"""公共知识库服务（Phase 10/11/12 统一数据来源）。

HTML/MD/TXT/JSON/搜索全部通过此 Service 获取数据，不各自写查询逻辑。
"""

from app.core.errors import NotFoundError
from app.core.security import hash_token
from app.models.document import Document
from app.models.knowledge_base import KnowledgeBase
from app.repositories.doc_repo import DocumentRepository
from app.repositories.kb_repo import KnowledgeBaseRepository
from sqlalchemy.orm import Session


class KbPublicService:
    def __init__(self, session: Session) -> None:
        self._session = session
        self._kb_repo = KnowledgeBaseRepository(session)
        self._doc_repo = DocumentRepository(session)

    def get_kb_by_token(self, token: str) -> KnowledgeBase:
        """通过 token 获取知识库。不存在/禁用/删除 → 404。"""
        token_hash = hash_token(token)
        kb = self._kb_repo.get_by_token_hash(token_hash)
        if kb is None or not kb.enabled or kb.status == "DELETED":
            raise NotFoundError("知识库不存在。")
        return kb

    def list_documents(
        self, kb: KnowledgeBase, *, page: int = 1, page_size: int = 50
    ) -> tuple[list[Document], int]:
        """获取知识库的文档列表（仅 READY 状态）。"""
        return self._doc_repo.list_by_knowledge_base(
            kb.id, page=page, page_size=page_size, status="READY"
        )

    def get_document_by_token(self, kb: KnowledgeBase, doc_token: str) -> Document:
        """通过 token 获取单个文档。"""
        doc_token_hash = hash_token(doc_token)
        doc = self._doc_repo.get_by_doc_token_hash(doc_token_hash)
        if doc is None or doc.knowledge_base_id != kb.id or doc.status != "READY":
            raise NotFoundError("文档不存在。")
        return doc

    def get_document_markdown(self, doc: Document) -> str:
        """读取文档的 Markdown 内容。"""
        from app.storage.local_storage import get_storage

        if not doc.markdown_path:
            return ""
        storage = get_storage()
        content = storage.read(doc.markdown_path)
        return content.decode("utf-8")

    def search_documents(
        self, kb: KnowledgeBase, query: str, *, page: int = 1, page_size: int = 20
    ) -> tuple[list[dict], int]:
        """关键词搜索文档（Phase 12：SQLite LIKE / FTS5）。"""
        # MVP 简化：使用 LIKE 搜索标题+描述+关键词
        from sqlalchemy import func, or_, select

        conditions = [
            Document.knowledge_base_id == kb.id,
            Document.status == "READY",
        ]

        like_pattern = f"%{query}%"
        search_condition = or_(
            Document.title.like(like_pattern),
            Document.description.like(like_pattern),
            Document.keywords.like(like_pattern),
            Document.content_summary.like(like_pattern),
        )
        conditions.append(search_condition)

        count_stmt = select(func.count()).select_from(Document).where(*conditions)
        total = self._session.scalar(count_stmt) or 0

        stmt = (
            select(Document)
            .where(*conditions)
            .order_by(Document.created_at.desc())
            .offset((page - 1) * page_size)
            .limit(page_size)
        )
        docs = list(self._session.scalars(stmt).all())

        results = []
        for doc in docs:
            results.append({
                "id": doc.id,
                "title": doc.title or doc.original_filename,
                "description": doc.description,
                "keywords": doc.keywords,
                "file_type": doc.file_ext,
                "updated_at": doc.updated_at,
                "url_hint": doc.doc_token_hint,
            })

        return results, total