#pragma once

/**
** \defgroup ssb SSB
** Everything about SSB, SHS, and MUXRPC happens here.
** @{
*/

#include "quickjs.h"

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

enum
{
	k_ssb_rpc_flag_binary = 0x0,
	k_ssb_rpc_flag_utf8 = 0x1,
	k_ssb_rpc_flag_json = 0x2,
	k_ssb_rpc_mask_type = 0x3,

	k_ssb_rpc_flag_end_error = 0x4,
	k_ssb_rpc_flag_stream = 0x8,
	k_ssb_rpc_mask_message = 0xC,

	k_ssb_rpc_mask_send = 0xf,

	k_ssb_rpc_flag_new_request = 0x10,

	k_ssb_blob_bytes_max = 5 * 1024 * 1024,
};

/**
** The type of change to a set of connections.
*/
typedef enum _tf_ssb_change_t
{
	k_tf_ssb_change_create,
	k_tf_ssb_change_connect,
	k_tf_ssb_change_remove,
} tf_ssb_change_t;

/** An SSB instance. */
typedef struct _tf_ssb_t tf_ssb_t;
/** An SSB connection. */
typedef struct _tf_ssb_connection_t tf_ssb_connection_t;
/** A trace instance. */
typedef struct _tf_trace_t tf_trace_t;
/** An SQLite database handle. */
typedef struct sqlite3 sqlite3;
/** An event loop. */
typedef struct uv_loop_s uv_loop_t;
/** A socket address. */
struct sockaddr_in;

enum
{
	k_id_base64_len = 57,
	k_id_bin_len = 32,
	k_blob_id_len = 53,
};

/**
** Statistics about an SSB instance.
*/
typedef struct _tf_ssb_stats_t
{
	/** Number of active connections. */
	int connections;
	/** Number of active hosts discovered by network broadcast. */
	int broadcasts;
	/** Number of messages stored. */
	int messages_stored;
	/** Number of blobs stored. */
	int blobs_stored;
	/** Number of RPC messages received. */
	int rpc_in;
	/** Number of RPC messages sent. */
	int rpc_out;
	/** Number of active RPC requests. */
	int request_count;
	/** Number of callbacks registered. */
	struct
	{
		int rpc;
		int connections_changed;
		int message_added;
		int blob_want_added;
		int broadcasts_changed;
	} callbacks;
} tf_ssb_stats_t;

/**
** State about requesting blobs.
*/
typedef struct _tf_ssb_blob_wants_t
{
	/** The request number of the blob.wants RPC call. */
	int32_t request_number;
	/** The number of blob wants we are waiting for a response to. */
	int wants_sent;
	/** The last blob ID considered. */
	char last_id[k_blob_id_len];
} tf_ssb_blob_wants_t;

/**
** A queue for storing messages.
*/
typedef struct _tf_ssb_store_queue_t
{
	/** The first node in the queue. */
	void* head;
	/** The last node in the queue. */
	void* tail;
	/** Whether the queue is currently running. */
	bool running;
} tf_ssb_store_queue_t;

/**
** Create an SSB instance.
** @param loop The event loop to use or NULL to create a new one.
** @param context The JS context to use or NULL to create a new one.
** @param db_path The path to the SQLite database to use.
** @param network_key The SSB network key to use or NULL to use the standard key.
*/
tf_ssb_t* tf_ssb_create(uv_loop_t* loop, JSContext* context, const char* db_path, const char* network_key);

/**
** Destroy an SSB instance.
** @param ssb The SSB instance to destroy.
*/
void tf_ssb_destroy(tf_ssb_t* ssb);

/**
** Start optional periodic work.
** @param ssb The SSB instance.
*/
void tf_ssb_start_periodic(tf_ssb_t* ssb);

/**
** Control logging verbosity.
** @param ssb The SSB instance.
** @param verbose True to log messages for every RPC message sent and received.
*/
void tf_ssb_set_verbose(tf_ssb_t* ssb, bool verbose);

/**
** Acquire an SQLite database for unrestricted reading.  Release qith tf_ssb_release_db_reader().
** @param ssb The SSB instance.
** @return A database with full read access to the database.
*/
sqlite3* tf_ssb_acquire_db_reader(tf_ssb_t* ssb);

/**
** Acquire an SQLite database for restricted reading.  Release qith
** tf_ssb_release_db_reader().
** @param ssb The SSB instance.
** @return A database with read access to a safe subset of the database.
*/
sqlite3* tf_ssb_acquire_db_reader_restricted(tf_ssb_t* ssb);

/**
** Release a database acquired with tf_ssb_acquire_db_reader() or
** tf_ssb_acquire_db_reader_restricted().
** @param ssb The SSB instance.
** @param db The database.
*/
void tf_ssb_release_db_reader(tf_ssb_t* ssb, sqlite3* db);

/**
** Acquire an SQLite database with full write access to the database.  Release
** with tf_ssb_release_db_writer().
** @param ssb The SSB instance.
** @return The writable database.
*/
sqlite3* tf_ssb_acquire_db_writer(tf_ssb_t* ssb);

/**
** Release a database acquired with tf_ssb_acquire_db_writer().
** @param ssb The SSB instance.
** @param db The database.
*/
void tf_ssb_release_db_writer(tf_ssb_t* ssb, sqlite3* db);

/**
** Get the SSB instance's event loop.
** @param ssb The SSB instance.
** @return The loop.
*/
uv_loop_t* tf_ssb_get_loop(tf_ssb_t* ssb);

/**
** Generate a public/private key pair for the SSB instance.
** @param ssb The SSB instance.
*/
void tf_ssb_generate_keys(tf_ssb_t* ssb);

/**
** Generate a public/private key pair and store in buffers.
** @param[out] out_public Buffer to receive the public key.
** @param public_size Size of the public key buffer.
** @param[out] out_private Buffer to receive the private key.
** @param private_size Size of the private key buffer.
*/
void tf_ssb_generate_keys_buffer(char* out_public, size_t public_size, char* out_private, size_t private_size);

/**
** Get the private key of the SSB instance.
** @param ssb The SSB instance.
** @param[out] out_private Buffer to receive the private key.
** @param private_size The size of the private key buffer.
*/
void tf_ssb_get_private_key(tf_ssb_t* ssb, uint8_t* out_private, size_t private_size);

/**
** Set the trace instance to use for the SSB instance.
** @param ssb The SSB instance.
** @param trace The trace instance to use.
*/
void tf_ssb_set_trace(tf_ssb_t* ssb, tf_trace_t* trace);

/**
** Get the SSB instance's trace instance.
** @param ssb The SSB instance.
** @return The trace instance.
*/
tf_trace_t* tf_ssb_get_trace(tf_ssb_t* ssb);

/**
** Get the SSB istance's JS context.
** @param ssb The SSB instance.
** @return The JS context.
*/
JSContext* tf_ssb_get_context(tf_ssb_t* ssb);

/**
** Begin listening for SSB discovery messages.
** @param ssb The SSB instance.
** @param linger True if listening for broadcasts should keep the event loop alive.
*/
void tf_ssb_broadcast_listener_start(tf_ssb_t* ssb, bool linger);

/**
** Begin sending SSB discovevry messages.
** @param ssb The SSB instance.
*/
void tf_ssb_broadcast_sender_start(tf_ssb_t* ssb);

/**
** Run the SSB instance until there is no work to do or stopped.
** @param ssb The SSB instance.
*/
void tf_ssb_run(tf_ssb_t* ssb);

/**
** Sign an SSB message.
** @param ssb The SSB instance.
** @param author The author's public key.
** @param private_key The author's private key.
** @param message The message to sign.
** @return The signed message.
*/
JSValue tf_ssb_sign_message(tf_ssb_t* ssb, const char* author, const uint8_t* private_key, JSValue message);

/**
** Get the server's identity.
** @param ssb The SSB instance.
** @param[out] out_id A buffer populated with the identity.
** @param out_id_size The size of the identity buffer.
** @return True if the identity was successfully retrieved.
*/
bool tf_ssb_whoami(tf_ssb_t* ssb, char* out_id, size_t out_id_size);

/**
** Call a callback for each active host discovered by network discovery broadcast.
** @param ssb The SSB instance.
** @param callback The callback.
** @param user_data User data for the callback.
*/
void tf_ssb_visit_broadcasts(
	tf_ssb_t* ssb, void (*callback)(const char* host, const struct sockaddr_in* addr, tf_ssb_connection_t* tunnel, const uint8_t* pub, void* user_data), void* user_data);

/**
** Get the identities of all active connections.
** @param ssb The SSB instance.
** @return A NULL-terminated array of SSB identities.  Free with tf_free().
*/
const char** tf_ssb_get_connection_ids(tf_ssb_t* ssb);

/**
** Retrieve a list of active connections.
** @param ssb The SSB instance.
** @param[out] out_connections An array to be populated with the connections.
** @param out_connections_count The size of the connections array.
** @return The number of connections populated in out_connections.
*/
int tf_ssb_get_connections(tf_ssb_t* ssb, tf_ssb_connection_t** out_connections, int out_connections_count);

/**
** Establish an SHS connection with a host.
** @param ssb The SSB instance.
** @param host The host name or address.
** @param port The host's SHS port.
** @param key The host's SSB identity.
*/
void tf_ssb_connect(tf_ssb_t* ssb, const char* host, int port, const uint8_t* key);

/**
** Establish an SHS connection with a host by string address.
** @param ssb The SSB instance.
** @param address The address.
*/
void tf_ssb_connect_str(tf_ssb_t* ssb, const char* address);

/**
** Begin listening for SHS connections on the given port.
** @param ssb The SSB instance.
** @param port The port number.
*/
void tf_ssb_server_open(tf_ssb_t* ssb, int port);

/**
** Stop listening for SHS connections.
** @param ssb The SSB instance.
*/
void tf_ssb_server_close(tf_ssb_t* ssb);

/**
** Close all active SHS connections.
** @param ssb The SSB instance.
*/
void tf_ssb_close_all(tf_ssb_t* ssb);

/**
** Send a graceful close message to all active SHS connections.
** @param ssb The SSB instance.
*/
void tf_ssb_send_close(tf_ssb_t* ssb);

/**
** Convert an SSB identity from string to binary.
** @param[out] bin A buffer to receive the binary identity.
** @param str The string identity.
** @return True if the conversion was successful.
*/
bool tf_ssb_id_str_to_bin(uint8_t* bin, const char* str);

/**
** Convert an SSB identity from binary to string.
** @param[out] str A buffer to receive the identity string.
** @param str_size The size of the string buffer.
** @param bin The binary identity.
** @return True if the conversion was successful.
*/
bool tf_ssb_id_bin_to_str(char* str, size_t str_size, const uint8_t* bin);

/**
** Verify a message's signature and remove the signature if successful.
** @param context A JS context.
** @param val The message.
** @param[out] out_id A buffer to receive the message's identity.
** @param out_id_size The size of out_id.
** @param[out] out_signature A buffer to receive the message's signature.
** @param out_signature_size The size of out_signature.
** @param[out] out_sequence_before_author A flag describing the order of the sequence and author fields.
** @return True if the signature is valid and was successfully extracted.
*/
bool tf_ssb_verify_and_strip_signature(
	JSContext* context, JSValue val, char* out_id, size_t out_id_size, char* out_signature, size_t out_signature_size, bool* out_sequence_before_author);

/**
** Determine the message identifier.
** @param context A JS context.
** @param message The message.
** @param[out] out_id A buffer to receive the identifier.
** @param out_id_size The size of out_id.
*/
void tf_ssb_calculate_message_id(JSContext* context, JSValue message, char* out_id, size_t out_id_size);

/**
** A function called on completion of tf_ssb_verify_strip_and_store_message().
** @param id The stored message identifier.
** @param verified True if the message was verified successfully.
** @param is_new True if the message was newly added to the database.
** @param user_data The user data.
*/
typedef void(tf_ssb_verify_strip_store_callback_t)(const char* id, bool verified, bool is_new, void* user_data);

/**
** Verify a message's signature, remove the signature, and store the message in the database.
** @param ssb The SSB instance.
** @param value The message.
** @param callback A callback called when the operation completed.
** @param user_data User data to pass to the callback.
*/
void tf_ssb_verify_strip_and_store_message(tf_ssb_t* ssb, JSValue value, tf_ssb_verify_strip_store_callback_t* callback, void* user_data);

/**
** Check if a connection is an outgoing connection.
** @param connection The connection.
** @return True if the connection is outgoing.
*/
bool tf_ssb_connection_is_client(tf_ssb_connection_t* connection);

/**
** Get the hostname of the remote end of a connection.
** @param connection The connection.
** @return The hostname or address.
*/
const char* tf_ssb_connection_get_host(tf_ssb_connection_t* connection);

/**
** Get a connection's remote port number.
** @param connection The connection.
** @return The port number.
*/
int tf_ssb_connection_get_port(tf_ssb_connection_t* connection);

/**
** If a connection is a tunnel, get its parent connection.
** @param connection The connection.
** @return The parent connection if the connection is tunneled or NULL.
*/
tf_ssb_connection_t* tf_ssb_connection_get_tunnel(tf_ssb_connection_t* connection);

/**
** Get a connection's SSB instance.
** @param connection The connection.
** @return The SSB instance.
*/
tf_ssb_t* tf_ssb_connection_get_ssb(tf_ssb_connection_t* connection);

/**
** Get a connection's JS context.
** @param connection The connection.
** @return The JS context.
*/
JSContext* tf_ssb_connection_get_context(tf_ssb_connection_t* connection);

/**
** Close a connection.
** @param connection The connection.
*/
void tf_ssb_connection_close(tf_ssb_connection_t* connection);

/**
** Check whether a connection is connected.
** @param connection The connection.
** @return True if the connection is alive.
*/
bool tf_ssb_connection_is_connected(tf_ssb_connection_t* connection);

/**
** Get the next outgoing request number for a connection.
** @param connection The connection.
** @return The next request number.
*/
int32_t tf_ssb_connection_next_request_number(tf_ssb_connection_t* connection);

/**
** Get an active connection by its identity.
** @param ssb The SSB instance.
** @param id The SSB identity.
** @return The connection if found or NULL.
*/
tf_ssb_connection_t* tf_ssb_connection_get(tf_ssb_t* ssb, const char* id);

/**
** Get the SSB identity of a connection.
** @param connection The connection.
** @param[out] out_id A buffer to be populated with the identity.
** @param out_id_size The size of out_id.
** @return True if the identity was retrieved.
*/
bool tf_ssb_connection_get_id(tf_ssb_connection_t* connection, char* out_id, size_t out_id_size);

/**
** Get the JS object representing a connection.
** @param connection The connection.
** @return The object.
*/
JSValue tf_ssb_connection_get_object(tf_ssb_connection_t* connection);

/**
** A callback called when a callback is cleaned up.
** @param ssb The SSB instance.
** @param user_data User data.
*/
typedef void(tf_ssb_callback_cleanup_t)(tf_ssb_t* ssb, void* user_data);

/**
** A callback called when the connection list changes.
** @param ssb The SSB instance.
** @param change The type of change.
** @param connection The connection that changed.
** @param user_data User data.
*/
typedef void(tf_ssb_connections_changed_callback_t)(tf_ssb_t* ssb, tf_ssb_change_t change, tf_ssb_connection_t* connection, void* user_data);

/**
** Register a callback when the connection list changes.
** @param ssb The SSB instance.
** @param callback The callback to register.
** @param cleanup The cleanup callback to register.
** @param user_data User data to pass to the callbacks.
*/
void tf_ssb_add_connections_changed_callback(tf_ssb_t* ssb, tf_ssb_connections_changed_callback_t* callback, tf_ssb_callback_cleanup_t* cleanup, void* user_data);

/**
** Remove a callback when the connection list changes.
** @param ssb The SSB instance.
** @param callback The callback.
** @param user_data The user data registered with the callback.
*/
void tf_ssb_remove_connections_changed_callback(tf_ssb_t* ssb, tf_ssb_connections_changed_callback_t* callback, void* user_data);

typedef void(tf_ssb_broadcasts_changed_callback_t)(tf_ssb_t* ssb, void* user_data);
void tf_ssb_add_broadcasts_changed_callback(tf_ssb_t* ssb, tf_ssb_broadcasts_changed_callback_t* callback, tf_ssb_callback_cleanup_t* cleanup, void* user_data);
void tf_ssb_remove_broadcasts_changed_callback(tf_ssb_t* ssb, tf_ssb_broadcasts_changed_callback_t* callback, void* user_data);

typedef void(tf_ssb_message_added_callback_t)(tf_ssb_t* ssb, const char* id, void* user_data);
void tf_ssb_add_message_added_callback(tf_ssb_t* ssb, tf_ssb_message_added_callback_t* callback, tf_ssb_callback_cleanup_t* cleanup, void* user_data);
void tf_ssb_remove_message_added_callback(tf_ssb_t* ssb, tf_ssb_message_added_callback_t* callback, void* user_data);
void tf_ssb_notify_message_added(tf_ssb_t* ssb, const char* id, JSValue message_with_keys);
void tf_ssb_notify_blob_stored(tf_ssb_t* ssb, const char* id);

typedef void(tf_ssb_blob_want_added_callback_t)(tf_ssb_t* ssb, const char* id, void* user_data);
void tf_ssb_add_blob_want_added_callback(tf_ssb_t* ssb, tf_ssb_blob_want_added_callback_t* callback, tf_ssb_callback_cleanup_t* cleanup, void* user_data);
void tf_ssb_remove_blob_want_added_callback(tf_ssb_t* ssb, tf_ssb_blob_want_added_callback_t* callback, void* user_data);
void tf_ssb_notify_blob_want_added(tf_ssb_t* ssb, const char* id);

typedef void(tf_ssb_rpc_callback_t)(tf_ssb_connection_t* connection, uint8_t flags, int32_t request_number, JSValue args, const uint8_t* message, size_t size, void* user_data);
void tf_ssb_add_rpc_callback(tf_ssb_t* ssb, const char** name, tf_ssb_rpc_callback_t* callback, tf_ssb_callback_cleanup_t* cleanup, void* user_data);
void tf_ssb_remove_rpc_callback(tf_ssb_t* ssb, const char** name, tf_ssb_rpc_callback_t* callback, void* user_data);

void tf_ssb_connection_rpc_send(tf_ssb_connection_t* connection, uint8_t flags, int32_t request_number, const uint8_t* message, size_t size, tf_ssb_rpc_callback_t* callback,
	tf_ssb_callback_cleanup_t* cleanup, void* user_data);
void tf_ssb_connection_rpc_send_json(
	tf_ssb_connection_t* connection, uint8_t flags, int32_t request_number, JSValue message, tf_ssb_rpc_callback_t* callback, tf_ssb_callback_cleanup_t* cleanup, void* user_data);
void tf_ssb_connection_rpc_send_error(tf_ssb_connection_t* connection, uint8_t flags, int32_t request_number, const char* error);
void tf_ssb_connection_rpc_send_error_method_not_allowed(tf_ssb_connection_t* connection, uint8_t flags, int32_t request_number, const char* name);
void tf_ssb_connection_add_request(tf_ssb_connection_t* connection, int32_t request_number, tf_ssb_rpc_callback_t* callback, tf_ssb_callback_cleanup_t* cleanup, void* user_data,
	tf_ssb_connection_t* dependent_connection);
void tf_ssb_connection_remove_request(tf_ssb_connection_t* connection, int32_t request_number);

typedef void(tf_ssb_scheduled_callback_t)(tf_ssb_connection_t* connection, void* user_data);
void tf_ssb_connection_schedule_idle(tf_ssb_connection_t* connection, tf_ssb_scheduled_callback_t* callback, void* user_data);
void tf_ssb_connection_run_work(tf_ssb_connection_t* connection, void (*work_callback)(tf_ssb_connection_t* connection, void* user_data),
	void (*after_work_callback)(tf_ssb_connection_t* connection, int result, void* user_data), void* user_data);

void tf_ssb_connection_add_new_message_request(tf_ssb_connection_t* connection, const char* author, int32_t request_number, bool keys);
void tf_ssb_connection_remove_new_message_request(tf_ssb_connection_t* connection, const char* author);

bool tf_ssb_connection_is_attendant(tf_ssb_connection_t* connection);
int32_t tf_ssb_connection_get_attendant_request_number(tf_ssb_connection_t* connection);
void tf_ssb_connection_set_attendant(tf_ssb_connection_t* connection, bool attendant, int request_number);
void tf_ssb_connection_clear_room_attendants(tf_ssb_connection_t* connection);
void tf_ssb_connection_add_room_attendant(tf_ssb_connection_t* connection, const char* id);
void tf_ssb_connection_remove_room_attendant(tf_ssb_connection_t* connection, const char* id);

tf_ssb_connection_t* tf_ssb_connection_tunnel_create(tf_ssb_t* ssb, const char* portal_id, int32_t request_number, const char* target_id);

int32_t tf_ssb_connection_get_ebt_request_number(tf_ssb_connection_t* connection);
void tf_ssb_connection_set_ebt_request_number(tf_ssb_connection_t* connection, int32_t request_number);
JSValue tf_ssb_connection_get_ebt_send_clock(tf_ssb_connection_t* connection);
void tf_ssb_connection_set_ebt_send_clock(tf_ssb_connection_t* connection, JSValue send_clock);
bool tf_ssb_connection_get_sent_clock(tf_ssb_connection_t* connection);
void tf_ssb_connection_set_sent_clock(tf_ssb_connection_t* connection, bool sent_clock);

JSClassID tf_ssb_get_connection_class_id();

void tf_ssb_get_stats(tf_ssb_t* ssb, tf_ssb_stats_t* out_stats);

tf_ssb_blob_wants_t* tf_ssb_connection_get_blob_wants_state(tf_ssb_connection_t* connection);

JSValue tf_ssb_get_disconnection_debug(tf_ssb_t* ssb, JSContext* context);

void tf_ssb_record_thread_busy(tf_ssb_t* ssb, bool busy);
float tf_ssb_get_average_thread_percent(tf_ssb_t* ssb);

void tf_ssb_set_hitch_callback(tf_ssb_t* ssb, void (*callback)(const char* name, uint64_t duration_ns, void* user_data), void* user_data);

tf_ssb_store_queue_t* tf_ssb_get_store_queue(tf_ssb_t* ssb);

void tf_ssb_ref(tf_ssb_t* ssb);
void tf_ssb_unref(tf_ssb_t* ssb);

void tf_ssb_set_main_thread(tf_ssb_t* ssb, bool main_thread);

bool tf_ssb_is_room(tf_ssb_t* ssb);
void tf_ssb_set_is_room(tf_ssb_t* ssb, bool is_room);
const char* tf_ssb_get_room_name(tf_ssb_t* ssb);
void tf_ssb_set_room_name(tf_ssb_t* ssb, const char* room_name);

void tf_ssb_schedule_work(tf_ssb_t* ssb, int delay_ms, void (*callback)(tf_ssb_t* ssb, void* user_data), void* user_data);

/** @} */