from typing import Optional

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import text
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.security import get_current_user
from app.models.drug import get_db

router = APIRouter(prefix="/drug", tags=["药品"])


@router.get("/search")
async def search_drug(
    keyword: Optional[str] = Query(None),
    category: Optional[str] = Query(None),
    page: int = Query(1, ge=1),
    page_size: int = Query(20, ge=1, le=100),
    user: dict = Depends(get_current_user),
):
    db = get_db()
    offset = (page - 1) * page_size

    conditions = ["is_active = TRUE"]
    params = {}

    if keyword:
        conditions.append("(name ILIKE :kw OR pinyin ILIKE :kw OR name_en ILIKE :kw)")
        params["kw"] = f"%{keyword}%"
    if category:
        conditions.append("category = :cat")
        params["cat"] = category

    where = "WHERE " + " AND ".join(conditions)

    count_query = f"SELECT COUNT(*) FROM drugs {where}"
    data_query = f"""
        SELECT drug_id, name, name_en, pinyin, category, subcategory,
               source_version, source_volume, source_page, is_active
        FROM drugs {where}
        ORDER BY name
        LIMIT :limit OFFSET :offset
    """

    params["limit"] = page_size
    params["offset"] = offset

    async with db() as session:
        total = (await session.execute(text(count_query), params)).scalar()
        rows = (await session.execute(text(data_query), params)).fetchall()

    items = []
    for row in rows:
        items.append({
            "drug_id": row.drug_id,
            "name": row.name,
            "name_en": row.name_en or "",
            "pinyin": row.pinyin or "",
            "category": row.category or "",
            "subcategory": row.subcategory or "",
            "source_version": row.source_version or "",
            "source_volume": row.source_volume or "",
            "source_page": row.source_page or "",
            "is_active": row.is_active,
        })

    total_pages = max(1, (total + page_size - 1) // page_size)

    return {
        "items": items,
        "total": total,
        "page": page,
        "page_size": page_size,
        "total_pages": total_pages,
    }


@router.get("/{drug_id}")
async def get_drug_detail(
    drug_id: str,
    user: dict = Depends(get_current_user),
):
    db = get_db()
    async with db() as session:
        row = (await session.execute(
            text("SELECT * FROM drugs WHERE drug_id = :drug_id"),
            {"drug_id": drug_id}
        )).fetchone()

    if not row:
        raise HTTPException(status_code=404, detail="Drug not found")

    return {
        "data": {
            "drug_id": row.drug_id,
            "name": row.name,
            "name_en": row.name_en or "",
            "pinyin": row.pinyin or "",
            "category": row.category or "",
            "subcategory": row.subcategory or "",
            "sections": row.sections or {},
            "source_version": row.source_version or "",
            "source_volume": row.source_volume or "",
            "source_page": row.source_page or "",
            "is_active": row.is_active,
        }
    }


@router.get("/category/tree")
async def get_category_tree(user: dict = Depends(get_current_user)):
    db = get_db()
    async with db() as session:
        rows = (await session.execute(
            text("SELECT DISTINCT category, subcategory FROM drugs WHERE category IS NOT NULL ORDER BY category, subcategory")
        )).fetchall()

    tree = {}
    for row in rows:
        cat = row.category
        sub = row.subcategory or ""
        if cat not in tree:
            tree[cat] = []
        if sub and sub not in tree[cat]:
            tree[cat].append(sub)

    return {"tree": [{"name": k, "children": v} for k, v in tree.items()]}