from app.models import *
from rest_framework.decorators import api_view
from rest_framework.response import Response
from django.db import transaction
from datetime import datetime


decimal = 0
#==========================================================================================
def getcode(code, Model):
  try:
    obj = Model.objects.latest('id')
    val = 1 if obj == None else obj.id + 1
  except Exception as e:
    val = 1
  length = len(str(val))
  text = ''
  for i in range(0, 6-length):
    text += '0'
  return '{}{}{}'.format(code, text, val)


#==========================================================================================
def account_entry_api(code, amount, content, type, category, userid, ref=None, product=None, customer=None, date=None):
    try:
        user = User.objects.get(id=userid)
        entry_type = Entry_Type.objects.get(code=type)
        entry_category = Entry_Category.objects.get(id=category)
        system_date = date if date else datetime.now().strftime("%Y-%m-%d")

        with transaction.atomic():
            account = Internal_Account.objects.select_for_update().get(code=code)
            start_balance = account.balance or 0
            
            if entry_type.code == 'DR' and start_balance < amount:
                return {'error': 'Số dư không đủ để thực hiện giao dịch.'}

            if entry_type.code == 'CR':
                # account.balance = F('balance') + amount
                account.balance += amount
            else:
                account.balance -= amount
            
            account.save()
            account.refresh_from_db()
            new_balance = account.balance

            entry = Internal_Entry.objects.create(
                category=entry_category,
                content=content,
                amount=amount,
                inputer=user,
                approver=user,
                type=entry_type,
                balance_before=start_balance,
                balance_after=new_balance,
                account=account,
                date=system_date,
                ref=ref,
                product=None if product==None else Product.objects.get(id=product),
                customer=None if customer==None else Customer.objects.get(id=customer)
            )

        text = 'id,account__currency__code,ref,balance_before,balance_after,code,account,account__code,account__branch__name,account__type__name,date,amount,content,inputer,inputer__fullname,approver,approver__fullname,create_time,update_time,type,type__code,type__name'
        fields = text.split(',')
        return Internal_Entry.objects.filter(id=entry.id).values(*fields).first()

    except User.DoesNotExist:
        return {'error': f"Người dùng với ID {userid} không tồn tại."}
    except Internal_Account.DoesNotExist:
        return {'error': f"Tài khoản nội bộ với mã '{code}' không tồn tại."}
    except Entry_Type.DoesNotExist:
        return {'error': f"Loại bút toán với mã '{type}' không tồn tại."}
    except Entry_Category.DoesNotExist:
        return {'error': f"Danh mục bút toán với ID '{category}' không tồn tại."}
    except Exception as e:
        return {'error': f"Đã xảy ra lỗi không mong muốn: {str(e)}"}

#==========================================================================================
@api_view(['POST'])
def account_entry(request):
  print(request.data.get('date'))
  ref = request.data.get('ref')
  data = account_entry_api(
      code=request.data['code'], 
      amount=request.data['amount'], 
      content=request.data['content'],
      type=request.data['type'], 
      category=request.data['category'], 
      userid=request.data['user'], 
      ref=ref,
      product=request.data['product'], 
      customer=request.data['customer'],
      date=request.data.get('date')
  )
  
  if 'error' in data:
      return Response(data, status=400)
      
  return Response(data)


#==========================================================================================
@api_view(['POST'])
def account_multi_entry(request):
    try:
        result = []
        data = request.data.get('data')
        for obj in data:
            row = account_entry_api(
                code=obj['Tài khoản'], 
                amount=obj['amount'], 
                content=obj['content'],
                type='CR', 
                category=obj['category'], 
                userid=request.data.get('user'), 
                ref=obj['ref'],
                product=obj['product'], 
                customer=obj['customer'],
                date=obj['date']
            )
            result.append(row)

        return Response(result)
         
    except Exception as e:
        print({'error': f"Đã xảy ra lỗi không mong muốn: {str(e)}"})
        return Response(data, status=400)