import uuid

from datetime import date, datetime, timedelta
from decimal import Decimal
from typing import List

from fastapi import APIRouter, Depends, Security
from sqlalchemy import and_, distinct, func
from sqlalchemy.orm import Session, aliased, joinedload_all

from ..core.security import get_current_active_user as get_user
from ..db.session import SessionLocal
from ..models import Batch, EmployeeBenefit, Inventory, Journal, Voucher, VoucherType
from ..models.master import Account, AccountBase, CostCentre, Employee
from ..models.voucher import Attendance, DbImage, Fingerprint, Incentive
from ..schemas.auth import UserToken


router = APIRouter()


# Dependency
def get_db() -> Session:
    try:
        db = SessionLocal()
        yield db
    finally:
        db.close()


@router.post("/{date_}")
def rebase(
    date_: str,
    db: Session = Depends(get_db),
    user: UserToken = Security(get_user, scopes=["rebase"]),
):
    # request.dbsession.execute('SET statement_timeout TO 300000;') # 5 minutes
    date_ = datetime.strptime(date_, "%d-%b-%Y")
    voucher_l = opening_accounts(date_, user.id_, db)
    voucher_b = opening_batches(date_, user.id_, db)
    starred_vouchers = save_starred(date_, db)
    db.flush()
    delete_data(date_, starred_vouchers, db)
    db.add(voucher_l)
    for j in voucher_l.journals:
        db.add(j)
    db.flush()
    db.add(voucher_b)
    for j in voucher_b.journals:
        db.add(j)
    for i in voucher_b.inventories:
        db.add(i)
    db.flush()
    cleanup_lint(date_, db)
    # request.dbsession.execute('RESET statement_timeout;')
    db.commit()
    return {}


def save_starred(date_: date, db: Session):
    accounts = [
        i.id
        for i in db.query(AccountBase.id).filter(AccountBase.is_starred == True).all()
    ]
    vouchers = []
    query = (
        db.query(Voucher)
        .options(joinedload_all(Voucher.journals, Journal.account, innerjoin=True))
        .filter(Voucher.date < date_)
        .filter(Voucher.journals.any(Journal.account_id.in_(accounts)))
        .all()
    )

    for voucher in query:
        vouchers.append(voucher.id)
        others = [
            journal
            for journal in voucher.journals
            if journal.account_id not in accounts
        ]
        if len(others) == 0:
            continue
        amount = round(Decimal(sum(o.signed_amount for o in others)), 2)
        if amount != 0:
            journal = Journal(
                amount=abs(amount),
                debit=-1 if amount < 0 else 1,
                account_id=AccountBase.suspense(),
                cost_centre_id=CostCentre.cost_centre_overall(),
            )
            voucher.journals.append(journal)
            db.add(journal)

        for other in others:
            if voucher.type != VoucherType.by_name("Opening Accounts").id:
                voucher.narration += (
                    f"\nSuspense \u20B9{other.amount:,.2f} is {other.account.name}"
                )
            if other.employee_benefit:
                db.delete(other.employee_benefit)
            if other.incentive:
                db.delete(other.incentive)
            db.delete(other)
        voucher.type = VoucherType.by_name("Journal")
        if len(voucher.narration) >= 1000:
            voucher.narration = voucher.narration[:1000]
    return vouchers


def opening_accounts(date_: date, user_id: uuid.UUID, db: Session):
    running_total = 0
    sum_func = func.sum(Journal.signed_amount)
    query = (
        db.query(AccountBase, sum_func)
        .join(Journal, Voucher.journals)
        .join(AccountBase, Journal.account)
        .filter(AccountBase.is_starred == False)
        .filter(AccountBase.id != AccountBase.suspense())
        .filter(Voucher.date < date_)
        .filter(Voucher.type != VoucherType.by_name("Issue").id)
        .having(sum_func != 0)
        .group_by(AccountBase)
        .all()
    )

    dt = date_ - timedelta(days=1)
    voucher = Voucher(
        date=dt,
        narration="Opening Accounts",
        user_id=user_id,
        posted=True,
        type_=VoucherType.by_name("Opening Accounts"),
    )
    for account, amount in query:
        amount = round(Decimal(amount), 2)
        if account.type_object.balance_sheet and amount != 0:
            running_total += amount
            journal = Journal(
                amount=abs(amount),
                debit=-1 if amount < 0 else 1,
                account_id=account.id,
                cost_centre_id=account.cost_centre_id,
            )
            voucher.journals.append(journal)
    if running_total != 0:
        journal = Journal(
            amount=abs(amount),
            debit=-1 if amount * -1 < 0 else 1,
            account_id=AccountBase.suspense(),
            cost_centre_id=CostCentre.cost_centre_overall(),
        )
        voucher.journals.append(journal)
    return voucher


def opening_batches(date_: date, user_id: uuid.UUID, db: Session):
    total = 0
    sum_func = func.sum(Journal.debit * Inventory.quantity)
    query = (
        db.query(Batch, sum_func)
        .join(Journal, Voucher.journals)
        .join(Inventory, Voucher.inventories)
        .join(Batch, Inventory.batch)
        .filter(Voucher.date < date_)
        .filter(Journal.cost_centre_id == CostCentre.cost_centre_purchase())
        .having(sum_func != 0)
        .group_by(Batch)
        .all()
    )

    dt = date_ - timedelta(days=1)
    voucher = Voucher(
        date=dt,
        narration="Opening Batches",
        user_id=user_id,
        posted=True,
        type_=VoucherType.by_name("Opening Batches"),
    )

    for batch, quantity in query:
        quantity = round(Decimal(quantity), 2)
        if quantity != 0:
            total += quantity * batch.rate * (1 + batch.tax) * (1 - batch.discount)
            inventory = Inventory(
                product_id=batch.product_id,
                batch=batch,
                quantity=quantity,
                rate=batch.rate,
                tax=batch.tax,
                discount=batch.discount,
            )
            voucher.inventories.append(inventory)
    voucher.journals.append(
        Journal(
            amount=abs(total),
            debit=-1,
            account_id=AccountBase.all_purchases(),
            cost_centre_id=CostCentre.cost_centre_overall(),
        )
    )
    voucher.journals.append(
        Journal(
            amount=abs(total),
            debit=1,
            account_id=AccountBase.all_purchases(),
            cost_centre_id=CostCentre.cost_centre_purchase(),
        )
    )
    return voucher


def delete_data(date_: date, vouchers: List[Voucher], db: Session):
    sub_voucher = aliased(Voucher)
    sub_query = db.query(sub_voucher.id).filter(sub_voucher.date < date_).subquery()

    db.execute(Inventory.__table__.delete(Inventory.voucher_id.in_(sub_query)))
    db.execute(
        EmployeeBenefit.__table__.delete(EmployeeBenefit.voucher_id.in_(sub_query))
    )
    db.execute(Incentive.__table__.delete(Incentive.voucher_id.in_(sub_query)))
    db.execute(
        Journal.__table__.delete(
            and_(Journal.voucher_id.in_(sub_query), ~Journal.voucher_id.in_(vouchers))
        )
    )
    db.execute(
        DbImage.__table__.delete(
            and_(
                DbImage.resource_type == "voucher",
                DbImage.resource_id.in_(sub_query),
                ~DbImage.resource_id.in_(vouchers),
            )
        )
    )
    db.execute(
        Voucher.__table__.delete(and_(Voucher.date < date_, ~Voucher.id.in_(vouchers)))
    )


def cleanup_lint(date_: date, db: Session):
    # Insert executes on the end so keep list of batches and journals
    db.execute(
        Batch.__table__.delete(
            ~Batch.id.in_(db.query(distinct(Inventory.batch_id)).subquery())
        )
    )
    db.execute(Fingerprint.__table__.delete(Fingerprint.date < date_))
    db.execute(Attendance.__table__.delete(Attendance.date < date_))
    db.execute(
        Employee.__table__.delete(
            and_(
                ~Employee.id.in_(db.query(distinct(Journal.account_id)).subquery()),
                ~Employee.id.in_(
                    db.query(distinct(Fingerprint.employee_id)).subquery()
                ),
                ~Employee.id.in_(db.query(distinct(Attendance.employee_id)).subquery()),
                Employee.id.in_(
                    db.query(AccountBase.id)
                    .filter(AccountBase.is_fixture == False)
                    .filter(AccountBase.is_active == False)
                    .filter(AccountBase.is_starred == False)
                    .subquery()
                ),
                Employee.leaving_date < date_,
            )
        )
    )
    db.execute(
        AccountBase.__table__.delete(
            and_(
                ~AccountBase.id.in_(db.query(Employee.id).subquery()),
                AccountBase.account_type
                == Employee.__mapper_args__["polymorphic_identity"],
            )
        )
    )
    db.execute(
        Account.__table__.delete(
            and_(
                ~Account.id.in_(db.query(distinct(Journal.account_id)).subquery()),
                Account.is_fixture == False,
                Account.is_starred == False,
                Account.account_type == Account.__mapper_args__["polymorphic_identity"],
            )
        )
    )