package postgres

import (
	"context"
	"time"

	"git.gocasts.ir/ebhomengo/niki/domain/wallet/entity"
	"git.gocasts.ir/ebhomengo/niki/pkg/database/postgres"
	errmsg "git.gocasts.ir/ebhomengo/niki/pkg/err_msg"
	richerror "git.gocasts.ir/ebhomengo/niki/pkg/rich_error"
	"git.gocasts.ir/ebhomengo/niki/pkg/types"
	"github.com/shopspring/decimal"
)

func (db *DB) InsertTransaction(ctx context.Context, transaction entity.Transaction, currencyRate decimal.Decimal) (balance decimal.Decimal, currency types.Currency, err error) {
	const op = richerror.Op("wallet.repo.InsertTransaction")

	// TODO : USE TX INSTANT QUERY

	query := `INSERT INTO  Transactions (user_id, amount ,currency ,action_type, timestamp) values ($1, $2, $3, $4, $5)`

	stmt, stErr := db.conn.PrepareStatement(ctx, postgres.StatementKeyWalletInsertTransaction, query)
	if stErr != nil {
		err = richerror.New(op).WithErr(stErr).WithKind(richerror.KindUnexpected)
		return
	}

	txHolder, newCtx := postgres.GetDBTxHolderFromContextOrNew(ctx)
	tx, txErr := txHolder.BeginTx(newCtx, db.conn.Conn())
	if txErr != nil {
		err = richerror.New(op).WithErr(txErr).WithKind(richerror.KindUnexpected)
		return
	}

	defer func() {
		if tx != nil {
			if err != nil {
				if rbErr := tx.Rollback(); rbErr != nil {
					// log rbErr
				}
			} else if cErr := tx.Commit(); cErr != nil {
				// log cErr
			}

		}

	}()

	params := []any{transaction.UserID, transaction.Amount, transaction.Currency, transaction.ActionType, transaction.Timestamp}

	_, execErr := tx.StmtExecContext(newCtx, stmt, params...)
	if execErr != nil {
		err = richerror.New(op).WithErr(execErr).WithKind(richerror.KindUnexpected).WithMessage(errmsg.ErrorMsgFailedQuery)

		return
	}

	newBalance, walletCurrency, balanceErr := db.UpsertBalance(newCtx, transaction, currencyRate)
	if balanceErr != nil {
		err = richerror.New(op).WithErr(balanceErr)
		return

	}

	balance = newBalance
	currency = walletCurrency
	return
}

func (db *DB) UpsertBalance(newCtx context.Context, transaction entity.Transaction, currencyRate decimal.Decimal) (balance decimal.Decimal, currency types.Currency, err error) {
	const op = richerror.Op("wallet.repo.UpdateBalance")

	txHolder, _ := postgres.GetDBTxHolderFromContextOrNew(newCtx)
	tx, txErr := txHolder.Conn()

	if txErr != nil {
		err = richerror.New(op).WithMessage(errmsg.ErrorMsgFailedQuery).WithKind(richerror.KindUnexpected)
		return
	}

	if tx == nil {
		err = richerror.New(op).WithMessage(errmsg.ErrorMsgFailedQuery).WithKind(richerror.KindUnexpected)
		return
	}

	upsertQuery := `INSERT INTO wallets (user_id, balance ,  updated_at) VALUES ($1,$2,$3 )
	ON CONFLICT (user_id) DO UPDATE SET balance = wallets.balance + $2
	RETURNING balance , currency`

	upsertStmt, stErr := db.conn.PrepareStatement(newCtx, postgres.StatementKeyWalletUpsertBalance, upsertQuery)
	if stErr != nil {
		err = richerror.New(op).WithMessage(errmsg.ErrorMsgFailedQuery).WithKind(richerror.KindUnexpected)
		return
	}
	amount := transaction.Amount.Mul(currencyRate)
	row := tx.StmtQueryRowContext(newCtx, upsertStmt, transaction.UserID, amount, time.Now())

	sErr := row.Scan(&balance, &currency)
	if sErr != nil {
		err = richerror.New(op).WithMessage(errmsg.ErrorMsgCantScanQueryResult).WithKind(richerror.KindUnexpected)
		return
	}

	return
}