/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2020 Scott Shawcroft for Adafruit Industries
 * Copyright (c) 2020 Dan Halbert for Adafruit Industries
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "py/gc.h"
#include "py/obj.h"
#include "py/objtuple.h"
#include "py/runtime.h"
#include <stdio.h>
#include <string.h>

#include "shared-bindings/alarm/__init__.h"
#include "shared-bindings/alarm/SleepMemory.h"
#include "shared-bindings/alarm/pin/PinAlarm.h"
#include "shared-bindings/alarm/time/TimeAlarm.h"
#include "shared-bindings/alarm/touch/TouchAlarm.h"
#include "shared-bindings/time/__init__.h"

#include "supervisor/port.h"
#include "supervisor/serial.h"  // serial_connected()
#ifdef NRF_DEBUG_PRINT
#include "supervisor/serial.h" // dbg_printf()
extern int dbg_check_RTCprescaler(void);
#endif
#include "supervisor/qspi_flash.h"

#include "nrf.h"
#include "nrf_power.h"
#include "nrfx.h"
#include "nrfx_gpiote.h"

// Singleton instance of SleepMemory.
const alarm_sleep_memory_obj_t alarm_sleep_memory_obj = {
    .base = {
        .type = &alarm_sleep_memory_type,
    },
};

void alarm_reset(void) {
    alarm_sleep_memory_reset();
    alarm_pin_pinalarm_reset();
    alarm_time_timealarm_reset();
    alarm_touch_touchalarm_reset();
}

extern uint32_t reset_reason_saved;
STATIC nrf_sleep_source_t _get_wakeup_cause(void) {
    if (alarm_pin_pinalarm_woke_us_up()) {
        return NRF_SLEEP_WAKEUP_GPIO;
    }
    if (alarm_time_timealarm_woke_us_up()) {
        return NRF_SLEEP_WAKEUP_TIMER;
    }
    if (alarm_touch_touchalarm_woke_us_up()) {
        return NRF_SLEEP_WAKEUP_TOUCHPAD;
    }
    if (reset_reason_saved & NRF_POWER_RESETREAS_RESETPIN_MASK) {
        return NRF_SLEEP_WAKEUP_RESETPIN;
    }
    else if (reset_reason_saved & NRF_POWER_RESETREAS_OFF_MASK) {
        return NRF_SLEEP_WAKEUP_GPIO;
    }
    else if (reset_reason_saved & NRF_POWER_RESETREAS_VBUS_MASK) {
        return NRF_SLEEP_WAKEUP_VBUS;
    }
    return NRF_SLEEP_WAKEUP_UNDEFINED;
}

#ifdef NRF_DEBUG_PRINT
static const char* cause_str[] = {
  "UNDEFINED",
  "GPIO",
  "TIMER",
  "TOUCHPAD",
  "VBUS",
  "RESETPIN",
};
void print_wakeup_cause(nrf_sleep_source_t cause) {
    if (cause >= 0 && cause < NRF_SLEEP_WAKEUP_ZZZ) {
        dbg_printf("wakeup cause = NRF_SLEEP_WAKEUP_%s\r\n",
		   cause_str[(int)cause]);
    }
}
#endif

bool alarm_woken_from_sleep(void) {
   nrf_sleep_source_t cause = _get_wakeup_cause();
#ifdef NRF_DEBUG_PRINT
   if (cause != NRF_SLEEP_WAKEUP_UNDEFINED) {
       //print_wakeup_cause(cause);
   }
#endif
   return (cause == NRF_SLEEP_WAKEUP_GPIO || cause == NRF_SLEEP_WAKEUP_TIMER
	   || cause == NRF_SLEEP_WAKEUP_TOUCHPAD);
}

nrf_sleep_source_t alarm_woken_from_sleep_2(void) {
    nrf_sleep_source_t cause = _get_wakeup_cause();
#ifdef NRF_DEBUG_PRINT
    if (cause != NRF_SLEEP_WAKEUP_UNDEFINED) {
        //print_wakeup_cause(cause);
    }
#endif
    if (cause == NRF_SLEEP_WAKEUP_GPIO  ||
	cause == NRF_SLEEP_WAKEUP_TIMER ||
	cause == NRF_SLEEP_WAKEUP_TOUCHPAD) {
        return cause;
    }
    else {
        return NRF_SLEEP_WAKEUP_UNDEFINED;
    }
}

STATIC mp_obj_t _get_wake_alarm(size_t n_alarms, const mp_obj_t *alarms) {
    nrf_sleep_source_t cause = _get_wakeup_cause();
#ifdef NRF_DEBUG_PRINT
    //print_wakeup_cause(cause);
#endif
    switch (cause) {
      case NRF_SLEEP_WAKEUP_TIMER: {
        return alarm_time_timealarm_get_wakeup_alarm(n_alarms, alarms);
      }
      case NRF_SLEEP_WAKEUP_TOUCHPAD: {
        return alarm_touch_touchalarm_get_wakeup_alarm(n_alarms, alarms);
      }
      case NRF_SLEEP_WAKEUP_GPIO: {
        return alarm_pin_pinalarm_get_wakeup_alarm(n_alarms, alarms);
      }
      default:
        break;
    }
    return mp_const_none;
}

mp_obj_t common_hal_alarm_get_wake_alarm(void) {
    mp_obj_t obj = _get_wake_alarm(0, NULL);
    return obj;
}

// Set up light sleep or deep sleep alarms.
STATIC void _setup_sleep_alarms(bool deep_sleep, size_t n_alarms, const mp_obj_t *alarms) {
    alarm_pin_pinalarm_set_alarms(deep_sleep, n_alarms, alarms);
    alarm_time_timealarm_set_alarms(deep_sleep, n_alarms, alarms);
    alarm_touch_touchalarm_set_alarm(deep_sleep, n_alarms, alarms);
}

nrf_sleep_source_t system_on_idle_until_alarm(int64_t timediff_ms, uint32_t prescaler) {
    bool have_timeout = false;
    uint64_t start_tick = 0, end_tick = 0;

#if defined(MICROPY_QSPI_CS)
    qspi_flash_enter_sleep();
#endif

    if (timediff_ms != -1) {
        have_timeout = true;
#if 0
	int64_t now = common_hal_time_monotonic_ms();
	dbg_printf("now_ms=%ld timediff_ms=%ld\r\n", (long)now, (long)timediff_ms);
#endif
	if (timediff_ms < 0)  timediff_ms = 0;
	int64_t tickdiff;
	if (prescaler == 0) {
	    // 1 tick = 1/1024 sec = 1000/1024 ms
	    // -> 1 ms = 1024/1000 ticks
	    tickdiff = (mp_uint_t)(timediff_ms * 1024 / 1000); // ms -> ticks
	}
	else {
	    // 1 tick = prescaler/1024 sec = prescaler*1000/1024 ms
	    // -> 1ms = 1024/(1000*prescaler) ticks
	    tickdiff = (mp_uint_t)(timediff_ms * 1024 / (1000 * prescaler));
	}
	start_tick = port_get_raw_ticks(NULL);
	end_tick = start_tick + tickdiff;
    }
#if 0
    dbg_printf("start_tick=%ld end_tick=%ld have_timeout=%c\r\n", (long)start_tick, (long)end_tick, have_timeout ? 'T' : 'F');
#endif

    int64_t remaining;
    nrf_sleep_source_t wakeup_cause = NRF_SLEEP_WAKEUP_UNDEFINED;
    sleepmem_wakeup_event = SLEEPMEM_WAKEUP_BY_NONE;
    sleepmem_wakeup_pin   = WAKEUP_PIN_UNDEF;

#ifdef NRF_DEBUG_PRINT
    int ct = 40;
    char reason = '?';
#define WAKEUP_REASON(x) reason = (x)
#else
#define WAKEUP_REASON(x)
#endif

    while(1) {
	if (mp_hal_is_interrupted()) {
	    WAKEUP_REASON('I');
	    break;
	}
        if (serial_connected() && serial_bytes_available()) {
	    WAKEUP_REASON('S');
	    break;
	}
        RUN_BACKGROUND_TASKS;
	wakeup_cause = alarm_woken_from_sleep_2();
	if (wakeup_cause != NRF_SLEEP_WAKEUP_UNDEFINED) {
	    WAKEUP_REASON('0'+wakeup_cause);
	    break;
	}
	if (have_timeout) {
	    remaining = end_tick - port_get_raw_ticks(NULL);
	    // We break a bit early so we don't risk setting the alarm before the time when we call
	    // sleep.
	    if (remaining < 1) {
	        WAKEUP_REASON('t');
	        break;
	    }
	    port_interrupt_after_ticks(remaining);
	}
        // Idle until an interrupt happens.
        port_idle_until_interrupt();
#ifdef NRF_DEBUG_PRINT
        if (ct > 0) {
            dbg_printf("_");
            --ct;
        }
#endif
	if (have_timeout) {
	    remaining = end_tick - port_get_raw_ticks(NULL);
	    if (remaining <= 0) {
	        wakeup_cause = NRF_SLEEP_WAKEUP_TIMER;
		sleepmem_wakeup_event = SLEEPMEM_WAKEUP_BY_TIMER;
	        WAKEUP_REASON('T');
		break;
	    }
	}
    }
#ifdef NRF_DEBUG_PRINT
    dbg_printf("%c\r\n", reason);
#endif

#if defined(MICROPY_QSPI_CS)
    qspi_flash_exit_sleep();
#endif

    return wakeup_cause;
}

mp_obj_t common_hal_alarm_light_sleep_until_alarms(size_t n_alarms, const mp_obj_t *alarms) {
    mp_obj_t r_obj = mp_const_none;
    alarm_time_timealarm_clear_wakeup_time();
    _setup_sleep_alarms(false, n_alarms, alarms);

#ifdef NRF_DEBUG_PRINT
    dbg_printf("\r\nlight sleep...");
#endif

    int64_t timediff_ms = alarm_time_timealarm_get_wakeup_timediff_ms();
    nrf_sleep_source_t cause = system_on_idle_until_alarm(timediff_ms, 0);
    (void)cause;

#ifdef NRF_DEBUG_PRINT
    //dbg_printf("wakeup! ");
    print_wakeup_cause(cause);
#endif

    if (mp_hal_is_interrupted()) {
#ifdef NRF_DEBUG_PRINT
        dbg_printf("mp_hal_is_interrupted\r\n");
#endif
        r_obj = mp_const_none;
    }
    else {
        r_obj = _get_wake_alarm(n_alarms, alarms);
    }
    alarm_reset();
    return r_obj;
}

void common_hal_alarm_set_deep_sleep_alarms(size_t n_alarms, const mp_obj_t *alarms) {
    alarm_time_timealarm_clear_wakeup_time();
    _setup_sleep_alarms(true, n_alarms, alarms);
}

#define PRESCALER_VALUE_IN_DEEP_SLEEP (1024)

void NORETURN alarm_enter_deep_sleep(void) {
    alarm_pin_pinalarm_prepare_for_deep_sleep();
    alarm_time_timealarm_prepare_for_deep_sleep();

#ifdef NRF_DEBUG_PRINT
    dbg_printf("\r\ndeep sleep...");
#endif
    int64_t timediff_ms = alarm_time_timealarm_get_wakeup_timediff_ms();
    tick_set_prescaler(PRESCALER_VALUE_IN_DEEP_SLEEP -1);
#ifdef NRF_DEBUG_PRINT
    dbg_check_RTCprescaler(); //XXX
#endif
    nrf_sleep_source_t cause;
    cause = system_on_idle_until_alarm(timediff_ms,
				       PRESCALER_VALUE_IN_DEEP_SLEEP);
    (void)cause;

#ifdef NRF_DEBUG_PRINT
    dbg_printf("wakeup! ");
    print_wakeup_cause(cause);
    dbg_printf("RESET...\r\n\r\n");
#endif

    reset_cpu();

    // should not reach here..
    while(1) ;
}

void alarm_pretending_deep_sleep(void) {
    alarm_pin_pinalarm_prepare_for_deep_sleep();
    alarm_time_timealarm_prepare_for_deep_sleep();

#ifdef NRF_DEBUG_PRINT
    dbg_printf("\r\npretending to deep sleep...");
#endif

    int64_t timediff_ms = alarm_time_timealarm_get_wakeup_timediff_ms();
    nrf_sleep_source_t cause = system_on_idle_until_alarm(timediff_ms, 0);
    (void)cause;

#ifdef NRF_DEBUG_PRINT
    dbg_printf("wakeup! ");
    print_wakeup_cause(cause);
    dbg_printf("continue..\r\n");
#endif

    alarm_reset();
}

void common_hal_alarm_gc_collect(void) {
    void* p = alarm_get_wake_alarm();
    gc_collect_ptr(p);
}