#include <common/wallet_tx.h>
#include <inttypes.h>
#include <lightningd/jsonrpc_errors.h>
#include <wallet/wallet.h>

void wtx_init(struct command *cmd, struct wallet_tx * wtx)
{
	wtx->cmd = cmd;
	wtx->amount = 0;
	wtx->change_key_index = 0;
	wtx->utxos = NULL;
	wtx->all_funds = false;
}

static bool check_amount(const struct wallet_tx *tx, u64 amount)
{
	if (!tx->utxos) {
		command_fail(tx->cmd, FUND_CANNOT_AFFORD,
			     "Cannot afford transaction");
		return false;
	}
	if (amount < 546) {
		command_fail(tx->cmd, FUND_OUTPUT_IS_DUST,
			     "Output %"PRIu64" satoshis would be dust",
			     amount);
		return false;
	}
	return true;
}

bool wtx_select_utxos(struct wallet_tx * tx, u32 fee_rate_per_kw,
	              size_t out_len)
{
	u64 fee_estimate;
	if (tx->all_funds) {
		u64 amount;
		tx->utxos = wallet_select_all(tx->cmd, tx->cmd->ld->wallet,
					      fee_rate_per_kw, out_len,
					      &amount,
					      &fee_estimate);
		if (!check_amount(tx, amount))
			return false;

		if (amount <= tx->amount) {
			tx->change = 0;
			tx->amount = amount;
			return true;
		}

		/* Too much?  Try again, but ask for limit instead. */
		tx->all_funds = false;
		tx->utxos = tal_free(tx->utxos);
	}

	tx->utxos = wallet_select_coins(tx->cmd, tx->cmd->ld->wallet,
					tx->amount,
					fee_rate_per_kw, out_len,
					&fee_estimate, &tx->change);
	if (!check_amount(tx, tx->amount))
		return false;

	if (tx->change < 546) {
		tx->change = 0;
		tx->change_key_index = 0;
	} else {
		tx->change_key_index = wallet_get_newindex(tx->cmd->ld);
	}
	return true;
}