// This is directly ported from github.com/SaveTheRbtz/generic-sync-map-go
// and does not test the new CompareAndSwap and related functions yet.
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package cmap_test

import (
	"math/rand"
	"runtime"
	"sync"
	"testing"

	"go.lindenii.runxiyu.org/lindenii-common/cmap"
)

func TestConcurrentRange(t *testing.T) {
	const mapSize = 1 << 10

	m := new(cmap.Map[int64, int64])
	for n := int64(1); n <= mapSize; n++ {
		m.Store(n, int64(n))
	}

	done := make(chan struct{})
	var wg sync.WaitGroup
	defer func() {
		close(done)
		wg.Wait()
	}()
	for g := int64(runtime.GOMAXPROCS(0)); g > 0; g-- {
		r := rand.New(rand.NewSource(g))
		wg.Add(1)
		go func(g int64) {
			defer wg.Done()
			for i := int64(0); ; i++ {
				select {
				case <-done:
					return
				default:
				}
				for n := int64(1); n < mapSize; n++ {
					if r.Int63n(mapSize) == 0 {
						m.Store(n, n*i*g)
					} else {
						m.Load(n)
					}
				}
			}
		}(g)
	}

	iters := 1 << 10
	if testing.Short() {
		iters = 16
	}
	for n := iters; n > 0; n-- {
		seen := make(map[int64]bool, mapSize)

		m.Range(func(k, v int64) bool {
			if v%k != 0 {
				t.Fatalf("while Storing multiples of %v, Range saw value %v", k, v)
			}
			if seen[k] {
				t.Fatalf("Range visited key %v twice", k)
			}
			seen[k] = true
			return true
		})

		if len(seen) != mapSize {
			t.Fatalf("Range visited %v elements of %v-element Map", len(seen), mapSize)
		}
	}
}