise ValueError(f'Action {func.__name__} requires page but none provided.')
							elif param.name == 'available_file_paths':
								raise ValueError(f'Action {func.__name__} requires available_file_paths but none provided.')
							elif param.name == 'file_system':
								raise ValueError(f'Action {func.__name__} requires file_system but none provided.')
							else:
								raise ValueError(f"{func.__name__}() missing required special parameter '{param.name}'")
						call_args.append(value)
					elif param.default != Parameter.empty:
						call_args.append(param.default)
					else:
						# Special param is required but not provided
						if param.name == 'browser_session':
							raise ValueError(f'Action {func.__name__} requires browser_session but none provided.')
						elif param.name == 'page_extraction_llm':
							raise ValueError(f'Action {func.__name__} requires page_extraction_llm but none provided.')
						elif param.name == 'file_system':
							raise ValueError(f'Action {func.__name__} requires file_system but none provided.')
						elif param.name == 'page':
							raise ValueError(f'Action {func.__name__} requires page but none provided.')
						elif param.name == 'available_file_paths':
							raise ValueError(f'Action {func.__name__} requires available_file_paths but none provided.')
						elif param.name == 'file_system':
							raise ValueError(f'Action {func.__name__} requires file_system but none provided.')
						else:
							raise ValueError(f"{func.__name__}() missing required special parameter '{param.name}'")
				else:
					# This is an action parameter
					if param.name in params_dict:
						call_args.append(params_dict[param.name])
					elif param.default != Parameter.empty:
						call_args.append(param.default)
					else:
						raise ValueError(f"{func.__name__}() missing required parameter '{param.name}'")

			# Call original function with positional args
			if iscoroutinefunction(func):
				return await func(*call_args)
			else:
				return await asyncio.to_thread(func, *call_args)

		# Update wrapper signature to be kwargs-only
		new_params = [Parameter('params', Parameter.KEYWORD_ONLY, default=None, annotation=Optional[param_model])]

		# Add special params as keyword-only
		for sp in special_params:
			new_params.append(Parameter(sp.name, Parameter.KEYWORD_ONLY, default=sp.default, annotation=sp.annotation))

		# Add **kwargs to accept and ignore extra params
		new_params.append(Parameter('kwargs', Parameter.VAR_KEYWORD))

		normalized_wrapper.__signature__ = sig.replace(parameters=new_params)  # type: ignore[attr-defined]

		return normalized_wrapper, param_model

	# @time_execution_sync('--create_param_model')
	def _create_param_model(self, function: Callable) -> type[BaseModel]:
		"""Creates a Pydantic model from function signature"""
		sig = signature(function)
		special_param_names = set(SpecialActionParameters.model_fields.keys())
		params = {
			name: (param.annotation, ... if param.default == param.empty else param.default)
			for name, param in sig.parameters.items()
			if name not in special_param_names
		}
		# TODO: make the types here work
		return create_model(
			f'{function.__name__}_parameters',
			__base__=ActionModel,
			**params,  # type: ignore
		)

	def action(
		self,
		description: str,
		param_model: type[BaseModel] | None = None,
		domains: list[str] | None = None,
		allowed_domains: list[str] | None = None,
	):
		"""Decorator for registering actions"""
		# Handle aliases: domains and allowed_domains are the same parameter
		if allowed_domains is not None and domains is not None:
			raise ValueError("Cannot specify both 'domains' and 'allowed_domains' - they are aliases for the same parameter")

		final_domains = allowed_domains if allowed_domains is not None else domains

		def decorator(func: Callable):
			# Skip registration if action is in exclude_actions
			if func.__name__ in self.exclude_actions:
				return func

			# Normalize the function signature
			normalized_func, actual_param_model = self._normalize_action_function_signature(func, description, param_model)

			action = RegisteredAction(
				name=func.__name__,
				description=description,
				function=normalized_func,
				param_model=actual_param_model,
				domains=final_domains,
			)
			self.registry.actions[func.__name__] = action

			# Return the normalized function so it can be called with kwargs
			return normalized_func

		return decorator

	@observe_debug(ignore_input=True, ignore_output=True, name='execute_action')
	@time_execution_async('--execute_action')
	async def execute_action(
		self,
		action_name: str,
		params: dict,
		browser_session: BrowserSession | None = None,
		page_extraction_llm: BaseChatModel | None = None,
		file_system: FileSystem | None = None,
		sensitive_data: dict[str, str | dict[str, str]] | None = None,
		available_file_paths: list[str] | None = None,
	) -> Any:
		"""Execute a registered action with simplified parameter handling"""
		if action_name not in self.registry.actions:
			raise ValueError(f'Action {action_name} not found')

		action = self.registry.actions[action_name]
		try:
			# Create the validated Pydantic model
			try:
				validated_params = action.param_model(**params)
			except Exception as e:
				raise ValueError(f'Invalid parameters {params} for action {action_name}: {type(e)}: {e}') from e

			if sensitive_data:
				# Get current URL if browser_session is provided
				current_url = None
				if browser_session and browser_session.current_target_id:
					try:
						# Get current page info using CDP
						targets = await browser_session.cdp_client.send.Target.getTargets()
						for target in targets.get('targetInfos', []):
							if target.get('targetId') == browser_session.current_target_id:
								current_url = target.get('url')
								break
					except Exception:
						pass
				validated_params = self._replace_sensitive_data(validated_params, sensitive_data, current_url)

			# Build special context dict
			special_context = {
				'browser_session': browser_session,
				'page_extraction_llm': page_extraction_llm,
				'available_file_paths': available_file_paths,
				'has_sensitive_data': action_name == 'input' and bool(sensitive_data),
				'file_system': file_system,
			}

			# Only pass sensitive_data to actions that explicitly need it (input)
			if action_name == 'input':
				special_context['sensitive_data'] = sensitive_data

			# Add CDP-related parameters if browser_session is available
			if browser_session:
				# Add page_url
				try:
					special_context['page_url'] = await browser_session.get_current_page_url()
				except Exception:
					special_context['page_url'] = None

				# Add cdp_client
				special_context['cdp_client'] = browser_session.cdp_client

			# All functions are now normalized to accept kwargs only
			# Call with params and unpacked special context
			try:
				return await action.function(params=validated_params, **special_context)
			except Exception as e:
				raise

		except ValueError as e:
			# Preserve ValueError messages from validation
			if 'requires browser_session but none provided' in str(e) or 'requires page_extraction_llm but none provided' in str(
				e
			):
				raise RuntimeError(str(e)) from e
			else:
				raise RuntimeError(f'Error executing action {action_name}: {str(e)}') from e
		except TimeoutError as e:
			raise RuntimeError(f'Error executing action {action_name} due to timeout.') from e
		except Exception as e:
			raise RuntimeError(f'Error executing action {action_name}: {str(e)}') from e

	def _log_sensitive_data_usage(self, placeholders_used: set[str], current_url: str | None) -> None:
		"""Log when sensitive data is being used on a page"""
		if placeholders_used:
			url_info = f' on {current_url}' if current_url and not is_new_tab_page(current_url) else ''
			logger.info(f'🔒 Using sensitive data placeholders: {", ".join(sorted(placeholders_used))}{url_info}')

	def _replace_sensitive_data(
		self, params: BaseModel, sensitive_data: dict[str, Any], current_url: str | None = None
	) -> BaseModel:
		"""
		Replaces sensitive data placeholders in params with actual values.

		Args:
			params: The parameter object containing <secret>placeholder</secret> tags
			sensitive_data: Dictionary of sensitive data, either in old format {key: value}
						   or new format {domain_pattern: {key: value}}
			current_url: Optional current URL for domain matching

		Returns:
			BaseModel: The parameter object with placeholders replaced by actual values
		"""
		secret_pattern = re.compile(r'<secret>(.*?)</secret>')

		# Set to track all missing placeholders across the full object
		all_missing_placeholders = set()
		# Set to track successfully replaced placeholders
		replaced_placeholders = set()

		# Process sensitive data based on format and current URL
		applicable_secrets = {}

		for domain_or_key, content in sensitive_data.items():
			if isinstance(content, dict):
				# New format: {domain_pattern: {key: value}}
				# Only include secrets for domains that match the current URL
				if current_url and not is_new_tab_page(current_url):
					# it's a real url, check it using our custom allowed_domains scheme://*.example.com glob matching
					if match_url_with_domain_pattern(current_url, domain_or_key):
						applicable_secrets.update(content)
			else:
				# Old format: {key: value}, expose to all domains (only allowed for legacy reasons)
				applicable_secrets[domain_or_key] = content

		# Filter out empty values
		applicable_secrets = {k: v for k, v in applicable_secrets.items() if v}

		def recursively_replace_secrets(value: str | dict | list) -> str | dict | list:
			if isinstance(value, str):
				matches = secret_pattern.findall(value)
				# check if the placeholder key, like x_password is in the output parameters of the LLM and replace it with the sensitive data
				for placeholder in matches:
					if placeholder in applicable_secrets:
						# generate a totp code if secret is a 2fa secret
						if 'bu_2fa_code' in placeholder:
							totp = pyotp.TOTP(applicable_secrets[placeholder], digits=6)
							replacement_value = totp.now()
						else:
							replacement_value = applicable_secrets[placeholder]

						value = value.replace(f'<secret>{placeholder}</secret>', replacement_value)
						replaced_placeholders.add(placeholder)
					else:
						# Keep track of missing placeholders
						all_missing_placeholders.add(placeholder)
						# Don't replace the tag, keep it as is

				return value
			elif isinstance(value, dict):
				return {k: recursively_replace_secrets(v) for k, v in value.items()}
			elif isinstance(value, list):
				return [recursively_replace_secrets(v) for v in value]
			return value

		params_dump = params.model_dump()
		processed_params = recursively_replace_secrets(params_dump)

		# Log sensitive data usage
		self._log_sensitive_data_usage(replaced_placeholders, current_url)

		# Log a warning if any placeholders are missing
		if all_missing_placeholders:
			logger.warning(f'Missing or empty keys in sensitive_data dictionary: {", ".join(all_missing_placeholders)}')

		return type(params).model_validate(processed_params)

	# @time_execution_sync('--create_action_model')
	def create_action_model(self, include_actions: list[str] | None = None, page_url: str | None = None) -> type[ActionModel]:
		"""Creates a Union of individual action models from registered actions,
		used by LLM APIs that support tool calling & enforce a schema.

		Each action model contains only the specific action being used,
		rather than all actions with most set to None.
		"""
		from typing import Union

		# Filter actions based on page_url if provided:
		#   if page_url is None, only include actions with no filters
		#   if page_url is provided, only include actions that match the URL

		available_actions: dict[str, RegisteredAction] = {}
		for name, action in self.registry.actions.items():
			if include_actions is not None and name not in include_actions:
				continue

			# If no page_url provided, only include actions with no filters
			if page_url is None:
				if action.domains is None:
					available_actions[name] = action
				continue

			# Check domain filter if present
			domain_is_allowed = self.registry._match_domains(action.domains, page_url)

			# Include action if domain filter matches
			if domain_is_allowed:
				available_actions[name] = action

		# Create individual action models for each action
		individual_action_models: list[type[BaseModel]] = []

		for name, action in available_actions.items():
			# Create an individual model for each action that contains only one field
			individual_model = create_model(
				f'{name.title().replace("_", "")}ActionModel',
				__base__=ActionModel,
				**{
					name: (
						action.param_model,
						Field(description=action.description),
					)  # type: ignore
				},
			)
			individual_action_models.append(individual_model)

		# If no actions available, return empty ActionModel
		if not individual_action_models:
			return create_model('EmptyActionModel', __base__=ActionModel)

		# Create proper Union type that maintains ActionModel interface
		if len(individual_action_models) == 1:
			# If only one action, return it directly (no Union needed)
			result_model = individual_action_models[0]

		# Meaning the length is more than 1
		else:
			# Create a Union type using RootModel that properly delegates ActionModel methods
			union_type = Union[tuple(individual_action_models)]  # type: ignore : Typing doesn't understand that the length is >= 2 (by design)

			class ActionModelUnion(RootModel[union_type]):  # type: ignore
				def get_index(self) -> int | None:
					"""Delegate get_index to the underlying action model"""
					if hasattr(self.root, 'get_index'):
						return self.root.get_index()  # type: ignore
					return None

				def set_index(self, index: int):
					"""Delegate set_index to the underlying action model"""
					if hasattr(self.root, 'set_index'):
						self.root.set_index(index)  # type: ignore

				def model_dump(self, **kwargs):
					"""Delegate model_dump to the underlying action model"""
					if hasattr(self.root, 'model_dump'):
						return self.root.model_dump(**kwargs)  # type: ignore
					return super().model_dump(**kwargs)

			# Set the name for better debugging
			ActionModelUnion.__name__ = 'ActionModel'
			ActionModelUnion.__qualname__ = 'ActionModel'

			result_model = ActionModelUnion

		return result_model  # type:ignore

	def get_prompt_description(self, page_url: str | None = None) -> str:
		"""Get a description of all actions for the prompt

		If page_url is provided, only include actions that are available for that URL
		based on their domain filters
		"""
		return self.registry.get_prompt_description(page_url=page_url)
