package compatibility

import (
	"fmt"
	"sync"
	"testing"
	"time"

	"github.com/gomodule/redigo/redis"
)

// dialRedis creates a new redigo connection for testing
func dialRedis(t *testing.T, addr string) redis.Conn {
	t.Helper()
	conn, err := redis.Dial("tcp", addr,
		redis.DialConnectTimeout(5*time.Second),
		redis.DialReadTimeout(5*time.Second),
		redis.DialWriteTimeout(5*time.Second),
	)
	if err != nil {
		t.Fatalf("Failed to dial: %v", err)
	}
	return conn
}

// TestRedigoBasicSubscribe tests basic SUBSCRIBE functionality
func TestRedigoBasicSubscribe(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	// Send SUBSCRIBE
	err := conn.Send("SUBSCRIBE", "rigo-test-channel")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = conn.Flush()

	// Read subscription confirmation
	msg, err := redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	// Should be ["subscribe", "channel", count]
	if len(msg) != 3 {
		t.Fatalf("Expected 3 elements, got %d", len(msg))
	}

	msgType, _ := redis.String(msg[0], nil)
	if msgType != "subscribe" {
		t.Errorf("Expected 'subscribe', got '%s'", msgType)
	}

	channel, _ := redis.String(msg[1], nil)
	if channel != "rigo-test-channel" {
		t.Errorf("Expected 'rigo-test-channel', got '%s'", channel)
	}
}

// TestRedigoBasicPublish tests basic PUBLISH functionality
func TestRedigoBasicPublish(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	// Subscriber
	subConn := dialRedis(t, ts.Addr())
	defer func() { _ = subConn.Close() }()

	err := subConn.Send("SUBSCRIBE", "rigo-pub-test")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = subConn.Flush()

	// Consume subscription confirmation
	_, err = redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive subscription failed: %v", err)
	}

	// Publisher
	pubConn := dialRedis(t, ts.Addr())
	defer func() { _ = pubConn.Close() }()

	reply, err := redis.Int(pubConn.Do("PUBLISH", "rigo-pub-test", "hello redigo"))
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	t.Logf("Published to %d subscribers", reply)

	// Receive message
	msg, err := redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive message failed: %v", err)
	}

	// Should be ["message", "channel", payload]
	if len(msg) != 3 {
		t.Fatalf("Expected 3 elements, got %d", len(msg))
	}

	msgType, _ := redis.String(msg[0], nil)
	if msgType != "message" {
		t.Errorf("Expected 'message', got '%s'", msgType)
	}

	payload, _ := redis.String(msg[2], nil)
	if payload != "hello redigo" {
		t.Errorf("Expected 'hello redigo', got '%s'", payload)
	}
}

// TestRedigoMultipleSubscribers tests multiple subscribers
func TestRedigoMultipleSubscribers(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	numSubs := 3
	conns := make([]redis.Conn, numSubs)

	// Create subscribers
	for i := 0; i < numSubs; i++ {
		conn := dialRedis(t, ts.Addr())
		conns[i] = conn

		err := conn.Send("SUBSCRIBE", "rigo-multi")
		if err != nil {
			t.Fatalf("Send failed for %d: %v", i, err)
		}
		_ = conn.Flush()

		// Consume confirmation
		_, err = redis.Values(conn.Receive())
		if err != nil {
			t.Fatalf("Receive confirmation failed for %d: %v", i, err)
		}
	}

	defer func() {
		for _, c := range conns {
			_ = c.Close()
		}
	}()

	// Publisher
	pubConn := dialRedis(t, ts.Addr())
	defer func() { _ = pubConn.Close() }()

	_, err := pubConn.Do("PUBLISH", "rigo-multi", "broadcast")
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	// All should receive
	for i, conn := range conns {
		msg, err := redis.Values(conn.Receive())
		if err != nil {
			t.Errorf("Subscriber %d failed to receive: %v", i, err)
			continue
		}

		payload, _ := redis.String(msg[2], nil)
		if payload != "broadcast" {
			t.Errorf("Subscriber %d got wrong payload: %s", i, payload)
		}
	}
}

// TestRedigoUnsubscribe tests UNSUBSCRIBE functionality
func TestRedigoUnsubscribe(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	// Subscribe
	err := conn.Send("SUBSCRIBE", "rigo-unsub-test")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = conn.Flush()

	// Consume confirmation
	_, err = redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	// Unsubscribe
	err = conn.Send("UNSUBSCRIBE", "rigo-unsub-test")
	if err != nil {
		t.Fatalf("Send unsubscribe failed: %v", err)
	}
	_ = conn.Flush()

	// Receive unsubscribe confirmation
	msg, err := redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive unsubscribe confirmation failed: %v", err)
	}

	msgType, _ := redis.String(msg[0], nil)
	if msgType != "unsubscribe" {
		t.Errorf("Expected 'unsubscribe', got '%s'", msgType)
	}
}

// TestRedigoPatternSubscribe tests PSUBSCRIBE functionality
func TestRedigoPatternSubscribe(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	// PSubscribe
	err := conn.Send("PSUBSCRIBE", "rigo-news.*")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = conn.Flush()

	// Receive confirmation
	msg, err := redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	msgType, _ := redis.String(msg[0], nil)
	if msgType != "psubscribe" {
		t.Errorf("Expected 'psubscribe', got '%s'", msgType)
	}

	pattern, _ := redis.String(msg[1], nil)
	if pattern != "rigo-news.*" {
		t.Errorf("Expected 'rigo-news.*', got '%s'", pattern)
	}
}

// TestRedigoPatternMatch tests pattern matching with PUBLISH
func TestRedigoPatternMatch(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	// Subscriber with pattern
	subConn := dialRedis(t, ts.Addr())
	defer func() { _ = subConn.Close() }()

	err := subConn.Send("PSUBSCRIBE", "rigo-pattern.*")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = subConn.Flush()

	// Consume confirmation
	_, err = redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive confirmation failed: %v", err)
	}

	t.Log("Pattern subscription confirmed, now publishing...")

	// Publisher
	pubConn := dialRedis(t, ts.Addr())
	defer func() { _ = pubConn.Close() }()

	reply, err := redis.Int(pubConn.Do("PUBLISH", "rigo-pattern.match", "pattern message"))
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}
	t.Logf("Publish returned: %d", reply)

	// Receive pmessage
	msg, err := redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	// Should be ["pmessage", "pattern", "channel", "payload"]
	if len(msg) != 4 {
		t.Fatalf("Expected 4 elements, got %d", len(msg))
	}

	msgType, _ := redis.String(msg[0], nil)
	if msgType != "pmessage" {
		t.Errorf("Expected 'pmessage', got '%s'", msgType)
	}

	pattern, _ := redis.String(msg[1], nil)
	if pattern != "rigo-pattern.*" {
		t.Errorf("Expected pattern 'rigo-pattern.*', got '%s'", pattern)
	}

	channel, _ := redis.String(msg[2], nil)
	if channel != "rigo-pattern.match" {
		t.Errorf("Expected channel 'rigo-pattern.match', got '%s'", channel)
	}

	payload, _ := redis.String(msg[3], nil)
	if payload != "pattern message" {
		t.Errorf("Expected 'pattern message', got '%s'", payload)
	}
}

// TestRedigoMultiplePatterns tests subscribing to multiple patterns
func TestRedigoMultiplePatterns(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	patterns := []string{"rigo-pat1.*", "rigo-pat2.*", "rigo-pat3.*"}

	for _, pattern := range patterns {
		err := conn.Send("PSUBSCRIBE", pattern)
		if err != nil {
			t.Fatalf("Send failed: %v", err)
		}
		_ = conn.Flush()

		// Consume confirmation
		_, err = redis.Values(conn.Receive())
		if err != nil {
			t.Fatalf("Receive confirmation failed: %v", err)
		}
	}
}

// TestRedigoPing tests PING command
func TestRedigoPing(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	result, err := redis.String(conn.Do("PING"))
	if err != nil {
		t.Fatalf("Ping failed: %v", err)
	}

	if result != "PONG" {
		t.Errorf("Expected 'PONG', got '%s'", result)
	}
}

// TestRedigoPingWithMessage tests PING with message
func TestRedigoPingWithMessage(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	result, err := redis.String(conn.Do("PING", "hello"))
	if err != nil {
		t.Fatalf("Ping failed: %v", err)
	}

	if result != "hello" {
		t.Errorf("Expected 'hello', got '%s'", result)
	}
}

// TestRedigoBinarySafe tests binary-safe messages
func TestRedigoBinarySafe(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	// Subscriber
	subConn := dialRedis(t, ts.Addr())
	defer func() { _ = subConn.Close() }()

	err := subConn.Send("SUBSCRIBE", "rigo-binary")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = subConn.Flush()

	_, err = redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive confirmation failed: %v", err)
	}

	// Publisher
	pubConn := dialRedis(t, ts.Addr())
	defer func() { _ = pubConn.Close() }()

	binaryMsg := []byte{0x00, 0x01, 0x02, 0xFF, 0xFE, '\r', '\n', 0x00}

	_, err = pubConn.Do("PUBLISH", "rigo-binary", binaryMsg)
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	// Receive message
	msg, err := redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	payload, _ := redis.String(msg[2], nil)
	if []byte(payload)[0] != binaryMsg[0] {
		t.Errorf("Binary message mismatch")
	}
}

// TestRedigisEmptyMessage tests empty message
func TestRedigisEmptyMessage(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	// Subscriber
	subConn := dialRedis(t, ts.Addr())
	defer func() { _ = subConn.Close() }()

	err := subConn.Send("SUBSCRIBE", "rigo-empty")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = subConn.Flush()

	_, err = redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive confirmation failed: %v", err)
	}

	// Publisher
	pubConn := dialRedis(t, ts.Addr())
	defer func() { _ = pubConn.Close() }()

	_, err = pubConn.Do("PUBLISH", "rigo-empty", "")
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	// Receive message
	msg, err := redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	payload, _ := redis.String(msg[2], nil)
	if payload != "" {
		t.Errorf("Expected empty payload, got '%s'", payload)
	}
}

// TestRedigoLongMessage tests long message
func TestRedigoLongMessage(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	// Subscriber
	subConn := dialRedis(t, ts.Addr())
	defer func() { _ = subConn.Close() }()

	err := subConn.Send("SUBSCRIBE", "rigo-long")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = subConn.Flush()

	_, err = redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive confirmation failed: %v", err)
	}

	// Publisher
	pubConn := dialRedis(t, ts.Addr())
	defer func() { _ = pubConn.Close() }()

	// 100KB message
	longMsg := make([]byte, 100*1024)
	for i := range longMsg {
		longMsg[i] = byte(i % 256)
	}

	_, err = pubConn.Do("PUBLISH", "rigo-long", longMsg)
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	// Receive message
	msg, err := redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	payload, _ := redis.String(msg[2], nil)
	if len(payload) != len(longMsg) {
		t.Errorf("Message length mismatch: got %d, want %d", len(payload), len(longMsg))
	}
}

// TestRedigoConcurrentSubscribers tests concurrent operations
func TestRedigoConcurrentSubscribers(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	var wg sync.WaitGroup

	for i := 0; i < 10; i++ {
		wg.Add(1)
		go func(id int) {
			defer wg.Done()

			conn := dialRedis(t, ts.Addr())
			defer func() { _ = conn.Close() }()

			channel := fmt.Sprintf("rigo-concurrent-%d", id%3)
			err := conn.Send("SUBSCRIBE", channel)
			if err != nil {
				t.Errorf("Send failed: %v", err)
				return
			}
			_ = conn.Flush()

			_, err = redis.Values(conn.Receive())
			if err != nil {
				t.Errorf("Receive failed: %v", err)
				return
			}

			time.Sleep(50 * time.Millisecond)
		}(i)
	}

	wg.Wait()
}

// TestRedigoPublishNoSubscribers tests PUBLISH with no subscribers
func TestRedigoPublishNoSubscribers(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	count, err := redis.Int(conn.Do("PUBLISH", "rigo-no-subs", "message"))
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	if count != 0 {
		t.Errorf("Expected 0 receivers, got %d", count)
	}
}

// TestRedigoUnicodeMessages tests Unicode messages
func TestRedigoUnicodeMessages(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	messages := []string{
		"Hello, 世界!",
		"Emoji: 🎉",
		"Cyrillic: Привет",
	}

	for _, testMsg := range messages {
		t.Run(testMsg[:min(20, len(testMsg))], func(t *testing.T) {
			// Subscriber
			subConn := dialRedis(t, ts.Addr())
			defer func() { _ = subConn.Close() }()

			err := subConn.Send("SUBSCRIBE", "rigo-unicode")
			if err != nil {
				t.Fatalf("Send failed: %v", err)
			}
			_ = subConn.Flush()

			_, err = redis.Values(subConn.Receive())
			if err != nil {
				t.Fatalf("Receive confirmation failed: %v", err)
			}

			// Publisher
			pubConn := dialRedis(t, ts.Addr())
			defer func() { _ = pubConn.Close() }()

			_, err = pubConn.Do("PUBLISH", "rigo-unicode", testMsg)
			if err != nil {
				t.Fatalf("Publish failed: %v", err)
			}

			// Receive
			msg, err := redis.Values(subConn.Receive())
			if err != nil {
				t.Fatalf("Receive failed: %v", err)
			}

			payload, _ := redis.String(msg[2], nil)
			if payload != testMsg {
				t.Errorf("Unicode mismatch: got %q, want %q", payload, testMsg)
			}
		})
	}
}

// TestRedigoChannelWithSpecialChars tests channels with special characters
func TestRedigoChannelWithSpecialChars(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	channels := []string{
		"rigo-with-dash",
		"rigo_with_underscore",
		"rigo.with.dots",
		"rigo:with:colons",
	}

	for _, channelName := range channels {
		t.Run(channelName, func(t *testing.T) {
			// Subscriber
			subConn := dialRedis(t, ts.Addr())
			defer func() { _ = subConn.Close() }()

			err := subConn.Send("SUBSCRIBE", channelName)
			if err != nil {
				t.Fatalf("Send failed: %v", err)
			}
			_ = subConn.Flush()

			_, err = redis.Values(subConn.Receive())
			if err != nil {
				t.Fatalf("Receive confirmation failed: %v", err)
			}

			// Publisher
			pubConn := dialRedis(t, ts.Addr())
			defer func() { _ = pubConn.Close() }()

			_, err = pubConn.Do("PUBLISH", channelName, "test")
			if err != nil {
				t.Fatalf("Publish failed: %v", err)
			}

			// Receive
			msg, err := redis.Values(subConn.Receive())
			if err != nil {
				t.Fatalf("Receive failed: %v", err)
			}

			channel, _ := redis.String(msg[1], nil)
			if channel != channelName {
				t.Errorf("Channel mismatch: got %s, want %s", channel, channelName)
			}
		})
	}
}

// TestRedigoMixedSubscribePSubscribe tests mixing SUBSCRIBE and PSUBSCRIBE
// nolint: cyclop
func TestRedigoMixedSubscribePSubscribe(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	// Subscribe to channel
	err := conn.Send("SUBSCRIBE", "rigo-mixed-ch")
	if err != nil {
		t.Fatalf("Send subscribe failed: %v", err)
	}
	_ = conn.Flush()

	_, err = redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive subscribe confirmation failed: %v", err)
	}

	// Also subscribe to pattern
	err = conn.Send("PSUBSCRIBE", "rigo-mixed-*")
	if err != nil {
		t.Fatalf("Send psubscribe failed: %v", err)
	}
	_ = conn.Flush()

	_, err = redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive psubscribe confirmation failed: %v", err)
	}

	// Publish to channel - should receive via channel subscription
	pubConn := dialRedis(t, ts.Addr())
	defer func() { _ = pubConn.Close() }()

	_, err = pubConn.Do("PUBLISH", "rigo-mixed-ch", "channel msg")
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	msg, err := redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	msgType, _ := redis.String(msg[0], nil)
	if msgType != "message" {
		t.Errorf("Expected 'message', got '%s'", msgType)
	}

	// Publish to pattern-matching channel - should receive via pattern subscription
	_, err = pubConn.Do("PUBLISH", "rigo-mixed-pattern", "pattern msg")
	if err != nil {
		t.Fatalf("Publish failed: %v", err)
	}

	msg, err = redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive failed: %v", err)
	}

	msgType, _ = redis.String(msg[0], nil)
	if msgType != "pmessage" {
		t.Errorf("Expected 'pmessage', got '%s'", msgType)
	}
}

// TestRedigoPunsubscribe tests PUNSUBSCRIBE functionality
func TestRedigoPunsubscribe(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	conn := dialRedis(t, ts.Addr())
	defer func() { _ = conn.Close() }()

	// PSubscribe
	err := conn.Send("PSUBSCRIBE", "rigo-punsub.*")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = conn.Flush()

	_, err = redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive confirmation failed: %v", err)
	}

	// Punsubscribe
	err = conn.Send("PUNSUBSCRIBE", "rigo-punsub.*")
	if err != nil {
		t.Fatalf("Send punsubscribe failed: %v", err)
	}
	_ = conn.Flush()

	msg, err := redis.Values(conn.Receive())
	if err != nil {
		t.Fatalf("Receive punsubscribe confirmation failed: %v", err)
	}

	msgType, _ := redis.String(msg[0], nil)
	if msgType != "punsubscribe" {
		t.Errorf("Expected 'punsubscribe', got '%s'", msgType)
	}
}

// TestRedigoConcurrentPublishSubscribe tests concurrent pub/sub
func TestRedigoConcurrentPublishSubscribe(t *testing.T) {
	ts := startTestServer(t)
	defer ts.Close()

	numMessages := 50

	// Subscriber
	subConn := dialRedis(t, ts.Addr())
	defer func() { _ = subConn.Close() }()

	err := subConn.Send("SUBSCRIBE", "rigo-concurrent-pub")
	if err != nil {
		t.Fatalf("Send failed: %v", err)
	}
	_ = subConn.Flush()

	_, err = redis.Values(subConn.Receive())
	if err != nil {
		t.Fatalf("Receive confirmation failed: %v", err)
	}

	// Publisher in goroutine
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()

		pubConn := dialRedis(t, ts.Addr())
		defer func() { _ = pubConn.Close() }()

		for i := 0; i < numMessages; i++ {
			_, err := pubConn.Do("PUBLISH", "rigo-concurrent-pub", fmt.Sprintf("msg-%d", i))
			if err != nil {
				t.Errorf("Publish %d failed: %v", i, err)
				return
			}
			time.Sleep(time.Millisecond)
		}
	}()

	// Receive messages
	received := 0
	timeout := time.After(10 * time.Second)
	for received < numMessages {
		select {
		case <-timeout:
			t.Logf("Received %d/%d messages", received, numMessages)
			wg.Wait()
			return
		default:
		}

		msg, err := redis.Values(subConn.Receive())
		if err != nil {
			t.Errorf("Receive failed: %v", err)
			break
		}

		msgType, _ := redis.String(msg[0], nil)
		if msgType == "message" {
			received++
		}
	}

	wg.Wait()
	t.Logf("Received all %d messages", received)
}