/*
 * Copyright (c) 2016 Samsung Electronics Co., Ltd
 *
 * Licensed under the Flora License, Version 1.1 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://floralicense.org/license/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <efl_extension.h>
#include "$(appName).h"
#include "view.h"
#include "view_defines.h"

typedef enum { STATE_NORMAL = 0, STATE_PRESS, STATE_DRAG } state_t;

static const char *source_text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna " \
								 "aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis" \
								 " aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat" \
								 " cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";

static struct view_info {
	Evas_Object *win;
	Evas_Object *conform;
	Evas_Object *main_layout;
	Evas_Object *source_label;
	Evas_Object *sink_entry;
	Evas_Object *hover;
	state_t state;
	int drag_start_x;
	int drag_start_y;
} s_info = {
	.win = NULL,
	.conform = NULL,
	.main_layout = NULL,
	.source_label = NULL,
	.sink_entry = NULL,
	.hover = NULL,
	.state = STATE_NORMAL,
	.drag_start_x = 0,
	.drag_start_y = 0,
};

static void _delete_win_request_cb(void *data, Evas_Object *obj, void *event_info);
static void _layout_back_cb(void *data, Evas_Object *obj, void *event_info);
static Eina_Bool _press_cb(void *data, int type, void *event);
static Eina_Bool _move_cb(void *data, int type, void *event);
static Eina_Bool _unpress_cb(void *data, int type, void *event);
static void _get_app_resource(const char *file_in, char *path_out);
static Eina_Bool _create_source(void);
static Eina_Bool _create_sink(void);
static Eina_Bool _create_hover_window(void);
static void _set_callbacks(void);
static bool _source_hit_test(int x, int y);
static bool _sink_hit_test(int x, int y);
static void _paste_to_hover(void);
static void _paste_to_sink(void);
static void _set_hover_window_size(void);
static void _set_hover_window_position(int x, int y);
static void _hide_hover_window(void);
static void _show_hover_window(void);

/**
 * @brief Creates essential objects: window, conformant and layout.
 */
Eina_Bool view_create(void)
{
	/* Create the window */
	s_info.win = view_create_win(PACKAGE);
	if (s_info.win == NULL) {
		dlog_print(DLOG_ERROR, LOG_TAG, "failed to create a window.");
		return EINA_FALSE;
	}

	/* Create the conformant */
	s_info.conform = view_create_conformant_without_indicator(s_info.win);
	if (s_info.conform == NULL) {
		dlog_print(DLOG_ERROR, LOG_TAG, "failed to create a conformant");
		return EINA_FALSE;
	}

	s_info.main_layout = view_create_layout(s_info.conform, EDJ_MAIN, GRP_MAIN, NULL);
	if (!s_info.main_layout) {
		dlog_print(DLOG_ERROR, LOG_TAG, "view_create_layout() failed.");
		return EINA_FALSE;
	}

	if (!_create_source()) {
		dlog_print(DLOG_ERROR, LOG_TAG, "_create_source() failed.");
		return false;
	}

	if (!_create_sink()) {
		dlog_print(DLOG_ERROR, LOG_TAG, "_create_sink() failed.");
		return false;
	}

	if (!_create_hover_window()) {
		dlog_print(DLOG_ERROR, LOG_TAG, "_create_hover_window() failed.");
		return false;
	}

	_set_callbacks();

	/* Show the window after main view is set up */
	evas_object_show(s_info.win);

	return EINA_TRUE;
}

/**
 * @brief Creates a basic window named package.
 * @param[in] pkg_name Name of the window
 */
Evas_Object *view_create_win(const char *pkg_name)
{
	Evas_Object *win = NULL;

	/*
	 * Window
	 * Create and initialize elm_win.
	 * elm_win is mandatory to manipulate the window.
	 */
	win = elm_win_util_standard_add(pkg_name, pkg_name);
	elm_win_conformant_set(win, EINA_TRUE);
	elm_win_autodel_set(win, EINA_TRUE);

	evas_object_pass_events_set(win, EINA_FALSE);
	evas_object_smart_callback_add(win, "delete,request", _delete_win_request_cb, NULL);

	return win;
}

/**
 * @brief Creates a conformant without indicator for wearable app.
 * @param[in] win The object to which you want to set this conformant
 * Conformant is mandatory for base GUI to have proper size
 */
Evas_Object *view_create_conformant_without_indicator(Evas_Object *win)
{
	/*
	 * Conformant
	 * Create and initialize elm_conformant.
	 * elm_conformant is mandatory for base GUI to have proper size
	 * when indicator or virtual keypad is visible.
	 */
	Evas_Object *conform = NULL;

	if (win == NULL) {
		dlog_print(DLOG_ERROR, LOG_TAG, "window is NULL.");
		return NULL;
	}

	conform = elm_conformant_add(win);
	evas_object_size_hint_weight_set(conform, EVAS_HINT_EXPAND, EVAS_HINT_EXPAND);
	elm_win_resize_object_add(win, conform);

	evas_object_show(conform);

	return conform;
}

/**
 * @brief Creates a layout object for parent object based on provided EDJE script.
 * @param[in] parent The parent object for layout object.
 * @param[in] edj_file_name The relative path to the layout EDJE script.
 * @param[in] edj_group The name of the group to be loaded from the EDJE script.
 * @param[in] target_part_name The EDJE part's name where the layout is to be set.
 * @return The function returns layout object if it was created successfully,
 * otherwise 'NULL' is returned.
 */
Evas_Object *view_create_layout(Evas_Object *parent, const char *edj_file_name, const char *edj_group, const char *target_part_name)
{
	char edj_path[PATH_MAX] = {0, };
	Evas_Object *layout = NULL;

	if (!parent || !edj_file_name || !edj_group) {
		dlog_print(DLOG_ERROR, LOG_TAG, "Wrong input arguments.");
		return NULL;
	}

	_get_app_resource(edj_file_name, edj_path);

	layout = elm_layout_add(parent);
	if (!layout) {
		dlog_print(DLOG_ERROR, LOG_TAG, "Function elm_layout_add() failed.");
		return NULL;
	}

	if (!elm_layout_file_set(layout, edj_path, edj_group)) {
		dlog_print(DLOG_ERROR, LOG_TAG, "Function elm_layout_file_set() failed.");
		evas_object_del(layout);
		return NULL;
	}

	if (target_part_name)
		elm_object_part_content_set(parent, target_part_name, layout);
	else
		elm_object_content_set(parent, layout);

	evas_object_size_hint_weight_set(layout, EVAS_HINT_EXPAND, EVAS_HINT_EXPAND);
	eext_object_event_callback_add(layout, EEXT_CALLBACK_BACK, _layout_back_cb, NULL);
	evas_object_show(layout);

	return layout;
}

/**
 * @brief Creates a hidden label object.
 * @param[in] parent The parent object for label object.
 * @param[in] caption The text to be displayed on a label.
 * @return The function returns label object if it was created successfully,
 * otherwise 'NULL' is returned.
 */
Evas_Object *view_create_label(Evas_Object *parent, const char *caption)
{
	char theme_ext_path[256] = {0,};
	Evas_Object *label;

	label = elm_label_add(parent);
	if (!label) {
		dlog_print(DLOG_ERROR, LOG_TAG, "elm_label_add() failed.");
		return NULL;
	}

	elm_label_line_wrap_set(label, ELM_WRAP_MIXED);
	elm_label_ellipsis_set(label, EINA_TRUE);
	evas_object_pass_events_set(label, EINA_TRUE);

	if (caption)
		elm_object_text_set(label, caption);

	_get_app_resource(EDJ_SOURCE_EXT, theme_ext_path);
	elm_theme_extension_add(NULL, theme_ext_path);
	elm_object_style_set(label, GRP_SOURCE_EXT);

	return label;
}

/**
 * @brief Function resets the application to normal state.
 */
void view_set_normal_state(void)
{
	s_info.state = STATE_NORMAL;
}

/**
 * @brief Destroys window and frees its resources.
 */
void view_destroy(void)
{
	ecore_event_handler_del((Ecore_Event_Handler *)_press_cb);
	ecore_event_handler_del((Ecore_Event_Handler *)_move_cb);
	ecore_event_handler_del((Ecore_Event_Handler *)_unpress_cb);

	if (s_info.win == NULL)
		return;

	evas_object_del(s_info.win);
}

/**
 * @brief Internal callback function invoked when the main window needs to be destroyed.
 * @param[in] data The user data passed to the evas_object_smart_callback_add() function.
 * @param[in] obj The object invoking this callback function.
 * @param[in] event_info The structure containing the information on this event.
 */
static void _delete_win_request_cb(void *data, Evas_Object *obj, void *event_info)
{
	ui_app_exit();
}

/**
 * @brief Internal callback function invoked on HW Back button press.
 * @param[in] data The user data passed to the eext_object_event_callback_add() function.
 * @param[in] obj The object invoking this callback function.
 * @param[in] event_info The structure containing the information on this event.
 */
static void _layout_back_cb(void *data, Evas_Object *obj, void *event_info)
{
	/* Let window go to hide state. */
	elm_win_lower(s_info.win);
}

/**
 * @brief Internal callback function invoked on text paste operation performed using
 * the elm_cnp_selection_set() / elm_cnp_selection_get() functions.
 * @param[in] data The user data passed to the eext_object_event_callback_add() function.
 * @param[in] obj The object invoking this callback function.
 * @param[in] event_info The structure containing the information on this event.
 * @return The function returns 'EINA_TRUE' if the text paste operation is successful,
 * otherwise 'EINA_FALSE' is returned.
 */
static Eina_Bool _text_paste_cb(void *data, Evas_Object *obj, Elm_Selection_Data *ev)
{
	if (!ev || ev->format != ELM_SEL_FORMAT_TEXT)
		return EINA_FALSE;

	elm_object_text_set(obj, (const char *)ev->data);

	return EINA_TRUE;
}

/**
 * @brief Internal callback function invoked on mouse button press event.
 * This function is responsible for copy the text from source widget and paste it
 * to the hover window. Afterward the hover window is displayed.
 * @param[in] data The user data passed to the ecore_event_handler_add() function.
 * @param[in] type The type of the event occurred .
 * @param[in] event The structure containing the information on this event.
 * @return The function returns 'EINA_TRUE' if the event is processed successfully,
 * otherwise 'EINA_FALSE' is returned.
 */
static Eina_Bool _press_cb(void *data, int type, void *event)
{
	Ecore_Event_Mouse_Button *press = (Ecore_Event_Mouse_Button *)event;

	if (s_info.state != STATE_NORMAL || !_source_hit_test(press->root.x, press->root.y))
		return EINA_TRUE;

	_paste_to_hover();

	s_info.state = STATE_PRESS;
	s_info.drag_start_x = press->root.x;
	s_info.drag_start_y = press->root.y;

	_set_hover_window_size();
	_set_hover_window_position(press->root.x, press->root.y);
	_show_hover_window();

	return EINA_TRUE;
}

/**
 * @brief Internal callback function invoked on mouse move event.
 * This function is responsible for hover window location update according to
 * the mouse position.
 * @param[in] data The user data passed to the ecore_event_handler_add() function.
 * @param[in] type The type of the event occurred .
 * @param[in] event The structure containing the information on this event.
 * @return The function returns 'EINA_TRUE' if the event is processed successfully,
 * otherwise 'EINA_FALSE' is returned.
 */
static Eina_Bool _move_cb(void *data, int type, void *event)
{
	Ecore_Event_Mouse_Move *move = (Ecore_Event_Mouse_Move *)event;

	if (s_info.state == STATE_PRESS)
		s_info.state = STATE_DRAG;

	if (s_info.state != STATE_DRAG)
		return EINA_TRUE;

	_set_hover_window_position(move->root.x, move->root.y);

	return EINA_TRUE;
}

/**
 * @brief Internal callback function invoked on mouse button unpressed event.
 * This function is responsible for copy the text from hover window and paste it
 * to the sink widget. Afterward the hover window is dismissed.
 * @param[in] data The user data passed to the ecore_event_handler_add() function.
 * @param[in] type The type of the event occurred .
 * @param[in] event The structure containing the information on this event.
 * @return The function returns 'EINA_TRUE' if the event is processed successfully,
 * otherwise 'EINA_FALSE' is returned.
 */
static Eina_Bool _unpress_cb(void *data, int type, void *event)
{
	Ecore_Event_Mouse_Button *unpress = (Ecore_Event_Mouse_Button *)event;

	_hide_hover_window();

	if (s_info.state == STATE_DRAG && _sink_hit_test(unpress->root.x, unpress->root.y))
		_paste_to_sink();

	 s_info.state = STATE_NORMAL;

	return EINA_TRUE;
}

/**
 * @brief Internal function which creates fully qualified path to the provided resource file.
 * @param[in] file_in The file name.
 * @param[out] path_out The fully qualified path to the edj_file_in file.
 */
static void _get_app_resource(const char *file_in, char *path_out)
{
	char *res_path = app_get_resource_path();
	if (res_path) {
		snprintf(path_out, PATH_MAX, "%s%s", res_path, file_in);
		free(res_path);
	}
}

/**
 * @brief Internal function which creates the source label set to the top of the layout.
 * @return The function returns 'EINA_TRUE' if the source label was created successfully,
 * otherwise 'EINA_FALSE' is returned.
 */
static Eina_Bool _create_source(void)
{
	s_info.source_label = view_create_label(s_info.main_layout, source_text);
	if (!s_info.source_label) {
		dlog_print(DLOG_ERROR, LOG_TAG, "view_create_label() failed.");
		return EINA_FALSE;
	}

	elm_object_part_content_set(s_info.main_layout, PART_MAIN_SOURCE, s_info.source_label);
	evas_object_show(s_info.source_label);

	return EINA_TRUE;
}

/**
 * @brief Internal function which creates the sink entry set to the bottom of the layout.
 * @return The function returns 'EINA_TRUE' if the sink entry was created successfully,
 * otherwise 'EINA_FALSE' is returned.
 */
static Eina_Bool _create_sink(void)
{
	s_info.sink_entry = elm_entry_add(s_info.main_layout);
	if (!s_info.sink_entry) {
		dlog_print(DLOG_ERROR, LOG_TAG, "elm_entry_add() failed.");
		return EINA_FALSE;
	}

	elm_entry_input_panel_enabled_set(s_info.sink_entry, EINA_FALSE);
	elm_entry_scrollable_set(s_info.sink_entry, EINA_TRUE);

	elm_entry_text_style_user_push(s_info.sink_entry, "DEFAULT='font_size=24 color=#ff0000'");

	elm_object_part_content_set(s_info.main_layout, PART_MAIN_SINK, s_info.sink_entry);

	return EINA_TRUE;
}

/**
 * @brief Internal function which creates the label object which plays a role of a hoover window.
 * In order to display the window properly, its position must be set before
 * _show_hover_window() function is called. The hover window's position shall be set with
 * _set_hover_window_position() function.
 * @return The function returns 'EINA_TRUE' if the hover window was created successfully,
 * otherwise 'EINA_FALSE' is returned.
 */
static Eina_Bool _create_hover_window(void)
{
	s_info.hover = view_create_label(s_info.win, NULL);
	if (!s_info.hover) {
		dlog_print(DLOG_ERROR, LOG_TAG, "view_create_label() failed.");
		return EINA_FALSE;
	}

	evas_object_layer_set(s_info.hover, EVAS_LAYER_MAX);

	return EINA_TRUE;
}

/**
 * @brief Internal function for mouse events callbacks setting.
 * The following callbacks are set:
 * - mouse button down,
 * - mouse button up,
 * - mouse move.
 */
static void _set_callbacks(void)
{
	ecore_event_handler_add(ECORE_EVENT_MOUSE_BUTTON_DOWN, _press_cb, NULL);
	ecore_event_handler_add(ECORE_EVENT_MOUSE_MOVE, _move_cb, NULL);
	ecore_event_handler_add(ECORE_EVENT_MOUSE_BUTTON_UP, _unpress_cb, NULL);
}

/**
 * @brief Internal function which checks whether the given coordinates are contained
 * within a specified object's boundaries.
 * @param[in] obj The object which is subject for coordinates containment test.
 * @param[in] hit_x The X coordinate.
 * @param[in] hit_y The Y coordinate.
 * @return The function returns 'true' if the given coordinates are contained within
 * a specified object's boundaries.
 */
static bool _hit_test(Evas_Object *obj, int hit_x, int hit_y)
{
	Evas_Coord x = 0, y = 0, w = 0, h = 0;
	evas_object_geometry_get(obj, &x, &y, &w, &h);

	return hit_x >= x && hit_x < (x + w) && hit_y >= y && hit_y < (y + h);
}

/**
 * @brief Internal function which checks whether the given coordinates are contained
 * within a source widget boundaries.
 * @param[in] x The X coordinate.
 * @param[in] y The Y coordinate.
 * @return The function returns 'true' if the given coordinates are contained within
 * a source widget boundaries.
 */
static bool _source_hit_test(int x, int y)
{
	return _hit_test(s_info.source_label, x, y);
}

/**
 * @brief Internal function which checks whether the given coordinates are contained
 * within a sink widget boundaries.
 * @param[in] x The X coordinate.
 * @param[in] y The Y coordinate.
 * @return The function returns 'true' if the given coordinates are contained within
 * a sink widget boundaries.
 */
static bool _sink_hit_test(int x, int y)
{
	return _hit_test(s_info.sink_entry, x, y);
}

/**
 * @brief Internal function which takes the text from the source widget and pastes it
 * to the hover window. The paste operation is performed using 'cnp' mechanism.
 */
static void _paste_to_hover(void)
{
	const char *text_to_paste = elm_object_part_text_get(s_info.source_label, "default");

	/* We could just use elm_object_text_set, but for the exemplary purpose the cnp mechanism is used:
	 * use copy mechanism, fill copy buffer associated with the label */
	elm_cnp_selection_set(s_info.hover, ELM_SEL_TYPE_PRIMARY, ELM_SEL_FORMAT_TEXT, text_to_paste, strlen(text_to_paste));

	/* get the text from the clipboard and since we use 'Label' widget type,
	 * we have to use custom drop callback: _text_paste_cb */
	elm_cnp_selection_get(s_info.hover, ELM_SEL_TYPE_PRIMARY, ELM_SEL_FORMAT_TEXT, _text_paste_cb, NULL);
}

/**
 * @brief Internal function which takes the text from the source widget and pastes it
 * to the hover window. The paste operation is performed using 'cnp' mechanism.
 */
static void _paste_to_sink(void)
{
	/* use paste mechanism. */
	elm_cnp_selection_get(s_info.sink_entry, ELM_SEL_TYPE_PRIMARY, ELM_SEL_FORMAT_TEXT, NULL, NULL);

	/* after text has been copied, clear selection in clipboard. */
	elm_object_cnp_selection_clear(s_info.source_label, ELM_SEL_TYPE_CLIPBOARD);
}

/**
 * @brief Internal function which sets the hover window size based on the size
 * of the main window.
 */
static void _set_hover_window_size(void)
{
	Evas_Coord w = 0;
	Evas_Coord h = 0;

	evas_object_geometry_get(s_info.win, NULL, NULL, &w, &h);

	w = (Evas_Coord)(w * 0.8);
	h = (Evas_Coord)(h * 0.3);

	evas_object_resize(s_info.hover, w, h);
}

/**
 * @brief Internal function which sets the display position of the hover window.
 * The position is set so the mouse hit point lies in the hover window's center point.
 * @param[in] x The X coordinate of the mouse hit point.
 * @param[in] y The Y coordinate of the mouse hit point.
 */
static void _set_hover_window_position(int x, int y)
{
	Evas_Coord w = 0;
	Evas_Coord h = 0;

	evas_object_geometry_get(s_info.hover, NULL, NULL, &w, &h);
	evas_object_move(s_info.hover, (Evas_Coord)(x - (int)(w / 2)), (Evas_Coord)(y - (int)(h / 2)));
}

/**
 * @brief Internal function which shows the hover window.
 */
static void _show_hover_window(void)
{
	evas_object_show(s_info.hover);
}

/**
 * @brief Internal function which hides the hover window.
 */
static void _hide_hover_window(void)
{
	evas_object_hide(s_info.hover);
}