import uuid

from datetime import date, datetime

import brewman.schemas.reports as schemas

from fastapi import APIRouter, Depends, Request, Security
from sqlalchemy.orm import Session, joinedload
from sqlalchemy.sql.expression import func

from ...core.security import get_current_active_user as get_user
from ...core.session import get_finish_date, get_start_date, set_period
from ...db.session import SessionLocal
from ...models.master import CostCentre, Product
from ...models.voucher import Inventory, Journal, Voucher, VoucherType
from ...schemas.auth import UserToken


router = APIRouter()


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


@router.get("", response_model=schemas.ProductLedger)
def show_blank(
    request: Request,
    user: UserToken = Security(get_user, scopes=["product-ledger"]),
):
    return {
        "startDate": get_start_date(request.session),
        "finishDate": get_finish_date(request.session),
        "product": None,
        "body": [],
    }


@router.get("/{id_}", response_model=schemas.ProductLedger)
def show_data(
    id_: uuid.UUID,
    request: Request,
    s: str = None,
    f: str = None,
    db: Session = Depends(get_db),
    user: UserToken = Security(get_user, scopes=["product-ledger"]),
):
    product = db.query(Product).filter(Product.id == id_).first()
    start_date = s if s is not None else get_start_date(request.session)
    finish_date = f if f is not None else get_finish_date(request.session)
    body = build_report(
        product.id,
        datetime.strptime(start_date, "%d-%b-%Y"),
        datetime.strptime(finish_date, "%d-%b-%Y"),
        db,
    )
    set_period(start_date, finish_date, request.session)
    return {
        "startDate": start_date,
        "finishDate": finish_date,
        "product": {"id": product.id, "name": product.name},
        "body": body,
    }


def build_report(
    product_id: uuid.UUID, start_date: date, finish_date: date, db: Session
):
    body = []
    running_total_q, running_total_a, opening = opening_balance(
        product_id, start_date, db
    )
    body.append(opening)

    query = (
        db.query(Voucher, Inventory, Journal)
        .options(
            joinedload(Journal.account, innerjoin=True),
            joinedload(Journal.cost_centre, innerjoin=True),
        )
        .filter(Voucher.id == Inventory.voucher_id)
        .filter(Voucher.id == Journal.voucher_id)
        .filter(Inventory.product_id == product_id)
        .filter(Journal.cost_centre_id != CostCentre.cost_centre_purchase())
        .filter(Voucher.date >= start_date)
        .filter(Voucher.date <= finish_date)
        .order_by(Voucher.date)
        .order_by(Voucher.last_edit_date)
        .all()
    )

    for row in query:
        journal_debit = row.Journal.debit * -1
        name = (
            row.Journal.cost_centre.name
            if row.Voucher.type == VoucherType.by_name("Issue").id
            else row.Journal.account.name
        )
        debit_q = row.Inventory.quantity if journal_debit == 1 else None
        debit_a = row.Inventory.amount if journal_debit == 1 else None
        credit_q = row.Inventory.quantity if journal_debit != 1 else None
        credit_a = row.Inventory.amount if journal_debit != 1 else None

        running_total_q += row.Inventory.quantity * journal_debit
        running_total_a += row.Inventory.amount * journal_debit

        body.append(
            {
                "id": row.Voucher.id,
                "date": row.Voucher.date.strftime("%d-%b-%Y"),
                "name": name,
                "url": [
                    "/",
                    VoucherType.by_id(row.Voucher.type).name.replace(" ", "-").lower(),
                    str(row.Voucher.id),
                ],
                "type": VoucherType.by_id(row.Voucher.type).name,
                "narration": row.Voucher.narration,
                "posted": row.Voucher.posted
                or VoucherType.by_id(row.Voucher.type).name == "Issue",
                "debitQuantity": debit_q,
                "debitAmount": debit_a,
                "creditQuantity": credit_q,
                "creditAmount": credit_a,
                "runningQuantity": running_total_q,
                "runningAmount": running_total_a,
            }
        )

    return body


def opening_balance(product_id: uuid.UUID, start_date: date, db: Session):
    quantity, amount = (
        db.query(
            func.sum(Inventory.quantity * Journal.debit),
            func.sum(Inventory.amount * Journal.debit),
        )
        .join(Inventory.voucher)
        .join(Voucher.journals)
        .filter(Voucher.id == Inventory.voucher_id)
        .filter(Voucher.id == Journal.voucher_id)
        .filter(Inventory.product_id == product_id)
        .filter(Journal.cost_centre_id == CostCentre.cost_centre_purchase())
        .filter(Voucher.date < start_date)
        .one()
    )

    if quantity and quantity > 0:
        debit_quantity = quantity
        debit_amount = amount
    else:
        debit_quantity = None
        debit_amount = None

    if quantity is None:
        quantity = 0
        amount = 0

    return (
        quantity,
        amount,
        {
            "id": None,
            "date": start_date.strftime("%d-%b-%Y"),
            "name": "Opening Balance",
            "url": [],
            "type": "Opening Balance",
            "narration": "",
            "posted": True,
            "debitQuantity": debit_quantity,
            "debitAmount": debit_amount,
            "creditQuantity": 0,
            "creditAmount": 0,
            "runningQuantity": quantity,
            "runningAmount": amount,
        },
    )