package lora_test

import (
	"math"
	"testing"
	"time"

	"github.com/soypat/lora"
)

func TestTimeOnAir(t *testing.T) {
	const (
		loraWANCodeRate       = lora.CR4_5
		loraWANPreambleLength = 12
	)
	testCases := []struct {
		desc     string
		expected time.Duration
		plen     int
		cfg      lora.Config
	}{
		{
			desc: "LoRaWAN 240bytes", // https://www.thethingsnetwork.org/airtime-calculator
			cfg: lora.Config{
				Bandwidth:       lora.BW125k,
				Frequency:       915e6,
				SpreadingFactor: lora.SF7,
				HeaderType:      lora.HeaderExplicit,
				CodingRate:      loraWANCodeRate,
				CRC:             true,
				PreambleLength:  loraWANPreambleLength,
			},
			plen:     240,
			expected: 394.5e3 * time.Microsecond,
		},
		{
			desc: "LoRaWAN 5byte BW=500kHz", // https://www.thethingsnetwork.org/airtime-calculator
			cfg: lora.Config{
				Bandwidth:       lora.BW500k,
				Frequency:       915e6,
				SpreadingFactor: lora.SF7,
				HeaderType:      lora.HeaderExplicit,
				CodingRate:      loraWANCodeRate,
				CRC:             true,
				PreambleLength:  loraWANPreambleLength,
			},
			plen:     10,
			expected: 15.4e3 * time.Microsecond,
		},
	}
	for _, tC := range testCases {
		t.Run(tC.desc, func(t *testing.T) {
			got := tC.cfg.TimeOnAir(tC.plen)
			expect := tC.expected.Seconds()
			if math.Abs(got.Seconds()-expect) > 10*expect/100 { // TODO: improve accuracy of TimeOnAir
				t.Errorf("%s: got %s, expected %s", tC.desc, got.String(), tC.expected.String())
			}
		})
	}
}

func TestTemperature(t *testing.T) {
	for _, cs := range []struct {
		tempVal uint8
		expect  uint8
		celsius int
	}{
		{tempVal: 63, expect: 0, celsius: -40},
		{tempVal: 33, expect: 36, celsius: -15},
		{tempVal: 0, expect: 100, celsius: 15},
		{tempVal: 245, expect: 128, celsius: 10},
		{tempVal: 211, expect: 220, celsius: 55},
		{tempVal: 181, expect: 255, celsius: 85},
	} {
		val := cs.tempVal
		val -= 64
		val = uint8(255 - 14*uint16(val)/8)
		// val += 128
		t.Errorf("regTemp=%d  val=%d  expect=%d  celsius=%d", cs.tempVal, val, cs.expect, cs.celsius)
	}
}