#include <string.h>
#include <gtk/gtk.h>
#include <gdk/gdk.h>
#include <gdk/gdkkeysyms.h>

#include "gm-world-input-view.h"
#include "gm-world-view.h"
#include "gm-world.h"
#include "gm-color-table.h"
#include "debug.h"

#define GM_WORLD_INPUT_VIEW_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE((object),	GM_TYPE_WORLD_INPUT_VIEW, GmWorldInputViewPrivate))

void on_gm_world_input_view_color_table_color_changed(GmColorTable *table,
		gchar *name, GmWorldInputView *view);
void on_gm_world_input_view_color_table_font_changed(GmColorTable *table,
		gchar *font_description, GmWorldInputView *view);

gboolean on_gm_world_input_view_key_pressed(GtkWidget *widget,
		GdkEventKey * event, gpointer userdata);
gboolean on_gm_world_input_view_key_released(GtkWidget *widget, 
		GdkEventKey *event,	gpointer userdata);

struct _GmWorldInputViewPrivate {
	GmColorTable *color_table;
	GList **history;
	GList *position;
	gchar *prefix;
};

/* Signals */

enum {
	TEXT_ACTIVATE,
  NUM_SIGNALS
};

static guint world_input_view_signals[NUM_SIGNALS] = {0};

G_DEFINE_TYPE(GmWorldInputView, gm_world_input_view, GTK_TYPE_TEXT_VIEW)

/* Private functions */
static void
gm_world_input_view_finalize(GObject *object) {
	GmWorldInputView *view = GM_WORLD_INPUT_VIEW(object);
	
	gm_world_input_view_set_color_table(view, NULL);
	
	G_OBJECT_CLASS(gm_world_input_view_parent_class)->finalize(object);
}

static void
gm_world_input_view_class_init(GmWorldInputViewClass *klass) {
	GObjectClass *object_class = G_OBJECT_CLASS(klass);
	
	object_class->finalize = gm_world_input_view_finalize;

	world_input_view_signals[TEXT_ACTIVATE] = 
		g_signal_new("text_activate",
			G_OBJECT_CLASS_TYPE(object_class),
			G_SIGNAL_RUN_LAST,
			G_STRUCT_OFFSET(GmWorldInputViewClass, text_activate),
			NULL, NULL,
			g_cclosure_marshal_VOID__STRING,
			G_TYPE_NONE,
			1,
			G_TYPE_STRING);
				
	g_type_class_add_private(object_class, sizeof(GmWorldInputViewPrivate));
}

static void
gm_world_input_view_init(GmWorldInputView *view) {
	view->priv = GM_WORLD_INPUT_VIEW_GET_PRIVATE(view);
	
	view->priv->color_table = NULL;
	view->priv->history = NULL;
	view->priv->position = NULL;
	view->priv->prefix = NULL;
	
	gtk_text_view_set_wrap_mode(GTK_TEXT_VIEW(view), GTK_WRAP_WORD_CHAR);
	gtk_text_view_set_accepts_tab(GTK_TEXT_VIEW(view), TRUE);
	gtk_text_view_set_left_margin(GTK_TEXT_VIEW(view), 3);
	gtk_text_view_set_right_margin(GTK_TEXT_VIEW(view), 3);
	gtk_text_view_set_pixels_above_lines(GTK_TEXT_VIEW(view), 1);
	gtk_text_view_set_pixels_below_lines(GTK_TEXT_VIEW(view), 1);
	
	g_signal_connect(view, "key_press_event", 
			G_CALLBACK(on_gm_world_input_view_key_pressed), NULL);
	g_signal_connect(view, "key_release_event", 
			G_CALLBACK(on_gm_world_input_view_key_released), NULL);
}

gchar *
gm_world_input_view_str_new_value(gchar *old, gchar *new) {
	g_free(old);

	if (new) {
		return g_strdup(new);
	} else {
		return NULL;
	}
}

void
gm_world_input_view_set_text(GmWorldInputView *view, gchar *text, gint len) {
	GtkTextIter end;
	GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(view));
	
	gtk_text_buffer_set_text(buffer, text, len);
	gtk_text_buffer_get_end_iter(buffer, &end);
	gtk_text_buffer_place_cursor(buffer, &end);
}

void
gm_world_input_view_update_colors(GmWorldInputView *view) {
	GdkColor col;
	
	if (view->priv->color_table != NULL) {
		if (gm_color_table_get(view->priv->color_table, "bg_default", &col)) {
			gtk_widget_modify_base(GTK_WIDGET(view), GTK_STATE_NORMAL,
					&col);
		}
		if (gm_color_table_get(view->priv->color_table, "fg_default", &col)) {
			gtk_widget_modify_text(GTK_WIDGET(view), GTK_STATE_NORMAL,
					&col);	
		}
	}
}

void
gm_world_input_view_update_font(GmWorldInputView *view) {
	PangoFontDescription *f = pango_font_description_from_string(
			gm_color_table_font_description(view->priv->color_table));
	
	if (f != NULL) {
		gtk_widget_modify_font(GTK_WIDGET(view), f);
		pango_font_description_free(f);
	}
}

/* Public functions */
GtkWidget *
gm_world_input_view_new() {
	GtkWidget *result;
	GmColorTable *table = gm_color_table_new();
	result = gm_world_input_view_new_with_color_table(table);
	g_object_unref(table);
	
	return result;
}

GtkWidget *
gm_world_input_view_new_with_color_table(GmColorTable *color_table) {
	GmWorldInputView *view = GM_WORLD_INPUT_VIEW(
			g_object_new(GM_TYPE_WORLD_INPUT_VIEW, NULL));
	
	gm_world_input_view_set_color_table(view, color_table);

	return GTK_WIDGET(view);
}

void
gm_world_input_view_set_history(GmWorldInputView *view, GList **history) {
	view->priv->history = history;
	
	view->priv->position = NULL;
	view->priv->prefix = NULL;
}

GList **
gm_world_input_view_history(GmWorldInputView *view) {
	return view->priv->history;
}

void
gm_world_input_view_set_color_table(GmWorldInputView *view, 
		GmColorTable *color_table) {
	if (view->priv->color_table != NULL) {
		g_signal_handlers_disconnect_by_func(view->priv->color_table, 
				on_gm_world_input_view_color_table_color_changed, view);
		g_signal_handlers_disconnect_by_func(view->priv->color_table, 
				on_gm_world_input_view_color_table_font_changed, view);
		g_object_unref(view->priv->color_table);
	}
	
	if (color_table != NULL) {
		view->priv->color_table = g_object_ref(color_table);
		g_signal_connect(view->priv->color_table, "color_changed",
				G_CALLBACK(on_gm_world_input_view_color_table_color_changed), view);
		g_signal_connect(view->priv->color_table, "font_changed",
				G_CALLBACK(on_gm_world_input_view_color_table_font_changed), view);

		gm_world_input_view_update_colors(view);
		gm_world_input_view_update_font(view);
	} else {
		view->priv->color_table = NULL;
	}
}

GmColorTable *
gm_world_input_view_color_table(GmWorldInputView *view) {
	return view->priv->color_table;
}

/* Callbacks */
void
on_gm_world_input_view_color_table_color_changed(GmColorTable *table,
		gchar *name, GmWorldInputView *view) {
	if (strcmp(name, "fg_default") == 0 || strcmp(name, "bg_default") == 0) {
		gm_world_input_view_update_colors(view);
	}
}

void
on_gm_world_input_view_color_table_font_changed(GmColorTable *table,
		gchar *font_description, GmWorldInputView *view) {
	gm_world_input_view_update_font(view);
}

gboolean
on_gm_world_input_view_key_released(GtkWidget *widget, GdkEventKey *event,
		gpointer userdata) {
	GmWorldInputView *view = GM_WORLD_INPUT_VIEW(widget);
	GtkTextBuffer *buffer;
	GtkTextIter start, end;
	gchar *text;
	
	buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(view));
	gtk_text_buffer_get_bounds(buffer, &start, &end);
	text = gtk_text_buffer_get_text(buffer, &start, &end, FALSE);
	
	switch (event->keyval) {
		case GDK_Delete: case GDK_BackSpace:
			if (text[0] == '\0') {
				// Reset position to the last item in the history
				view->priv->position = g_list_last(*view->priv->history);
				
				// Reset prefix to NULL
				view->priv->prefix = gm_world_input_view_str_new_value(
						view->priv->prefix, NULL);
			}
		break;
	}
	
	g_free(text);
	return FALSE;
}

gboolean
on_gm_world_input_view_key_pressed(GtkWidget *widget, GdkEventKey *event, 
		gpointer userdata) {
	GmWorldInputView *view = GM_WORLD_INPUT_VIEW(widget);
	gchar *text;
	gboolean result = TRUE, isUp;
	GtkTextBuffer *buf;
	GtkTextIter start, end;
	GList *item, *found = NULL;
	
	buf = gtk_text_view_get_buffer(GTK_TEXT_VIEW(view));

	gtk_text_buffer_get_bounds(buf, &start, &end);
	text = gtk_text_buffer_get_text(buf, &start, &end, FALSE);

	switch (event->keyval) {
		case GDK_Up: case GDK_Down:
			isUp = event->keyval == GDK_Up;
			
			if (!view->priv->history) {
				break;
			}

			// If the current position is empty then append a new history item
			if (!view->priv->position) {
				*view->priv->history = g_list_append(*view->priv->history, 
						g_strdup(text));
				view->priv->position = g_list_last(*view->priv->history);
			}
			
			// If there is nowhere to move, don't even bother
			if ((isUp && !view->priv->position->prev) 
					|| (!isUp && !view->priv->position->next)) {
				break;		
			}

			// If the current prefix is NULL then we set the new prefix to
			// the current text
			if (view->priv->prefix == NULL) {
				debug_msg(0, "Prefix: %s", text);
				view->priv->prefix = g_strdup(text);
			}
			
			// If the prefix is an empty string then simply advance to the
			// next item
			if (view->priv->prefix[0] == '\0') {
				if (isUp) {
					found = view->priv->position->prev;
				} else {
					found = view->priv->position->next;
				}
			} else {
				// Else find the closest matching history line
				item = isUp ? view->priv->position->prev : 
						view->priv->position->next;
				while (item) {
					if (strncmp((gchar *)item->data, view->priv->prefix,
							strlen(view->priv->prefix)) == 0) {
						// Change current position to the matched item
						found = item;
						break;
					}
					
					item = isUp ? item->prev : item->next;
				}
			}

			// If a match is found then set this history text
			if (found) {
				// Change the data of the current position to the text
				// now in the buffer.
				view->priv->position->data = 
						gm_world_input_view_str_new_value(
								view->priv->position->data, text);
				gm_world_input_view_set_text(view, (gchar *)found->data, -1);
				view->priv->position = found;
				
				if (found == g_list_last(*view->priv->history)) {
					view->priv->prefix = gm_world_input_view_str_new_value(
						view->priv->prefix, NULL);
				}
			}
		break;
		case GDK_Return:
			// Emit the text_activate signal
			if (!(event->state & GDK_CONTROL_MASK) && 
					!(event->state & GDK_SHIFT_MASK)) {

				g_signal_emit(view, world_input_view_signals[TEXT_ACTIVATE], 0,
						text);

				debug_msg(0, "%d", view->priv->history);
				
				if (view->priv->history) {
					item = g_list_last(*view->priv->history);
					
					if (item) {
						item->data = gm_world_input_view_str_new_value(
								(gchar *)(item->data), text);
					} else {
						*view->priv->history = 
								g_list_append(*view->priv->history, 
								g_strdup(text));
					}
				}

				// TODO: manage history length
				
				// Append new empty history item which will become our new 
				// current item
				if (view->priv->history) {
					*view->priv->history = 
							g_list_append(*view->priv->history, g_strdup(""));
					view->priv->position = g_list_last(*view->priv->history);
				}
				
				// Reset prefix to NULL
				view->priv->prefix = gm_world_input_view_str_new_value(
						view->priv->prefix, NULL);
				
				// Set textview text to an empty string
				gm_world_input_view_set_text(view, "", 0);
    		} else {
    			result = FALSE;
    		}
		break;
		default:
			result = FALSE;
		break;
	}

	g_free(text);
	return result;
}