package softfloat64

import (
	"math"
	"math/rand/v2"
	"strconv"
	"testing"
)

func TestAdd(t *testing.T) {
	t.Parallel()

	base := []float64{
		0,
		math.Copysign(0, -1),
		-1,
		1,
		math.NaN(),
		math.Inf(+1),
		math.Inf(-1),
		0.1,
		1.5,
		1.9999999999999998,     // all 1s mantissa
		1.3333333333333333,     // 1.010101010101...
		1.1428571428571428,     // 1.001001001001...
		1.112536929253601e-308, // first normal
		2,
		4,
		8,
		16,
		32,
		64,
		128,
		256,
		3,
		12,
		1234,
		123456,
		-0.1,
		-1.5,
		-1.9999999999999998,
		-1.3333333333333333,
		-1.1428571428571428,
		-2,
		-3,
		1e-200,
		1e-300,
		1e-310,
		5e-324,
		1e-105,
		1e-305,
		1e+200,
		1e+306,
		1e+307,
		1e+308,
	}
	all := make([]float64, 2000)
	copy(all, base)
	for i := len(base); i < len(all); i++ {
		if i%2 == 0 {
			all[i] = rand.NormFloat64()
		} else {
			all[i] = rand.ExpFloat64()
		}
	}
	mode := RoundingModeToNearest

	for i := range all {
		for j := range all {
			a := all[i] + all[j]
			b := Add(all[i], all[j], mode)
			if math.Float64bits(a) != math.Float64bits(b) {
				t.Errorf("[%d+%d] Add(0x%016x (%s), 0x%016x (%s), %d) = 0x%016x (%s), want 0x%016x (%s)", i, j,
					math.Float64bits(all[i]), strconv.FormatFloat(all[i], 'f', -1, 64),
					math.Float64bits(all[j]), strconv.FormatFloat(all[j], 'f', -1, 64),
					mode, math.Float64bits(b), strconv.FormatFloat(b, 'f', -1, 64),
					math.Float64bits(a), strconv.FormatFloat(a, 'f', -1, 64),
				)
			}
		}
	}
}