from __future__ import annotations

from abc import ABC, abstractmethod
from collections.abc import AsyncIterator, Awaitable, Callable
from typing import TYPE_CHECKING, Any, ClassVar

from yuxi.channels.capabilities import CAPS_SIMPLE_TEXT, ChannelCapabilities
from yuxi.channels.meta import ChannelMeta
from yuxi.channels.models import (
    ChannelMessage,
    ChannelResponse,
    ChannelType,
    DeliveryResult,
    HealthStatus,
)
from yuxi.channels.protocols.gateway import ChannelGatewayProtocol
from yuxi.channels.protocols.lifecycle import ChannelLifecycleProtocol

if TYPE_CHECKING:
    from yuxi.channels.auth.backoff import ExponentialBackoff
    from yuxi.channels.auth.secret_manager import SecretManager
    from yuxi.channels.services.plugin_state_store import PluginStateStore


class BaseChannelAdapter(ChannelLifecycleProtocol, ChannelGatewayProtocol, ABC):
    channel_id: ClassVar[str]
    channel_type: ClassVar[ChannelType]

    text_chunk_limit: ClassVar[int] = 4096
    supports_markdown: ClassVar[bool] = False
    supports_streaming: ClassVar[bool] = False
    streaming_modes: ClassVar[list[str]] = ["off"]
    max_media_size_mb: ClassVar[int] = 100

    webhook_path: ClassVar[str | None] = None

    capabilities: ClassVar[ChannelCapabilities] = CAPS_SIMPLE_TEXT
    meta: ClassVar[ChannelMeta] = ChannelMeta(id="", label="")

    _state_store: PluginStateStore | None = None

    def __init__(self, config: dict[str, Any] | None = None):
        self.config = config or {}
        self._status: Any = None
        self._message_handler: Callable[[ChannelMessage], Awaitable[None]] | None = None
        self._stream_state: dict[str, int] = {}
        self._credential_backoff = self._create_backoff()

    @property
    def secret_manager(self) -> SecretManager:
        from yuxi.channels.auth.secret_manager import get_secret_manager

        return get_secret_manager()

    @staticmethod
    def _create_backoff() -> ExponentialBackoff:
        from yuxi.channels.auth.backoff import BackoffConfig, ExponentialBackoff

        return ExponentialBackoff(BackoffConfig(base_seconds=5.0, max_seconds=300.0, jitter_pct=0.2))

    async def resolve_credential(self, key: str, fallback_keys: list[str] | None = None) -> str | None:
        from yuxi.channels.auth.secret_manager import SecretSource

        sm = self.secret_manager
        sources = [
            SecretSource.CONFIG,
            SecretSource.ENV,
            SecretSource.FILE,
            SecretSource.SECRET_REF,
            SecretSource.EXEC,
        ]
        resolved = await sm.resolve_secret(key, sources=sources, config=self.config)
        if resolved:
            return resolved

        if fallback_keys:
            for fk in fallback_keys:
                resolved = await sm.resolve_secret(fk, sources=sources, config=self.config)
                if resolved:
                    return resolved

        return None

    def _log_config_safely(self) -> None:
        from yuxi.channels.auth.secret_manager import SecretManager
        from yuxi.utils.logging_config import logger

        safe_config = SecretManager.redact_config(self.config)
        logger.debug(f"[{self.channel_id}] Config (redacted): {safe_config}")

    async def state_get(self, key: str, namespace: str = "default") -> Any | None:
        if self._state_store is None:
            return None
        return await self._state_store.get(self.channel_id, key, namespace)

    async def state_set(
        self,
        key: str,
        value: Any,
        namespace: str = "default",
        ttl_seconds: int | None = None,
    ) -> None:
        if self._state_store is None:
            return
        await self._state_store.set(self.channel_id, key, value, namespace, ttl_seconds)

    async def state_delete(self, key: str, namespace: str = "default") -> None:
        if self._state_store is None:
            return
        await self._state_store.delete(self.channel_id, key, namespace)

    def _get_stream_state(self, chat_id: str, msg_id: str) -> int:
        return self._stream_state.get(f"{chat_id}:{msg_id}", 0)

    def _set_stream_state(self, chat_id: str, msg_id: str, state: int) -> None:
        self._stream_state[f"{chat_id}:{msg_id}"] = state

    def _clear_stream_state(self, chat_id: str, msg_id: str) -> None:
        self._stream_state.pop(f"{chat_id}:{msg_id}", None)

    @abstractmethod
    async def connect(self) -> None: ...

    @abstractmethod
    async def disconnect(self) -> None: ...

    @abstractmethod
    async def send(self, response: ChannelResponse) -> DeliveryResult: ...

    async def receive(self) -> AsyncIterator[ChannelMessage]:
        raise NotImplementedError
        yield  # type: ignore[misc]

    @abstractmethod
    def normalize_inbound(self, raw: Any) -> ChannelMessage: ...

    @abstractmethod
    def format_outbound(self, response: ChannelResponse) -> Any: ...

    @abstractmethod
    async def health_check(self) -> HealthStatus: ...

    def on_message(self, handler: Callable[[ChannelMessage], Awaitable[None]]) -> None:
        self._message_handler = handler

    async def _handle_message(self, message: ChannelMessage) -> None:
        if self._message_handler:
            await self._message_handler(message)

    async def send_media(self, chat_id: str, media_type: str, data: Any) -> DeliveryResult:
        raise NotImplementedError

    async def edit_message(self, chat_id: str, msg_id: str, content: str) -> DeliveryResult:
        raise NotImplementedError

    async def delete_message(self, chat_id: str, msg_id: str) -> DeliveryResult:
        raise NotImplementedError

    async def send_reaction(self, chat_id: str, msg_id: str, emoji: str) -> DeliveryResult:
        raise NotImplementedError

    async def send_stream_chunk(self, chat_id: str, msg_id: str, chunk: str, finished: bool) -> DeliveryResult:
        identity = self._build_stream_identity(chat_id, msg_id)
        response = ChannelResponse(identity=identity, content=chunk)
        return await self.send(response)

    def _build_stream_identity(self, chat_id: str, msg_id: str) -> Any:
        from yuxi.channels.models import ChannelIdentity

        return ChannelIdentity(
            channel_id=self.channel_id,
            channel_type=self.channel_type,
            channel_user_id="",
            channel_chat_id=chat_id,
            channel_message_id=msg_id,
        )

    async def verify_webhook_signature(self, headers: dict, body: bytes) -> bool:
        return True

    async def _refresh_token_if_needed(self) -> bool:

        from yuxi.utils.logging_config import logger

        try:
            self._credential_backoff.mark_attempt()
            return True
        except Exception as e:
            delay = self._credential_backoff.next_delay
            logger.warning(
                f"[{self.channel_id}] Token refresh failed "
                f"(attempt {self._credential_backoff.attempt}), "
                f"next retry in {delay:.1f}s: {e}"
            )
            await self._credential_backoff.wait()
            return False

    async def pre_connect(self) -> dict:
        return {}

    def is_enabled(self) -> bool:
        return bool(self.config.get("enabled", False))

    def is_configured(self) -> bool:
        return bool(self.config)

    @property
    def status(self) -> str:
        return getattr(self, "_status", "unknown") or "unknown"

    def snapshot(self) -> dict[str, Any]:
        from yuxi.channels.models import build_snapshot_from_adapter

        return build_snapshot_from_adapter(self).model_dump()

    def resolve_account_state(self, configured: bool, enabled: bool) -> str:
        if not configured:
            return "not_configured"
        if not enabled:
            return "disabled"
        return "active"

    def collect_status_issues(self, accounts: list) -> list[str]:
        issues = []
        if not self.is_configured():
            issues.append("not_configured")
        if not self.is_enabled():
            issues.append("disabled")
        return issues

    async def check_ready(self) -> bool:
        return self.is_enabled() and self.is_configured()

    def on_config_changed(self, prev_cfg: dict, next_cfg: dict) -> None:
        pass

    async def run_startup_maintenance(self) -> None:
        pass

    async def logout_account(self, ctx) -> None:
        raise NotImplementedError

    async def login_with_qr_start(self, force: bool, timeout_ms: int) -> str:
        raise NotImplementedError