from __future__ import annotations

import asyncio
from dataclasses import dataclass
from datetime import date
import hashlib
from typing import Any, Protocol
from urllib.parse import urlparse

import dashscope
from ag_ui.core import RunAgentInput, StateSnapshotEvent
from dashscope.audio.asr import Recognition, RecognitionCallback
from fastapi import HTTPException
from sqlalchemy.exc import IntegrityError

from core.auth.models import CurrentUser
from core.agentscope.schemas.agui_input import extract_latest_user_payload
from core.config.settings import config
from core.logging import get_logger

logger = get_logger(__name__)
_ALLOWED_ATTACHMENT_MIME_TYPES = {"image/png", "image/jpeg", "image/webp"}
_MAX_ATTACHMENT_BYTES = 5 * 1024 * 1024
_MAX_TOTAL_ATTACHMENT_BYTES = 12 * 1024 * 1024


@dataclass(frozen=True)
class TaskAccepted:
    task_id: str
    thread_id: str
    run_id: str
    created: bool


class AgentRepositoryLike(Protocol):
    async def get_session_owner(self, *, session_id: str) -> str: ...

    async def create_session_for_user(
        self, *, user_id: str, session_id: str | None = None
    ) -> str: ...

    async def commit(self) -> None: ...

    async def rollback(self) -> None: ...

    async def get_history_day(
        self, *, session_id: str, before: date | None
    ) -> dict[str, object] | None: ...

    async def get_latest_session_id_for_user(self, *, user_id: str) -> str | None: ...

    async def persist_user_message(
        self,
        *,
        session_id: str,
        run_id: str,
        content_text: str,
        metadata: dict[str, object] | None,
    ) -> None: ...


class QueueClientLike(Protocol):
    async def enqueue(
        self, *, command: dict[str, object], dedup_key: str | None
    ) -> str: ...


class EventStreamLike(Protocol):
    async def read(
        self,
        *,
        session_id: str,
        last_event_id: str | None,
    ) -> list[dict[str, object]]: ...


class AttachmentStorageLike(Protocol):
    async def upload_bytes(
        self,
        *,
        bucket: str,
        path: str,
        content: bytes,
        content_type: str,
    ) -> str: ...

    async def download_bytes(self, *, bucket: str, path: str) -> bytes: ...

    async def create_signed_url(
        self,
        *,
        bucket: str,
        path: str,
        expires_in_seconds: int,
    ) -> str: ...

    def parse_signed_url(self, url: str) -> tuple[str, str]: ...


def ensure_session_owner(*, owner_id: str, current_user: CurrentUser) -> None:
    if owner_id != str(current_user.id):
        raise HTTPException(status_code=403, detail="Forbidden")


class AgentService:
    _repository: AgentRepositoryLike
    _queue: QueueClientLike
    _stream: EventStreamLike
    _attachment_storage: AttachmentStorageLike | None

    _SIGNED_URL_EXPIRES_IN_SECONDS = 3600

    def __init__(
        self,
        *,
        repository: AgentRepositoryLike,
        queue: QueueClientLike,
        stream: EventStreamLike,
        attachment_storage: AttachmentStorageLike | None = None,
    ) -> None:
        self._repository = repository
        self._queue = queue
        self._stream = stream
        self._attachment_storage = attachment_storage

    async def enqueue_run(
        self,
        *,
        run_input: RunAgentInput,
        current_user: CurrentUser,
    ) -> TaskAccepted:
        created = False
        thread_id = run_input.thread_id
        run_id = run_input.run_id
        try:
            owner = await self._repository.get_session_owner(session_id=thread_id)
        except HTTPException as exc:
            if exc.status_code != 404:
                raise
            try:
                await self._repository.create_session_for_user(
                    user_id=str(current_user.id),
                    session_id=thread_id,
                )
                await self._repository.commit()
                created = True
            except IntegrityError:
                await self._repository.rollback()
                owner = await self._repository.get_session_owner(session_id=thread_id)
                ensure_session_owner(owner_id=owner, current_user=current_user)
        else:
            ensure_session_owner(owner_id=owner, current_user=current_user)

        user_message_text, user_message_metadata = await self._prepare_user_message(
            run_input=run_input,
            current_user=current_user,
        )
        await self._repository.persist_user_message(
            session_id=thread_id,
            run_id=run_id,
            content_text=user_message_text,
            metadata=user_message_metadata,
        )
        await self._repository.commit()

        task_id = await self._queue.enqueue(
            command={
                "command": "run",
                "owner_id": str(current_user.id),
                "run_input": run_input.model_dump(mode="json", by_alias=True),
            },
            dedup_key=None,
        )
        return TaskAccepted(
            task_id=task_id,
            thread_id=thread_id,
            run_id=run_id,
            created=created,
        )

    async def _prepare_user_message(
        self,
        *,
        run_input: RunAgentInput,
        current_user: CurrentUser,
    ) -> tuple[str, dict[str, object] | None]:
        from schemas.messages.chat_message import UserMessageAttachments

        text, content_blocks = extract_latest_user_payload(run_input)

        user_attachments: UserMessageAttachments | None = None
        for block in content_blocks:
            if not isinstance(block, dict):
                continue
            block_type = block.get("type")
            if block_type != "binary":
                continue

            url = block.get("url")
            mime_type = block.get("mimeType")
            if not isinstance(url, str) or not url:
                continue
            if not isinstance(mime_type, str):
                mime_type = "application/octet-stream"

            if self._attachment_storage is None:
                raise HTTPException(
                    status_code=503,
                    detail="Attachment storage unavailable",
                )

            try:
                bucket, path = self._validate_binary_signed_url(
                    url=url,
                    thread_id=run_input.thread_id,
                    current_user=current_user,
                )
                user_attachments = UserMessageAttachments(
                    bucket=bucket,
                    path=path,
                    mime_type=mime_type,
                )
                break
            except HTTPException:
                raise
            except Exception as exc:  # noqa: BLE001
                logger.warning("Failed to parse signed URL", url=url, error=str(exc))
                raise HTTPException(status_code=422, detail="Invalid signed image url")

        metadata: dict[str, object] | None = None
        if user_attachments is not None:
            metadata = {
                "user_message_attachments": user_attachments.model_dump(by_alias=True),
            }

        return text, metadata

    async def upload_attachment(
        self,
        *,
        thread_id: str,
        filename: str | None,
        content_type: str | None,
        payload: bytes,
        current_user: CurrentUser,
    ) -> dict[str, str]:
        try:
            owner = await self._repository.get_session_owner(session_id=thread_id)
        except HTTPException as exc:
            if exc.status_code != 404:
                raise
            try:
                await self._repository.create_session_for_user(
                    user_id=str(current_user.id),
                    session_id=thread_id,
                )
                await self._repository.commit()
            except IntegrityError:
                await self._repository.rollback()
                owner = await self._repository.get_session_owner(session_id=thread_id)
                ensure_session_owner(owner_id=owner, current_user=current_user)
        else:
            ensure_session_owner(owner_id=owner, current_user=current_user)
        if self._attachment_storage is None:
            raise HTTPException(
                status_code=503, detail="Attachment storage unavailable"
            )

        if not isinstance(content_type, str):
            raise HTTPException(status_code=422, detail="Unsupported attachment type")
        mime_type = content_type.lower()
        if mime_type not in _ALLOWED_ATTACHMENT_MIME_TYPES:
            raise HTTPException(status_code=422, detail="Unsupported attachment type")
        if not payload:
            raise HTTPException(status_code=422, detail="Empty attachment")
        if len(payload) > _MAX_ATTACHMENT_BYTES:
            raise HTTPException(status_code=413, detail="Attachment too large")

        suffix = _mime_to_suffix(mime_type)
        checksum = hashlib.sha1(payload).hexdigest()[:16]
        filename_seed = filename if isinstance(filename, str) and filename else "upload"
        filename_hash = hashlib.sha1(filename_seed.encode("utf-8")).hexdigest()[:8]
        path = (
            f"agent-inputs/{current_user.id}/{thread_id}/uploads/"
            f"{filename_hash}-{checksum}.{suffix}"
        )
        bucket_name = config.storage.bucket
        try:
            stored_path = await self._attachment_storage.upload_bytes(
                bucket=bucket_name,
                path=path,
                content=payload,
                content_type=mime_type,
            )
            signed_url = await self._attachment_storage.create_signed_url(
                bucket=bucket_name,
                path=stored_path,
                expires_in_seconds=self._SIGNED_URL_EXPIRES_IN_SECONDS,
            )
        except Exception:  # noqa: BLE001
            logger.exception(
                "Attachment upload failed",
                extra={
                    "bucket": bucket_name,
                    "path": path,
                    "mime_type": mime_type,
                    "thread_id": thread_id,
                },
            )
            raise HTTPException(status_code=502, detail="Failed to upload attachment")

        return {
            "bucket": bucket_name,
            "path": stored_path,
            "mimeType": mime_type,
            "url": signed_url,
        }

    async def create_attachment_signed_url(
        self,
        *,
        bucket: str,
        path: str,
        current_user: CurrentUser,
    ) -> dict[str, str]:
        if self._attachment_storage is None:
            raise HTTPException(
                status_code=503, detail="Attachment storage unavailable"
            )
        normalized_bucket = bucket.strip()
        if normalized_bucket != config.storage.bucket:
            raise HTTPException(status_code=422, detail="Invalid attachment bucket")

        normalized_path = path.strip()
        expected_prefix = f"agent-inputs/{current_user.id}/"
        if not _is_safe_attachment_path(
            normalized_path, expected_prefix=expected_prefix
        ):
            raise HTTPException(status_code=422, detail="Invalid attachment path scope")

        try:
            signed_url = await self._attachment_storage.create_signed_url(
                bucket=normalized_bucket,
                path=normalized_path,
                expires_in_seconds=self._SIGNED_URL_EXPIRES_IN_SECONDS,
            )
        except Exception:  # noqa: BLE001
            logger.exception(
                "Attachment signed URL generation failed",
                extra={
                    "bucket": normalized_bucket,
                    "path": normalized_path,
                    "user_id": str(current_user.id),
                },
            )
            raise HTTPException(status_code=502, detail="Failed to generate signed URL")

        return {
            "bucket": normalized_bucket,
            "path": normalized_path,
            "url": signed_url,
        }

    async def enqueue_resume(
        self,
        *,
        thread_id: str,
        run_input: RunAgentInput,
        current_user: CurrentUser,
    ) -> TaskAccepted:
        owner = await self._repository.get_session_owner(session_id=thread_id)
        ensure_session_owner(owner_id=owner, current_user=current_user)

        dedup_key = f"resume:{thread_id}:{run_input.run_id}"
        task_id = await self._queue.enqueue(
            command={
                "command": "resume",
                "owner_id": str(current_user.id),
                "run_input": run_input.model_dump(mode="json", by_alias=True),
            },
            dedup_key=dedup_key,
        )

        return TaskAccepted(
            task_id=task_id,
            thread_id=thread_id,
            run_id=run_input.run_id,
            created=False,
        )

    async def stream_events(
        self,
        *,
        thread_id: str,
        last_event_id: str | None,
        current_user: CurrentUser,
    ) -> list[dict[str, object]]:
        owner = await self._repository.get_session_owner(session_id=thread_id)
        ensure_session_owner(owner_id=owner, current_user=current_user)
        return await self._stream.read(
            session_id=thread_id,
            last_event_id=last_event_id,
        )

    async def get_history_snapshot(
        self,
        *,
        thread_id: str,
        before: date | None,
        current_user: CurrentUser,
    ) -> dict[str, object]:
        owner = await self._repository.get_session_owner(session_id=thread_id)
        ensure_session_owner(owner_id=owner, current_user=current_user)
        day_payload = await self._repository.get_history_day(
            session_id=thread_id,
            before=before,
        )
        snapshot = {
            "scope": "history_day",
            "threadId": thread_id,
            "day": day_payload["day"] if day_payload else None,
            "hasMore": day_payload["hasMore"] if day_payload else False,
            "messages": day_payload["messages"] if day_payload else [],
        }
        event = StateSnapshotEvent(snapshot=snapshot).model_dump(
            mode="json",
            by_alias=True,
            exclude_none=True,
        )
        event["threadId"] = thread_id
        return event

    async def get_user_history_snapshot(
        self,
        *,
        current_user: CurrentUser,
        thread_id: str | None,
        before: date | None,
    ) -> dict[str, object]:
        target_thread_id = thread_id
        if target_thread_id is None:
            target_thread_id = await self._repository.get_latest_session_id_for_user(
                user_id=str(current_user.id)
            )
        if target_thread_id is None:
            return StateSnapshotEvent(
                snapshot={
                    "scope": "history_day",
                    "threadId": None,
                    "day": None,
                    "hasMore": False,
                    "messages": [],
                }
            ).model_dump(mode="json", by_alias=True, exclude_none=True)
        return await self.get_history_snapshot(
            thread_id=target_thread_id,
            before=before,
            current_user=current_user,
        )

    def _validate_binary_signed_url(
        self,
        *,
        url: str,
        thread_id: str,
        current_user: CurrentUser,
    ) -> tuple[str, str]:
        if self._attachment_storage is None:
            raise HTTPException(
                status_code=503, detail="Attachment storage unavailable"
            )
        parsed = urlparse(url)
        expected_host = urlparse(config.supabase.url).netloc
        if parsed.netloc != expected_host:
            raise HTTPException(status_code=422, detail="INVALID_BINARY_URL_HOST")

        try:
            bucket, path = self._attachment_storage.parse_signed_url(url)
        except Exception as exc:  # noqa: BLE001
            raise HTTPException(
                status_code=422, detail="Invalid signed image url"
            ) from exc

        if bucket != config.storage.bucket:
            raise HTTPException(status_code=422, detail="INVALID_BINARY_URL_BUCKET")

        expected_prefix = f"agent-inputs/{current_user.id}/{thread_id}/uploads/"
        if not _is_safe_attachment_path(path, expected_prefix=expected_prefix):
            raise HTTPException(status_code=422, detail="INVALID_BINARY_URL_PATH_SCOPE")
        return bucket, path


class AsrService:
    def __init__(self) -> None:
        self._api_key: str | None = None

    def _get_api_key(self) -> str:
        if self._api_key is None:
            dashscope_key = config.llm.provider_keys.get("dashscope")
            if not dashscope_key:
                raise ValueError(
                    "DASHSCOPE_API_KEY not configured. Set SOCIAL_LLM__PROVIDER_KEYS__DASHSCOPE in environment."
                )
            self._api_key = dashscope_key
        return self._api_key

    async def transcribe_file(self, file_path: str, filename: str) -> str:
        try:
            dashscope.api_key = self._get_api_key()

            loop = asyncio.get_event_loop()

            class SyncCallback(RecognitionCallback):
                error: str | None = None

                def on_error(self, result: Any) -> None:
                    self.error = str(result)

            callback = SyncCallback()
            recognizer = Recognition(
                model="fun-asr-realtime-2026-02-28",
                callback=callback,
                format="wav",
                sample_rate=16000,
            )

            result: Any = await loop.run_in_executor(
                None,
                lambda: recognizer.call(file=file_path),
            )

            if callback.error:
                raise RuntimeError(f"ASR error: {callback.error}")
            status_code = self._extract_field(result, "status_code")
            if status_code != 200:
                message = self._extract_field(result, "message")
                raise RuntimeError(f"ASR transcription failed: {message}")

            sentence = self._extract_sentence_payload(result)
            if sentence is None:
                request_id = self._extract_field(result, "request_id")
                logger.warning(
                    "ASR returned empty result", extra={"request_id": request_id}
                )
                return ""

            if isinstance(sentence, dict):
                transcription = sentence.get("text", "")
            elif isinstance(sentence, list):
                transcription = " ".join(
                    item.get("text", "") for item in sentence if isinstance(item, dict)
                )
            else:
                transcription = str(sentence) if sentence else ""

            logger.info(
                "ASR transcription completed",
                extra={"filename": filename, "transcript_length": len(transcription)},
            )
            return transcription

        except asyncio.CancelledError:
            raise
        except RuntimeError:
            raise
        except Exception as exc:
            logger.exception("ASR transcription error")
            raise RuntimeError(f"ASR transcription failed: {exc}") from exc

    def _extract_sentence_payload(self, result: Any) -> Any | None:
        if isinstance(result, dict):
            output = result.get("output")
            if isinstance(output, dict):
                return output.get("sentence")
            if output is not None:
                return getattr(output, "sentence", None)
            return result.get("sentence")

        get_sentence = getattr(result, "get_sentence", None)
        if callable(get_sentence):
            sentence = get_sentence()
            if sentence is not None:
                return sentence

        output = getattr(result, "output", None)
        if output is None:
            return None
        if isinstance(output, dict):
            return output.get("sentence")
        return getattr(output, "sentence", None)

    def _extract_field(self, result: Any, field: str) -> Any | None:
        if isinstance(result, dict):
            return result.get(field)
        return getattr(result, field, None)


asr_service = AsrService()


def _mime_to_suffix(mime_type: str) -> str:
    mapping = {
        "image/png": "png",
        "image/jpeg": "jpg",
        "image/webp": "webp",
    }
    return mapping.get(mime_type.lower(), "bin")


def _is_safe_attachment_path(path: str, *, expected_prefix: str) -> bool:
    normalized = path.strip()
    if not normalized:
        return False
    if normalized.startswith("/"):
        return False
    if ".." in normalized:
        return False
    return normalized.startswith(expected_prefix)