//go:build stm32wlx
// +build stm32wlx

package sx126x

import (
	"device/stm32"
	"errors"
	"machine"
	"tinygo.org/x/drivers"
)

// New creates a new SX126x connection.
func New(spi drivers.SPI) *Device {
	c := make(chan RadioEvent, 10)
	d := Device{
		spi:            spi,
		radioEventChan: c,
	}
	if d.spi == machine.SPI3 {
		d.SubGhzInit()
		d.SetDeviceType(DEVICE_TYPE_SX1262)
	} else {
		panic("Driver only support SUBGHZSPI (SPI3) on stm32wlx targets")
	}
	return &d
}

//SpiSetNss Sets the NSS line
func (d *Device) SpiSetNss(state bool) {
	if state {
		stm32.PWR.SUBGHZSPICR.SetBits(stm32.PWR_SUBGHZSPICR_NSS)
	} else {
		stm32.PWR.SUBGHZSPICR.ClearBits(stm32.PWR_SUBGHZSPICR_NSS)

	}
}

// WaitBusy sleep until all busy flags clears
func (d *Device) WaitBusy() error {
	count := 100
	var rfbusyms, rfbusys bool
	for count > 0 {
		rfbusyms = stm32.PWR.SR2.HasBits(stm32.PWR_SR2_RFBUSYMS)
		rfbusys = stm32.PWR.SR2.HasBits(stm32.PWR_SR2_RFBUSYS)

		if !(rfbusyms && rfbusys) {
			return nil
		}
		count--
	}
	return errors.New("WaitBusy Timeout")
}

// SubGhzInit() configures internal SX1262's SPI bus.
func (d *Device) SubGhzInit() {

	// Enable APB3 Periph clock and delay
	stm32.RCC.APB3ENR.SetBits(stm32.RCC_APB3ENR_SUBGHZSPIEN)
	_ = stm32.RCC.APB3ENR.Get()

	// Disable radio reset and wait it's ready
	stm32.RCC.CSR.ClearBits(stm32.RCC_CSR_RFRST)
	for stm32.RCC.CSR.HasBits(stm32.RCC_CSR_RFRSTF) {
	}

	// Set NSS line low
	stm32.PWR.SUBGHZSPICR.SetBits(stm32.PWR_SUBGHZSPICR_NSS)

	// Enable radio busy wakeup from Standby for CPU
	stm32.PWR.CR3.SetBits(stm32.PWR_CR3_EWRFBUSY)

	// Clear busy flag
	stm32.PWR.SCR.Set(stm32.PWR_SCR_CWRFBUSYF)

	// Enable SUBGHZ Spi
	// - /8 Prescaler
	// - Software Slave Management (NSS)
	// - FIFO Threshold and 8bit size
	stm32.SPI3.CR1.ClearBits(stm32.SPI_CR1_SPE)
	stm32.SPI3.CR1.Set(stm32.SPI_CR1_MSTR | stm32.SPI_CR1_SSI | (0b010 << 3) | stm32.SPI_CR1_SSM)
	stm32.SPI3.CR2.Set(stm32.SPI_CR2_FRXTH | (0b111 << 8))
	stm32.SPI3.CR1.SetBits(stm32.SPI_CR1_SPE)

}