package rpc

import (
	"context"
	"testing"

	"github.com/iamxvbaba/td/clock"
	"github.com/iamxvbaba/td/tg"
	"go.uber.org/zap/zaptest"

	appchannels "telesrv/internal/app/channels"
	appusers "telesrv/internal/app/users"
	"telesrv/internal/domain"
	"telesrv/internal/store/memory"
)

// A public forum's topic list is browsable before joining, like its history.
// Regression: getForumTopics used the member-only access path and returned
// CHANNEL_PRIVATE / an empty list to non-members, so the topic list (and even
// General) was invisible until they joined.
func TestGetForumTopicsVisibleToPublicNonMember(t *testing.T) {
	ctx := context.Background()
	userStore := memory.NewUserStore()
	owner, _ := userStore.Create(ctx, domain.User{AccessHash: 81, Phone: "15550008101", FirstName: "Owner"})
	outsider, _ := userStore.Create(ctx, domain.User{AccessHash: 82, Phone: "15550008102", FirstName: "Outsider"})
	channelStore := memory.NewChannelStore()
	channelSvc := appchannels.NewService(channelStore)
	r := New(Config{}, Deps{
		Users:    appusers.NewService(userStore),
		Channels: channelSvc,
	}, zaptest.NewLogger(t), clock.System)

	ownerCtx := WithUserID(ctx, owner.ID)
	outsiderCtx := WithUserID(ctx, outsider.ID)

	created, err := r.onChannelsCreateChannel(ownerCtx, &tg.ChannelsCreateChannelRequest{Title: "Public Forum", Megagroup: true})
	if err != nil {
		t.Fatalf("create channel: %v", err)
	}
	channel := created.(*tg.Updates).Chats[0].(*tg.Channel)
	input := &tg.InputChannel{ChannelID: channel.ID, AccessHash: channel.AccessHash}
	forumPeer := &tg.InputPeerChannel{ChannelID: channel.ID, AccessHash: channel.AccessHash}

	if _, err := r.onChannelsToggleForum(ownerCtx, &tg.ChannelsToggleForumRequest{Channel: input, Enabled: true, Tabs: true}); err != nil {
		t.Fatalf("toggle forum: %v", err)
	}
	if _, err := channelSvc.UpdateUsername(ctx, owner.ID, domain.UpdateChannelUsernameRequest{
		ChannelID: channel.ID,
		Username:  "publicforum",
	}); err != nil {
		t.Fatalf("set channel username: %v", err)
	}
	if _, err := r.onMessagesCreateForumTopic(ownerCtx, &tg.MessagesCreateForumTopicRequest{
		Peer:      forumPeer,
		Title:     "Test",
		IconColor: domain.DefaultForumTopicIconColor,
		RandomID:  8101001,
	}); err != nil {
		t.Fatalf("create forum topic: %v", err)
	}

	res, err := r.onMessagesGetForumTopics(outsiderCtx, &tg.MessagesGetForumTopicsRequest{
		Peer:  forumPeer,
		Limit: 100,
	})
	if err != nil {
		t.Fatalf("getForumTopics as non-member: %v", err)
	}
	titles := map[string]bool{}
	testTopicID := 0
	for _, tc := range res.Topics {
		switch topic := tc.(type) {
		case *tg.ForumTopic:
			titles[topic.Title] = true
			if topic.Title == "Test" {
				testTopicID = topic.ID
			}
		case *tg.ForumTopicDeleted:
		}
	}
	if !titles["General"] {
		t.Fatalf("non-member did not see the General topic: %+v", res.Topics)
	}
	if !titles["Test"] {
		t.Fatalf("non-member did not see the Test topic: %+v", res.Topics)
	}

	// A non-member can also read the replies inside a topic (preview), the same
	// way ListChannelHistory lets them preview a public group's flat history.
	if testTopicID == 0 {
		t.Fatal("no Test topic id to open")
	}
	if _, err := r.onMessagesGetReplies(outsiderCtx, &tg.MessagesGetRepliesRequest{
		Peer:  forumPeer,
		MsgID: testTopicID,
		Limit: 20,
	}); err != nil {
		t.Fatalf("getReplies as non-member of a public forum: %v", err)
	}

	// The forum's own channel must come back with left=true so the client still
	// offers a Join button instead of treating the forum as already joined.
	var forumChat *tg.Channel
	for _, c := range res.Chats {
		if ch, ok := c.(*tg.Channel); ok && ch.ID == channel.ID {
			forumChat = ch
		}
	}
	if forumChat == nil {
		t.Fatalf("forum channel missing from getForumTopics chats: %+v", res.Chats)
	}
	if !forumChat.Left {
		t.Fatalf("non-member forum chat = %#v, want left=true", forumChat)
	}

	// A private forum still refuses a non-member.
	priv, err := r.onChannelsCreateChannel(ownerCtx, &tg.ChannelsCreateChannelRequest{Title: "Private Forum", Megagroup: true})
	if err != nil {
		t.Fatalf("create private channel: %v", err)
	}
	privCh := priv.(*tg.Updates).Chats[0].(*tg.Channel)
	privInput := &tg.InputChannel{ChannelID: privCh.ID, AccessHash: privCh.AccessHash}
	privPeer := &tg.InputPeerChannel{ChannelID: privCh.ID, AccessHash: privCh.AccessHash}
	if _, err := r.onChannelsToggleForum(ownerCtx, &tg.ChannelsToggleForumRequest{Channel: privInput, Enabled: true, Tabs: true}); err != nil {
		t.Fatalf("toggle private forum: %v", err)
	}
	if _, err := r.onMessagesGetForumTopics(outsiderCtx, &tg.MessagesGetForumTopicsRequest{Peer: privPeer, Limit: 100}); err == nil {
		t.Fatal("non-member read a private forum's topic list")
	}
	if _, err := r.onMessagesGetReplies(outsiderCtx, &tg.MessagesGetRepliesRequest{Peer: privPeer, MsgID: 1, Limit: 20}); err == nil {
		t.Fatal("non-member read a private forum topic's replies")
	}
}