#ifndef IRC_LINE_H
#define IRC_LINE_H

/**
 * @file
 *
 * The low-level IRC protocol unit is a line, with prefix, command and arguments
 */
#include "error.h"

/**
 * The maximum length of a line, without terminating CRLF
 */
#define IRC_LINE_MAX 510

/**
 * The maximum number of arguments for a single command
 */
#define IRC_ARG_MAX 15

/**
 * Chars that are invalid inside of tokens
 */
#define IRC_TOKEN_INVALID "\r\n\n "
#define IRC_TOKEN_TRAILING_INVALID "\r\n\n"

/**
 * Low-level IRC protocol unit
 */
struct irc_line {
    /** The message source, either a server name or a nickmask */
    const char *prefix;

    /** The command, either a numeric or a primary command */
    const char *command;

    /** The arguments, with unused ones set to NULL */
    const char *args[IRC_ARG_MAX];
};

/**
 * Parse an IRC message to fill in an irc_line. This mutates the value of data (to insert NULs between tokens), and
 * stores pointers into this data into the irc_line.
 *
 * The irc_line will have the first N args values set to valid values, and all the rest set to NULL.
 */
err_t irc_line_parse (struct irc_line *line, char *data);

/**
 * Formats an irc_line as a protocol line into the given buffer (which should hold at least IRC_LINE_MAX bytes).
 *
 * The irc_line.args are ignored from the first NULL argument onwards.
 *
 * An error is returned if a token has an invalid value (e.g. a space in the command or an argument other than the last
 * one), or if the resulting line is too long.
 */
err_t irc_line_build (const struct irc_line *line, char *buf);

#endif /* IRC_LINE_H */