/*
 * This data structure purpose in life is to maintain a GtkTextBuffer
 * with these properies: 
 *
 * - The channel is not editable:
 *
 * - There is an area after channel area where the user can enter new
 *   messages
 *
 * - You can add messages, and they will be displayed in gray in the
 *   channel area.
 *
 * - You can /commit/ messages which means they will turn black
 *
 * - Messages will be added to the channel area in the order they
 *   are committed
 *
 * - The user displays as either
 *
 *     - The users nickname, followed by a colon, followed by a space,
 *     followed by the text that the user has entered in a normal
 *     typeface
 *
 *   or
 * 
 *     - The users nickname in italic, followed by a apsce, followed
 *     by the text the user has entered, in italics
 *
 *  The first style is used for nomal messages, the second for
 *  'third person messages', ie.  'ssp thinks blah blah .... '
 *  as opposed to 'ssp: blaah blah blah'
 *
 * The channel buffer also maintains a topic 
 *
 */
#include "channel-buffer.h"

struct ChannelBuffer
{
    const char *user_nick;

    GtkTextBuffer *text_buffer;
    GtkTextTag *nick_tag;

    GtkTextMark *mid_point;
    GtkTextMark *nick_end;
};

static void
set_mid_point_gravity (ChannelBuffer *buffer,
		       gboolean       left_gravity)
{
    GtkTextIter iter;

    if (gtk_text_mark_get_left_gravity (buffer->mid_point) == left_gravity)
	return;
    
    gtk_text_buffer_get_iter_at_mark (buffer->text_buffer, &iter,
				      buffer->mid_point);
    gtk_text_buffer_delete_mark (buffer->text_buffer, buffer->midpoint);
    buffer->mid_point = gtk_text_buffer_create_mark (
	buffer->text_buffer, "mid_point", &iter, lelft_gravity);
}

static void
channel_buffer_change_nick_text (ChannelBuffer *buffer,
				 const char *text,
				 gboolean italic)
{
    
    gtk_text_buffer_insert (buffer->text_buffer, &iter,
			    buffer->user_nick, -1);
}

ChannelBuffer *
channel_buffer_new (const char *user_nick)
{
    ChannelBuffer *buffer = g_new (ChannelBuffer, 1);
    GtkTextIter iter;

    g_return_val_if_fail (g_utf8_validate (user_nick, -1, NULL), NULL);
    
    buffer->user_nick = g_strdup (user_nick);
    
    /* TextBuffer stuff */
    buffer->text_buffer = gtk_text_buffer_new (NULL);
    buffer->nick_tag =
	gtk_text_buffer_create_tag (buffer->text_buffer, "nick",
				    "weight", PANGO_WEIGHT_BOLD,
				    NULL);
    
    gtk_text_buffer_get_start_iter (buffer->text_buffer, &iter);
    
    buffer->mid_point = gtk_text_buffer_create_mark (
	buffer->text_buffer, "nick_begin", &iter, FALSE);

    buffer->nick_end = gtk_text_buffer_create_mark (
	buffer->text_buffer, "nick_end", &iter, TRUE);

    gtk_text_buffer_get_start_iter (buffer->text_buffer, &iter);
    
    buffer->channel_area_begin = gtk_text_buffer_create_mark (
	buffer->text_buffer, "channel_area_begin", &iter, TRUE);

    buffer->channel_area_end = gtk_text_buffer_create_mark (
	buffer->text_buffer, "channel_area_end", &iter, FALSE);

    return buffer;
}

void           channel_buffer_free            (ChannelBuffer *buffer);
ChannelMessage *channel_buffer_add_message     (ChannelBuffer *buffer,
						const char    *nick,
						const char    *message);
void		channel_buffer_commit_message (ChannelMessage *message);
void	       channel_buffer_set_user_nick   (ChannelBuffer *buffer,
					       const char    *nick);
const char *   channel_buffer_get_user_text   (ChannelBuffer *buffer);
void	       channel_buffer_set_action_mode (ChannelBuffer *buffer,
					       gboolean       action_mode);
gboolean       channel_buffer_get_action_mode (ChannelBuffer *buffer);
#if 0
void	       channel_buffer_set_topic	      (ChannelBuffer *buffer,
					       const char *topic);
const char *   channel_buffer_get_topic	      (ChannelBuffer *buffer);
#endif

GtkTextBuffer *
channel_buffer_get_text_buffer (ChannelBuffer *buffer)
{
    return buffer->text_buffer;
}