package dispatch

import (
	"context"
	"encoding/json"
	"fmt"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/gochat/gochat/internal/channel"
	"github.com/gochat/gochat/internal/model"
)

// --- mock listener for testing ---

type mockListener_Cov3 struct {
	name   string
	err    error
	calls  int32
	events []*channel.ChannelEvent
	mu     sync.Mutex
}

func (m *mockListener_Cov3) Name() string { return m.name }
func (m *mockListener_Cov3) OnEvent(ctx context.Context, event *channel.ChannelEvent) error {
	atomic.AddInt32(&m.calls, 1)
	m.mu.Lock()
	m.events = append(m.events, event)
	m.mu.Unlock()
	return m.err
}

func newMockListener_Cov3(name string, err error) *mockListener_Cov3 {
	return &mockListener_Cov3{name: name, err: err}
}

// --- ListenerRegistry tests ---

func TestListenerRegistry_SubscribeWildcard_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1") // wildcard
	subs := r.SubscribersForEvent("message.created")
	assert.Contains(t, subs, "listener1")
}

func TestListenerRegistry_SubscribeSpecific_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1", "message.created")
	subs := r.SubscribersForEvent("message.created")
	assert.Contains(t, subs, "listener1")
	// Should NOT be returned for other events
	subs2 := r.SubscribersForEvent("conversation.created")
	assert.NotContains(t, subs2, "listener1")
}

func TestListenerRegistry_SubscribeMultipleEvents_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1", "message.created", "conversation.created")
	subs1 := r.SubscribersForEvent("message.created")
	assert.Contains(t, subs1, "listener1")
	subs2 := r.SubscribersForEvent("conversation.created")
	assert.Contains(t, subs2, "listener1")
}

func TestListenerRegistry_Unsubscribe_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1", "message.created")
	r.Unsubscribe("listener1")
	subs := r.SubscribersForEvent("message.created")
	assert.NotContains(t, subs, "listener1")
}

func TestListenerRegistry_UnsubscribeCleansEmpty_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1", "message.created")
	r.Unsubscribe("listener1")
	// Event should be removed from subscriptions when no more listeners
	assert.Empty(t, r.subscriptions["message.created"])
}

func TestListenerRegistry_AllSubscriptions_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1", "message.created")
	r.Subscribe("listener2", "conversation.created")
	subs := r.AllSubscriptions()
	assert.Contains(t, subs, "message.created")
	assert.Contains(t, subs, "conversation.created")
}

func TestListenerRegistry_HasSubscribers_Wildcard_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1") // wildcard
	assert.True(t, r.HasSubscribers("any.event"))
}

func TestListenerRegistry_HasSubscribers_Specific_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1", "message.created")
	assert.True(t, r.HasSubscribers("message.created"))
	assert.False(t, r.HasSubscribers("conversation.created"))
}

func TestListenerRegistry_HasSubscribers_None_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	assert.False(t, r.HasSubscribers("message.created"))
}

func TestListenerRegistry_SubscribersForEvent_NoMatch_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	subs := r.SubscribersForEvent("nonexistent.event")
	assert.Empty(t, subs)
}

func TestListenerRegistry_SubscribersForEvent_Dedup_Cov3(t *testing.T) {
	r := NewListenerRegistry()
	r.Subscribe("listener1")                    // wildcard
	r.Subscribe("listener1", "message.created") // specific (same listener)
	subs := r.SubscribersForEvent("message.created")
	// Should be deduplicated — only one entry
	assert.Len(t, subs, 1)
	assert.Contains(t, subs, "listener1")
}

// --- Event helpers tests ---

func TestExtractConversationID_Uint_Cov3(t *testing.T) {
	data := map[string]interface{}{"conversation_id": uint(42)}
	id, err := ExtractConversationID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(42), id)
}

func TestExtractConversationID_Int_Cov3(t *testing.T) {
	data := map[string]interface{}{"conversation_id": int(42)}
	id, err := ExtractConversationID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(42), id)
}

func TestExtractConversationID_Float64_Cov3(t *testing.T) {
	data := map[string]interface{}{"conversation_id": float64(42)}
	id, err := ExtractConversationID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(42), id)
}

func TestExtractConversationID_Missing_Cov3(t *testing.T) {
	data := map[string]interface{}{}
	_, err := ExtractConversationID(data)
	assert.Error(t, err)
}

func TestExtractConversationID_WrongType_Cov3(t *testing.T) {
	data := map[string]interface{}{"conversation_id": "not a number"}
	_, err := ExtractConversationID(data)
	assert.Error(t, err)
}

func TestExtractAccountID_Uint_Cov3(t *testing.T) {
	data := map[string]interface{}{"account_id": uint(1)}
	id, err := ExtractAccountID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(1), id)
}

func TestExtractAccountID_Int_Cov3(t *testing.T) {
	data := map[string]interface{}{"account_id": int(1)}
	id, err := ExtractAccountID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(1), id)
}

func TestExtractAccountID_Float64_Cov3(t *testing.T) {
	data := map[string]interface{}{"account_id": float64(1)}
	id, err := ExtractAccountID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(1), id)
}

func TestExtractAccountID_Missing_Cov3(t *testing.T) {
	data := map[string]interface{}{}
	_, err := ExtractAccountID(data)
	assert.Error(t, err)
}

func TestExtractAccountID_WrongType_Cov3(t *testing.T) {
	data := map[string]interface{}{"account_id": true}
	_, err := ExtractAccountID(data)
	assert.Error(t, err)
}

func TestExtractInboxID_Uint_Cov3(t *testing.T) {
	data := map[string]interface{}{"inbox_id": uint(5)}
	id, err := ExtractInboxID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(5), id)
}

func TestExtractInboxID_Int_Cov3(t *testing.T) {
	data := map[string]interface{}{"inbox_id": int(5)}
	id, err := ExtractInboxID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(5), id)
}

func TestExtractInboxID_Float64_Cov3(t *testing.T) {
	data := map[string]interface{}{"inbox_id": float64(5)}
	id, err := ExtractInboxID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(5), id)
}

func TestExtractInboxID_Missing_Cov3(t *testing.T) {
	data := map[string]interface{}{}
	_, err := ExtractInboxID(data)
	assert.Error(t, err)
}

func TestExtractInboxID_WrongType_Cov3(t *testing.T) {
	data := map[string]interface{}{"inbox_id": "abc"}
	_, err := ExtractInboxID(data)
	assert.Error(t, err)
}

func TestExtractAssigneeID_Uint_Cov3(t *testing.T) {
	data := map[string]interface{}{"assignee_id": uint(3)}
	id, err := ExtractAssigneeID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(3), id)
}

func TestExtractAssigneeID_Int_Cov3(t *testing.T) {
	data := map[string]interface{}{"assignee_id": int(3)}
	id, err := ExtractAssigneeID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(3), id)
}

func TestExtractAssigneeID_Float64_Cov3(t *testing.T) {
	data := map[string]interface{}{"assignee_id": float64(3)}
	id, err := ExtractAssigneeID(data)
	require.NoError(t, err)
	assert.Equal(t, uint(3), id)
}

func TestExtractAssigneeID_Missing_Cov3(t *testing.T) {
	data := map[string]interface{}{}
	_, err := ExtractAssigneeID(data)
	assert.Error(t, err)
}

func TestExtractAssigneeID_WrongType_Cov3(t *testing.T) {
	data := map[string]interface{}{"assignee_id": []int{1}}
	_, err := ExtractAssigneeID(data)
	assert.Error(t, err)
}

// --- Event constructors ---

func TestNewChannelEvent_Cov3(t *testing.T) {
	event := NewChannelEvent("message.created", map[string]interface{}{"foo": "bar"})
	assert.Equal(t, "message.created", string(event.Type))
	assert.Equal(t, "bar", event.Data["foo"])
	assert.NotZero(t, event.Timestamp)
}

func TestNewChannelEvent_NilData_Cov3(t *testing.T) {
	event := NewChannelEvent("test.event", nil)
	assert.NotNil(t, event.Data)
}

func TestNewDispatchEvent_Cov3(t *testing.T) {
	event := NewDispatchEvent(DispatchEventCampaignStarted, map[string]interface{}{"id": 1})
	assert.Equal(t, "campaign.started", string(event.Type))
}

func TestEventDataWithConversation_Cov3(t *testing.T) {
	data := EventDataWithConversation(1, 2, 3)
	assert.Equal(t, uint(1), data["conversation_id"])
	assert.Equal(t, uint(2), data["account_id"])
	assert.Equal(t, uint(3), data["inbox_id"])
}

func TestEventDataWithAssignment_Cov3(t *testing.T) {
	data := EventDataWithAssignment(1, 2, 3, 4)
	assert.Equal(t, uint(1), data["conversation_id"])
	assert.Equal(t, uint(2), data["account_id"])
	assert.Equal(t, uint(3), data["inbox_id"])
	assert.Equal(t, uint(4), data["assignee_id"])
}

// --- Dispatcher tests ---

func TestEventDispatcher_Dispatch_Sync_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	l1 := newMockListener_Cov3("sync_listener", nil)
	ed.RegisterSync(l1, "message.created")

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	err := ed.Dispatch(context.Background(), event)
	require.NoError(t, err)
	assert.Equal(t, int32(1), atomic.LoadInt32(&l1.calls))
}

func TestEventDispatcher_Dispatch_SyncError_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	l1 := newMockListener_Cov3("err_listener", fmt.Errorf("listener error"))
	ed.RegisterSync(l1, "message.created")

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	err := ed.Dispatch(context.Background(), event)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "listener error")
}

func TestEventDispatcher_Dispatch_Async_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	l1 := newMockListener_Cov3("async_listener", nil)
	ed.RegisterAsync(l1, "message.created")

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	err := ed.Dispatch(context.Background(), event)
	require.NoError(t, err) // async errors are not returned

	// Wait for async goroutine to complete
	time.Sleep(100 * time.Millisecond)
	assert.Equal(t, int32(1), atomic.LoadInt32(&l1.calls))
}

func TestEventDispatcher_Dispatch_Wildcard_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	l1 := newMockListener_Cov3("wildcard_listener", nil)
	ed.RegisterSync(l1) // wildcard — all events

	event := &channel.ChannelEvent{
		Type: "any.event",
		Data: map[string]interface{}{},
	}
	err := ed.Dispatch(context.Background(), event)
	require.NoError(t, err)
	assert.Equal(t, int32(1), atomic.LoadInt32(&l1.calls))
}

func TestEventDispatcher_Dispatch_NoSubscribers_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	err := ed.Dispatch(context.Background(), event)
	require.NoError(t, err)
}

func TestEventDispatcher_DispatchAsync_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	l1 := newMockListener_Cov3("sync_listener", nil)
	ed.RegisterSync(l1, "message.created")

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	ed.DispatchAsync(context.Background(), event)

	time.Sleep(100 * time.Millisecond)
	assert.Equal(t, int32(1), atomic.LoadInt32(&l1.calls))
}

func TestEventDispatcher_DispatchAsync_NoSubscribers_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	ed.DispatchAsync(context.Background(), event)
	// should not panic
}

func TestEventDispatcher_DispatchAsync_UnknownListener_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	// Manually add a subscriber name that doesn't exist in entries
	ed.registry.Subscribe("nonexistent_listener", "message.created")

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	ed.DispatchAsync(context.Background(), event)
	// should not panic — just skips unknown listener
}

func TestEventDispatcher_Dispatch_UnknownListenerEntry_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	// Add subscriber that doesn't have an entry
	ed.registry.Subscribe("ghost", "message.created")

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	err := ed.Dispatch(context.Background(), event)
	require.NoError(t, err)
}

func TestEventDispatcher_PerformListenerJob_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	l1 := newMockListener_Cov3("job_listener", nil)
	ed.RegisterSync(l1, "message.created")

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	payload := listenerJobPayload{ListenerName: "job_listener", Event: event}
	payloadBytes, _ := json.Marshal(payload)

	job := &model.BackgroundJob{
		Payload: payloadBytes,
	}

	err := ed.performListenerJob(context.Background(), job)
	require.NoError(t, err)
	assert.Equal(t, int32(1), atomic.LoadInt32(&l1.calls))
}

func TestEventDispatcher_PerformListenerJob_BadPayload_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	job := &model.BackgroundJob{
		Payload: json.RawMessage(`{"bad": "json"`),
	}

	err := ed.performListenerJob(context.Background(), job)
	assert.Error(t, err)
}

func TestEventDispatcher_PerformListenerJob_UnknownListener_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	event := &channel.ChannelEvent{
		Type: "message.created",
		Data: map[string]interface{}{},
	}
	payload := listenerJobPayload{ListenerName: "unknown", Event: event}
	payloadBytes, _ := json.Marshal(payload)

	job := &model.BackgroundJob{
		Payload: payloadBytes,
	}

	err := ed.performListenerJob(context.Background(), job)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "not registered")
}

func TestEventDispatcher_PerformListenerJob_NilEvent_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)

	l1 := newMockListener_Cov3("job_listener", nil)
	ed.RegisterSync(l1, "message.created")

	payload := listenerJobPayload{ListenerName: "job_listener", Event: nil}
	payloadBytes, _ := json.Marshal(payload)

	job := &model.BackgroundJob{
		Payload: payloadBytes,
	}

	err := ed.performListenerJob(context.Background(), job)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "missing event")
}

func TestEventDispatcher_ChannelDispatcher_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)
	assert.NotNil(t, ed.ChannelDispatcher())
}

func TestEventDispatcher_Registry_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)
	assert.NotNil(t, ed.Registry())
}

func TestEventDispatcher_RegisterSync_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)
	l := newMockListener_Cov3("test", nil)
	ed.RegisterSync(l, "event1")
	assert.Contains(t, ed.entries, "test")
	assert.Equal(t, SyncMode, ed.entries["test"].mode)
}

func TestEventDispatcher_RegisterAsync_Cov3(t *testing.T) {
	cd := channel.NewDispatcher()
	ed := NewEventDispatcher(cd)
	l := newMockListener_Cov3("test", nil)
	ed.RegisterAsync(l, "event1")
	assert.Contains(t, ed.entries, "test")
	assert.Equal(t, AsyncMode, ed.entries["test"].mode)
}