/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2017 Scott Shawcroft 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 "csr.h"
#include "tick.h"
#include "irq.h"

#include "supervisor/shared/autoreload.h"
#include "supervisor/filesystem.h"
#include "supervisor/shared/tick.h"
#include "shared-module/gamepad/__init__.h"
#include "shared-bindings/microcontroller/Processor.h"

// Global millisecond tick count
// volatile uint64_t ticks_ms = 0;

__attribute__((section(".ramtext")))
void SysTick_Handler(void) {
    timer0_ev_pending_write(1);
    supervisor_tick();
}

void tick_init() {
    int t;

    timer0_en_write(0);
    t = CONFIG_CLOCK_FREQUENCY / 1000; // 1000 kHz tick
    timer0_reload_write(t);
    timer0_load_write(t);
    timer0_en_write(1);
    timer0_ev_enable_write(1);
    timer0_ev_pending_write(1);
    irq_setmask(irq_getmask() | (1 << TIMER0_INTERRUPT));
}

void tick_delay(uint32_t us) {
    // uint32_t ticks_per_us = SystemCoreClock / 1000 / 1000;
    // uint32_t us_between_ticks = SysTick->VAL / ticks_per_us;
    // uint64_t start_ms = ticks_ms;
    // while (us > 1000) {
    //     while (ticks_ms == start_ms) {}
    //     us -= us_between_ticks;
    //     start_ms = ticks_ms;
    //     us_between_ticks = 1000;
    // }
    // while (SysTick->VAL > ((us_between_ticks - us) * ticks_per_us)) {}
}

// us counts down!
void current_tick(uint64_t* ms, uint32_t* us_until_ms) {
    // uint32_t ticks_per_us = SystemCoreClock / 1000 / 1000;
    // *ms = ticks_ms;
    // *us_until_ms = SysTick->VAL / ticks_per_us;
}

void wait_until(uint64_t ms, uint32_t us_until_ms) {
    // uint32_t ticks_per_us = SystemCoreClock / 1000 / 1000;
    // while(ticks_ms <= ms && SysTick->VAL / ticks_per_us >= us_until_ms) {}
}