# 项目文件：catalog_project/src/cataloghub/web.py
from contextlib import asynccontextmanager, closing
from pathlib import Path
import sqlite3
from typing import Literal
from urllib.parse import urlencode

from fastapi import Depends, FastAPI, HTTPException, Query, Request
from fastapi.responses import JSONResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates

from .config import Settings
from .storage import SCHEMA, open_db, public, query
from .telemetry import install_logging

ROOT = Path(__file__).parent


def create_app(settings=None):
    settings = settings or Settings.from_env()

    @asynccontextmanager
    async def lifespan(app):
        # 服务只查询已迁移数据库；初始化由单独管理命令完成。
        with closing(open_db(settings.database, readonly=True)) as connection:
            if connection.execute("PRAGMA user_version").fetchone()[0] != SCHEMA:
                raise ValueError("请先执行 catalog migrate")
        yield

    app = FastAPI(title="采集书目查询", lifespan=lifespan)
    install_logging(app, "cataloghub")
    app.mount("/static", StaticFiles(directory=ROOT / "static"), name="static")
    templates = Jinja2Templates(directory=ROOT / "templates")

    def database():
        with closing(open_db(settings.database, readonly=True)) as connection:
            connection.execute("BEGIN")  # 本次计数和分页读取同一个数据库快照。
            yield connection

    def filters(
        q: str = Query("", max_length=100),
        finished: Literal["all", "0", "1"] = "all",
        tag: str = Query("", max_length=30),
        page: int = Query(1, ge=1),
    ):
        return {"q": q.strip(), "finished": finished, "tag": tag.strip(), "page": page}

    @app.get("/api/books")
    def books(options=Depends(filters), connection=Depends(database)):
        return query(connection, **options)

# 续写同一文件：catalog_project/src/cataloghub/web.py
    @app.get("/")
    def index(request: Request, options=Depends(filters), connection=Depends(database)):
        result = query(connection, **options)
        # 翻页只改 page，其余查询条件继续交回服务器。
        links = {
            name: "/?" + urlencode({**options, "page": value})
            for name, value in [
                ("previous", max(1, options["page"] - 1)),
                ("next", options["page"] + 1),
            ]
        }
        return templates.TemplateResponse(
            request=request,
            name="index.html",
            context={"result": result, "filters": options, "links": links},
        )

    @app.get("/books/{source_id}")
    def detail(source_id: str, request: Request, connection=Depends(database)):
        row = connection.execute(
            "SELECT * FROM books WHERE source_id=?", (source_id,)
        ).fetchone()
        if row is None:
            raise HTTPException(404, "没有找到这本书")
        return templates.TemplateResponse(
            request=request, name="detail.html", context={"book": public(row)}
        )

    @app.get("/health/live")
    def live():
        return {"status": "ok"}

    @app.get("/health/ready")
    def ready():
        try:
            with closing(open_db(settings.database, readonly=True)) as connection:
                version = connection.execute("PRAGMA user_version").fetchone()[0]
                connection.execute("SELECT 1 FROM books LIMIT 1").fetchone()
            if version != SCHEMA:
                raise ValueError("schema")
        except (OSError, sqlite3.Error, ValueError):
            return JSONResponse({"status": "not_ready"}, status_code=503)
        return {"status": "ready", "schema": version}

    return app

<!-- 项目文件：catalog_project/src/cataloghub/templates/index.html -->
{% extends 'base.html' %}
{% block content %}
<!-- GET 表单把当前筛选保留在地址中；翻页链接继续携带这些条件。 -->
<form class="panel filters" method="get">
<label>书名关键词<input name="q" value="{{ filters.q }}" maxlength="100"></label>
<label>阅读状态<select name="finished"><option value="all">全部</option><option value="0" {% if filters.finished == '0' %}selected{% endif %}>未读</option><option value="1" {% if filters.finished == '1' %}selected{% endif %}>已读</option></select></label>
<label>标签<input name="tag" value="{{ filters.tag }}" maxlength="30"></label><button>查询</button><a href="/">重置</a></form>
<p class="metrics">共 <strong>{{ result.total }}</strong> 本 · 第 {{ result.page }} / {{ result.pages }} 页</p>
<!-- 明确按键取出书目列表；书名由模板自动转义后显示。 -->
<section class="grid">{% for book in result['items'] %}<article class="panel book" data-id="{{ book.source_id }}">
<p class="badge">{{ '已读' if book.finished else '未读' }} · {{ book.source_id }}</p><h2><a href="/books/{{ book.source_id }}">{{ book.title }}</a></h2>
<p>{{ book.tags|join(' · ') }}</p><a href="/books/{{ book.source_id }}">查看导入记录</a></article>{% else %}<div class="panel">没有符合条件的书目，可以调整筛选。</div>{% endfor %}</section>
<nav class="pagination">{% if result.page > 1 %}<a href="{{ links.previous }}">上一页</a>{% endif %}
{% if result.page < result.pages %}<a href="{{ links.next }}">下一页</a>{% endif %}</nav>
{% endblock %}