package notify

import "testing"

func TestFileAckPoolPreparedWaitConsumesEarlyAck(t *testing.T) {
	pool := newFileAckPool()
	wait := pool.prepare("client:a", "file-1", "chunk", 64)

	ok := pool.deliver("client:a", FileEvent{
		Packet: FilePacket{
			FileID: "file-1",
			Stage:  "chunk",
			Offset: 64,
		},
	})
	if !ok {
		t.Fatalf("deliver should match prepared waiter")
	}

	if err := pool.waitPrepared(wait, defaultFileAckTimeout); err != nil {
		t.Fatalf("waitPrepared failed: %v", err)
	}
}

func TestFileAckPoolPreparedWaitReturnsAckError(t *testing.T) {
	pool := newFileAckPool()
	wait := pool.prepare("client:a", "file-2", "meta", 0)

	ok := pool.deliver("client:a", FileEvent{
		Packet: FilePacket{
			FileID: "file-2",
			Stage:  "meta",
			Offset: 0,
			Error:  "checksum mismatch",
		},
	})
	if !ok {
		t.Fatalf("deliver should match prepared waiter")
	}

	err := pool.waitPrepared(wait, defaultFileAckTimeout)
	if err == nil {
		t.Fatal("waitPrepared should return ack error")
	}
	if got, want := err.Error(), "checksum mismatch"; got != want {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestFileAckPoolCancelRemovesPreparedWaiter(t *testing.T) {
	pool := newFileAckPool()
	wait := pool.prepare("client:a", "file-3", "end", 0)
	wait.cancel()

	ok := pool.deliver("client:a", FileEvent{
		Packet: FilePacket{
			FileID: "file-3",
			Stage:  "end",
			Offset: 0,
		},
	})
	if ok {
		t.Fatal("deliver should not match canceled waiter")
	}
}

func TestFileAckPoolScopeIsolation(t *testing.T) {
	pool := newFileAckPool()
	waitA := pool.prepare("server:client-a", "file-4", "chunk", 128)
	waitB := pool.prepare("server:client-b", "file-4", "chunk", 128)

	ok := pool.deliver("server:client-a", FileEvent{
		Packet: FilePacket{
			FileID: "file-4",
			Stage:  "chunk",
			Offset: 128,
		},
	})
	if !ok {
		t.Fatal("deliver should match scopeA waiter")
	}

	if err := pool.waitPrepared(waitA, defaultFileAckTimeout); err != nil {
		t.Fatalf("waitPrepared scopeA failed: %v", err)
	}

	ok = pool.deliver("server:client-a", FileEvent{
		Packet: FilePacket{
			FileID: "file-4",
			Stage:  "chunk",
			Offset: 128,
		},
	})
	if ok {
		t.Fatal("scopeA ack should not consume scopeB waiter")
	}

	ok = pool.deliver("server:client-b", FileEvent{
		Packet: FilePacket{
			FileID: "file-4",
			Stage:  "chunk",
			Offset: 128,
		},
	})
	if !ok {
		t.Fatal("deliver should match scopeB waiter")
	}

	if err := pool.waitPrepared(waitB, defaultFileAckTimeout); err != nil {
		t.Fatalf("waitPrepared scopeB failed: %v", err)
	}
}

func TestFileAckPoolCloseAllCancelsPreparedWaiters(t *testing.T) {
	pool := newFileAckPool()
	wait := pool.prepare("client:a", "file-5", "chunk", 256)

	pool.closeAll()

	err := pool.waitPrepared(wait, defaultFileAckTimeout)
	if err == nil {
		t.Fatal("waitPrepared should return cancel error after closeAll")
	}
	if got, want := err.Error(), "file ack canceled"; got != want {
		t.Fatalf("unexpected error after closeAll: got %q want %q", got, want)
	}
}

func TestFileAckPoolCloseScopeCancelsMatchingWaitersOnly(t *testing.T) {
	pool := newFileAckPool()
	waitA := pool.prepare("server:client-a", "file-6", "chunk", 256)
	waitB := pool.prepare("server:client-b", "file-6", "chunk", 256)

	pool.closeScope("server:client-a")

	err := pool.waitPrepared(waitA, defaultFileAckTimeout)
	if err == nil {
		t.Fatal("scopeA waiter should be canceled")
	}
	if got, want := err.Error(), "file ack canceled"; got != want {
		t.Fatalf("unexpected scopeA error: got %q want %q", got, want)
	}

	ok := pool.deliver("server:client-b", FileEvent{
		Packet: FilePacket{
			FileID: "file-6",
			Stage:  "chunk",
			Offset: 256,
		},
	})
	if !ok {
		t.Fatal("scopeB waiter should remain deliverable")
	}

	if err := pool.waitPrepared(waitB, defaultFileAckTimeout); err != nil {
		t.Fatalf("waitPrepared scopeB failed: %v", err)
	}
}

func TestServerRemoveClientClosesScopedFileAckWaiters(t *testing.T) {
	server := NewServer().(*ServerCommon)
	clientA := &ClientConn{ClientID: "client-a"}
	clientB := &ClientConn{ClientID: "client-b"}
	pool := server.getFileAckPool()

	waitA := pool.prepare(serverFileScope(clientA), "file-7", "end", 0)
	waitB := pool.prepare(serverFileScope(clientB), "file-7", "end", 0)

	server.removeClient(clientA)

	err := pool.waitPrepared(waitA, defaultFileAckTimeout)
	if err == nil {
		t.Fatal("clientA waiter should be canceled when client is removed")
	}
	if got, want := err.Error(), "file ack canceled"; got != want {
		t.Fatalf("unexpected clientA error: got %q want %q", got, want)
	}

	ok := pool.deliver(serverFileScope(clientB), FileEvent{
		Packet: FilePacket{
			FileID: "file-7",
			Stage:  "end",
			Offset: 0,
		},
	})
	if !ok {
		t.Fatal("clientB waiter should remain deliverable")
	}

	if err := pool.waitPrepared(waitB, defaultFileAckTimeout); err != nil {
		t.Fatalf("waitPrepared clientB failed: %v", err)
	}
}