"""知识库 API 路由。"""

from fastapi import APIRouter, Depends, Query
from sqlalchemy.orm import Session

from app.api.deps import get_current_user, get_db
from app.models.user import User
from app.schemas.knowledge_base import (
    KbCreateRequest,
    KbListResponse,
    KbResponse,
    KbSetExpiryRequest,
    KbTokenResponse,
    KbUpdateRequest,
)
from app.services.kb_service import KnowledgeBaseService

router = APIRouter(prefix="/knowledge-bases", tags=["knowledge-bases"])


@router.get("", response_model=KbListResponse)
def list_knowledge_bases(
    page: int = Query(1, ge=1),
    page_size: int = Query(20, ge=1, le=100),
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbListResponse:
    svc = KnowledgeBaseService(db)
    items, total = svc.list_by_user(user, page=page, page_size=page_size)
    doc_count_map = db and svc._kb_repo.get_document_count_map(user.id)
    return KbListResponse(
        items=[_to_response(kb, doc_count_map.get(kb.id, 0)) for kb in items],
        total=total,
    )


@router.post("", response_model=KbResponse, status_code=201)
def create_knowledge_base(
    body: KbCreateRequest,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbResponse:
    svc = KnowledgeBaseService(db)
    kb, token = svc.create(user, body.name, body.description)
    return _to_response(kb, ai_url=f"/k/{token}")


@router.get("/{kb_id}", response_model=KbResponse)
def get_knowledge_base(
    kb_id: str,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbResponse:
    svc = KnowledgeBaseService(db)
    kb = svc.get_or_404(kb_id, user)
    doc_count = svc._kb_repo.count_documents(kb_id)
    return _to_response(kb, doc_count)


@router.put("/{kb_id}", response_model=KbResponse)
def update_knowledge_base(
    kb_id: str,
    body: KbUpdateRequest,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbResponse:
    svc = KnowledgeBaseService(db)
    kb = svc.update(kb_id, user, body.name, body.description)
    return _to_response(kb)


@router.delete("/{kb_id}", status_code=204)
def delete_knowledge_base(
    kb_id: str,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> None:
    svc = KnowledgeBaseService(db)
    svc.delete(kb_id, user)


@router.post("/{kb_id}/regenerate-token", response_model=KbTokenResponse)
def regenerate_token(
    kb_id: str,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbTokenResponse:
    svc = KnowledgeBaseService(db)
    kb, token = svc.regenerate_token(kb_id, user)
    return KbTokenResponse(
        token=token, ai_url=f"/k/{token}", token_hint=kb.token_hint,
        expires_at=kb.token_expires_at, is_expired=False,
    )


@router.post("/{kb_id}/enable", response_model=KbResponse)
def enable_knowledge_base(
    kb_id: str,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbResponse:
    svc = KnowledgeBaseService(db)
    kb = svc.set_enabled(kb_id, user, True)
    return _to_response(kb)


@router.post("/{kb_id}/disable", response_model=KbResponse)
def disable_knowledge_base(
    kb_id: str,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbResponse:
    svc = KnowledgeBaseService(db)
    kb = svc.set_enabled(kb_id, user, False)
    return _to_response(kb)


@router.get("/{kb_id}/link", response_model=KbTokenResponse)
def get_knowledge_base_link(
    kb_id: str,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbTokenResponse:
    """获取完整 AI 链接（解密 token）+ 有效期信息。"""
    from app.services.kb_public_service import KbPublicService

    svc = KnowledgeBaseService(db)
    kb = svc.get_or_404(kb_id, user)
    token = svc.get_full_token(kb)
    if token is None:
        return KbTokenResponse(
            token="", ai_url="", token_hint=kb.token_hint or "",
            expires_at=None, is_expired=False,
        )
    return KbTokenResponse(
        token=token,
        ai_url=f"/k/{token}",
        token_hint=kb.token_hint or "",
        expires_at=kb.token_expires_at,
        is_expired=KbPublicService.is_expired(kb),
    )


@router.post("/{kb_id}/set-expiry", response_model=KbResponse)
def set_link_expiry(
    kb_id: str,
    body: KbSetExpiryRequest,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> KbResponse:
    """设置 AI 链接有效期。expires_in_minutes 为 null 表示长期有效。"""
    svc = KnowledgeBaseService(db)
    kb = svc.set_expiry(kb_id, user, body.expires_in_minutes)
    doc_count = svc._kb_repo.count_documents(kb_id)
    return KbResponse(
        id=kb.id, name=kb.name, description=kb.description, enabled=kb.enabled,
        token_hint=kb.token_hint, document_count=doc_count,
        created_at=kb.created_at, updated_at=kb.updated_at,
    )


def _to_response(kb, doc_count: int = 0, ai_url: str | None = None) -> KbResponse:
    return KbResponse(
        id=kb.id,
        name=kb.name,
        description=kb.description,
        enabled=kb.enabled,
        token_hint=kb.token_hint,
        ai_url=ai_url,
        document_count=doc_count,
        created_at=kb.created_at,
        updated_at=kb.updated_at,
    )