package proxy

import (
	"bytes"
	"io"
	"sync"
	"testing"
)

func TestLogMonitor(t *testing.T) {
	logMonitor := NewLogMonitorWriter(io.Discard)

	// Test subscription
	client1 := logMonitor.Subscribe()
	client2 := logMonitor.Subscribe()

	defer logMonitor.Unsubscribe(client1)
	defer logMonitor.Unsubscribe(client2)

	client1Messages := make([]byte, 0)
	client2Messages := make([]byte, 0)

	var wg sync.WaitGroup
	wg.Add(1)

	go func() {
		defer wg.Done()
		for {
			select {
			case data := <-client1:
				client1Messages = append(client1Messages, data...)
			case data := <-client2:
				client2Messages = append(client2Messages, data...)
			default:
				return
			}
		}
	}()

	logMonitor.Write([]byte("1"))
	logMonitor.Write([]byte("2"))
	logMonitor.Write([]byte("3"))

	// Wait for the goroutine to finish
	wg.Wait()

	// Check the buffer
	expectedHistory := "123"
	history := string(logMonitor.GetHistory())

	if history != expectedHistory {
		t.Errorf("Expected history: %s, got: %s", expectedHistory, history)
	}

	c1Data := string(client1Messages)
	if c1Data != expectedHistory {
		t.Errorf("Client1 expected %s, got: %s", expectedHistory, c1Data)
	}

	c2Data := string(client2Messages)
	if c2Data != expectedHistory {
		t.Errorf("Client2 expected %s, got: %s", expectedHistory, c2Data)
	}
}

func TestWrite_ImmutableBuffer(t *testing.T) {
	// Create a new LogMonitor instance
	lm := NewLogMonitorWriter(io.Discard)

	// Prepare a message to write
	msg := []byte("Hello, World!")
	lenmsg := len(msg)

	// Write the message to the LogMonitor
	n, err := lm.Write(msg)
	if err != nil {
		t.Fatalf("Write failed: %v", err)
	}

	if n != lenmsg {
		t.Errorf("Expected %d bytes written but got %d", lenmsg, n)
	}

	// Change the original message
	msg[0] = 'B' // This should not affect the buffer

	// Get the history from the LogMonitor
	history := lm.GetHistory()

	// Check that the history contains the original message, not the modified one
	expected := []byte("Hello, World!")
	if !bytes.Equal(history, expected) {
		t.Errorf("Expected history to be %q, got %q", expected, history)
	}
}