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/*
* This file is part of LibEuFin.
* Copyright (C) 2023 Taler Systems S.A.
* LibEuFin is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation; either version 3, or
* (at your option) any later version.
* LibEuFin is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General
* Public License for more details.
* You should have received a copy of the GNU Affero General Public
* License along with LibEuFin; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>
*/
package tech.libeufin.bank.db
import tech.libeufin.bank.ConversionRate
import tech.libeufin.bank.RoundingMode
import tech.libeufin.common.*
import tech.libeufin.common.db.*
/** Data access logic for conversion */
class ConversionDAO(private val db: Database) {
/** Update in-db conversion config */
suspend fun updateConfig(cfg: ConversionRate) = db.serializable {
it.transaction { conn ->
var stmt = conn.prepareStatement("CALL config_set_amount(?, (?, ?)::taler_amount)")
for ((name, amount) in listOf(
Pair("cashin_ratio", cfg.cashin_ratio),
Pair("cashout_ratio", cfg.cashout_ratio),
)) {
stmt.setString(1, name)
stmt.setLong(2, amount.value)
stmt.setInt(3, amount.frac)
stmt.executeUpdate()
}
for ((name, amount) in listOf(
Pair("cashin_fee", cfg.cashin_fee),
Pair("cashin_tiny_amount", cfg.cashin_tiny_amount),
Pair("cashin_min_amount", cfg.cashin_min_amount),
Pair("cashout_fee", cfg.cashout_fee),
Pair("cashout_tiny_amount", cfg.cashout_tiny_amount),
Pair("cashout_min_amount", cfg.cashout_min_amount),
)) {
stmt.setString(1, name)
stmt.setLong(2, amount.value)
stmt.setInt(3, amount.frac)
stmt.executeUpdate()
}
stmt = conn.prepareStatement("CALL config_set_rounding_mode(?, ?::rounding_mode)")
for ((name, value) in listOf(
Pair("cashin_rounding_mode", cfg.cashin_rounding_mode),
Pair("cashout_rounding_mode", cfg.cashout_rounding_mode)
)) {
stmt.setString(1, name)
stmt.setString(2, value.name)
stmt.executeUpdate()
}
}
}
/** Get in-db conversion config */
suspend fun getConfig(regional: String, fiat: String): ConversionRate? = db.conn {
it.transaction { conn ->
val check = conn.prepareStatement("select exists(select 1 from config where key='cashin_ratio')").oneOrNull { it.getBoolean(1) }!!
if (!check) return@transaction null
val amount = conn.prepareStatement("SELECT (amount).val as amount_val, (amount).frac as amount_frac FROM config_get_amount(?) as amount")
val roundingMode = conn.prepareStatement("SELECT config_get_rounding_mode(?)")
fun getAmount(name: String, currency: String): TalerAmount {
amount.setString(1, name)
return amount.oneOrNull { it.getAmount("amount", currency) }!!
}
fun getRatio(name: String): DecimalNumber = getAmount(name, "").run { DecimalNumber(value, frac) }
fun getMode(name: String): RoundingMode {
roundingMode.setString(1, name)
return roundingMode.oneOrNull { RoundingMode.valueOf(it.getString(1)) }!!
}
ConversionRate(
cashin_ratio = getRatio("cashin_ratio"),
cashin_fee = getAmount("cashin_fee", regional),
cashin_tiny_amount = getAmount("cashin_tiny_amount", regional),
cashin_rounding_mode = getMode("cashin_rounding_mode"),
cashin_min_amount = getAmount("cashin_min_amount", fiat),
cashout_ratio = getRatio("cashout_ratio"),
cashout_fee = getAmount("cashout_fee", fiat),
cashout_tiny_amount = getAmount("cashout_tiny_amount", fiat),
cashout_rounding_mode = getMode("cashout_rounding_mode"),
cashout_min_amount = getAmount("cashout_min_amount", regional),
)
}
}
/** Clear in-db conversion config */
suspend fun clearConfig() = db.serializable { conn ->
conn.prepareStatement("DELETE FROM config WHERE key LIKE 'cashin%' OR key like 'cashout%'").executeUpdate()
}
/** Result of conversions operations */
sealed interface ConversionResult {
data class Success(val converted: TalerAmount): ConversionResult
data object ToSmall: ConversionResult
data object MissingConfig: ConversionResult
}
/** Perform [direction] conversion of [amount] using in-db [function] */
private suspend fun conversion(amount: TalerAmount, direction: String, function: String): ConversionResult = db.conn { conn ->
val stmt = conn.prepareStatement("SELECT too_small, no_config, (converted).val AS amount_val, (converted).frac AS amount_frac FROM $function((?, ?)::taler_amount, ?, (0, 0)::taler_amount)")
stmt.setLong(1, amount.value)
stmt.setInt(2, amount.frac)
stmt.setString(3, direction)
stmt.executeQuery().use {
when {
!it.next() ->
throw internalServerError("No result from DB procedure $function")
it.getBoolean("no_config") -> ConversionResult.MissingConfig
it.getBoolean("too_small") -> ConversionResult.ToSmall
else -> ConversionResult.Success(
it.getAmount("amount", if (amount.currency == db.bankCurrency) db.fiatCurrency!! else db.bankCurrency)
)
}
}
}
/** Convert [regional] amount to fiat using cashout rate */
suspend fun toCashout(regional: TalerAmount): ConversionResult = conversion(regional, "cashout", "conversion_to")
/** Convert [fiat] amount to regional using cashin rate */
suspend fun toCashin(fiat: TalerAmount): ConversionResult = conversion(fiat, "cashin", "conversion_to")
/** Convert [fiat] amount to regional using inverse cashout rate */
suspend fun fromCashout(fiat: TalerAmount): ConversionResult = conversion(fiat, "cashout", "conversion_from")
/** Convert [regional] amount to fiat using inverse cashin rate */
suspend fun fromCashin(regional: TalerAmount): ConversionResult = conversion(regional, "cashin", "conversion_from")
}
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