package db_test

import (
	"context"
	"fmt"
	"path/filepath"
	"testing"
	"time"

	"git.eeqj.de/sneak/chat/internal/db"
)

const (
	nickAlice   = "alice"
	nickBob     = "bob"
	nickCharlie = "charlie"
)

// setupTestDB creates a fresh database in a temp directory with
// all migrations applied.
func setupTestDB(t *testing.T) *db.Database {
	t.Helper()

	dir := t.TempDir()
	dsn := fmt.Sprintf(
		"file:%s?_journal_mode=WAL",
		filepath.Join(dir, "test.db"),
	)

	d, err := db.NewTest(dsn)
	if err != nil {
		t.Fatalf("failed to create test database: %v", err)
	}

	t.Cleanup(func() { _ = d.GetDB().Close() })

	return d
}

func TestCreateUser(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	id, token, err := d.CreateUser(ctx, nickAlice)
	if err != nil {
		t.Fatalf("CreateUser: %v", err)
	}

	if id <= 0 {
		t.Errorf("expected positive id, got %d", id)
	}

	if token == "" {
		t.Error("expected non-empty token")
	}
}

func TestGetUserByToken(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	_, token, _ := d.CreateUser(ctx, nickAlice)

	id, nick, err := d.GetUserByToken(ctx, token)
	if err != nil {
		t.Fatalf("GetUserByToken: %v", err)
	}

	if id <= 0 || nick != nickAlice {
		t.Errorf(
			"got id=%d nick=%s, want nick=%s",
			id, nick, nickAlice,
		)
	}
}

func TestGetUserByNick(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	origID, _, _ := d.CreateUser(ctx, nickAlice)

	id, err := d.GetUserByNick(ctx, nickAlice)
	if err != nil {
		t.Fatalf("GetUserByNick: %v", err)
	}

	if id != origID {
		t.Errorf("got id %d, want %d", id, origID)
	}
}

func TestGetOrCreateChannel(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	id1, err := d.GetOrCreateChannel(ctx, "#general")
	if err != nil {
		t.Fatalf("GetOrCreateChannel: %v", err)
	}

	if id1 <= 0 {
		t.Errorf("expected positive id, got %d", id1)
	}

	// Same channel returns same ID.
	id2, err := d.GetOrCreateChannel(ctx, "#general")
	if err != nil {
		t.Fatalf("GetOrCreateChannel(2): %v", err)
	}

	if id1 != id2 {
		t.Errorf("got different ids: %d vs %d", id1, id2)
	}
}

func TestJoinAndListChannels(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid, _, _ := d.CreateUser(ctx, nickAlice)
	ch1, _ := d.GetOrCreateChannel(ctx, "#alpha")
	ch2, _ := d.GetOrCreateChannel(ctx, "#beta")

	_ = d.JoinChannel(ctx, ch1, uid)
	_ = d.JoinChannel(ctx, ch2, uid)

	channels, err := d.ListChannels(ctx, uid)
	if err != nil {
		t.Fatalf("ListChannels: %v", err)
	}

	if len(channels) != 2 {
		t.Fatalf("expected 2 channels, got %d", len(channels))
	}
}

func TestListChannelsEmpty(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid, _, _ := d.CreateUser(ctx, nickAlice)

	channels, err := d.ListChannels(ctx, uid)
	if err != nil {
		t.Fatalf("ListChannels: %v", err)
	}

	if len(channels) != 0 {
		t.Errorf("expected 0 channels, got %d", len(channels))
	}
}

func TestPartChannel(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid, _, _ := d.CreateUser(ctx, nickAlice)
	chID, _ := d.GetOrCreateChannel(ctx, "#general")

	_ = d.JoinChannel(ctx, chID, uid)
	_ = d.PartChannel(ctx, chID, uid)

	channels, err := d.ListChannels(ctx, uid)
	if err != nil {
		t.Fatalf("ListChannels: %v", err)
	}

	if len(channels) != 0 {
		t.Errorf("expected 0 after part, got %d", len(channels))
	}
}

func TestSendAndGetMessages(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid, _, _ := d.CreateUser(ctx, nickAlice)
	chID, _ := d.GetOrCreateChannel(ctx, "#general")
	_ = d.JoinChannel(ctx, chID, uid)

	_, err := d.SendMessage(ctx, chID, uid, "hello world")
	if err != nil {
		t.Fatalf("SendMessage: %v", err)
	}

	msgs, err := d.GetMessages(ctx, chID, 0, 0)
	if err != nil {
		t.Fatalf("GetMessages: %v", err)
	}

	if len(msgs) != 1 {
		t.Fatalf("expected 1 message, got %d", len(msgs))
	}

	if msgs[0].Content != "hello world" {
		t.Errorf(
			"got content %q, want %q",
			msgs[0].Content, "hello world",
		)
	}
}

func TestChannelMembers(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid1, _, _ := d.CreateUser(ctx, nickAlice)
	uid2, _, _ := d.CreateUser(ctx, nickBob)
	uid3, _, _ := d.CreateUser(ctx, nickCharlie)
	chID, _ := d.GetOrCreateChannel(ctx, "#general")

	_ = d.JoinChannel(ctx, chID, uid1)
	_ = d.JoinChannel(ctx, chID, uid2)
	_ = d.JoinChannel(ctx, chID, uid3)

	members, err := d.ChannelMembers(ctx, chID)
	if err != nil {
		t.Fatalf("ChannelMembers: %v", err)
	}

	if len(members) != 3 {
		t.Fatalf("expected 3 members, got %d", len(members))
	}
}

func TestChannelMembersEmpty(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	chID, _ := d.GetOrCreateChannel(ctx, "#empty")

	members, err := d.ChannelMembers(ctx, chID)
	if err != nil {
		t.Fatalf("ChannelMembers: %v", err)
	}

	if len(members) != 0 {
		t.Errorf("expected 0, got %d", len(members))
	}
}

func TestSendDM(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid1, _, _ := d.CreateUser(ctx, nickAlice)
	uid2, _, _ := d.CreateUser(ctx, nickBob)

	msgID, err := d.SendDM(ctx, uid1, uid2, "hey bob")
	if err != nil {
		t.Fatalf("SendDM: %v", err)
	}

	if msgID <= 0 {
		t.Errorf("expected positive msgID, got %d", msgID)
	}

	msgs, err := d.GetDMs(ctx, uid1, uid2, 0, 0)
	if err != nil {
		t.Fatalf("GetDMs: %v", err)
	}

	if len(msgs) != 1 {
		t.Fatalf("expected 1 DM, got %d", len(msgs))
	}

	if msgs[0].Content != "hey bob" {
		t.Errorf("got %q, want %q", msgs[0].Content, "hey bob")
	}
}

func TestPollMessages(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid1, _, _ := d.CreateUser(ctx, nickAlice)
	uid2, _, _ := d.CreateUser(ctx, nickBob)
	chID, _ := d.GetOrCreateChannel(ctx, "#general")

	_ = d.JoinChannel(ctx, chID, uid1)
	_ = d.JoinChannel(ctx, chID, uid2)

	_, _ = d.SendMessage(ctx, chID, uid2, "hello")
	_, _ = d.SendDM(ctx, uid2, uid1, "private")

	time.Sleep(10 * time.Millisecond)

	msgs, err := d.PollMessages(ctx, uid1, 0, 0)
	if err != nil {
		t.Fatalf("PollMessages: %v", err)
	}

	if len(msgs) < 2 {
		t.Fatalf("expected >=2 messages, got %d", len(msgs))
	}
}

func TestChangeNick(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	_, token, _ := d.CreateUser(ctx, nickAlice)

	err := d.ChangeNick(ctx, 1, "alice2")
	if err != nil {
		t.Fatalf("ChangeNick: %v", err)
	}

	_, nick, err := d.GetUserByToken(ctx, token)
	if err != nil {
		t.Fatalf("GetUserByToken: %v", err)
	}

	if nick != "alice2" {
		t.Errorf("got nick %q, want alice2", nick)
	}
}

func TestSetTopic(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid, _, _ := d.CreateUser(ctx, nickAlice)
	_, _ = d.GetOrCreateChannel(ctx, "#general")

	err := d.SetTopic(ctx, "#general", uid, "new topic")
	if err != nil {
		t.Fatalf("SetTopic: %v", err)
	}

	channels, err := d.ListAllChannels(ctx)
	if err != nil {
		t.Fatalf("ListAllChannels: %v", err)
	}

	found := false

	for _, ch := range channels {
		if ch.Name == "#general" && ch.Topic == "new topic" {
			found = true
		}
	}

	if !found {
		t.Error("topic was not updated")
	}
}

func TestGetMessagesBefore(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	uid, _, _ := d.CreateUser(ctx, nickAlice)
	chID, _ := d.GetOrCreateChannel(ctx, "#general")

	_ = d.JoinChannel(ctx, chID, uid)

	for i := range 5 {
		_, _ = d.SendMessage(
			ctx, chID, uid,
			fmt.Sprintf("msg%d", i),
		)

		time.Sleep(10 * time.Millisecond)
	}

	msgs, err := d.GetMessagesBefore(ctx, chID, 0, 3)
	if err != nil {
		t.Fatalf("GetMessagesBefore: %v", err)
	}

	if len(msgs) != 3 {
		t.Fatalf("expected 3, got %d", len(msgs))
	}
}

func TestListAllChannels(t *testing.T) {
	t.Parallel()

	d := setupTestDB(t)
	ctx := context.Background()

	_, _ = d.GetOrCreateChannel(ctx, "#alpha")
	_, _ = d.GetOrCreateChannel(ctx, "#beta")

	channels, err := d.ListAllChannels(ctx)
	if err != nil {
		t.Fatalf("ListAllChannels: %v", err)
	}

	if len(channels) != 2 {
		t.Errorf("expected 2, got %d", len(channels))
	}
}