package extraction

import (
	"context"
	"sync"
	"testing"
	"time"
)

func TestMemoryStoreNeverExtractsProxyTwice(t *testing.T) {
	now := time.Date(2026, 7, 28, 10, 0, 0, 0, time.UTC)
	store := NewMemoryStore([]Candidate{
		{ID: "p1", State: Available, ExpiresAt: now.Add(time.Minute), LastCheckedAt: now},
	})

	var wg sync.WaitGroup
	results := make(chan string, 1000)
	for range 1000 {
		wg.Add(1)
		go func() {
			defer wg.Done()
			result, err := store.Extract(context.Background(), Command{
				Requested:         1,
				Fulfillment:       Partial,
				Now:               now,
				MinRemainingTTL:   30 * time.Second,
				MaxHealthCheckAge: 10 * time.Second,
			})
			if err != nil {
				t.Errorf("Extract(): %v", err)
				return
			}
			for _, item := range result.Items {
				results <- item.ID
			}
		}()
	}
	wg.Wait()
	close(results)

	count := 0
	for id := range results {
		if id != "p1" {
			t.Fatalf("unexpected proxy %q", id)
		}
		count++
	}
	if count != 1 {
		t.Fatalf("proxy extracted %d times, want exactly once", count)
	}
}

func TestAllOrNothingDoesNotConsumePartialInventory(t *testing.T) {
	now := time.Date(2026, 7, 28, 10, 0, 0, 0, time.UTC)
	store := NewMemoryStore([]Candidate{
		{ID: "p1", State: Available, ExpiresAt: now.Add(time.Minute), LastCheckedAt: now},
	})

	result, err := store.Extract(context.Background(), Command{
		Requested:         2,
		Fulfillment:       AllOrNothing,
		Now:               now,
		MinRemainingTTL:   30 * time.Second,
		MaxHealthCheckAge: 10 * time.Second,
	})
	if err != ErrInsufficientProxies {
		t.Fatalf("Extract() error = %v, want ErrInsufficientProxies", err)
	}
	if len(result.Items) != 0 {
		t.Fatalf("Extract() returned %d items, want 0", len(result.Items))
	}

	partial, err := store.Extract(context.Background(), Command{
		Requested:         1,
		Fulfillment:       Partial,
		Now:               now,
		MinRemainingTTL:   30 * time.Second,
		MaxHealthCheckAge: 10 * time.Second,
	})
	if err != nil || len(partial.Items) != 1 {
		t.Fatalf("inventory was consumed by failed all-or-nothing: result=%+v err=%v", partial, err)
	}
}