"""记忆域路由（WP-04）。"""

from typing import Annotated, Any

from fastapi import APIRouter, BackgroundTasks, Depends, Header, HTTPException, Request, status
from pydantic import BaseModel, ConfigDict, Field

from app.auth.dependencies import get_current_user, require_state_change
from app.characters.service import require_character
from app.conversations.routes import _domain_of
from app.db.session import DbSession
from app.memories import service
from app.models import Memory, MemoryCandidate, MemoryVersion, User

router = APIRouter(prefix="/v1/memories", tags=["memories"])
cycle_router = APIRouter(prefix="/v1/characters", tags=["big-cycle"])


class CandidateIn(BaseModel):
    model_config = ConfigDict(extra="forbid")

    character_id: str | None = None
    kind: str
    sensitivity: str = "none"
    realm: str = "reality"
    payload: dict[str, Any]
    source: str = "manual"
    source_ref: dict[str, Any] = Field(default_factory=dict)


def _candidate_out(c: MemoryCandidate, memory: Memory | None = None) -> dict[str, Any]:
    return {
        "id": c.id,
        "kind": c.kind,
        "sensitivity": c.sensitivity,
        "realm": c.realm,
        "payload": c.payload,
        "source": c.source,
        "status": c.status,
        "created_memory_id": memory.id if memory else None,
        "created_at": c.created_at.isoformat(),
    }


def _memory_out(m: Memory, v: MemoryVersion | None) -> dict[str, Any]:
    return {
        "id": m.id,
        "character_id": m.character_id,
        "kind": m.kind,
        "sensitivity": m.sensitivity,
        "realm": m.realm,
        "status": m.status,
        "payload": v.payload if v else None,
        "version": v.version if v else None,
        "resource_version": m.resource_version,
        "expires_at": m.expires_at.isoformat() if m.expires_at else None,
        "created_at": m.created_at.isoformat(),
    }


@router.post("/candidates", status_code=201)
async def submit_candidate(
    db: DbSession,
    user: Annotated[User, Depends(require_state_change)],
    request: Request,
    body: CandidateIn,
) -> dict[str, Any]:
    domain = await _domain_of(db, user)
    candidate, memory = await service.submit_candidate(
        db, domain.id, body.model_dump(), getattr(request.state, "trace_id", None)
    )
    return _candidate_out(candidate, memory)


@router.get("/candidates")
async def list_candidates(
    db: DbSession,
    user: Annotated[User, Depends(get_current_user)],
    status_filter: str = "pending",
) -> dict[str, Any]:
    from sqlalchemy import select

    domain = await _domain_of(db, user)
    stmt = (
        select(MemoryCandidate)
        .where(
            MemoryCandidate.owner_personal_domain_id == domain.id,
            MemoryCandidate.status == status_filter,
        )
        .order_by(MemoryCandidate.created_at.asc())
    )
    rows = list((await db.scalars(stmt)).all())
    return {"data": [_candidate_out(c) for c in rows]}


@router.post("/candidates/{candidate_id}/decisions", status_code=201)
async def decide_candidate(
    candidate_id: str,
    db: DbSession,
    user: Annotated[User, Depends(require_state_change)],
    request: Request,
    body: dict[str, bool],
) -> dict[str, Any]:
    domain = await _domain_of(db, user)
    candidate, memory = await service.decide_candidate(
        db, domain.id, candidate_id, bool(body.get("approve")),
        getattr(request.state, "trace_id", None),
    )
    return _candidate_out(candidate, memory)


@router.get("")
async def search_memories(
    db: DbSession,
    user: Annotated[User, Depends(get_current_user)],
    q: str | None = None,
    character_id: str | None = None,
    limit: int = 50,
    cursor: str | None = None,
) -> dict[str, Any]:
    if not 1 <= limit <= 200:
        raise HTTPException(status.HTTP_422_UNPROCESSABLE_ENTITY, "limit 取值范围 1-200")
    domain = await _domain_of(db, user)
    page, next_cursor, has_more = await service.search_memories(
        db, domain.id, character_id, q, limit, cursor
    )
    # 召回证据：进入结果即附（ContextSnapshot 的响应级最小形态）
    return {
        "data": [
            {**_memory_out(m, v), "recall": {"matched": bool(q), "channel": "text"}}
            for m, v in page
        ],
        "next_cursor": next_cursor,
        "has_more": has_more,
    }


@router.patch("/{memory_id}")
async def correct_memory(
    memory_id: str,
    db: DbSession,
    user: Annotated[User, Depends(require_state_change)],
    request: Request,
    if_match: Annotated[str | None, Header(alias="If-Match")] = None,
    body: dict[str, Any] | None = None,
) -> dict[str, Any]:
    domain = await _domain_of(db, user)
    memory = await service.correct_memory(
        db, domain.id, memory_id, if_match, (body or {}).get("payload", {}),
        getattr(request.state, "trace_id", None),
    )
    version = await db.get(MemoryVersion, memory.current_version_id)
    return _memory_out(memory, version)


@router.delete("/{memory_id}", status_code=204)
async def delete_memory(
    memory_id: str,
    db: DbSession,
    user: Annotated[User, Depends(require_state_change)],
    request: Request,
) -> None:
    domain = await _domain_of(db, user)
    await service.delete_memory(
        db, domain.id, memory_id, getattr(request.state, "trace_id", None)
    )


@cycle_router.post("/{character_id}/big-cycles", status_code=201)
async def trigger_big_cycle(
    character_id: str,
    db: DbSession,
    user: Annotated[User, Depends(require_state_change)],
    request: Request,
    background_tasks: BackgroundTasks,
) -> dict[str, Any]:
    """手动触发大周天：评估经模型网关，产物为待审核 persona_candidate。"""
    from app.models import BigCycle

    domain = await _domain_of(db, user)
    character = await require_character(db, domain.id, character_id)
    if character.status not in {"active", "resting"}:
        raise HTTPException(status.HTTP_422_UNPROCESSABLE_ENTITY, "当前状态不可触发大周天")
    await db.commit()
    cycle = BigCycle(
        character_id=character.id, status="pending", trigger={"type": "manual"}
    )
    async with db.begin():
        db.add(cycle)
    await db.refresh(cycle)
    from app.memories.big_cycle import execute_big_cycle

    background_tasks.add_task(
        execute_big_cycle,
        request.app.state.session_factory,
        cycle.id,
        transport=getattr(request.app.state, "gw_transport", None),
    )
    return {"id": cycle.id, "character_id": character.id, "status": cycle.status}