"""Fast taskId + goPath history lookup for single-agent deep-link workspaces.

Messages and execution state remain canonical LangGraph threads.  This API
reads only the dedicated ``task_deeplink_threads`` cards and never joins or
scans the generic ``threads_meta`` catalogue.
"""

from __future__ import annotations

from fastapi import APIRouter, HTTPException, Query, Request
from pydantic import BaseModel

from app.gateway.deps import get_task_deeplink_thread_store
from app.gateway.routers.threads import ThreadResponse
from deerflow.persistence.task_deeplink_threads.base import is_valid_task_deeplink_go_path
from deerflow.utils.time import coerce_iso

router = APIRouter(
    prefix="/api/task-deeplink-threads",
    tags=["task-deeplink-threads"],
)


class TaskDeeplinkThreadListResponse(BaseModel):
    threads: list[ThreadResponse]


@router.get("", response_model=TaskDeeplinkThreadListResponse)
async def list_task_deeplink_threads(
    request: Request,
    task_id: str = Query(min_length=1, max_length=128),
    go_path: str = Query(min_length=1, max_length=32),
    limit: int = Query(default=100, ge=1, le=500),
    # b5-1 ?type= partition. Provided (even empty) → only that sub-type;
    # omitted → every sub-type of the task/goPath partition (legacy callers).
    sub_type: str | None = Query(default=None, max_length=64),
) -> TaskDeeplinkThreadListResponse:
    """Return one shared deep-link history partition, newest first."""

    normalized_go_path = go_path.strip().lower()
    if not is_valid_task_deeplink_go_path(normalized_go_path):
        raise HTTPException(status_code=422, detail="Invalid task deep-link goPath")
    store = get_task_deeplink_thread_store(request)
    rows = await store.list_threads(
        task_id.strip(),
        normalized_go_path,
        limit=limit,
        sub_type=sub_type.strip() if sub_type is not None else None,
    )
    return TaskDeeplinkThreadListResponse(
        threads=[
            ThreadResponse(
                thread_id=row["thread_id"],
                status=row.get("status", "idle"),
                created_at=coerce_iso(row.get("created_at", "")),
                updated_at=coerce_iso(row.get("updated_at", "")),
                metadata=row.get("metadata", {}),
                values=row.get("values", {}),
                interrupts=row.get("interrupts", {}),
            )
            for row in rows
        ]
    )