#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 "gm-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_changed(GtkTextBuffer *buffer, 
		GmWorldInputView *view);

struct _GmWorldInputViewPrivate {
	GmColorTable *color_table;
	GList **history;
	GList *position;
	gchar *prefix;
	
	gulong changed_id;
	guint idle_scroll;
	gboolean is_scrolled;
};

/* Signals */

enum {
	TEXT_ACTIVATE,
  NUM_SIGNALS
};

static guint world_input_view_signals[NUM_SIGNALS] = {0};
static GtkWidgetClass *widget_parent_class;

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);
	
	if (view->priv->idle_scroll) {
		g_source_remove(view->priv->idle_scroll);
	}
	
	G_OBJECT_CLASS(gm_world_input_view_parent_class)->finalize(object);
}

static 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));
	
	g_signal_handlers_block_by_func(buffer, on_gm_world_input_view_changed, 
			view);

	gtk_text_buffer_set_text(buffer, text, len);
	gtk_text_buffer_get_end_iter(buffer, &end);
	gtk_text_buffer_place_cursor(buffer, &end);

	g_signal_handlers_unblock_by_func(buffer, on_gm_world_input_view_changed, 
			view);
}

static void
gm_world_input_view_reset_prefix(GmWorldInputView *view) {
	view->priv->prefix = gm_world_input_view_str_new_value(
			view->priv->prefix, NULL);
}


gboolean
gm_world_input_view_key_press_event(GtkWidget *widget, GdkEventKey *event) {
	GmWorldInputView *view = GM_WORLD_INPUT_VIEW(widget);
	gchar *text;
	gboolean result = FALSE, isUp;
	GtkTextBuffer *buf;
	GtkTextIter start, end, cursor;
	GtkTextMark *insert;
	GList *item, *found = NULL;
	gint line, len;
	
	buf = gtk_text_view_get_buffer(GTK_TEXT_VIEW(view));

	gtk_text_buffer_get_bounds(buf, &start, &end);

	switch (event->keyval) {
		case GDK_Up: case GDK_Down:
			isUp = event->keyval == GDK_Up;
			
			if (!view->priv->history) {
				break;
			}
			
			insert = gtk_text_buffer_get_insert(buf);
			gtk_text_buffer_get_iter_at_mark(buf, &cursor, insert);
			line = gtk_text_iter_get_line(&cursor);
			
			if ((isUp && line != 0) || (!isUp && line != 
					gtk_text_buffer_get_line_count(buf) - 1)) {
				break;
			}

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

			// 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)) {
				result = TRUE;
				break;
			}

			// If the current prefix is NULL then we set the new prefix to
			// the current text
			if (view->priv->prefix == NULL) {
				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') {
				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)) {
					gm_world_input_view_reset_prefix(view);
				}
			}
			
			g_free(text);
			result = TRUE;
		break;
		case GDK_Return:
			// Emit the text_activate signal
			if (!(event->state & GDK_CONTROL_MASK) && 
					!(event->state & GDK_SHIFT_MASK)) {
				text = gtk_text_buffer_get_text(buf, &start, &end, FALSE);
				g_signal_emit(view, world_input_view_signals[TEXT_ACTIVATE], 0,
						text);
				
				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));
					}
				}

				len = g_list_length(*view->priv->history);
				
				for (line = 0; line < len - 500; ++line) {
					*view->priv->history = g_list_remove(*view->priv->history,
							(*view->priv->history)->data);
				}
				
				// 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);
				}
				
				gm_world_input_view_reset_prefix(view);
				
				// Set textview text to an empty string
				gm_world_input_view_set_text(view, "", 0);
				on_gm_world_input_view_changed(buf, view);
				g_free(text);
				result = TRUE;
    		}
		break;
		default:
		break;
	}

	if (!result) {
		if (widget_parent_class->key_press_event) {
			return widget_parent_class->key_press_event(widget, event);
		}
	}
	
	return result;
}

static void
gm_world_input_view_class_init(GmWorldInputViewClass *klass) {
	GObjectClass *object_class = G_OBJECT_CLASS(klass);
	GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
		
	object_class->finalize = gm_world_input_view_finalize;
	widget_class->key_press_event = gm_world_input_view_key_press_event;

	widget_parent_class = GTK_WIDGET_CLASS(gm_world_input_view_parent_class);
	
	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(gtk_text_view_get_buffer(GTK_TEXT_VIEW(view)), "changed", 
			G_CALLBACK(on_gm_world_input_view_changed), view);
}

/* 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;
	
	gm_world_input_view_reset_prefix(view);
}

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) {

	// This will register the view as being schemed by color_table
	gm_register_schemed(GTK_WIDGET(view), color_table, 
			GM_SCHEMED_COLORS | GM_SCHEMED_FONT);

	if (view->priv->color_table != NULL) {
		g_object_unref(view->priv->color_table);
	}
	
	if (color_table != NULL) {
		view->priv->color_table = g_object_ref(color_table);
	} else {
		view->priv->color_table = NULL;
	}
}

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

/* Callbacks */

gboolean
idle_scroll(gpointer user_data) {
	GmWorldInputView *view = GM_WORLD_INPUT_VIEW(user_data);
	GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(view));
	
	view->priv->idle_scroll = 0;
	
	gtk_text_view_scroll_to_mark(GTK_TEXT_VIEW(view), 
			gtk_text_buffer_get_insert(buffer), 0.0, TRUE, 0.5, 1.0);
	return FALSE;
}

void
on_gm_world_input_view_changed(GtkTextBuffer *buffer, 
		GmWorldInputView *view) {
	GtkTextIter start, end;
	GtkWidget *parent = gtk_widget_get_parent(GTK_WIDGET(view));
	GtkScrolledWindow *sw;
	gint lineheight, y;

	if (view->priv->prefix) {
		gtk_text_buffer_get_bounds(buffer, &start, &end);

		if (gtk_text_iter_equal(&start, &end)) {
			// Reset position to the last item in the history
			view->priv->position = g_list_last(*view->priv->history);
				
			gm_world_input_view_reset_prefix(view);
		}
	}
	
	if (!GTK_IS_SCROLLED_WINDOW(parent)) {
		return;
	}
	
	if (!view->priv->is_scrolled && 
			gtk_text_buffer_get_line_count(buffer) > 6) {
		sw = GTK_SCROLLED_WINDOW(parent);
		view->priv->is_scrolled = TRUE;
		
		gtk_text_buffer_get_start_iter(buffer, &start);
		gtk_text_view_get_line_yrange(GTK_TEXT_VIEW(view), &start, &y, 
				&lineheight); 

		gtk_widget_set_size_request(parent, -1, 
				lineheight * 6 + 
				gtk_container_get_border_width(GTK_CONTAINER(sw))
				+ 2);
		
		gtk_scrolled_window_set_policy(sw, GTK_POLICY_NEVER, GTK_POLICY_ALWAYS);
		view->priv->idle_scroll = g_idle_add(idle_scroll, view);
	} else if (view->priv->is_scrolled && 
			gtk_text_buffer_get_line_count(buffer) <= 6) {
		sw = GTK_SCROLLED_WINDOW(parent);
		view->priv->is_scrolled = FALSE;

		gtk_scrolled_window_set_policy(sw, GTK_POLICY_NEVER, GTK_POLICY_NEVER);
		gtk_widget_set_size_request(parent, -1, -1);
	}
}