from __future__ import annotations

from collections.abc import Callable
from typing import Any, Literal

from temporalio import activity, workflow
from temporalio.workflow import ActivityConfig

from pydantic_ai import FunctionToolset, ToolsetTool
from pydantic_ai.exceptions import UserError
from pydantic_ai.tools import AgentDepsT, RunContext
from pydantic_ai.toolsets.function import FunctionToolsetTool

from ._run_context import TemporalRunContext
from ._toolset import (
    CallToolParams,
    CallToolResult,
    TemporalWrapperToolset,
)


class TemporalFunctionToolset(TemporalWrapperToolset[AgentDepsT]):
    def __init__(
        self,
        toolset: FunctionToolset[AgentDepsT],
        *,
        activity_name_prefix: str,
        activity_config: ActivityConfig,
        tool_activity_config: dict[str, ActivityConfig | Literal[False]],
        deps_type: type[AgentDepsT],
        run_context_type: type[TemporalRunContext[AgentDepsT]] = TemporalRunContext[AgentDepsT],
    ):
        super().__init__(toolset)
        self.activity_config = activity_config
        self.tool_activity_config = tool_activity_config
        self.run_context_type = run_context_type

        async def call_tool_activity(params: CallToolParams, deps: AgentDepsT) -> CallToolResult:
            name = params.name
            ctx = self.run_context_type.deserialize_run_context(params.serialized_run_context, deps=deps)
            try:
                tool = (await toolset.get_tools(ctx))[name]
            except KeyError as e:  # pragma: no cover
                raise UserError(
                    f'Tool {name!r} not found in toolset {self.id!r}. '
                    'Removing or renaming tools during an agent run is not supported with Temporal.'
                ) from e

            # The tool args will already have been validated into their proper types in the `ToolManager`,
            # but `execute_activity` would have turned them into simple Python types again, so we need to re-validate them.
            args_dict = tool.args_validator.validate_python(params.tool_args)
            return await self._wrap_call_tool_result(self.wrapped.call_tool(name, args_dict, ctx, tool))

        # Set type hint explicitly so that Temporal can take care of serialization and deserialization
        call_tool_activity.__annotations__['deps'] = deps_type

        self.call_tool_activity = activity.defn(name=f'{activity_name_prefix}__toolset__{self.id}__call_tool')(
            call_tool_activity
        )

    @property
    def temporal_activities(self) -> list[Callable[..., Any]]:
        return [self.call_tool_activity]

    async def call_tool(
        self, name: str, tool_args: dict[str, Any], ctx: RunContext[AgentDepsT], tool: ToolsetTool[AgentDepsT]
    ) -> Any:
        if not workflow.in_workflow():
            return await super().call_tool(name, tool_args, ctx, tool)

        tool_activity_config = self.tool_activity_config.get(name, {})
        if tool_activity_config is False:
            assert isinstance(tool, FunctionToolsetTool)
            if not tool.is_async:
                raise UserError(
                    f'Temporal activity config for tool {name!r} has been explicitly set to `False` (activity disabled), '
                    'but non-async tools are run in threads which are not supported outside of an activity. Make the tool function async instead.'
                )
            return await super().call_tool(name, tool_args, ctx, tool)

        tool_activity_config = self.activity_config | tool_activity_config
        serialized_run_context = self.run_context_type.serialize_run_context(ctx)
        return self._unwrap_call_tool_result(
            await workflow.execute_activity(
                activity=self.call_tool_activity,
                args=[
                    CallToolParams(
                        name=name,
                        tool_args=tool_args,
                        serialized_run_context=serialized_run_context,
                        tool_def=None,
                    ),
                    ctx.deps,
                ],
                **tool_activity_config,
            )
        )