package main

import (
	"fmt"
	"time"
)

func main() {
	eb := NewEventBus()

	fmt.Println("=== EventBus Demo ===")

	// Subscribe to specific topic
	ch1 := eb.Subscribe("orders.created")

	// Subscribe to wildcard
	ch2 := eb.Subscribe("orders.*")

	// Subscribe using a callback
	eb.SubscribeCallback("payments.*", func(topic string, data Data) {
		fmt.Printf("[Callback] Payment event received: %s -> %+v\n", topic, data)
	})

	// Run listener goroutines
	go func() {
		for evt := range ch1 {
			fmt.Printf("[Listener 1] Topic=%s Data=%v\n", evt.Topic, evt.Data)
			time.Sleep(50 * time.Millisecond) // simulate work
			evt.Done()
		}
	}()

	go func() {
		for evt := range ch2 {
			fmt.Printf("[Listener 2] Wildcard match for %s Data=%v\n", evt.Topic, evt.Data)
			evt.Done()
		}
	}()

	// ---- PUBLISH SYNCHRONOUS EVENTS ----
	fmt.Println("\n--- Publish Sync ---")
	eb.Publish("orders.created", Data{"id": 42, "customer": "Alice"})
	eb.Publish("orders.updated", Data{"id": 42, "status": "shipped"})

	// ---- PUBLISH ASYNC EVENTS ----
	fmt.Println("\n--- Publish Async ---")
	eb.PublishAsync("payments.received", Data{"id": 1001, "amount": 99.50})
	eb.PublishAsync("payments.refunded", Data{"id": 1002, "amount": 20.00})

	// Give async events time to deliver
	time.Sleep(200 * time.Millisecond)

	// ---- PUBLISH ONCE semantics ----
	fmt.Println("\n--- Publish Once ---")
	eb.PublishOnce("orders.once", Data{"msg": "first time"})
	eb.PublishOnce("orders.once", Data{"msg": "second time (ignored)"})
	eb.PublishAsyncOnce("payments.once", Data{"msg": "async first"})
	eb.PublishAsyncOnce("payments.once", Data{"msg": "async second (ignored)"})

	time.Sleep(100 * time.Millisecond)

	// ---- UNSUBSCRIBE ----
	fmt.Println("\n--- Unsubscribe Listener 2 (orders.*) ---")
	eb.Unsubscribe("orders.*", ch2)
	close(ch2)

	eb.Publish("orders.updated", Data{"id": 42, "status": "delivered"})

	time.Sleep(100 * time.Millisecond)

	// ---- PRINT STATS ----
	fmt.Println("\n--- Stats ---")
	for _, ts := range eb.Stats().GetTopicStats() {
		fmt.Printf("Topic: %-20s | Published: %-3d | Subscribers: %-3d\n",
			ts.Name, ts.PublishedCount.Value(), ts.SubscriberCount.Value())
	}

	fmt.Println("\n=== Done ===")
}