from app.extensions import db
from app.models.inbound.buy import StockBuy
from app.models.base import MaterialBase

# 尝试导入出库模型，如果不存在则忽略
try:
    from app.models.outbound import TransOutbound
except ImportError:
    TransOutbound = None

from datetime import datetime, timedelta, timezone
from sqlalchemy import or_, func, text, and_
import traceback
import json


class BuyInboundService:

    # ============================================================
    # 0. 辅助：唯一性校验 (核心修复)
    # ============================================================
    @staticmethod
    def _check_unique(base_id, serial_number, batch_number, exclude_id=None):
        """
        校验序列号和批号的唯一性逻辑
        :param base_id: 当前物料的基础ID
        :param serial_number: 序列号
        :param batch_number: 批号
        :param exclude_id: 排除的ID (用于编辑模式)
        """
        # 1. 序列号 (SN) 全局唯一校验
        # 解释: 不同规格的物料通常也不应该有相同的SN，防止扫码混淆
        if serial_number:
            query = StockBuy.query.filter(StockBuy.serial_number == serial_number)
            if exclude_id:
                query = query.filter(StockBuy.id != exclude_id)

            exists = query.first()
            if exists:
                # 获取占用该SN的物料名称，提示更友好
                occupied_name = exists.material.name if exists.material else "未知物料"
                raise ValueError(f"序列号【{serial_number}】已存在！被物料 [{occupied_name}] 占用，请核查。")

        # 2. 批号 (BN) 同物料唯一校验
        # 解释: 不同规格的物料可以有相同的批号(如都有 001 批次)，但同一个物料不能重复建单
        if batch_number and base_id:
            query = StockBuy.query.filter(
                StockBuy.base_id == base_id,
                StockBuy.batch_number == batch_number
            )
            if exclude_id:
                query = query.filter(StockBuy.id != exclude_id)

            if query.first():
                raise ValueError(f"该物料已存在批号【{batch_number}】，请勿重复录入，可直接在该批次下追加库存。")

    # ============================================================
    # 1. 基础物料搜索
    # ============================================================
    @staticmethod
    def search_base_material(keyword):
        try:
            query = MaterialBase.query.filter(MaterialBase.is_enabled == True)
            if keyword:
                query = query.filter(
                    or_(
                        MaterialBase.name.ilike(f'%{keyword}%'),
                        MaterialBase.spec_model.ilike(f'%{keyword}%'),
                        MaterialBase.pinyin.ilike(f'%{keyword}%')  # 假设有拼音搜索
                    )
                )
            query = query.order_by(MaterialBase.id.desc()).limit(20)
            results = []
            for item in query.all():
                results.append({
                    'id': item.id,
                    'name': item.name,
                    'spec': item.spec_model,  # 确保这里字段对应正确
                    'category': item.category,
                    'unit': item.unit,
                    'type': item.material_type,
                    'status': '启用'
                })
            return results
        except Exception as e:
            traceback.print_exc()
            return []

    # ============================================================
    # 2. 新增入库逻辑
    # ============================================================
    @staticmethod
    def handle_inbound(data):
        try:
            base_id = data.get('base_id')
            if not base_id:
                raise ValueError("必须选择基础物料")

            material = MaterialBase.query.get(base_id)
            if not material:
                raise ValueError("所选物料不存在")

            # --- [修复点] 执行唯一性校验 ---
            BuyInboundService._check_unique(
                base_id=base_id,
                serial_number=data.get('serial_number'),
                batch_number=data.get('batch_number')
            )

            # 时间处理 (强制北京时间)
            beijing_tz = timezone(timedelta(hours=8))
            current_time = datetime.now(beijing_tz).replace(tzinfo=None)
            in_date_val = current_time

            if data.get('in_date'):
                try:
                    date_str = str(data['in_date'])
                    if len(date_str) > 10:
                        in_date_val = datetime.strptime(date_str, '%Y-%m-%d %H:%M:%S')
                    else:
                        d_temp = datetime.strptime(date_str, '%Y-%m-%d')
                        in_date_val = datetime(d_temp.year, d_temp.month, d_temp.day,
                                               current_time.hour, current_time.minute, current_time.second)
                except:
                    in_date_val = current_time

            in_qty = float(data.get('in_quantity') or 0)
            u_price = float(data.get('unit_price') or 0)

            # 获取全局打印ID
            try:
                seq_sql = text("SELECT nextval('global_print_seq')")
                result = db.session.execute(seq_sql)
                next_global_id = result.scalar()
            except:
                next_global_id = None

            # SKU 生成
            if next_global_id:
                generated_sku = str(next_global_id).zfill(10)
            else:
                generated_sku = datetime.now().strftime('%Y%m%d%H%M%S')

            final_barcode = data.get('barcode') or generated_sku

            arrival_list = data.get('arrival_photo', [])
            report_list = data.get('inspection_report', [])

            new_stock = StockBuy(
                base_id=material.id,
                global_print_id=next_global_id,
                sku=generated_sku,
                barcode=final_barcode,
                in_date=in_date_val,
                serial_number=data.get('serial_number'),
                batch_number=data.get('batch_number'),
                status=data.get('status', '在库'),
                in_quantity=in_qty,
                stock_quantity=in_qty,  # 初始库存等于入库数
                available_quantity=in_qty,
                inspection_status=data.get('inspection_status', '未检'),
                warehouse_location=data.get('warehouse_location'),
                unit_price=u_price,
                total_price=in_qty * u_price,
                currency=data.get('currency', 'CNY'),
                exchange_rate=data.get('exchange_rate', 1.0),
                supplier_name=data.get('supplier_name'),
                buyer_name=data.get('purchaser'),
                buyer_email=data.get('purchaser_email'),
                original_link=data.get('source_link'),
                detail_link=data.get('detail_link'),
                arrival_photo=json.dumps(arrival_list),
                inspection_report=json.dumps(report_list)
            )
            db.session.add(new_stock)
            db.session.commit()
            return new_stock
        except Exception as e:
            db.session.rollback()
            raise e

    # ============================================================
    # 3. 更新入库逻辑
    # ============================================================
    @staticmethod
    def update_inbound(stock_id, data):
        try:
            stock = StockBuy.query.get(stock_id)
            if not stock:
                raise ValueError("记录不存在")

            # --- [修复点] 编辑时也要校验唯一性 (排除自身ID) ---
            # 如果修改了物料(base_id)，或者修改了SN/BN，都需要校验
            new_base_id = data.get('base_id', stock.base_id)
            new_sn = data.get('serial_number', stock.serial_number)
            new_bn = data.get('batch_number', stock.batch_number)

            BuyInboundService._check_unique(
                base_id=new_base_id,
                serial_number=new_sn,
                batch_number=new_bn,
                exclude_id=stock_id
            )

            # 更新字段
            field_mapping = {
                'sku': 'sku', 'barcode': 'barcode', 'base_id': 'base_id',
                'warehouse_location': 'warehouse_location',
                'serial_number': 'serial_number', 'batch_number': 'batch_number',
                'status': 'status', 'inspection_status': 'inspection_status',
                'supplier_name': 'supplier_name', 'detail_link': 'detail_link',
                'currency': 'currency', 'exchange_rate': 'exchange_rate',
                'purchaser': 'buyer_name', 'purchaser_email': 'buyer_email',
                'source_link': 'original_link'
            }
            for k, v in field_mapping.items():
                if k in data: setattr(stock, v, data[k])

            if 'arrival_photo' in data and isinstance(data['arrival_photo'], list):
                stock.arrival_photo = json.dumps(data['arrival_photo'])
            if 'inspection_report' in data and isinstance(data['inspection_report'], list):
                stock.inspection_report = json.dumps(data['inspection_report'])

            # 库存数量变更逻辑
            if 'in_quantity' in data:
                new_qty = float(data['in_quantity'])
                diff = new_qty - float(stock.in_quantity)
                if diff != 0:
                    stock.in_quantity = new_qty
                    stock.stock_quantity = float(stock.stock_quantity) + diff
                    stock.available_quantity = float(stock.available_quantity) + diff

            if 'unit_price' in data:
                stock.unit_price = float(data['unit_price'])

            stock.total_price = float(stock.in_quantity) * float(stock.unit_price)
            db.session.commit()
            return stock
        except Exception as e:
            db.session.rollback()
            raise e

    # ============================================================
    # 4. 删除逻辑
    # ============================================================
    @staticmethod
    def delete_inbound(stock_id):
        try:
            stock = StockBuy.query.get(stock_id)
            if not stock: raise ValueError("记录不存在")
            db.session.delete(stock)
            db.session.commit()
            return True
        except Exception as e:
            db.session.rollback()
            raise e

    # ============================================================
    # 5. 获取列表
    # ============================================================
    @staticmethod
    def get_list(page, limit, keyword=None, statuses=None):
        try:
            query = db.session.query(StockBuy).outerjoin(MaterialBase, StockBuy.base_id == MaterialBase.id)

            if keyword:
                kw = f'%{keyword}%'
                query = query.filter(
                    or_(
                        MaterialBase.name.ilike(kw),
                        MaterialBase.spec_model.ilike(kw),
                        StockBuy.batch_number.ilike(kw),
                        StockBuy.serial_number.ilike(kw),
                        StockBuy.sku.ilike(kw),
                        StockBuy.supplier_name.ilike(kw)
                    )
                )

            if not statuses:
                statuses = ['在库', '借库']

            if '已出库' in statuses:
                query = query.filter(StockBuy.status.in_(statuses))
            else:
                query = query.filter(and_(StockBuy.status.in_(statuses), StockBuy.stock_quantity > 0))

            pagination = query.order_by(StockBuy.in_date.desc()).paginate(page=page, per_page=limit, error_out=False)
            current_items = pagination.items

            def parse_img(json_str):
                if not json_str: return []
                try:
                    return json.loads(json_str) if json_str.startswith('[') else [json_str]
                except:
                    return []

            items = []
            for item in current_items:
                qty_stock = float(item.stock_quantity or 0)
                qty_avail = float(item.available_quantity or 0)

                date_display = ''
                if item.in_date:
                    try:
                        date_display = item.in_date.strftime('%Y-%m-%d')
                    except:
                        date_display = str(item.in_date)[:10]

                d = {
                    'id': item.id,
                    'base_id': item.base_id,
                    # 确保这里从关联的 MaterialBase 获取规格型号
                    'material_name': item.material.name if item.material else '',
                    'spec_model': item.material.spec_model if item.material else '',
                    'category': item.material.category if item.material else '',
                    'unit': item.material.unit if item.material else '',
                    'material_type': item.material.material_type if item.material else '',

                    'sku': item.sku,
                    'inbound_date': date_display,
                    'barcode': item.barcode,
                    'serial_number': item.serial_number,
                    'batch_number': item.batch_number,
                    'status': item.status,
                    'inspection_status': item.inspection_status,
                    'qty_inbound': float(item.in_quantity or 0),
                    'qty_stock': qty_stock,
                    'qty_available': qty_avail,
                    'warehouse_loc': item.warehouse_location,
                    'unit_price': float(item.unit_price or 0),
                    'total_price': float(item.total_price or 0),
                    'currency': item.currency,
                    'exchange_rate': float(item.exchange_rate or 1),
                    'supplier_name': item.supplier_name,
                    'purchaser': item.buyer_name,
                    'purchaser_email': item.buyer_email,
                    'source_link': item.original_link,
                    'detail_link': item.detail_link,
                    'arrival_photo': parse_img(item.arrival_photo),
                    'inspection_report': parse_img(item.inspection_report),
                    'global_print_id': item.global_print_id
                }
                items.append(d)

            return {"total": pagination.total, "items": items}
        except Exception as e:
            traceback.print_exc()
            return {"total": 0, "items": []}