# ruff: noqa: N803
import hashlib
import hmac
import logging
import math

from fastapi import Depends, Form, HTTPException
from fastapi.routing import APIRouter
from sqlalchemy.ext.asyncio import AsyncSession

from config import cfg
from core.deps import get_db
from db.models.transactions import BalanceTxType
from external.pally import BillStatus
from repositories.invoices import InvoiceRepository
from repositories.users import UserRepository
from schemas.invoices import InvoiceStatus

router = APIRouter(prefix="/payments/pally")

logger = logging.getLogger(__name__)


@router.post("/result")
async def pally_callback(  # noqa: PLR0911
    *,
    InvId: str = Form(...),
    OutSum: str = Form(...),
    Commission: str = Form(...),
    TrsId: str = Form(...),
    Status: str = Form(...),
    CurrencyIn: str = Form(...),
    custom: str | None = Form(None),
    SignatureValue: str = Form(...),
    # Optional fields for additional information
    AccountType: str | None = Form(None),
    AccountNumber: str | None = Form(None),
    BalanceAmount: str | None = Form(None),
    BalanceCurrency: str | None = Form(None),
    PayerPhone: str | None = Form(None),
    PayerEmail: str | None = Form(None),
    PayerName: str | None = Form(None),
    PayerComment: str | None = Form(None),
    ErrorCode: int | None = Form(None),
    ErrorMessage: str | None = Form(None),
    session: AsyncSession = Depends(get_db),
):
    users_repo = UserRepository(session)
    invoice_repo = InvoiceRepository(session)
    invoice_id_str = InvId

    logger.info(
        "Pally webhook received - InvId: %s, OutSum: %s, Commission: %s, TrsId: %s, Status: %s, "
        "CurrencyIn: %s, custom: %s, BalanceAmount: %s, SignatureValue: %s",
        InvId,
        OutSum,
        Commission,
        TrsId,
        Status,
        CurrencyIn,
        custom,
        BalanceAmount,
        SignatureValue,
    )

    if Status != BillStatus.SUCCESS:
        logger.warning(
            "Non-success payment received - Status: %s, ErrorCode: %s, ErrorMessage: %s, TrsId: %s",
            Status,
            ErrorCode,
            ErrorMessage,
            TrsId,
        )

    # Validate signature
    raw_string = f"{OutSum}:{InvId}:{cfg.pally_token}"
    expected_signature = hashlib.md5(raw_string.encode("utf-8")).hexdigest().upper()

    logger.debug("Signature validation for TrsId %s", TrsId)

    if not hmac.compare_digest(SignatureValue, expected_signature):
        logger.critical(
            "SECURITY ALERT: Invalid signature for TrsId %s - Expected: %s, Received: %s",
            TrsId,
            expected_signature,
            SignatureValue,
        )
        raise HTTPException(403, detail="Invalid signature.")

    # Only process successful payments
    if Status != BillStatus.SUCCESS:
        logger.info("Bill %s skipped: status=%s", TrsId, Status)
        return "OK"

    logger.info("Processing successfully paid bill %s", TrsId)

    # Validate bill ID (from InvId field, which contains the order_id from bill creation)
    if not invoice_id_str or not invoice_id_str.isdigit():
        logger.critical(
            "Invalid or non-numeric bill ID in InvId field for TrsId %s: '%s'",
            TrsId,
            invoice_id_str,
        )
        return "OK"

    # Find bill in database
    invoice = await invoice_repo.get_by_id(int(invoice_id_str))

    if not invoice:
        logger.critical("Bill %s not found in database for TrsId %s", invoice_id_str, TrsId)
        return "OK"

    # Check if already processed
    if invoice.status != InvoiceStatus.ACTIVE:
        logger.warning(
            "Bill %s (TrsId: %s) is already processed with status: %s",
            invoice.id,
            TrsId,
            invoice.status,
        )
        return "OK"

    try:
        # Handle fee scenarios: use BalanceAmount if available (net amount after fees),
        # otherwise use OutSum (gross amount paid by customer)
        if BalanceAmount is not None:
            # Customer pays fees - BalanceAmount is the net amount credited to merchant
            credited_amount = int(float(BalanceAmount))
            gross_amount = int(float(OutSum))

            logger.info(
                "Customer-pays-fees payment: bill_id=%s, expected=%s, gross_paid=%s, net_credited=%s",
                invoice.id,
                invoice.amount,
                gross_amount,
                credited_amount,
            )

            # Validate that the net credited amount matches our bill amount
            if invoice.amount != credited_amount:
                logger.error(
                    "Net amount mismatch for bill %s (TrsId: %s) - Expected: %s, Net credited: %s, Gross paid: %s",
                    invoice.id,
                    TrsId,
                    invoice.amount,
                    credited_amount,
                    gross_amount,
                )
                return "OK"

            amount = credited_amount  # Credit the net amount (without fees)

        else:
            # Standard payment - OutSum should match bill amount exactly
            amount = int(float(OutSum))

            logger.info(
                "Standard payment: bill_id=%s, expected=%s, received=%s",
                invoice.id,
                invoice.amount,
                amount,
            )

            if invoice.amount != amount:
                logger.error(
                    "Amount mismatch for bill %s (TrsId: %s) - Expected: %s, Received: %s",
                    invoice.id,
                    TrsId,
                    invoice.amount,
                    amount,
                )
                return "OK"

        logger.info(
            "Processing payment: bill_id=%s, user_id=%s, amount=%s",
            invoice.id,
            invoice.creator_id,
            amount,
        )

        # Credit user balance
        await users_repo.increase_balance(
            invoice.creator_id,
            amount=amount,
            tx_type=BalanceTxType.DEPOSIT,
            description=f"payment via PALLY (TrsId: {TrsId})",
        )

        # Process referral bonus
        user = invoice.creator
        referal = user.referal
        if referal is not None:
            referal_amount = math.floor(amount * (cfg.referal_bonus / 100))
            await users_repo.increase_balance(
                referal,
                referal_amount,
                tx_type=BalanceTxType.REFERRAL_BONUS,
                description=f"referral reward for user {invoice.creator_id} (TrsId: {TrsId})",
            )
            logger.info(
                "Referral bonus processed: referrer_id=%s, amount=%s", referal, referal_amount
            )

        logger.info("Payment processing completed successfully for TrsId %s", TrsId)

    except Exception as e:
        logger.exception(
            "CRITICAL ERROR processing payment for TrsId %s, bill_id %s, user_id %s: %s",
            TrsId,
            invoice.id,
            invoice.creator_id,
            str(e),
        )
        # Don't return early - still mark as success to prevent retries
        # The balance operation might have partially succeeded

    # Update bill status to success
    await invoice_repo.update_status_by_id(int(invoice.id), status=InvoiceStatus.PAID)

    logger.info("Bill %s marked as SUCCESS for TrsId %s", invoice.id, TrsId)

    return "OK"