//go:build llgo

package tls_test

import (
	"fmt"
	"sync"
	"testing"

	"github.com/goplus/llgo/runtime/internal/clite/tls"
)

func TestAllocReadWrite(t *testing.T) {
	h := tls.Alloc[int](nil)
	if got := h.Get(); got != 0 {
		t.Fatalf("zero slot = %d, want 0", got)
	}
	h.Set(42)
	if got := h.Get(); got != 42 {
		t.Fatalf("Set/Get mismatch: got %d", got)
	}
	h.Clear()
	if got := h.Get(); got != 0 {
		t.Fatalf("Clear() did not reset slot, got %d", got)
	}
}

func TestAllocThreadLocalIsolation(t *testing.T) {
	h := tls.Alloc[int](nil)
	h.Set(7)

	const want = 99
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()
		if got := h.Get(); got != 0 {
			t.Errorf("new goroutine initial value = %d, want 0", got)
		}
		h.Set(want)
		if got := h.Get(); got != want {
			t.Errorf("goroutine value = %d, want %d", got, want)
		}
	}()
	wg.Wait()

	if got := h.Get(); got != 7 {
		t.Fatalf("main goroutine value changed to %d", got)
	}
}

func TestDestructorRuns(t *testing.T) {
	var mu sync.Mutex
	var calls int
	values := make([]int, 0, 1)

	h := tls.Alloc[*int](func(p **int) {
		mu.Lock()
		defer mu.Unlock()
		if p != nil && *p != nil {
			calls++
			values = append(values, **p)
		}
	})

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()
		val := new(int)
		*val = 123
		h.Set(val)
	}()
	wg.Wait()

	mu.Lock()
	defer mu.Unlock()
	if calls == 0 {
		t.Fatalf("expected destructor to be invoked")
	}
	if len(values) != 1 || values[0] != 123 {
		t.Fatalf("destructor saw unexpected values: %v", values)
	}
}

func TestAllocStress(t *testing.T) {
	const sequentialIterations = 200_000

	h := tls.Alloc[int](nil)
	for i := 0; i < sequentialIterations; i++ {
		h.Set(i)
		if got := h.Get(); got != i {
			t.Fatalf("stress iteration %d: got %d want %d", i, got, i)
		}
	}

	var wg sync.WaitGroup
	const (
		goroutines             = 32
		iterationsPerGoroutine = 1_000
	)
	errs := make(chan error, goroutines)
	wg.Add(goroutines)
	for g := 0; g < goroutines; g++ {
		go func(offset int) {
			defer wg.Done()
			local := tls.Alloc[int](nil)
			for i := 0; i < iterationsPerGoroutine; i++ {
				v := offset*iterationsPerGoroutine + i
				local.Set(v)
				if got := local.Get(); got != v {
					errs <- fmt.Errorf("goroutine %d iteration %d: got %d want %d", offset, i, got, v)
					return
				}
			}
		}(g)
	}
	wg.Wait()
	close(errs)
	for err := range errs {
		if err != nil {
			t.Fatal(err)
		}
	}
}