"""数学学习系统后端入口。"""
from __future__ import annotations

import json
import os

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from sqlalchemy import text

from database import REPO_ROOT, SessionLocal, ensure_schema
from routers import (
    analytics,
    archive,
    auth,
    catalog,
    courses,
    data,
    ebooks,
    llm,
    knowledge_graph,
    overview,
    practice,
    question_bank,
    users,
)
from seed.catalog import ensure_catalog
from services import ebooks as ebook_store
from seed.ebooks import ensure_ebooks
from seed.knowledge_graph import ensure_knowledge_graph
from seed.rbac import ensure_rbac
from services.learning_profile import (
    ensure_default_profiles,
    remove_unused_admin_profile,
    user_has_admin_role,
)
from services.llm_config import ensure_llm_channels
from models import AttemptItem, ErrorEntry, Question, User
from services.knowledge_service import set_question_knowledge_names


ensure_schema()
db = SessionLocal()
try:
    ensure_rbac(db)
    ensure_knowledge_graph(db)
    ensure_default_profiles(db)
    for user in db.query(User).all():
        if user_has_admin_role(db, user.id):
            remove_unused_admin_profile(db, user.id)
    ensure_catalog(db)
    ensure_ebooks(db)
    ebook_store.backfill_pages(db)
    ensure_llm_channels(db)
    db.execute(
        text(
            "UPDATE questions SET used_count = ("
            "SELECT COUNT(*) FROM attempt_items "
            "WHERE attempt_items.question_id = questions.id"
            ") WHERE id IN (SELECT DISTINCT question_id FROM attempt_items "
            "WHERE question_id IS NOT NULL)"
        )
    )
    for question in db.query(Question).all():
        has_links = db.execute(
            text(
                "SELECT 1 FROM question_knowledge "
                "WHERE question_id = :qid LIMIT 1"
            ),
            {"qid": question.id},
        ).first()
        if has_links is None:
            set_question_knowledge_names(
                db,
                question,
                [question.knowledge_name],
                attach_to_chapter=True,
            )
    for row in db.query(ErrorEntry).all():
        if not row.knowledge_names or row.knowledge_names == "[]":
            row.knowledge_names = json.dumps(
                [row.knowledge_name], ensure_ascii=False
            )
    for row in db.query(AttemptItem).all():
        if not row.knowledge_names or row.knowledge_names == "[]":
            row.knowledge_names = json.dumps(
                [row.knowledge_name], ensure_ascii=False
            )
    db.commit()
finally:
    db.close()


def _cors_origins() -> list[str]:
    raw = os.getenv("CORS_ORIGINS", "http://localhost:5173,http://127.0.0.1:5173")
    return [origin.strip() for origin in raw.split(",") if origin.strip()]


app = FastAPI(
    title="数学学习系统 API",
    description="个人数学学习系统后端：章节组卷判分、掌握度引擎、错题与学习档案。",
    version="1.0.0",
)
app.add_middleware(
    CORSMiddleware,
    allow_origins=_cors_origins(),
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
    # 阅读器依赖 Range 分段加载，需要能读到这几个响应头
    expose_headers=["Accept-Ranges", "Content-Range", "Content-Length"],
)

app.include_router(overview.router, prefix="/api")
app.include_router(data.router, prefix="/api")
app.include_router(analytics.router, prefix="/api")
app.include_router(practice.router, prefix="/api")
app.include_router(archive.router, prefix="/api")
app.include_router(catalog.router, prefix="/api")
app.include_router(courses.router, prefix="/api")
app.include_router(ebooks.router, prefix="/api")
app.include_router(ebooks.progress_router, prefix="/api")
app.include_router(question_bank.router, prefix="/api")
app.include_router(llm.router, prefix="/api")
app.include_router(auth.router, prefix="/api")
app.include_router(users.router, prefix="/api")
app.include_router(knowledge_graph.router, prefix="/api")

image_dir = REPO_ROOT / "data" / "question_images"
image_dir.mkdir(parents=True, exist_ok=True)
app.mount(
    "/api/question-images",
    StaticFiles(directory=image_dir),
    name="question-images",
)


@app.get("/api/health")
def health():
    return {"status": "ok", "service": "math-learning-backend"}