/**
 * @File:    flexible_button.h
 * @Author:  MurphyZhao
 * @Date:    2018-09-29
 * 
 * Copyright (c) 2018-2019 MurphyZhao <d2014zjt@163.com>
 *               https://github.com/murphyzhao
 * All rights reserved.
 * License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 *
 * Change logs:
 * Date        Author       Notes
 * 2018-09-29  MurphyZhao   First add
 * 2019-08-02  MurphyZhao   Migrate code to github.com/murphyzhao account
 * 2019-12-26  MurphyZhao   Refactor code and implement multiple clicks
 * 
*/

#ifndef __FLEXIBLE_BUTTON_H__
#define __FLEXIBLE_BUTTON_H__

#include "stdint.h"

#define FLEX_BTN_SCAN_FREQ_HZ 50 // How often flex_button_scan () is called
#define FLEX_MS_TO_SCAN_CNT(ms) (ms / (1000 / FLEX_BTN_SCAN_FREQ_HZ))

/* Multiple clicks interval, default 300ms */
#define MAX_MULTIPLE_CLICKS_INTERVAL (FLEX_MS_TO_SCAN_CNT(300))

typedef void (*flex_button_response_callback)(void*);

typedef enum
{
    FLEX_BTN_PRESS_DOWN = 0,
    FLEX_BTN_PRESS_CLICK,
    FLEX_BTN_PRESS_DOUBLE_CLICK,
    FLEX_BTN_PRESS_REPEAT_CLICK,
    FLEX_BTN_PRESS_SHORT_START,
    FLEX_BTN_PRESS_SHORT_UP,
    FLEX_BTN_PRESS_LONG_START,
    FLEX_BTN_PRESS_LONG_UP,
    FLEX_BTN_PRESS_LONG_HOLD,
    FLEX_BTN_PRESS_LONG_HOLD_UP,
    FLEX_BTN_PRESS_MAX,
    FLEX_BTN_PRESS_NONE,
} flex_button_event_t;

/**
 * flex_button_t
 * 
 * @brief Button data structure
 *        Below are members that need to user init before scan.
 * 
 * @member next
 *         Internal use.
 *         One-way linked list, pointing to the next button.
 * 
 * @member usr_button_read
 *         User function is used to read button vaule.
 * 
 * @member cb
 *         Button event callback function.
 * 
 * @member scan_cnt
 *         Internal use, user read-only.
 *         Number of scans, counted when the button is pressed, plus one per scan cycle.
 * 
 * @member click_cnt
 *         Internal use, user read-only.
 *         Number of button clicks
 * 
 * @member max_multiple_clicks_interval
 *         Multiple click interval. Default 'MAX_MULTIPLE_CLICKS_INTERVAL'.
 *         Need to use FLEX_MS_TO_SCAN_CNT to convert milliseconds into scan cnts.
 * 
 * @member debounce_tick
 *         Debounce. Not used yet.
 *         Need to use FLEX_MS_TO_SCAN_CNT to convert milliseconds into scan cnts.
 * 
 * @member short_press_start_tick
 *         Short press start time. Requires user configuration.
 *         Need to use FLEX_MS_TO_SCAN_CNT to convert milliseconds into scan cnts.
 * 
 * @member long_press_start_tick
 *         Long press start time. Requires user configuration.
 *         Need to use FLEX_MS_TO_SCAN_CNT to convert milliseconds into scan cnts.
 * 
 * @member long_hold_start_tick
 *         Long hold press start time. Requires user configuration.
 * 
 * @member id
 *         Button id. Requires user configuration.
 *         When multiple buttons use the same button callback function, 
 *         they are used to distinguish the buttons. 
 *         Each button id must be unique.
 * 
 * @member pressed_logic_level
 *         Requires user configuration.
 *         The logic level of the button pressed, each bit represents a button.
 * 
 * @member event
 *         Internal use, users can call 'flex_button_event_read' to get current button event.
 *         Used to record the current button event.
 * 
 * @member status
 *         Internal use, user unavailable.
 *         Used to record the current state of buttons.
 * 
*/
typedef struct flex_button
{
    struct flex_button* next;

    uint8_t  (*usr_button_read)(void *);
    flex_button_response_callback  cb;

    uint16_t scan_cnt;
    uint16_t click_cnt;
    uint16_t max_multiple_clicks_interval;

    uint16_t debounce_tick;
    uint16_t short_press_start_tick;
    uint16_t long_press_start_tick;
    uint16_t long_hold_start_tick;

    uint8_t id;
    uint8_t pressed_logic_level : 1;
    uint8_t event               : 4;
    uint8_t status              : 3;
} flex_button_t;

#ifdef __cplusplus
extern "C" {
#endif

int8_t flex_button_register(flex_button_t *button);
flex_button_event_t flex_button_event_read(flex_button_t* button);
void flex_button_scan(void);

#ifdef __cplusplus
}
#endif  
#endif /* __FLEXIBLE_BUTTON_H__ */