// The BOOTSEL button doubles as the touch button.
#include "button.h"

#include "hardware/gpio.h"
#include "hardware/structs/ioqspi.h"
#include "hardware/structs/sio.h"
#include "hardware/sync.h"
#include "platform.h"

#define SAMPLE_INTERVAL_MS 10
#define DEBOUNCE_MS 30
#define QSPI_SS_INDEX 1

static bool pressed;
static uint32_t last_sample_ms;
static uint32_t last_change_ms;
static bool press_pending;
static uint32_t press_ms;

// BOOTSEL pulls the flash chip-select line low. Reading it means briefly
// releasing that line, so flash is unusable: run from RAM with interrupts off.
static bool __no_inline_not_in_flash_func(bootsel_pressed)(void) {
    uint32_t irq = save_and_disable_interrupts();
    hw_write_masked(&ioqspi_hw->io[QSPI_SS_INDEX].ctrl, GPIO_OVERRIDE_LOW << IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_LSB,
                    IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_BITS);
    for (volatile int i = 0; i < 1000; i++) {
        // let the line settle; sleep functions live in flash
    }
#if PICO_RP2040
    bool down = !(sio_hw->gpio_hi_in & (1u << QSPI_SS_INDEX));
#else
    bool down = !(sio_hw->gpio_hi_in & SIO_GPIO_HI_IN_QSPI_CSN_BITS);
#endif
    hw_write_masked(&ioqspi_hw->io[QSPI_SS_INDEX].ctrl, GPIO_OVERRIDE_NORMAL << IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_LSB,
                    IO_QSPI_GPIO_QSPI_SS_CTRL_OEOVER_BITS);
    restore_interrupts(irq);
    return down;
}

void button_poll(void) {
    uint32_t now = platform_millis();
    if (now - last_sample_ms < SAMPLE_INTERVAL_MS) return;
    last_sample_ms = now;

    bool down = bootsel_pressed();
    if (down == pressed || now - last_change_ms < DEBOUNCE_MS) return;
    pressed = down;
    last_change_ms = now;
    if (pressed) {
        press_pending = true;
        press_ms = now;
    }
}

bool platform_button_take_press(uint32_t max_age_ms) {
    button_poll();
    if (!press_pending) return false;
    press_pending = false;
    return platform_millis() - press_ms <= max_age_ms;
}