package langext

import (
	"git.blackforestbytes.com/BlackForestBytes/goext/tst"
	"testing"
	"time"
)

type stringerImpl struct{ v string }

func (s stringerImpl) String() string { return s.v }

func TestCoalesceWithValue(t *testing.T) {
	v := 42
	tst.AssertEqual(t, Coalesce(&v, 0), 42)
}

func TestCoalesceWithNil(t *testing.T) {
	var p *int
	tst.AssertEqual(t, Coalesce(p, 99), 99)
}

func TestCoalesceOpt(t *testing.T) {
	v := 1
	w := 2
	tst.AssertDeRefEqual(t, CoalesceOpt(&v, &w), 1)

	var p *int
	tst.AssertDeRefEqual(t, CoalesceOpt(p, &w), 2)

	tst.AssertPtrEqual(t, CoalesceOpt[int](nil, nil), nil)
}

func TestCoalesce3(t *testing.T) {
	v := 1
	w := 2
	tst.AssertEqual(t, Coalesce3(&v, &w, 99), 1)
	tst.AssertEqual(t, Coalesce3[int](nil, &w, 99), 2)
	tst.AssertEqual(t, Coalesce3[int](nil, nil, 99), 99)
}

func TestCoalesce3Opt(t *testing.T) {
	v := 1
	tst.AssertDeRefEqual(t, Coalesce3Opt[int](nil, nil, &v), 1)
	tst.AssertPtrEqual(t, Coalesce3Opt[int](nil, nil, nil), nil)
}

func TestCoalesce4(t *testing.T) {
	v := 1
	w := 2
	x := 3
	tst.AssertEqual(t, Coalesce4(&v, &w, &x, 99), 1)
	tst.AssertEqual(t, Coalesce4[int](nil, &w, &x, 99), 2)
	tst.AssertEqual(t, Coalesce4[int](nil, nil, &x, 99), 3)
	tst.AssertEqual(t, Coalesce4[int](nil, nil, nil, 99), 99)
}

func TestCoalesce4Opt(t *testing.T) {
	v := 4
	tst.AssertDeRefEqual(t, Coalesce4Opt[int](nil, nil, nil, &v), 4)
	tst.AssertPtrEqual(t, Coalesce4Opt[int](nil, nil, nil, nil), nil)
}

func TestCoalesceString(t *testing.T) {
	s := "hello"
	tst.AssertEqual(t, CoalesceString(&s, "def"), "hello")
	tst.AssertEqual(t, CoalesceString(nil, "def"), "def")
}

func TestCoalesceInt(t *testing.T) {
	v := 5
	tst.AssertEqual(t, CoalesceInt(&v, 99), 5)
	tst.AssertEqual(t, CoalesceInt(nil, 99), 99)
}

func TestCoalesceInt32(t *testing.T) {
	v := int32(7)
	tst.AssertEqual(t, CoalesceInt32(&v, 99), int32(7))
	tst.AssertEqual(t, CoalesceInt32(nil, 99), int32(99))
}

func TestCoalesceBool(t *testing.T) {
	v := true
	tst.AssertEqual(t, CoalesceBool(&v, false), true)
	tst.AssertEqual(t, CoalesceBool(nil, true), true)
	tst.AssertEqual(t, CoalesceBool(nil, false), false)
}

func TestCoalesceTime(t *testing.T) {
	now := time.Now()
	def := time.Unix(0, 0)
	tst.AssertEqual(t, CoalesceTime(&now, def), now)
	tst.AssertEqual(t, CoalesceTime(nil, def), def)
}

func TestCoalesceStringer(t *testing.T) {
	s := stringerImpl{v: "hi"}
	tst.AssertEqual(t, CoalesceStringer(s, "def"), "hi")

	var nilStringer *stringerImpl
	tst.AssertEqual(t, CoalesceStringer(nilStringer, "def"), "def")
}

func TestCoalesceDefault(t *testing.T) {
	tst.AssertEqual(t, CoalesceDefault(0, 99), 99)
	tst.AssertEqual(t, CoalesceDefault(5, 99), 5)
	tst.AssertEqual(t, CoalesceDefault("", "def"), "def")
	tst.AssertEqual(t, CoalesceDefault("v", "def"), "v")
}

func TestSafeCastMatching(t *testing.T) {
	var v any = "hello"
	tst.AssertEqual(t, SafeCast(v, "default"), "hello")
}

func TestSafeCastMismatch(t *testing.T) {
	var v any = 42
	tst.AssertEqual(t, SafeCast(v, "default"), "default")
}

func TestSafeCastNil(t *testing.T) {
	tst.AssertEqual(t, SafeCast(nil, 99), 99)
}

func TestCoalesceDblPtrWithValue(t *testing.T) {
	v := 1
	pv := &v
	tst.AssertDeRefEqual(t, CoalesceDblPtr(&pv, nil), 1)
}

func TestCoalesceDblPtrFallback(t *testing.T) {
	w := 2
	tst.AssertDeRefEqual(t, CoalesceDblPtr[int](nil, &w), 2)
}