import inspect
from collections.abc import Awaitable, Callable, Iterable, Sequence
from copy import deepcopy
from dataclasses import dataclass
from typing import Any

from agent_lab.application.events import (
    ConfirmationPolicy,
    CalendarSchedulePort,
    DeviceVolumePort,
    EventDefinition,
    EventExecutionContext,
    EventKernel,
    EventRegistry,
    EventRequest,
    EventResult,
    EventSource,
    EventStatus,
    ResultPolicy,
    RiskLevel,
    SessionTerminationPort,
    WebSearchPort,
    build_builtin_event_definitions,
)
from agent_lab.domain.events import EVENT_BLOCK_END, EVENT_BLOCK_START, ToolCallEvent
from agent_lab.domain.messages import ChatMessage


ToolExecutionContext = EventExecutionContext


ToolHandler = Callable[
    [ToolCallEvent],
    dict[str, Any] | Awaitable[dict[str, Any]],
]
ToolArgumentResolver = Callable[
    [ToolCallEvent, ToolExecutionContext],
    dict[str, Any],
]
ToolArgumentNormalizer = Callable[[dict[str, Any]], dict[str, Any]]


@dataclass(frozen=True)
class ToolDefinition:
    name: str
    description: str
    parameters: dict[str, Any]
    handler: ToolHandler
    argument_resolver: ToolArgumentResolver | None = None
    schema_version: str = "1"
    fallback_allowed: bool = True
    result_policy: ResultPolicy = ResultPolicy.LLM_FOLLOW_UP
    confirmation_policy: ConfirmationPolicy = ConfirmationPolicy.NONE
    risk_level: RiskLevel = RiskLevel.LOW
    idempotency_key_fields: tuple[str, ...] = ()
    concurrency_class: str | None = None
    conflict_keys: tuple[str, ...] = ()
    timeout_seconds: float | None = None
    terminal: bool = False
    normalizer: ToolArgumentNormalizer | None = None


class ToolRegistry:
    def __init__(
        self,
        definitions: Iterable[ToolDefinition | EventDefinition],
    ) -> None:
        self._definitions: dict[str, EventDefinition] = {}
        event_definitions: list[EventDefinition] = []
        for definition in definitions:
            if definition.name in self._definitions:
                raise ValueError(f"duplicate event definition: {definition.name}")
            event_definition = (
                definition
                if isinstance(definition, EventDefinition)
                else self._to_event_definition(definition)
            )
            self._definitions[definition.name] = event_definition
            event_definitions.append(event_definition)
        self.event_registry = EventRegistry(event_definitions)
        self.kernel = EventKernel(self.event_registry)

    def available_tools(self) -> list[dict[str, Any]]:
        return self.event_registry.catalog()

    def chat_event_system_message(self, enabled_names: Iterable[str]) -> str:
        enabled = set(enabled_names)
        event_lines = [
            f"- {definition.name}: {definition.description}"
            for definition in self._definitions.values()
            if definition.name in enabled
        ]
        if not event_lines:
            return ""

        return "\n".join(
            [
                "You may request EventAgent work using this text protocol.",
                "Available events:",
                *event_lines,
                (
                    "First write the user-facing reply normally. If events are needed, "
                    "append this block after the visible reply:"
                ),
                EVENT_BLOCK_START,
                "event_name",
                EVENT_BLOCK_END,
                "Use exact event names only, one per line. Do not include parameters.",
            ]
        )

    def tool_schema(self, name: str) -> dict[str, Any] | None:
        return self.event_registry.tool_schema(name)

    def provider_tool_schemas(
        self,
        enabled_names: Iterable[str],
    ) -> list[dict[str, Any]]:
        return [
            schema
            for schema in (
                self.tool_schema(name)
                for name in enabled_names
            )
            if schema is not None
        ]

    def handle(
        self,
        event: ToolCallEvent,
        context: ToolExecutionContext | None = None,
    ) -> dict[str, Any]:
        result = self.kernel.execute_sync(
            self.event_request(event),
            context=context or ToolExecutionContext(history=()),
        )
        return self.tool_payload(result)

    def execute(self, event: ToolCallEvent) -> dict[str, Any]:
        result = self.kernel.execute_sync(
            self.event_request(event, source=EventSource.PROVIDER_RESOLVED)
        )
        return self.tool_payload(result)

    async def handle_async(
        self,
        event: ToolCallEvent,
        context: ToolExecutionContext | None = None,
    ) -> dict[str, Any]:
        result = await self.kernel.execute(
            self.event_request(event),
            context=context or ToolExecutionContext(history=()),
        )
        return self.tool_payload(result)

    async def execute_async(
        self,
        event: ToolCallEvent,
        *,
        enabled_names: Iterable[str] | None = None,
    ) -> dict[str, Any]:
        result = await self.kernel.execute(
            self.event_request(event, source=EventSource.PROVIDER_RESOLVED),
            enabled_names=enabled_names,
        )
        return self.tool_payload(result)

    def event_request(
        self,
        event: ToolCallEvent,
        source: EventSource = EventSource.TEXT_EVENT,
    ) -> EventRequest:
        return EventRequest(
            id=event.id,
            name=event.name,
            arguments=deepcopy(event.arguments),
            raw_arguments=event.raw_arguments,
            source=source,
        )

    def tool_payload(self, result: EventResult) -> dict[str, Any]:
        if result.status is EventStatus.SUCCESS:
            return result.payload
        error = result.error or result.status.value
        if result.status is EventStatus.UNKNOWN:
            error = "unknown tool"
        elif result.status is EventStatus.DISABLED:
            error = "tool disabled"
        elif result.status is EventStatus.DEFINITION_ERROR:
            error = error.replace(
                "event argument validation failed:",
                "tool definition validation failed:",
                1,
            )
        elif result.status is EventStatus.HANDLER_ERROR:
            error = error.replace("event handler failed:", "tool handler failed:", 1)
            error = error.replace("EventKernel.execute", "execute_async")
        return {"tool": result.event_name, "error": error}

    def _to_event_definition(self, definition: ToolDefinition) -> EventDefinition:
        def resolver(
            request: EventRequest,
            context: EventExecutionContext,
        ) -> dict[str, Any]:
            event = self._tool_event(request)
            if definition.argument_resolver is not None:
                return definition.argument_resolver(event, context)
            if context.history:
                return {}
            return deepcopy(request.arguments)

        if inspect.iscoroutinefunction(definition.handler):

            async def handler(request: EventRequest) -> dict[str, Any]:
                return await definition.handler(self._tool_event(request))
        else:

            def handler(
                request: EventRequest,
            ) -> dict[str, Any] | Awaitable[dict[str, Any]]:
                return definition.handler(self._tool_event(request))

        return EventDefinition(
            name=definition.name,
            description=definition.description,
            parameters=deepcopy(definition.parameters),
            handler=handler,
            resolver=resolver,
            normalizer=definition.normalizer,
            schema_version=definition.schema_version,
            fallback_allowed=definition.fallback_allowed,
            result_policy=definition.result_policy,
            confirmation_policy=definition.confirmation_policy,
            risk_level=definition.risk_level,
            idempotency_key_fields=definition.idempotency_key_fields,
            concurrency_class=definition.concurrency_class,
            conflict_keys=definition.conflict_keys,
            timeout_seconds=definition.timeout_seconds,
            terminal=definition.terminal,
        )

    def _tool_event(self, request: EventRequest) -> ToolCallEvent:
        return ToolCallEvent(
            id=request.id,
            name=request.name,
            arguments=deepcopy(request.arguments),
            raw_arguments=request.raw_arguments,
        )


def build_default_tool_registry(
    *,
    session_termination_port: SessionTerminationPort | None = None,
    device_volume_port: DeviceVolumePort | None = None,
    calendar_schedule_port: CalendarSchedulePort | None = None,
    web_search_port: WebSearchPort | None = None,
    clock: Callable[[], Any] | None = None,
) -> ToolRegistry:
    return ToolRegistry(
        [
            ToolDefinition(
                name="handoff_note",
                description="Send a note to the event agent.",
                parameters={
                    "type": "object",
                    "properties": {
                        "message": {"type": "string"},
                    },
                    "required": ["message"],
                },
                handler=_handle_handoff_note,
                argument_resolver=_resolve_handoff_note_arguments,
            ),
            ToolDefinition(
                name="mock_search",
                description="Search mock external knowledge for the current turn.",
                parameters={
                    "type": "object",
                    "properties": {
                        "query": {"type": "string"},
                    },
                    "required": ["query"],
                },
                handler=_handle_mock_search,
                argument_resolver=_resolve_mock_search_arguments,
            ),
            ToolDefinition(
                name="mock_ticket",
                description="Create a mock support ticket for follow-up work.",
                parameters={
                    "type": "object",
                    "properties": {
                        "title": {"type": "string"},
                    },
                    "required": ["title"],
                },
                handler=_handle_mock_ticket,
                argument_resolver=_resolve_mock_ticket_arguments,
            ),
            *build_builtin_event_definitions(
                session_termination_port=session_termination_port,
                device_volume_port=device_volume_port,
                calendar_schedule_port=calendar_schedule_port,
                web_search_port=web_search_port,
                clock=clock,
            ),
        ]
    )


def _resolve_handoff_note_arguments(
    event: ToolCallEvent,
    context: ToolExecutionContext,
) -> dict[str, Any]:
    content = _latest_content(context.history, preferred_roles=("assistant", "user"))
    if not content and not context.history:
        content = str(event.arguments.get("message", ""))
    return {"message": content}


def _resolve_mock_search_arguments(
    event: ToolCallEvent,
    context: ToolExecutionContext,
) -> dict[str, Any]:
    query = _latest_content(context.history, preferred_roles=("assistant", "user"))
    if not query and not context.history:
        query = str(event.arguments.get("query", ""))
    return {"query": query}


def _resolve_mock_ticket_arguments(
    event: ToolCallEvent,
    context: ToolExecutionContext,
) -> dict[str, Any]:
    title = _latest_content(context.history, preferred_roles=("assistant", "user"))
    if not title and not context.history:
        title = str(event.arguments.get("title", ""))
    return {"title": title}


def _latest_content(
    history: Sequence[ChatMessage],
    preferred_roles: tuple[str, ...],
) -> str:
    for role in preferred_roles:
        for message in reversed(history):
            if message.role == role and message.content.strip():
                return message.content.strip()
    return ""


def _handle_handoff_note(event: ToolCallEvent) -> dict[str, Any]:
    return {
        "tool": "handoff_note",
        "message": str(event.arguments.get("message", "")),
    }


def _handle_mock_search(event: ToolCallEvent) -> dict[str, Any]:
    query = str(event.arguments.get("query", ""))
    return {
        "tool": "mock_search",
        "query": query,
        "results": [
            {
                "title": "Mock knowledge base result",
                "snippet": f"Simulated external context for: {query}",
            }
        ],
    }


def _handle_mock_ticket(event: ToolCallEvent) -> dict[str, Any]:
    title = str(event.arguments.get("title", ""))
    return {
        "tool": "mock_ticket",
        "ticket_id": "MOCK-001",
        "title": title,
        "status": "created",
    }