core-lightning/wallet/wallet.h

#ifndef LIGHTNING_WALLET_WALLET_H
#define LIGHTNING_WALLET_WALLET_H

#include "config.h"
#include "db.h"
#include <common/penalty_base.h>
#include <common/utxo.h>
#include <common/wallet.h>
#include <lightningd/bitcoind.h>
#include <lightningd/log.h>
#include <lightningd/peer_htlcs.h>

struct amount_msat;
struct invoices;
struct channel;
struct channel_inflight;
struct lightningd;
struct node_id;
struct oneshot;
struct peer;
struct timers;
enum channel_state;
enum state_change;

struct wallet {
	struct lightningd *ld;
	struct db *db;
	struct log *log;
	struct ext_key *bip32_base;
	struct invoices *invoices;
	struct list_head unstored_payments;
	u64 max_channel_dbid;

	/* Filter matching all outpoints corresponding to our owned outputs,
	 * including all spent ones */
	struct outpointfilter *owned_outpoints;

	/* Filter matching all outpoints that might be a funding transaction on
	 * the blockchain. This is currently all P2WSH outputs */
	struct outpointfilter *utxoset_outpoints;

	/* How many keys should we look ahead at most? */
	u64 keyscan_gap;
};

static inline enum output_status output_status_in_db(enum output_status s)
{
	switch (s) {
	case OUTPUT_STATE_AVAILABLE:
		BUILD_ASSERT(OUTPUT_STATE_AVAILABLE == 0);
		return s;
	case OUTPUT_STATE_RESERVED:
		BUILD_ASSERT(OUTPUT_STATE_RESERVED == 1);
		return s;
	case OUTPUT_STATE_SPENT:
		BUILD_ASSERT(OUTPUT_STATE_SPENT == 2);
		return s;
	/* This one doesn't go into db */
	case OUTPUT_STATE_ANY:
		break;
	}
	fatal("%s: %u is invalid", __func__, s);
}

/* Enumeration of all known output types. These include all types that
 * could ever end up on-chain and we may need to react upon. Notice
 * that `to_local`, `htlc_offer`, and `htlc_recv` may need immediate
 * action since they are encumbered with a CSV. */
/* /!\ This is a DB ENUM, please do not change the numbering of any
 * already defined elements (adding is ok) /!\ */
enum wallet_output_type {
	p2sh_wpkh = 0,
	to_local = 1,
	htlc_offer = 3,
	htlc_recv = 4,
	our_change = 5,
	p2wpkh = 6
};

static inline enum wallet_output_type wallet_output_type_in_db(enum wallet_output_type w)
{
	switch (w) {
	case p2sh_wpkh:
		BUILD_ASSERT(p2sh_wpkh == 0);
		return w;
	case to_local:
		BUILD_ASSERT(to_local == 1);
		return w;
	case htlc_offer:
		BUILD_ASSERT(htlc_offer == 3);
		return w;
	case htlc_recv:
		BUILD_ASSERT(htlc_recv == 4);
		return w;
	case our_change:
		BUILD_ASSERT(our_change == 5);
		return w;
	case p2wpkh:
		BUILD_ASSERT(p2wpkh == 6);
		return w;
	}
	fatal("%s: %u is invalid", __func__, w);
}

/**
 * Possible states for forwards
 *
 */
/* /!\ This is a DB ENUM, please do not change the numbering of any
 * already defined elements (adding is ok) /!\ */
enum forward_status {
	FORWARD_OFFERED = 0,
	FORWARD_SETTLED = 1,
	FORWARD_FAILED = 2,
	FORWARD_LOCAL_FAILED = 3,
	/* Special status used to express that we don't care in
	 * queries */
	FORWARD_ANY = 255

};

static inline enum forward_status wallet_forward_status_in_db(enum forward_status s)
{
	switch (s) {
	case FORWARD_OFFERED:
		BUILD_ASSERT(FORWARD_OFFERED == 0);
		return s;
	case FORWARD_SETTLED:
		BUILD_ASSERT(FORWARD_SETTLED == 1);
		return s;
	case FORWARD_FAILED:
		BUILD_ASSERT(FORWARD_FAILED == 2);
		return s;
	case FORWARD_LOCAL_FAILED:
		BUILD_ASSERT(FORWARD_LOCAL_FAILED == 3);
		return s;
	case FORWARD_ANY:
		break;
	}
	fatal("%s: %u is invalid", __func__, s);
}

static inline const char* forward_status_name(enum forward_status status)
{
	switch(status) {
	case FORWARD_OFFERED:
		return "offered";
	case FORWARD_SETTLED:
		return "settled";
	case FORWARD_FAILED:
		return "failed";
	case FORWARD_LOCAL_FAILED:
		return "local_failed";
	case FORWARD_ANY:
		return "any";
	}
	abort();
}

bool string_to_forward_status(const char *status_str, enum forward_status *status);

struct forwarding {
	struct short_channel_id channel_in, channel_out;
	struct amount_msat msat_in, msat_out, fee;
	struct sha256 *payment_hash;
	enum forward_status status;
	enum onion_wire failcode;
	struct timeabs received_time;
	/* May not be present if the HTLC was not resolved yet. */
	struct timeabs *resolved_time;
};

/* A database backed shachain struct. The datastructure is
 * writethrough, reads are performed from an in-memory version, all
 * writes are passed through to the DB. */
struct wallet_shachain {
	u64 id;
	struct shachain chain;
};

/* Possible states for a wallet_payment. Payments start in
 * `PENDING`. Outgoing payments are set to `PAYMENT_COMPLETE` once we
 * get the preimage matching the rhash, or to
 * `PAYMENT_FAILED`. */
/* /!\ This is a DB ENUM, please do not change the numbering of any
 * already defined elements (adding is ok but you should append the
 * test case test_wallet_payment_status_enum() ) /!\ */
enum wallet_payment_status {
	PAYMENT_PENDING = 0,
	PAYMENT_COMPLETE = 1,
	PAYMENT_FAILED = 2
};

struct tx_annotation {
	enum wallet_tx_type type;
	struct short_channel_id channel;
};

static inline enum wallet_payment_status wallet_payment_status_in_db(enum wallet_payment_status w)
{
	switch (w) {
	case PAYMENT_PENDING:
		BUILD_ASSERT(PAYMENT_PENDING == 0);
		return w;
	case PAYMENT_COMPLETE:
		BUILD_ASSERT(PAYMENT_COMPLETE == 1);
		return w;
	case PAYMENT_FAILED:
		BUILD_ASSERT(PAYMENT_FAILED == 2);
		return w;
	}
	fatal("%s: %u is invalid", __func__, w);
}

/* Outgoing payments. A simple persisted representation
 * of a payment we initiated. This can be used by
 * a UI (alongside invoices) to display the balance history.
 */
struct wallet_payment {
	/* If it's in unstored_payments */
	struct list_node list;
	u64 id;
	u32 timestamp;

	/* The combination of these three fields is unique: */
	struct sha256 payment_hash;
	u64 partid;
	u64 groupid;

	enum wallet_payment_status status;

	/* The destination may not be known if we used `sendonion` */
	struct node_id *destination;
	struct amount_msat msatoshi;
	struct amount_msat msatoshi_sent;
	struct amount_msat total_msat;
	/* If and only if PAYMENT_COMPLETE */
	struct preimage *payment_preimage;
	/* Needed for recovering from routing failures. */
	struct secret *path_secrets;
	struct node_id *route_nodes;
	struct short_channel_id *route_channels;
	/* bolt11/bolt12 string; NULL for old payments. */
	const char *invstring;

	/* The label of the payment. Must support `tal_len` */
	const char *label;

	/* If we could not decode the fail onion, just add it here. */
	const u8 *failonion;

	/* If we are associated with an internal offer */
	struct sha256 *local_offer_id;
};

struct outpoint {
	struct bitcoin_txid txid;
	u32 blockheight;
	u32 txindex;
	u32 outnum;
	struct amount_sat sat;
	u8 *scriptpubkey;
	u32 spendheight;
};

/* Statistics for a channel */
struct channel_stats {
	u64  in_payments_offered,  in_payments_fulfilled;
	struct amount_msat  in_msatoshi_offered,  in_msatoshi_fulfilled;
	u64 out_payments_offered, out_payments_fulfilled;
	struct amount_msat out_msatoshi_offered, out_msatoshi_fulfilled;
};

struct channeltx {
	u32 channel_id;
	int type;
	u32 blockheight;
	struct bitcoin_txid txid;
	struct bitcoin_tx *tx;
	u32 input_num;
	u32 depth;
};

struct wallet_transaction {
	struct bitcoin_txid id;
	u32 blockheight;
	u32 txindex;
	u8 *rawtx;

	/* Fully parsed transaction */
	const struct bitcoin_tx *tx;

	struct tx_annotation annotation;

	/* tal_arr containing the annotation types, if any, for the respective
	 * inputs and outputs. 0 if there are no annotations for the
	 * element. */
	struct tx_annotation *input_annotations;
	struct tx_annotation *output_annotations;
};

/**
 * wallet_new - Constructor for a new DB based wallet
 *
 * This is guaranteed to either return a valid wallet, or abort with
 * `fatal` if it cannot be initialized.
 */
struct wallet *wallet_new(struct lightningd *ld, struct timers *timers,
			  struct ext_key *bip32_base);

/**
 * wallet_confirm_tx - Confirm a tx which contains a UTXO.
 */
void wallet_confirm_tx(struct wallet *w,
		       const struct bitcoin_txid *txid,
		       const u32 confirmation_height);

/**
 * wallet_update_output_status - Perform an output state transition
 *
 * Change the current status of an output we are tracking in the
 * database. Returns true if the output exists with the @oldstatus and
 * was successfully updated to @newstatus. May fail if either the
 * output does not exist, or it does not have the expected
 * @oldstatus. In case we don't care about the previous state use
 * `output_state_any` as @oldstatus.
 */
bool wallet_update_output_status(struct wallet *w,
				 const struct bitcoin_txid *txid,
				 const u32 outnum, enum output_status oldstatus,
				 enum output_status newstatus);

/**
 * wallet_get_utxos - Retrieve all utxos matching a given state
 *
 * Returns a `tal_arr` of `utxo` structs. Double indirection in order
 * to be able to steal individual elements onto something else.
 */
struct utxo **wallet_get_utxos(const tal_t *ctx, struct wallet *w,
			      const enum output_status state);


/**
 * wallet_get_unconfirmed_closeinfo_utxos - Retrieve any unconfirmed utxos w/ closeinfo
 *
 * Returns a `tal_arr` of `utxo` structs. Double indirection in order
 * to be able to steal individual elements onto something else.
 */
struct utxo **wallet_get_unconfirmed_closeinfo_utxos(const tal_t *ctx,
						     struct wallet *w);

/**
 * wallet_find_utxo - Select an available UTXO (does not reserve it!).
 * @ctx: tal context
 * @w: wallet
 * @current_blockheight: current chain length.
 * @amount_we_are_short: optional amount.
 * @feerate_per_kw: feerate we are using.
 * @maxheight: zero (if caller doesn't care) or maximum blockheight to accept.
 * @excludes: UTXOs not to consider.
 *
 * If @amount_we_are_short is not NULL, we try to get something very close
 * (i.e. when we add this input, we will add => @amount_we_are_short, but
 * less than @amount_we_are_short + dustlimit).
 *
 * Otherwise we give a random UTXO.
 */
struct utxo *wallet_find_utxo(const tal_t *ctx, struct wallet *w,
			      unsigned current_blockheight,
			      struct amount_sat *amount_we_are_short,
			      unsigned feerate_per_kw,
			      u32 maxheight,
			      const struct utxo **excludes);

/**
 * wallet_add_onchaind_utxo - Add a UTXO with spending info from onchaind.
 *
 * Usually we add UTXOs by looking at transactions, but onchaind tells
 * us about other UTXOs we can spend with some extra metadata.
 *
 * Returns false if we already have it in db (that's fine).
 */
bool wallet_add_onchaind_utxo(struct wallet *w,
			      const struct bitcoin_txid *txid,
			      u32 outnum,
			      const u8 *scriptpubkey,
			      u32 blockheight,
			      struct amount_sat amount,
			      const struct channel *chan,
			      /* NULL if option_static_remotekey */
			      const struct pubkey *commitment_point,
			      /* option_will_fund makes the csv_lock variable */
			      u32 csv_lock);

/**
 * wallet_reserve_utxo - set a reservation on a UTXO.
 *
 * If the reservation is already reserved:
 *   refreshes the reservation by @reserve, return true.
 * Otherwise if it's available:
 *   reserves until @current_height + @reserve, returns true.
 * Otherwise:
 *   returns false.
 */
bool wallet_reserve_utxo(struct wallet *w,
			 struct utxo *utxo,
			 u32 current_height,
			 u32 reserve);

/* wallet_unreserve_utxo - make a reserved UTXO available again.
 *
 * Must be reserved.
 */
void wallet_unreserve_utxo(struct wallet *w, struct utxo *utxo,
			   u32 current_height, u32 unreserve);

/** wallet_utxo_get - Retrive a utxo.
 *
 * Returns a utxo, or NULL if not found.
 */
struct utxo *wallet_utxo_get(const tal_t *ctx, struct wallet *w,
			     const struct bitcoin_txid *txid,
			     u32 outnum);

/**
 * wallet_select_specific - Select utxos given an array of txids and an array of outputs index
 *
 * Returns an array of `utxo` structs.
 */
const struct utxo **wallet_select_specific(const tal_t *ctx, struct wallet *w,
					struct bitcoin_txid **txids,
					u32 **outnums);

/**
 * wallet_confirm_utxos - Once we've spent a set of utxos, mark them confirmed.
 *
 * May be called once the transaction spending these UTXOs has been
 * broadcast. If something fails use `tal_free(utxos)` instead to undo
 * the reservation.
 */
void wallet_confirm_utxos(struct wallet *w, const struct utxo **utxos);

/**
 * wallet_can_spend - Do we have the private key matching this scriptpubkey?
 *
 * FIXME: This is very slow with lots of inputs!
 *
 * @w: (in) wallet holding the pubkeys to check against (privkeys are on HSM)
 * @script: (in) the script to check
 * @index: (out) the bip32 derivation index that matched the script
 * @output_is_p2sh: (out) whether the script is a p2sh, or p2wpkh
 */
bool wallet_can_spend(struct wallet *w, const u8 *script,
		      u32 *index, bool *output_is_p2sh);

/**
 * wallet_get_newindex - get a new index from the wallet.
 * @ld: (in) lightning daemon
 *
 * Returns -1 on error (key exhaustion).
 */
s64 wallet_get_newindex(struct lightningd *ld);

/**
 * wallet_shachain_add_hash -- wallet wrapper around shachain_add_hash
 */
bool wallet_shachain_add_hash(struct wallet *wallet,
			      struct wallet_shachain *chain,
			      uint64_t index,
			      const struct secret *hash);

/**
 * wallet_shachain_load -- Load an existing shachain from the wallet.
 *
 * @wallet: the wallet to load from
 * @id: the shachain id to load
 * @chain: where to load the shachain into
 */
bool wallet_shachain_load(struct wallet *wallet, u64 id,
			  struct wallet_shachain *chain);


/**
 * wallet_get_uncommitted_channel_dbid -- get a unique channel dbid
 *
 * @wallet: the wallet
 */
u64 wallet_get_channel_dbid(struct wallet *wallet);

/**
 * wallet_channel_save -- Upsert the channel into the database
 *
 * @wallet: the wallet to save into
 * @chan: the instance to store (not const so we can update the unique_id upon
 *   insert)
 */
void wallet_channel_save(struct wallet *w, struct channel *chan);

/**
 * wallet_channel_insert -- Insert the initial channel into the database
 *
 * @wallet: the wallet to save into
 * @chan: the instance to store
 */
void wallet_channel_insert(struct wallet *w, struct channel *chan);

/**
 * Save an inflight transaction for a channel
 */
void wallet_inflight_add(struct wallet *w, struct channel_inflight *inflight);

/**
 * Update an existing inflight channel transaction
 */
void wallet_inflight_save(struct wallet *w,
			  struct channel_inflight *inflight);

/**
 * Remove all the inflights from a channel. Also cleans up
 * the channel's inflight list
 */
void wallet_channel_clear_inflights(struct wallet *w,
				    struct channel *chan);
/**
 * After fully resolving a channel, only keep a lightweight stub
 */
void wallet_channel_close(struct wallet *w, u64 wallet_id);

/**
 * Adds a channel state change history entry into the database
 */
void wallet_state_change_add(struct wallet *w,
			     const u64 channel_id,
			     struct timeabs *timestamp,
			     enum channel_state old_state,
			     enum channel_state new_state,
			     enum state_change cause,
			     char *message);

/**
 * Gets all state change history entries for a channel from the database
 */
struct state_change_entry *wallet_state_change_get(struct wallet *w,
						   const tal_t *ctx,
						   u64 channel_id);

/**
 * wallet_peer_delete -- After no more channels in peer, forget about it
 */
void wallet_peer_delete(struct wallet *w, u64 peer_dbid);

/**
 * wallet_channel_config_load -- Load channel_config from database into cc
 */
bool wallet_channel_config_load(struct wallet *w, const u64 id,
				struct channel_config *cc);

/**
 * wallet_init_channels -- Loads active channels into peers
 *    and inits the dbid counter for next channel.
 *
 *    @w: wallet to load from
 *
 * Be sure to call this only once on startup since it'll append peers
 * loaded from the database to the list without checking.
 */
bool wallet_init_channels(struct wallet *w);

/**
 * wallet_channel_stats_incr_* - Increase channel statistics.
 *
 * @w: wallet containing the channel
 * @cdbid: channel database id
 * @msatoshi: amount in msatoshi being transferred
 */
void wallet_channel_stats_incr_in_offered(struct wallet *w, u64 cdbid, struct amount_msat msatoshi);
void wallet_channel_stats_incr_in_fulfilled(struct wallet *w, u64 cdbid, struct amount_msat msatoshi);
void wallet_channel_stats_incr_out_offered(struct wallet *w, u64 cdbid, struct amount_msat msatoshi);
void wallet_channel_stats_incr_out_fulfilled(struct wallet *w, u64 cdbid, struct amount_msat msatoshi);

/**
 * wallet_channel_stats_load - Load channel statistics
 *
 * @w: wallet containing the channel
 * @cdbid: channel database id
 * @stats: location to load statistics to
 */
void wallet_channel_stats_load(struct wallet *w, u64 cdbid, struct channel_stats *stats);

/**
 * Retrieve the blockheight of the last block processed by lightningd.
 *
 * Will set min/max either the minimal/maximal blockheight or the default value
 * if the wallet was never used before.
 *
 * @w: wallet to load from.
 * @def: the default value to return if we've never used the wallet before
 * @min(out): height of the first block we track
 * @max(out): height of the last block we added
 */
void wallet_blocks_heights(struct wallet *w, u32 def, u32 *min, u32 *max);

/**
 * wallet_extract_owned_outputs - given a tx, extract all of our outputs
 */
int wallet_extract_owned_outputs(struct wallet *w, const struct wally_tx *tx,
				 const u32 *blockheight,
				 struct amount_sat *total);

/**
 * wallet_htlc_save_in - store an htlc_in in the database
 *
 * @wallet: wallet to store the htlc into
 * @chan: the channel this HTLC is associated with
 * @in: the htlc_in to store
 *
 * This will store the contents of the `struct htlc_in` in the
 * database. Since `struct htlc_in` commonly only change state after
 * being created we do not support updating arbitrary fields and this
 * function will fail when attempting to call it multiple times for
 * the same `struct htlc_in`. Instead `wallet_htlc_update` may be used
 * for state transitions or to set the `payment_key` for completed
 * HTLCs.
 */
void wallet_htlc_save_in(struct wallet *wallet,
			 const struct channel *chan, struct htlc_in *in);

/**
 * wallet_htlc_save_out - store an htlc_out in the database
 *
 * See comment for wallet_htlc_save_in.
 */
void wallet_htlc_save_out(struct wallet *wallet,
			  const struct channel *chan,
			  struct htlc_out *out);

/**
 * wallet_htlc_update - perform state transition or add payment_key
 *
 * @wallet: the wallet containing the HTLC to update
 * @htlc_dbid: the database ID used to identify the HTLC
 * @new_state: the state we should transition to
 * @payment_key: the `payment_key` which hashes to the `payment_hash`,
 *   or NULL if unknown.
 * @badonion: the current BADONION failure code, or 0.
 * @failonion: the current failure onion message (from peer), or NULL.
 * @failmsg: the current local failure message, or NULL.
 * @we_filled: for htlc-ins, true if we originated the preimage.
 *
 * Used to update the state of an HTLC, either a `struct htlc_in` or a
 * `struct htlc_out` and optionally set the `payment_key` should the
 * HTLC have been settled, or `failcode`/`failonion` if failed.
 */
void wallet_htlc_update(struct wallet *wallet, const u64 htlc_dbid,
			const enum htlc_state new_state,
			const struct preimage *payment_key,
			enum onion_wire badonion,
			const struct onionreply *failonion,
			const u8 *failmsg,
			bool *we_filled);

/**
 * wallet_htlcs_load_in_for_channel - Load incoming HTLCs associated with chan from DB.
 *
 * @wallet: wallet to load from
 * @chan: load HTLCs associated with this channel
 * @htlcs_in: htlc_in_map to store loaded htlc_in in
 *
 * This function looks for incoming HTLCs that are associated with the given
 * channel and loads them into the provided map.
 */
bool wallet_htlcs_load_in_for_channel(struct wallet *wallet,
				      struct channel *chan,
				      struct htlc_in_map *htlcs_in);

/**
 * wallet_htlcs_load_out_for_channel - Load outgoing HTLCs associated with chan from DB.
 *
 * @wallet: wallet to load from
 * @chan: load HTLCs associated with this channel
 * @htlcs_out: htlc_out_map to store loaded htlc_out in.
 * @remaining_htlcs_in: htlc_in_map with unconnected htlcs (removed as we progress)
 *
 * We populate htlc_out->in by looking up in remaining_htlcs_in.  It's
 * possible that it's still NULL, since we can have outgoing HTLCs
 * outlive their corresponding incoming.
 */
bool wallet_htlcs_load_out_for_channel(struct wallet *wallet,
				       struct channel *chan,
				       struct htlc_out_map *htlcs_out,
				       struct htlc_in_map *remaining_htlcs_in);

/**
 * wallet_announcement_save - Save remote announcement information with channel.
 *
 * @wallet: wallet to load from
 * @id: channel database id
 * @remote_ann_node_sig: location to load remote_ann_node_sig to
 * @remote_ann_bitcoin_sig: location to load remote_ann_bitcoin_sig to
 *
 * This function is only used to save REMOTE announcement information into DB
 * when the channel has set the announce_channel bit and don't send the shutdown
 * message(BOLT#7).
 */
void wallet_announcement_save(struct wallet *wallet, u64 id,
			      secp256k1_ecdsa_signature *remote_ann_node_sig,
			      secp256k1_ecdsa_signature *remote_ann_bitcoin_sig);

/* /!\ This is a DB ENUM, please do not change the numbering of any
 * already defined elements (adding is ok) /!\ */
enum invoice_status {
	UNPAID,
	PAID,
	EXPIRED,
};

static inline enum invoice_status invoice_status_in_db(enum invoice_status s)
{
	switch (s) {
	case UNPAID:
		BUILD_ASSERT(UNPAID == 0);
		return s;
	case PAID:
		BUILD_ASSERT(PAID == 1);
		return s;
	case EXPIRED:
		BUILD_ASSERT(EXPIRED == 2);
		return s;
	}
	fatal("%s: %u is invalid", __func__, s);
}

/* The information about an invoice */
struct invoice_details {
	/* Current invoice state */
	enum invoice_status state;
	/* Preimage for this invoice */
	struct preimage r;
	/* Hash of preimage r */
	struct sha256 rhash;
	/* Label assigned by user */
	const struct json_escape *label;
	/* NULL if they specified "any" */
	struct amount_msat *msat;
	/* Absolute UNIX epoch time this will expire */
	u64 expiry_time;
	/* Set if state == PAID; order to be returned by waitanyinvoice */
	u64 pay_index;
	/* Set if state == PAID; amount received */
	struct amount_msat received;
	/* Set if state == PAID; time paid */
	u64 paid_timestamp;
	/* BOLT11 or BOLT12 encoding for this invoice */
	const char *invstring;

	/* The description of the payment. */
	char *description;
	/* The features, if any (tal_arr) */
	u8 *features;
	/* The offer this refers to, if any. */
	struct sha256 *local_offer_id;
};

/* An object that handles iteration over the set of invoices */
struct invoice_iterator {
	/* The contents of this object is subject to change
	 * and should not be depended upon */
	void *p;
};

struct invoice {
	/* Internal, rest of lightningd should not use */
	/* Database ID */
	u64 id;
};

#define INVOICE_MAX_LABEL_LEN 128

/**
 * wallet_invoice_create - Create a new invoice.
 *
 * @wallet - the wallet to create the invoice in.
 * @pinvoice - pointer to location to load new invoice in.
 * @msat - the amount the invoice should have, or
 * NULL for any-amount invoices.
 * @label - the unique label for this invoice. Must be
 * non-NULL.
 * @expiry - the number of seconds before the invoice
 * expires
 *
 * Returns false if label already exists or expiry is 0.
 * Returns true if created invoice.
 * FIXME: Fallback addresses
 */
bool wallet_invoice_create(struct wallet *wallet,
			   struct invoice *pinvoice,
			   const struct amount_msat *msat TAKES,
			   const struct json_escape *label TAKES,
			   u64 expiry,
			   const char *b11enc,
			   const char *description,
			   const u8 *features,
			   const struct preimage *r,
			   const struct sha256 *rhash,
			   const struct sha256 *local_offer_id);

/**
 * wallet_invoice_find_by_label - Search for an invoice by label
 *
 * @wallet - the wallet to search.
 * @pinvoice - pointer to location to load found invoice in.
 * @label - the label to search for.
 *
 * Returns false if no invoice with that label exists.
 * Returns true if found.
 */
bool wallet_invoice_find_by_label(struct wallet *wallet,
				  struct invoice *pinvoice,
				  const struct json_escape *label);

/**
 * wallet_invoice_find_by_rhash - Search for an invoice by payment_hash
 *
 * @wallet - the wallet to search.
 * @pinvoice - pointer to location to load found invoice in.
 * @rhash - the payment_hash to search for.
 *
 * Returns false if no invoice with that rhash exists.
 * Returns true if found.
 */
bool wallet_invoice_find_by_rhash(struct wallet *wallet,
				  struct invoice *pinvoice,
				  const struct sha256 *rhash);

/**
 * wallet_invoice_find_unpaid - Search for an unpaid, unexpired invoice by
 * payment_hash
 *
 * @wallet - the wallet to search.
 * @pinvoice - pointer to location to load found invoice in.
 * @rhash - the payment_hash to search for.
 *
 * Returns false if no unpaid invoice with that rhash exists.
 * Returns true if found.
 */
bool wallet_invoice_find_unpaid(struct wallet *wallet,
				struct invoice *pinvoice,
				const struct sha256 *rhash);

/**
 * wallet_invoice_delete - Delete an invoice
 *
 * @wallet - the wallet to delete the invoice from.
 * @invoice - the invoice to delete.
 *
 * Return false on failure.
 */
bool wallet_invoice_delete(struct wallet *wallet,
			   struct invoice invoice);

/**
 * wallet_invoice_delete_expired - Delete all expired invoices
 * with expiration time less than or equal to the given.
 *
 * @wallet - the wallet to delete invoices from.
 * @max_expiry_time - the maximum expiry time to delete.
 */
void wallet_invoice_delete_expired(struct wallet *wallet,
				   u64 max_expiry_time);

/**
 * wallet_invoice_autoclean - Set up a repeating autoclean of
 * expired invoices.
 * Cleans (deletes) expired invoices every @cycle_seconds.
 * Clean only those invoices that have been expired for at
 * least @expired_by seconds or more.
 */
void wallet_invoice_autoclean(struct wallet * wallet,
			      u64 cycle_seconds,
			      u64 expired_by);

/**
 * wallet_invoice_iterate - Iterate over all existing invoices
 *
 * @wallet - the wallet whose invoices are to be iterated over.
 * @iterator - the iterator object to use.
 *
 * Return false at end-of-sequence, true if still iterating.
 * Usage:
 *
 *   struct invoice_iterator it;
 *   memset(&it, 0, sizeof(it))
 *   while (wallet_invoice_iterate(wallet, &it)) {
 *       ...
 *   }
 */
bool wallet_invoice_iterate(struct wallet *wallet,
			    struct invoice_iterator *it);

/**
 * wallet_invoice_iterator_deref - Read the details of the
 * invoice currently pointed to by the given iterator.
 *
 * @ctx - the owner of the label and msatoshi fields returned.
 * @wallet - the wallet whose invoices are to be iterated over.
 * @iterator - the iterator object to use.
 * @return pointer to the invoice details allocated off of `ctx`.
 */
const struct invoice_details *wallet_invoice_iterator_deref(const tal_t *ctx,
			      struct wallet *wallet,
			      const struct invoice_iterator *it);

/**
 * wallet_invoice_resolve - Mark an invoice as paid
 *
 * @wallet - the wallet containing the invoice.
 * @invoice - the invoice to mark as paid.
 * @received - the actual amount received.
 *
 * If the invoice is not UNPAID, returns false.
 */
bool wallet_invoice_resolve(struct wallet *wallet,
			    struct invoice invoice,
			    struct amount_msat received);

/**
 * wallet_invoice_waitany - Wait for any invoice to be paid.
 *
 * @ctx - the owner of the callback. If the owner is freed,
 * the callback is cancelled.
 * @wallet - the wallet to query.
 * @lastpay_index - wait for invoices after the specified
 * pay_index. Use 0 to wait for the first invoice.
 * @cb - the callback to invoke. If an invoice is already
 * paid with pay_index greater than lastpay_index, this
 * is called immediately, otherwise it is called during
 * an invoices_resolve call. Will never be given a NULL
 * pointer-to-invoice.
 * @cbarg - the callback data.
 */
void wallet_invoice_waitany(const tal_t *ctx,
			    struct wallet *wallet,
			    u64 lastpay_index,
			    void (*cb)(const struct invoice *, void*),
			    void *cbarg);

/**
 * wallet_invoice_waitone - Wait for a specific invoice to be paid,
 * deleted, or expired.
 *
 * @ctx - the owner of the callback. If the owner is freed,
 * the callback is cancelled.
 * @wallet - the wallet to query.
 * @invoice - the invoice to wait on.
 * @cb - the callback to invoice. If invoice is already paid
 * or expired, this is called immediately, otherwise it is
 * called during an invoices_resolve or invoices_delete call.
 * If the invoice was deleted, the callback is given a NULL
 * invoice.
 * @cbarg - the callback data.
 *
 */
void wallet_invoice_waitone(const tal_t *ctx,
			    struct wallet *wallet,
			    struct invoice invoice,
			    void (*cb)(const struct invoice *, void*),
			    void *cbarg);

/**
 * wallet_invoice_details - Get the invoice_details of an invoice.
 *
 * @ctx - the owner of the label and msatoshi fields returned.
 * @wallet - the wallet to query.
 * @invoice - the invoice to get details on.
 * @return pointer to the invoice details allocated off of `ctx`.
 */
const struct invoice_details *wallet_invoice_details(const tal_t *ctx,
						     struct wallet *wallet,
						     struct invoice invoice);

/**
 * wallet_htlc_stubs - Retrieve HTLC stubs for the given channel
 *
 * Load minimal necessary information about HTLCs for the on-chain
 * settlement. This returns a `tal_arr` allocated off of @ctx with the
 * necessary size to hold all HTLCs.
 *
 * @ctx: Allocation context for the return value
 * @wallet: Wallet to load from
 * @chan: Channel to fetch stubs for
 */
struct htlc_stub *wallet_htlc_stubs(const tal_t *ctx, struct wallet *wallet,
				    struct channel *chan);

/**
 * wallet_payment_setup - Remember this payment for later committing.
 *
 * Either wallet_payment_store() gets called to put in db once hout
 * is ready to go (and frees @payment), or @payment is tal_free'd.
 *
 * @wallet: wallet we're going to store it in.
 * @payment: the payment for later committing.
 */
void wallet_payment_setup(struct wallet *wallet, struct wallet_payment *payment);

/**
 * wallet_payment_store - Record a new incoming/outgoing payment
 *
 * Stores the payment in the database.
 */
void wallet_payment_store(struct wallet *wallet,
			  struct wallet_payment *payment TAKES);

/**
 * wallet_payment_delete - Remove a payment
 *
 * Removes the payment from the database.
 */
void wallet_payment_delete(struct wallet *wallet,
			   const struct sha256 *payment_hash,
			   u64 partid);

/**
 * wallet_payment_delete_by_hash - Remove a payment
 *
 * Removes the payment from the database by hash; if it is a MPP payment
 * it remove all parts with a single query.
 */
void wallet_payment_delete_by_hash(struct wallet *wallet, const struct sha256 *payment_hash);

/**
 * wallet_local_htlc_out_delete - Remove a local outgoing failed HTLC
 *
 * This is not a generic HTLC cleanup!  This is specifically for the
 * narrow (and simple!) case of removing the HTLC associated with a
 * local outgoing payment.
 */
void wallet_local_htlc_out_delete(struct wallet *wallet,
				  struct channel *chan,
				  const struct sha256 *payment_hash,
				  u64 partid);

/**
 * wallet_payment_by_hash - Retrieve a specific payment
 *
 * Given the `payment_hash` retrieve the matching payment.
 */
struct wallet_payment *
wallet_payment_by_hash(const tal_t *ctx, struct wallet *wallet,
		       const struct sha256 *payment_hash,
		       u64 partid);

/**
 * Retrieve maximum groupid for a given payment_hash.
 *
 * Useful to either wait on the latest payment that was iniated with
 * the hash or start a new one by incrementing the groupid.
 */
u64 wallet_payment_get_groupid(struct wallet *wallet,
			       const struct sha256 *payment_hash);

/**
 * wallet_payment_set_status - Update the status of the payment
 *
 * Search for the payment with the given `payment_hash` and update
 * its state.
 */
void wallet_payment_set_status(struct wallet *wallet,
			       const struct sha256 *payment_hash,
			       u64 partid, u64 groupid,
			       const enum wallet_payment_status newstatus,
			       const struct preimage *preimage);

/**
 * wallet_payment_get_failinfo - Get failure information for a given
 * `payment_hash`.
 *
 * Data is allocated as children of the given context. *faildirection
 * is only set if *failchannel is set non-NULL.
 */
void wallet_payment_get_failinfo(const tal_t *ctx,
				 struct wallet *wallet,
				 const struct sha256 *payment_hash,
				 u64 partid,
				 /* outputs */
				 struct onionreply **failonionreply,
				 bool *faildestperm,
				 int *failindex,
				 enum onion_wire *failcode,
				 struct node_id **failnode,
				 struct short_channel_id **failchannel,
				 u8 **failupdate,
				 char **faildetail,
				 int *faildirection);
/**
 * wallet_payment_set_failinfo - Set failure information for a given
 * `payment_hash`.
 */
void wallet_payment_set_failinfo(struct wallet *wallet,
				 const struct sha256 *payment_hash,
				 u64 partid,
				 const struct onionreply *failonionreply,
				 bool faildestperm,
				 int failindex,
				 enum onion_wire failcode,
				 const struct node_id *failnode,
				 const struct short_channel_id *failchannel,
				 const u8 *failupdate,
				 const char *faildetail,
				 int faildirection);

/**
 * wallet_payment_list - Retrieve a list of payments
 *
 * payment_hash: optional filter for only this payment hash.
 */
const struct wallet_payment **wallet_payment_list(const tal_t *ctx,
						  struct wallet *wallet,
						  const struct sha256 *payment_hash,
						  enum wallet_payment_status *status);

/**
 * wallet_payments_by_offer - Retrieve a list of payments for this local_offer_id
 */
const struct wallet_payment **wallet_payments_by_offer(const tal_t *ctx,
						       struct wallet *wallet,
						       const struct sha256 *local_offer_id);

/**
 * wallet_htlc_sigs_save - Store the latest HTLC sigs for the channel
 */
void wallet_htlc_sigs_save(struct wallet *w, u64 channel_id,
			   const struct bitcoin_signature *htlc_sigs);

/**
 * wallet_network_check - Check that the wallet is setup for this chain
 *
 * Ensure that the genesis_hash from the chainparams matches the
 * genesis_hash with which the DB was initialized. Returns false if
 * the check failed, i.e., if the genesis hashes do not match.
 */
bool wallet_network_check(struct wallet *w);

/**
 * wallet_block_add - Add a block to the blockchain tracked by this wallet
 */
void wallet_block_add(struct wallet *w, struct block *b);

/**
 * wallet_block_remove - Remove a block (and all its descendants) from the tracked blockchain
 */
void wallet_block_remove(struct wallet *w, struct block *b);

/**
 * wallet_blocks_rollback - Roll the blockchain back to the given height
 */
void wallet_blocks_rollback(struct wallet *w, u32 height);

/**
 * Return whether we have a block for the given height.
 */
bool wallet_have_block(struct wallet *w, u32 blockheight);

/**
 * Mark an outpoint as spent, both in the owned as well as the UTXO set
 *
 * Given the outpoint (txid, outnum), and the blockheight, mark the
 * corresponding DB entries as spent at the blockheight.
 *
 * @return true if found in our wallet's output set, false otherwise
 */
bool wallet_outpoint_spend(struct wallet *w, const tal_t *ctx,
			   const u32 blockheight,
			   const struct bitcoin_txid *txid, const u32 outnum);

struct outpoint *wallet_outpoint_for_scid(struct wallet *w, tal_t *ctx,
					  const struct short_channel_id *scid);

void wallet_utxoset_add(struct wallet *w, const struct bitcoin_tx *tx,
			const u32 outnum, const u32 blockheight,
			const u32 txindex, const u8 *scriptpubkey,
			struct amount_sat sat);

/**
 * Retrieve all UTXO entries that were spent by the given blockheight.
 *
 * This allows us to retrieve any UTXO entries that were spent by a block,
 * after the block has been processed. It's main use is to be able to tell
 * `gossipd` about potential channel outpoints being spent, without having to
 * track all outpoints in memory.
 *
 * In order to return correct results `blockheight` should not be called with
 * a height below the UTXO set pruning height (see `UTXO_PRUNE_DEPTH` for the
 * current value).
 */
const struct short_channel_id *
wallet_utxoset_get_spent(const tal_t *ctx, struct wallet *w, u32 blockheight);

/**
 * Retrieve all UTXO entries that were created at a given blockheight.
 */
const struct short_channel_id *
wallet_utxoset_get_created(const tal_t *ctx, struct wallet *w, u32 blockheight);

void wallet_transaction_add(struct wallet *w, const struct wally_tx *tx,
			    const u32 blockheight, const u32 txindex);

void wallet_annotate_txout(struct wallet *w, const struct bitcoin_txid *txid,
			   int outnum, enum wallet_tx_type type, u64 channel);

void wallet_annotate_txin(struct wallet *w, const struct bitcoin_txid *txid,
			  int innum, enum wallet_tx_type type, u64 channel);

/**
 * Annotate a transaction in the DB with its type and channel referemce.
 *
 * We add transactions when filtering the block, but often know its type only
 * when we trigger the txwatches, at which point we've already discarded the
 * full transaction. This function can be used to annotate the transactions
 * after the fact with a channel number for grouping and a type for filtering.
 */
void wallet_transaction_annotate(struct wallet *w,
				 const struct bitcoin_txid *txid,
				 enum wallet_tx_type type, u64 channel_id);

/**
 * Get the type of a transaction we are watching by its
 * txid.
 *
 * Returns false if the transaction was not stored in DB.
 * Returns true if the transaction exists and sets the `type` parameter.
 */
bool wallet_transaction_type(struct wallet *w, const struct bitcoin_txid *txid,
			     enum wallet_tx_type *type);

/**
 * Get the transaction from the database
 *
 * Looks up a transaction we have in the database and returns it, or NULL if
 * not found.
 */
struct bitcoin_tx *wallet_transaction_get(const tal_t *ctx, struct wallet *w,
					  const struct bitcoin_txid *txid);

/**
 * Get the confirmation height of a transaction we are watching by its
 * txid. Returns 0 if the transaction was not part of any block.
 */
u32 wallet_transaction_height(struct wallet *w, const struct bitcoin_txid *txid);

/**
 * Locate a transaction in the blockchain, returns NULL if the transaction is
 * not tracked or is not yet confirmed.
 */
struct txlocator *wallet_transaction_locate(const tal_t *ctx, struct wallet *w,
					    const struct bitcoin_txid *txid);

/**
 * Get transaction IDs for transactions that we are tracking.
 */
struct bitcoin_txid *wallet_transactions_by_height(const tal_t *ctx,
						   struct wallet *w,
						   const u32 blockheight);

/**
 * Store transactions of interest in the database to replay on restart
 */
void wallet_channeltxs_add(struct wallet *w, struct channel *chan,
			    const int type, const struct bitcoin_txid *txid,
			   const u32 input_num, const u32 blockheight);

/**
 * List channels for which we had an onchaind running
 */
u32 *wallet_onchaind_channels(struct wallet *w,
			      const tal_t *ctx);

/**
 * Get transactions that we'd like to replay for a channel.
 */
struct channeltx *wallet_channeltxs_get(struct wallet *w, const tal_t *ctx,
					u32 channel_id);

/**
 * Add of update a forwarded_payment
 */
void wallet_forwarded_payment_add(struct wallet *w, const struct htlc_in *in,
				  const struct short_channel_id *scid_out,
				  const struct htlc_out *out,
				  enum forward_status state,
				  enum onion_wire failcode);

/**
 * Retrieve summary of successful forwarded payments' fees
 */
struct amount_msat wallet_total_forward_fees(struct wallet *w);

/**
 * Retrieve a list of all forwarded_payments
 */
const struct forwarding *wallet_forwarded_payments_get(struct wallet *w,
						       const tal_t *ctx,
						       enum forward_status state,
						       const struct short_channel_id *chan_in,
						       const struct short_channel_id *chan_out);

/**
 * Load remote_ann_node_sig and remote_ann_bitcoin_sig
 *
 * @ctx: allocation context for the return value
 * @w: wallet containing the channel
 * @id: channel database id
 * @remote_ann_node_sig: location to load remote_ann_node_sig to
 * @remote_ann_bitcoin_sig: location to load remote_ann_bitcoin_sig to
 */
bool wallet_remote_ann_sigs_load(const tal_t *ctx, struct wallet *w, u64 id,
				 secp256k1_ecdsa_signature **remote_ann_node_sig,
				 secp256k1_ecdsa_signature **remote_ann_bitcoin_sig);

/**
 * wallet_clean_utxos: clean up any reserved UTXOs on restart.
 * @w: wallet
 *
 * If we crash, it's unclear if we have actually used the inputs.  eg. if
 * we crash around transaction broadcast.
 *
 * We ask bitcoind to clarify in this case.
 */
void wallet_clean_utxos(struct wallet *w, struct bitcoind *bitcoind);

/* Operations for unreleased transactions */
struct unreleased_tx *find_unreleased_tx(struct wallet *w,
					 const struct bitcoin_txid *txid);
void remove_unreleased_tx(struct unreleased_tx *utx);
void add_unreleased_tx(struct wallet *w, struct unreleased_tx *utx);

/* These will touch the db, so need to be explicitly freed. */
void free_unreleased_txs(struct wallet *w);

/* wallet_persist_utxo_reservation - Removes destructor
 *
 * Persists the reservation in the database (until a restart)
 * instead of clearing the reservation when the utxo object
 * is destroyed */
void wallet_persist_utxo_reservation(struct wallet *w, const struct utxo **utxos);

/* wallet_unreserve_output - Unreserve a utxo
 *
 * We unreserve utxos so that they can be spent elsewhere.
 * */
bool wallet_unreserve_output(struct wallet *w,
			     const struct bitcoin_txid *txid,
			     const u32 outnum);
/**
 * Get a list of transactions that we track in the wallet.
 *
 * @param ctx: allocation context for the returned list
 * @param wallet: Wallet to load from.
 * @return A tal_arr of wallet annotated transactions
 */
struct wallet_transaction *wallet_transactions_get(struct wallet *w, const tal_t *ctx);

/**
 * Add a filteredblock to the blocks and utxoset tables.
 *
 * This can be used to backfill the blocks and still unspent UTXOs that were before our wallet birth height.
 */
void wallet_filteredblock_add(struct wallet *w, const struct filteredblock *fb);

/**
 * Store a penalty base in the database.
 *
 * Required to eventually create a penalty transaction when we get a
 * revocation.
 */
void wallet_penalty_base_add(struct wallet *w, u64 chan_id,
			     const struct penalty_base *pb);

/**
 * Retrieve all pending penalty bases for a given channel.
 *
 * This list should stay relatively small since we remove items from it as we
 * get revocations. We retrieve this list whenever we start a new `channeld`.
 */
struct penalty_base *wallet_penalty_base_load_for_channel(const tal_t *ctx,
							  struct wallet *w,
							  u64 chan_id);

/**
 * Delete a penalty_base, after we created and delivered it to the hook.
 */
void wallet_penalty_base_delete(struct wallet *w, u64 chan_id, u64 commitnum);

/* /!\ This is a DB ENUM, please do not change the numbering of any
 * already defined elements (adding is ok) /!\ */
#define OFFER_STATUS_ACTIVE_F  0x1
#define OFFER_STATUS_SINGLE_F  0x2
#define OFFER_STATUS_USED_F    0x4
enum offer_status {
	OFFER_MULTIPLE_USE_UNUSED = OFFER_STATUS_ACTIVE_F,
	OFFER_MULTIPLE_USE_USED = OFFER_STATUS_ACTIVE_F|OFFER_STATUS_USED_F,
	OFFER_SINGLE_USE_UNUSED = OFFER_STATUS_ACTIVE_F|OFFER_STATUS_SINGLE_F,
	OFFER_SINGLE_USE_USED = OFFER_STATUS_SINGLE_F|OFFER_STATUS_USED_F,
	OFFER_SINGLE_DISABLED = OFFER_STATUS_SINGLE_F,
	OFFER_MULTIPLE_USED_DISABLED = OFFER_STATUS_USED_F,
	OFFER_MULTIPLE_DISABLED = 0,
};

static inline enum offer_status offer_status_in_db(enum offer_status s)
{
	switch (s) {
	case OFFER_MULTIPLE_USE_UNUSED:
		BUILD_ASSERT(OFFER_MULTIPLE_USE_UNUSED == 1);
		return s;
	case OFFER_MULTIPLE_USE_USED:
		BUILD_ASSERT(OFFER_MULTIPLE_USE_USED == 5);
		return s;
	case OFFER_SINGLE_USE_UNUSED:
		BUILD_ASSERT(OFFER_SINGLE_USE_UNUSED == 3);
		return s;
	case OFFER_SINGLE_USE_USED:
		BUILD_ASSERT(OFFER_SINGLE_USE_USED == 6);
		return s;
	case OFFER_SINGLE_DISABLED:
		BUILD_ASSERT(OFFER_SINGLE_DISABLED == 2);
		return s;
	case OFFER_MULTIPLE_USED_DISABLED:
		BUILD_ASSERT(OFFER_MULTIPLE_USED_DISABLED == 4);
		return s;
	case OFFER_MULTIPLE_DISABLED:
		BUILD_ASSERT(OFFER_MULTIPLE_DISABLED == 0);
		return s;
	}
	fatal("%s: %u is invalid", __func__, s);
}

static inline bool offer_status_active(enum offer_status s)
{
	return s & OFFER_STATUS_ACTIVE_F;
}

static inline bool offer_status_single(enum offer_status s)
{
	return s & OFFER_STATUS_SINGLE_F;
}

static inline bool offer_status_used(enum offer_status s)
{
	return s & OFFER_STATUS_USED_F;
}

/**
 * Store an offer in the database.
 * @w: the wallet
 * @offer_id: the merkle root, as used for signing (must be unique)
 * @bolt12: offer as text.
 * @label: optional label for this offer.
 * @status: OFFER_SINGLE_USE or OFFER_MULTIPLE_USE
 */
bool wallet_offer_create(struct wallet *w,
			 const struct sha256 *offer_id,
			 const char *bolt12,
			 const struct json_escape *label,
			 enum offer_status status)
	NON_NULL_ARGS(1,2,3);

/**
 * Retrieve an offer from the database.
 * @ctx: the tal context to allocate return from.
 * @w: the wallet
 * @offer_id: the merkle root, as used for signing (must be unique)
 * @label: the label of the offer, set to NULL if none (or NULL)
 * @status: set if succeeds (or NULL)
 *
 * If @offer_id is found, returns the bolt12 text, sets @label and
 * @state.  Otherwise returns NULL.
 */
char *wallet_offer_find(const tal_t *ctx,
			struct wallet *w,
			const struct sha256 *offer_id,
			const struct json_escape **label,
			enum offer_status *status)
	NON_NULL_ARGS(1,2,3);

/**
 * Iterate through all the offers.
 * @w: the wallet
 * @offer_id: the first offer id (if returns non-NULL)
 *
 * Returns pointer to hand as @stmt to wallet_offer_next(), or NULL.
 * If you choose not to call wallet_offer_id_next() you must free it!
 */
struct db_stmt *wallet_offer_id_first(struct wallet *w,
				      struct sha256 *offer_id);

/**
 * Iterate through all the offers.
 * @w: the wallet
 * @stmt: return from wallet_offer_id_first() or previous wallet_offer_id_next()
 * @offer_id: the next offer id (if returns non-NULL)
 *
 * Returns NULL once we're out of offers.  If you choose not to call
 * wallet_offer_id_next() again you must free return.
 */
struct db_stmt *wallet_offer_id_next(struct wallet *w,
				     struct db_stmt *stmt,
				     struct sha256 *offer_id);

/**
 * Disable an offer in the database.
 * @w: the wallet
 * @offer_id: the merkle root, as used for signing (must be unique)
 * @s: the current status (must be active).
 *
 * Must exist.  Returns new status. */
enum offer_status wallet_offer_disable(struct wallet *w,
				       const struct sha256 *offer_id,
				       enum offer_status s)
	NO_NULL_ARGS;

/**
 * Mark an offer in the database used.
 * @w: the wallet
 * @offer_id: the merkle root, as used for signing (must be unique)
 *
 * Must exist and be active.
 */
void wallet_offer_mark_used(struct db *db, const struct sha256 *offer_id)
	NO_NULL_ARGS;

/**
 * Add an new key/value to the datastore (generation 0)
 * @w: the wallet
 * @key: the new key (if returns non-NULL)
 * @data: the new data (if returns non-NULL)
 */
void wallet_datastore_create(struct wallet *w, const char **key, const u8 *data);

/**
 * Update an existing key/value to the datastore.
 * @w: the wallet
 * @key: the first key (if returns non-NULL)
 * @data: the first data (if returns non-NULL)
 */
void wallet_datastore_update(struct wallet *w,
			     const char **key,
			     const u8 *data);

/**
 * Remove a key from the datastore
 * @w: the wallet
 * @key: the key
 */
void wallet_datastore_remove(struct wallet *w, const char **key);

/**
 * Iterate through the datastore.
 * @ctx: the tal ctx to allocate off
 * @w: the wallet
 * @startkey: NULL, or the first key to start with
 * @key: the first key (if returns non-NULL)
 * @data: the first data (if returns non-NULL)
 * @generation: the first generation (if returns non-NULL)
 *
 * Returns pointer to hand as @stmt to wallet_datastore_next(), or NULL.
 * If you choose not to call wallet_datastore_next() you must free it!
 */
struct db_stmt *wallet_datastore_first(const tal_t *ctx,
				       struct wallet *w,
				       const char **startkey,
				       const char ***key,
				       const u8 **data,
				       u64 *generation);

/**
 * Iterate through the datastore.
 * @ctx: the tal ctx to allocate off
 * @w: the wallet
 * @stmt: the previous statement.
 * @key: the key (if returns non-NULL)
 * @data: the data (if returns non-NULL)
 * @generation: the generation (if returns non-NULL)
 *
 * Returns pointer to hand as @stmt to wallet_datastore_next(), or NULL.
 * If you choose not to call wallet_datastore_next() you must free it!
 */
struct db_stmt *wallet_datastore_next(const tal_t *ctx,
				      struct wallet *w,
				      struct db_stmt *stmt,
				      const char ***key,
				      const u8 **data,
				      u64 *generation);

#endif /* LIGHTNING_WALLET_WALLET_H */