"""
物料管理路由模块

提供物料价格历史和供应商关联管理功能，包括：
- 物料价格历史记录
- 物料供应商关联管理
- 物料价格趋势分析

路由前缀: /api/materials
"""
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func, desc
from typing import Optional, List

from shared.database.database import get_db_session
from shared.services.auth_service import get_current_active_user
from shared.models.database import User, Product, MaterialPriceHistory, MaterialSupplier, Supplier
from .schemas import (
    MaterialPriceHistoryCreate,
    MaterialPriceHistoryResponse,
    MaterialSupplierCreate,
    MaterialSupplierResponse,
    MaterialPriceTrendResponse
)

router = APIRouter(prefix="/materials", tags=["物料管理"])


async def _get_product(db_session: AsyncSession, product_id: int) -> Product:
    result = await db_session.execute(
        select(Product).where(Product.id == product_id, Product.is_active == True)
    )
    product = result.scalar_one_or_none()
    if not product:
        raise HTTPException(status_code=404, detail="物料不存在")
    if product.item_type != "material":
        raise HTTPException(status_code=400, detail="仅物料类型支持价格历史管理")
    return product


@router.post("/{product_id}/price-history", response_model=MaterialPriceHistoryResponse, status_code=201)
async def add_material_price_history(
    product_id: int,
    price_data: MaterialPriceHistoryCreate,
    db_session: AsyncSession = Depends(get_db_session),
    current_user: User = Depends(get_current_active_user)
):
    product = await _get_product(db_session, product_id)
    
    # 检查供应商是否存在
    if price_data.supplier_id:
        supplier_result = await db_session.execute(
            select(Supplier).where(Supplier.id == price_data.supplier_id, Supplier.is_active == True)
        )
        if not supplier_result.scalar_one_or_none():
            raise HTTPException(status_code=400, detail="供应商不存在")
    
    price_history = MaterialPriceHistory(
        product_id=product_id,
        price=price_data.price,
        supplier_id=price_data.supplier_id,
        remark=price_data.remark
    )
    db_session.add(price_history)
    await db_session.commit()
    await db_session.refresh(price_history)
    
    # 更新产品的成本价格为最新价格
    product.cost_price = price_data.price
    await db_session.commit()
    
    return MaterialPriceHistoryResponse(
        id=price_history.id,
        product_id=price_history.product_id,
        product_sku=product.sku,
        product_name=product.name,
        price=price_history.price,
        effective_date=price_history.effective_date,
        supplier_id=price_history.supplier_id,
        supplier_name=price_history.supplier.name if price_history.supplier else None,
        remark=price_history.remark,
        created_at=price_history.created_at
    )


@router.get("/{product_id}/price-history", response_model=List[MaterialPriceHistoryResponse])
async def get_material_price_history(
    product_id: int,
    limit: int = Query(20, ge=1, le=100),
    db_session: AsyncSession = Depends(get_db_session),
    current_user: User = Depends(get_current_active_user)
):
    product = await _get_product(db_session, product_id)
    
    result = await db_session.execute(
        select(MaterialPriceHistory)
        .where(MaterialPriceHistory.product_id == product_id)
        .order_by(desc(MaterialPriceHistory.effective_date))
        .limit(limit)
    )
    price_history_list = result.scalars().all()
    
    return [
        MaterialPriceHistoryResponse(
            id=ph.id,
            product_id=ph.product_id,
            product_sku=product.sku,
            product_name=product.name,
            price=ph.price,
            effective_date=ph.effective_date,
            supplier_id=ph.supplier_id,
            supplier_name=ph.supplier.name if ph.supplier else None,
            remark=ph.remark,
            created_at=ph.created_at
        )
        for ph in price_history_list
    ]


@router.get("/{product_id}/price-trend", response_model=MaterialPriceTrendResponse)
async def get_material_price_trend(
    product_id: int,
    months: int = Query(6, ge=1, le=24),
    db_session: AsyncSession = Depends(get_db_session),
    current_user: User = Depends(get_current_active_user)
):
    product = await _get_product(db_session, product_id)
    
    # 计算价格趋势
    result = await db_session.execute(
        select(MaterialPriceHistory)
        .where(MaterialPriceHistory.product_id == product_id)
        .order_by(desc(MaterialPriceHistory.effective_date))
        .limit(months)
    )
    price_history_list = result.scalars().all()
    
    if not price_history_list:
        raise HTTPException(status_code=404, detail="无价格历史记录")
    
    prices = [ph.price for ph in reversed(price_history_list)]
    dates = [ph.effective_date for ph in reversed(price_history_list)]
    
    # 计算价格变化
    current_price = price_history_list[0].price
    first_price = price_history_list[-1].price
    price_change = current_price - first_price
    price_change_percent = (price_change / first_price * 100) if first_price > 0 else 0
    
    return MaterialPriceTrendResponse(
        product_id=product_id,
        product_sku=product.sku,
        product_name=product.name,
        current_price=current_price,
        price_change=round(price_change, 2),
        price_change_percent=round(price_change_percent, 2),
        price_history=[
            {
                "date": ph.effective_date,
                "price": ph.price,
                "supplier_name": ph.supplier.name if ph.supplier else None
            }
            for ph in price_history_list
        ]
    )


@router.post("/{product_id}/suppliers", response_model=MaterialSupplierResponse, status_code=201)
async def add_material_supplier(
    product_id: int,
    supplier_data: MaterialSupplierCreate,
    db_session: AsyncSession = Depends(get_db_session),
    current_user: User = Depends(get_current_active_user)
):
    product = await _get_product(db_session, product_id)
    
    # 检查供应商是否存在
    supplier_result = await db_session.execute(
        select(Supplier).where(Supplier.id == supplier_data.supplier_id, Supplier.is_active == True)
    )
    supplier = supplier_result.scalar_one_or_none()
    if not supplier:
        raise HTTPException(status_code=400, detail="供应商不存在")
    
    # 检查是否已存在关联
    existing = await db_session.execute(
        select(MaterialSupplier)
        .where(
            MaterialSupplier.product_id == product_id,
            MaterialSupplier.supplier_id == supplier_data.supplier_id
        )
    )
    if existing.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="该供应商已关联到该物料")
    
    # 如果设置为主要供应商，将其他供应商设置为非主要
    if supplier_data.is_primary:
        await db_session.execute(
            MaterialSupplier.__table__.update()
            .where(MaterialSupplier.product_id == product_id)
            .values(is_primary=False)
        )
    
    material_supplier = MaterialSupplier(
        product_id=product_id,
        supplier_id=supplier_data.supplier_id,
        is_primary=supplier_data.is_primary,
        contact_person=supplier_data.contact_person,
        contact_phone=supplier_data.contact_phone,
        lead_time=supplier_data.lead_time,
        min_order_quantity=supplier_data.min_order_quantity
    )
    db_session.add(material_supplier)
    await db_session.commit()
    await db_session.refresh(material_supplier)
    
    return MaterialSupplierResponse(
        id=material_supplier.id,
        product_id=material_supplier.product_id,
        product_sku=product.sku,
        product_name=product.name,
        supplier_id=material_supplier.supplier_id,
        supplier_name=supplier.name,
        is_primary=material_supplier.is_primary,
        contact_person=material_supplier.contact_person,
        contact_phone=material_supplier.contact_phone,
        lead_time=material_supplier.lead_time,
        min_order_quantity=material_supplier.min_order_quantity,
        created_at=material_supplier.created_at,
        updated_at=material_supplier.updated_at
    )


@router.get("/{product_id}/suppliers", response_model=List[MaterialSupplierResponse])
async def get_material_suppliers(
    product_id: int,
    db_session: AsyncSession = Depends(get_db_session),
    current_user: User = Depends(get_current_active_user)
):
    product = await _get_product(db_session, product_id)
    
    result = await db_session.execute(
        select(MaterialSupplier)
        .where(MaterialSupplier.product_id == product_id)
        .order_by(MaterialSupplier.is_primary.desc(), MaterialSupplier.id.asc())
    )
    supplier_list = result.scalars().all()
    
    return [
        MaterialSupplierResponse(
            id=ms.id,
            product_id=ms.product_id,
            product_sku=product.sku,
            product_name=product.name,
            supplier_id=ms.supplier_id,
            supplier_name=ms.supplier.name if ms.supplier else None,
            is_primary=ms.is_primary,
            contact_person=ms.contact_person,
            contact_phone=ms.contact_phone,
            lead_time=ms.lead_time,
            min_order_quantity=ms.min_order_quantity,
            created_at=ms.created_at,
            updated_at=ms.updated_at
        )
        for ms in supplier_list
    ]


@router.delete("/suppliers/{supplier_id}")
async def remove_material_supplier(
    supplier_id: int,
    db_session: AsyncSession = Depends(get_db_session),
    current_user: User = Depends(get_current_active_user)
):
    result = await db_session.execute(
        select(MaterialSupplier).where(MaterialSupplier.id == supplier_id)
    )
    material_supplier = result.scalar_one_or_none()
    if not material_supplier:
        raise HTTPException(status_code=404, detail="物料供应商关联不存在")
    
    await db_session.delete(material_supplier)
    await db_session.commit()
    
    return {"message": "物料供应商关联已删除"}


@router.get("/suppliers/{supplier_id}/materials", response_model=List[MaterialSupplierResponse])
async def get_supplier_materials(
    supplier_id: int,
    db_session: AsyncSession = Depends(get_db_session),
    current_user: User = Depends(get_current_active_user)
):
    # 检查供应商是否存在
    supplier_result = await db_session.execute(
        select(Supplier).where(Supplier.id == supplier_id, Supplier.is_active == True)
    )
    supplier = supplier_result.scalar_one_or_none()
    if not supplier:
        raise HTTPException(status_code=404, detail="供应商不存在")
    
    result = await db_session.execute(
        select(MaterialSupplier)
        .where(MaterialSupplier.supplier_id == supplier_id)
        .order_by(MaterialSupplier.is_primary.desc(), MaterialSupplier.id.asc())
    )
    material_list = result.scalars().all()
    
    return [
        MaterialSupplierResponse(
            id=ms.id,
            product_id=ms.product_id,
            product_sku=ms.product.sku if ms.product else None,
            product_name=ms.product.name if ms.product else None,
            supplier_id=ms.supplier_id,
            supplier_name=supplier.name,
            is_primary=ms.is_primary,
            contact_person=ms.contact_person,
            contact_phone=ms.contact_phone,
            lead_time=ms.lead_time,
            min_order_quantity=ms.min_order_quantity,
            created_at=ms.created_at,
            updated_at=ms.updated_at
        )
        for ms in material_list
    ]