/*
 * Copyright (C) 2012 - Juan Ferrer Toribio
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "vn-field.h"

G_DEFINE_ABSTRACT_TYPE (VnField, vn_field, GTK_TYPE_EVENT_BOX);

enum {
	 VALUE_CHANGED
	,LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = {0};

/**
 * VnFieldStyleFunc:
 * @obj: a #VnField
 * @widget: the #GtkWidget held by the field
 * @value: (transfer none): the current value in the cell
 * 
 * Function used to modify the field depending on @value.
 **/

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Private

static void vn_field_spec_changed (VnField * obj)
{
	gvn_param_spec_unset (obj->spec);
	gvn_param_spec_merge (obj->spec, obj->user_spec);
	
	if (obj->param)
		gvn_param_spec_merge (obj->spec,
			gvn_param_get_spec (obj->param));
}

static void vn_field_on_param_spec_changed (GvnParam * param, VnField * obj)
{
	vn_field_spec_changed (obj);
}

static void vn_field_on_param_value_changed (GvnParam * param, const GValue * value, VnField * obj)
{
	obj->update_param = FALSE;
	vn_field_set_value (obj, value);
	obj->update_param = TRUE;
}

static void vn_field_set_invalid (VnField * obj, const GError * err)
{
/*	GdkRGBA color = {0.95, 0.8, 0.8, 1};	
	gtk_widget_override_background_color (GTK_WIDGET (obj->field),
		GTK_STATE_FLAG_NORMAL, &color);
*/}

static void vn_field_on_param_status_changed (GvnParam * param, VnField * obj)
{
	switch (gvn_param_get_status (param))
	{
		case GVN_PARAM_STATUS_OK:
			gtk_widget_set_sensitive (obj->field, TRUE);
			break;
		case GVN_PARAM_STATUS_BUSY:
			gtk_widget_set_sensitive (obj->field, FALSE);
			break;
		case GVN_PARAM_STATUS_ERROR:
			vn_field_set_invalid (obj, gvn_param_get_error (param));
			break;
	}
}

static void vn_field_changed (VnField * obj)
{
	if (obj->param && obj->update_param)
	{
		GError * err = NULL;

		g_signal_handlers_block_by_func (obj->param,
			vn_field_on_param_value_changed, obj);

		if (!gvn_param_set_value (obj->param, obj->value, &err))
		{
			vn_field_set_invalid (obj, err);
			g_error_free (err);
		}

		g_signal_handlers_unblock_by_func (obj->param,
			vn_field_on_param_value_changed, obj);
	}

	if (obj->style_func)
		obj->style_func (obj, obj->field, obj->value);

	g_signal_emit (obj, signals[VALUE_CHANGED], 0, obj->value);
}

static void vn_field_value_changed (VnField * obj, const GValue * value)
{
	GType type;
	gboolean changed;
	
	if (obj->lock_changed_done)
		return;

	type = gvn_param_spec_get_gtype (obj->spec);

	if (type != G_TYPE_NONE && !gvn_value_is_null (value))
	{
		if (G_VALUE_TYPE (obj->value) != type)
		{
			g_value_unset (obj->value);
			g_value_init (obj->value, type);
		}
		
		g_value_transform (value, obj->value);
		changed = TRUE;
	}
	else
		changed = gvn_value_ccopy (value, obj->value);

	if (changed)
		vn_field_changed (obj);
}

static void vn_field_make_param (VnField * obj)
{
	GvnParam * param;

	if (!obj->iterator || !obj->column_name)
		return;

	param = db_iterator_get_param (obj->iterator, obj->column_name);
	vn_field_set_param (obj, param);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Public

/**
 * vn_field_get_value:
 * @obj: the #VnField
 *
 * Gets the current field value.
 *
 * Return value: (transfer none): the #GValue
 **/
const GValue * vn_field_get_value (VnField * obj)
{
	return obj->value;
}

/**
 * vn_field_set_value:
 * @obj: the #VnField
 * @value: a #GValue
 *
 * Sets the field value.
 **/
void vn_field_set_value (VnField * obj, const GValue * value)
{
	g_return_if_fail (VN_IS_FIELD (obj));
	g_return_if_fail (G_IS_VALUE (value));

	if (gvn_value_ccopy (value, obj->value))
	{
		obj->lock_changed_done = TRUE;
		VN_FIELD_GET_CLASS (obj)->set_value (obj, obj->value);
		obj->lock_changed_done = FALSE;
		vn_field_changed (obj);
	}
}

/**
 * vn_field_get_param:
 * @obj: the #VnField
 * 
 * Return value: (transfer none):
**/
GvnParam * vn_field_get_param (VnField * obj)
{
	g_return_val_if_fail (VN_IS_FIELD (obj), NULL);

	return obj->param;
}

/**
 * vn_field_set_param:
 * @obj: the #VnField
 * @param: a #GvnParam
 *
 * Binds the field with a #GvnParam.
 **/
void vn_field_set_param (VnField * obj, GvnParam * param)
{
	g_return_if_fail (VN_IS_FIELD (obj));
	g_return_if_fail (GVN_IS_PARAM (param) || !param);
	
	if (obj->param)
	{
		g_object_disconnect (obj->param
			,"any_signal", vn_field_on_param_value_changed, obj
			,"any_signal", vn_field_on_param_spec_changed, obj
			,"any_signal", vn_field_on_param_status_changed, obj
			,NULL
		);
		g_clear_object (&obj->param);
	}
	if (param)
	{
		obj->param = g_object_ref_sink (param);
		g_object_connect (param
			,"signal::value-changed", vn_field_on_param_value_changed, obj
			,"signal::spec-changed", vn_field_on_param_spec_changed, obj
			,"signal::status-changed", vn_field_on_param_status_changed, obj
			,NULL
		);
		vn_field_on_param_spec_changed (param, obj);
		vn_field_on_param_value_changed (param,
			gvn_param_get_value (param), obj);
		vn_field_on_param_status_changed (param, obj);
	}
	
/*	GFile * css = g_file_new_for_path ("vn/gui/style.css");	
	
	if (g_file_query_exists (css, NULL))
	{
		GError * err = NULL;
		GtkCssProvider * provider = gtk_css_provider_get_default ();
	
		if (gtk_css_provider_load_from_file (provider, css, &err))
		{
			GtkStyleContext * style;
			style = gtk_widget_get_style_context (GTK_WIDGET (obj->field));
			gtk_style_context_add_provider (style, GTK_STYLE_PROVIDER (provider),
				GTK_STYLE_PROVIDER_PRIORITY_USER);
			gtk_style_context_add_class (style, "invalid");
		}
		else
		{
			g_warning ("Vn: %s", err->message);
			g_error_free (err);
		}
	}
	else
		g_warning ("Vn: Can't load CSS styles");
	
	g_object_unref (css);
*/
}

/**
 * vn_field_get_gtype:
 * @obj: the #VnField
 *
 * Gets the field type.
 *
 * Return value: the field type or %G_TYPE_NONE if it havent.
 **/
GType vn_field_get_gtype (VnField * obj)
{
	g_return_val_if_fail (VN_IS_FIELD (obj), G_TYPE_INVALID);

	return gvn_param_spec_get_gtype (obj->spec);
}

/**
 * vn_field_set_gtype:
 * @obj: the #VnField
 * @type: a valid #GType
 *
 * Sets the type of the field. When you set a value, it will be converted to
 * this type.
 **/
void vn_field_set_gtype (VnField * obj, GType type)
{
	g_return_if_fail (VN_IS_FIELD (obj));

	gvn_param_spec_set_gtype (obj->user_spec, type);
	vn_field_spec_changed (obj);
}

/**
 * vn_field_get_null:
 * @obj: the #VnField
 *
 * If field allows values with %GVN_TYPE_NULL type.
 *
 * Return value: %TRUE if it can, %FALSE otherwise.
 **/
gboolean vn_field_get_null (VnField * obj)
{
	g_return_val_if_fail (VN_IS_FIELD (obj), FALSE);

	return gvn_param_spec_get_null (obj->spec);
}

/**
 * vn_field_set_null:
 * @obj: the #VnField
 * @null: %TRUE if field should accept NULL values
 *
 * Sets if field allows values with %GVN_TYPE_NULL type. If param property of
 * the field is set, this attribute will be merged with the same #GvnParam
 * attribute, remaining the most restrictive.
 **/
void vn_field_set_null (VnField * obj, gboolean null)
{
	g_return_if_fail (VN_IS_FIELD (obj));

	gvn_param_spec_set_null (obj->user_spec, null);
	vn_field_spec_changed (obj);
}

/**
 * vn_field_get_editable:
 * @obj: the #VnField
 *
 * Gets whether the field value can be modified.
 *
 * Return value: %TRUE if field value can be edited, %FALSE otherwise.
 **/
gboolean vn_field_get_editable (VnField * obj)
{
	g_return_val_if_fail (VN_IS_FIELD (obj), FALSE);

	return gvn_param_spec_get_editable (obj->spec);
}

/**
 * vn_field_set_editable:
 * @obj: the #VnField
 * @editable: %TRUE if field can be editable
 *
 * Sets if field value can be modified. If param property of
 * the field is set, this attribute will be merged with the same #GvnParam
 * attribute, remaining the most restrictive.
 **/
void vn_field_set_editable (VnField * obj, gboolean editable)
{
	g_return_if_fail (VN_IS_FIELD (obj));

	gvn_param_spec_set_editable (obj->user_spec, editable);
	vn_field_spec_changed (obj);
}

/**
 * vn_field_get_default:
 * @obj: the #VnField
 **/
const GValue * vn_field_get_default (VnField * obj)
{
	g_return_val_if_fail (VN_IS_FIELD (obj), NULL);

	return gvn_param_spec_get_default (obj->spec);
}

/**
 * vn_field_set_default:
 * @obj: the #VnField
 * @def: the default #GValue
 *
 * Sets the default value of the field.
 **/
void vn_field_set_default (VnField * obj, const GValue * def)
{
	g_return_if_fail (VN_IS_FIELD (obj));

	gvn_param_spec_set_default (obj->user_spec, def);
	vn_field_spec_changed (obj);
}

/**
 * vn_field_set_to_default:
 * @obj: the #VnField
 **/
void vn_field_set_to_default (VnField * obj)
{
	g_return_if_fail (VN_IS_FIELD (obj));

	vn_field_set_value (obj,
		gvn_param_spec_get_default (obj->spec));
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Properties

enum
{
	 PROP_VALUE = 1
	,PROP_PARAM
	,PROP_ITERATOR
	,PROP_COLUMN_NAME
	,PROP_GTYPE
	,PROP_EDITABLE
	,PROP_NULL
	,PROP_DEFAULT
	,PROP_STYLE_FUNC
};

static void vn_field_set_property (VnField * obj, guint id,
	const GValue * value, GParamSpec * pspec)
{
	switch (id)
	{
		case PROP_VALUE:
			vn_field_set_value (obj, g_value_get_boxed (value));
			break;
		case PROP_PARAM:
			vn_field_set_param (obj, g_value_get_object (value));
			break;
		case PROP_ITERATOR:
			g_clear_object (&obj->iterator);
			obj->iterator = g_value_dup_object (value);
			vn_field_make_param (obj);
			break;
		case PROP_COLUMN_NAME:
			g_free (obj->column_name);
			obj->column_name = g_value_dup_string (value);
			vn_field_make_param (obj);
			break;
		case PROP_GTYPE:
			vn_field_set_gtype (obj, g_value_get_gtype (value));
			break;
		case PROP_EDITABLE:
			vn_field_set_editable (obj, g_value_get_boolean (value));
			break;
		case PROP_NULL:
			vn_field_set_null (obj, g_value_get_boolean (value));
			break;
		case PROP_DEFAULT:
			vn_field_set_default (obj, g_value_get_boxed (value));
			break;
		case PROP_STYLE_FUNC:
			obj->style_func = g_value_get_pointer (value);
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, id, pspec);
	}
}

static void vn_field_get_property (VnField * obj, guint id,
	GValue * value, GParamSpec * pspec)
{
	switch (id)
	{
		case PROP_VALUE:
			g_value_set_boxed (value, obj->value);
			break;
		case PROP_PARAM:
			g_value_set_object (value, obj->param);
			break;
		case PROP_ITERATOR:
			g_value_set_object (value, obj->iterator);
			break;
		case PROP_COLUMN_NAME:
			g_value_set_string (value, obj->column_name);
			break;
		case PROP_GTYPE:
			g_value_set_gtype (value, vn_field_get_gtype (obj));
			break;
		case PROP_EDITABLE:
			g_value_set_boolean (value, vn_field_get_editable (obj));
			break;
		case PROP_NULL:
			g_value_set_boolean (value, vn_field_get_null (obj));
			break;
		case PROP_DEFAULT:
			g_value_set_boxed (value, vn_field_get_default (obj));
			break;
		case PROP_STYLE_FUNC:
			g_value_set_pointer (value, obj->style_func);
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, id, pspec);
	}
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Class

static void vn_field_init (VnField * obj)
{
	GdkRGBA color = {0.0, 0.0, 0.0, 0.0};

	obj->param = NULL;
	obj->update_param = TRUE;
	obj->lock_changed_done = FALSE;
	obj->user_spec = gvn_param_spec_new ();
	obj->spec = gvn_param_spec_new ();
	obj->iterator = NULL;
	obj->column_name = NULL;
	obj->style_func = NULL;
	
	obj->value = g_new0 (GValue, 1);
	g_value_init (obj->value, GVN_TYPE_NULL);
	
	gtk_widget_override_background_color (GTK_WIDGET (obj),
		GTK_STATE_FLAG_NORMAL, &color);
}

static void vn_field_finalize (VnField * obj)
{
	gvn_param_spec_free (obj->spec);
	gvn_param_spec_free (obj->user_spec);
	g_clear_object (&obj->iterator);
	vn_field_set_param (obj, NULL);
	g_value_unset (obj->value);
	g_free (obj->value);
	g_free (obj->column_name);
	G_OBJECT_CLASS (vn_field_parent_class)->finalize (G_OBJECT (obj));
}

static void vn_field_class_init (VnFieldClass * klass)
{
	GObjectClass * k = G_OBJECT_CLASS (klass);
	k->finalize = (GObjectFinalizeFunc) vn_field_finalize;
	k->set_property = (GObjectSetPropertyFunc) vn_field_set_property;
	k->get_property = (GObjectGetPropertyFunc) vn_field_get_property;
	klass->value_changed = vn_field_value_changed;

	signals[VALUE_CHANGED] = g_signal_new ("value-changed",
		VN_TYPE_FIELD, G_SIGNAL_RUN_FIRST, 0, NULL, NULL,
		g_cclosure_marshal_VOID__BOXED, G_TYPE_NONE, 1, G_TYPE_VALUE
	);

	g_object_class_install_property (k, PROP_VALUE,
		g_param_spec_boxed ("value"
			,_("Value")
			,_("The current value of the field")
			,G_TYPE_VALUE
			,G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_PARAM,
		g_param_spec_object ("param"
			,_("Parameter")
			,_("The param where the field can read/write its value")
			,GVN_TYPE_PARAM
			,G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_ITERATOR,
		g_param_spec_object ("iterator"
			,_("Iterator")
			,_("The iterator used to get the field param")
			,DB_TYPE_ITERATOR
			,G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_COLUMN_NAME,
		g_param_spec_string ("column-name"
			,_("Column name")
			,_("The column name on the iterator")
			,NULL
			,G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_GTYPE,
		g_param_spec_gtype ("gtype"
			,_("Glib Type")
			,_("The type of the value")
			,G_TYPE_NONE
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_EDITABLE,
		g_param_spec_boolean ("editable"
			,_("Editable")
			,_("Whether the field value is user editable")
			,TRUE
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_NULL,
		g_param_spec_boolean ("null"
			,_("Null")
			,_("Whether the field value can be of type GVN_TYPE_NULL")
			,TRUE
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_DEFAULT,
		g_param_spec_boxed ("default"
			,_("Default Value")
			,_("The default value")
			,G_TYPE_VALUE
			,G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_STYLE_FUNC,
		g_param_spec_pointer ("style-func"
			,_("Style function")
			,_("A VnFieldStyleFunc to set the properties of each field "
			"depending on its value")
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
}