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#ifndef LIGHTNING_DAEMON_CHANNEL_H
#define LIGHTNING_DAEMON_CHANNEL_H
#include "config.h"
#include "bitcoin/locktime.h"
#include "daemon/htlc.h"
#include <assert.h>
#include <ccan/crypto/sha256/sha256.h>
#include <ccan/tal/tal.h>
#include <stdbool.h>
struct channel_oneside {
/* Payment and fee is in millisatoshi. */
uint32_t pay_msat, fee_msat;
/* Number of HTLCs (required for limiting total number) */
unsigned int num_htlcs;
};
struct channel_state {
/* Satoshis paid by anchor. */
uint64_t anchor;
/* Satoshis per 1000 bytes. */
uint64_t fee_rate;
/* Number of non-dust htlcs (to calculate txsize) */
unsigned int num_nondust;
struct channel_oneside side[2];
};
/**
* initial_cstate: Given initial fees and funding anchor, what is initial state?
* @ctx: tal context to allocate return value from.
* @anchor_satoshis: The anchor amount.
* @fee_rate: amount to pay in fees per kb (in satoshi).
* @dir: which side paid for the anchor.
*
* Returns state, or NULL if malformed.
*/
struct channel_state *initial_cstate(const tal_t *ctx,
uint64_t anchor_satoshis,
uint64_t fee_rate,
enum side side);
/**
* copy_cstate: Make a deep copy of channel_state
* @ctx: tal context to allocate return value from.
* @cstate: state to copy.
*/
struct channel_state *copy_cstate(const tal_t *ctx,
const struct channel_state *cstate);
/**
* cstate_add_htlc: append an HTLC to cstate if it can afford it
* @cstate: The channel state
* @htlc: the htlc pointer.
* @must_afford_fee: true if payer must meet fee.
*
* If that direction can't afford the HTLC this will return false and
* leave @cstate unchanged. If @must_afford_fee is true, and the
* direction can't afford its half of the fees, it will also return
* false and leave @cstate unchanged. Otherwise, pay_msat and fee_msat
* are adjusted accordingly; true is returned.
*/
bool cstate_add_htlc(struct channel_state *cstate, const struct htlc *htlc,
bool must_afford_fee);
/**
* cstate_fail_htlc: remove an HTLC, funds to the side which offered it.
* @cstate: The channel state
* @htlc: the htlc to remove.
*
* This will remove the @index'th entry in cstate->side[dir].htlcs[], and credit
* the value of the HTLC (back) to cstate->side[dir].
*/
void cstate_fail_htlc(struct channel_state *cstate, const struct htlc *htlc);
/**
* cstate_fulfill_htlc: remove an HTLC, funds to side which accepted it.
* @cstate: The channel state
* @htlc: the htlc to remove
*
* This will remove the @index'th entry in cstate->side[dir].htlcs[], and credit
* the value of the HTLC to cstate->side[!dir].
*/
void cstate_fulfill_htlc(struct channel_state *cstate, const struct htlc *htlc);
/**
* approx_max_feerate: what's the most side could raise fee rate to?
* @cstate: The channel state
* @side: LOCAL or REMOTE
*
* This is not exact! To check if their offer is valid, use can_afford_feerate.
*/
uint64_t approx_max_feerate(const struct channel_state *cstate,
enum side side);
/**
* can_afford_feerate: could this side pay for the fee if changed to fee_rate?
* @cstate: The channel state
* @fee_rate: the new fee rate proposed
* @side: LOCAL or REMOTE
*/
bool can_afford_feerate(const struct channel_state *cstate, uint64_t fee_rate,
enum side side);
/**
* adjust_fee: Change fee rate.
* @cstate: The channel state
* @fee_rate: fee in satoshi per 1000 bytes.
*/
void adjust_fee(struct channel_state *cstate, uint64_t fee_rate);
/**
* force_fee: Change fee to a specific value.
* @cstate: The channel state
* @fee: fee in satoshi.
*
* This is used for the close transaction, which specifies an exact fee.
* If the fee cannot be paid in full, this return false (but cstate will
* still be altered).
*/
bool force_fee(struct channel_state *cstate, uint64_t fee);
/**
* fee_for_feerate: calculate the fee (in satoshi) for a given fee_rate.
* @txsize: transaction size in bytes.
* @fee_rate: satoshi per 1000 bytes.
*/
uint64_t fee_by_feerate(size_t txsize, uint64_t fee_rate);
/**
* anchor_too_large: does anchor amount fit in 32-bits of millisatoshi.
* @anchor_satoshis: amount in satoshis
*/
bool anchor_too_large(uint64_t anchor_satoshis);
/* Routines to db to force HTLC changes out-of-order which may wrap. */
void force_add_htlc(struct channel_state *cstate, const struct htlc *htlc);
void force_fail_htlc(struct channel_state *cstate, const struct htlc *htlc);
void force_fulfill_htlc(struct channel_state *cstate, const struct htlc *htlc);
bool balance_after_force(struct channel_state *cstate);
#endif /* LIGHTNING_DAEMON_CHANNEL_H */