package db_test

import (
	"encoding/json"
	"testing"

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

	_ "modernc.org/sqlite"
)

func setupTestDB(t *testing.T) *db.Database {
	t.Helper()

	database, err := db.NewTestDatabase()
	if err != nil {
		t.Fatal(err)
	}

	t.Cleanup(func() {
		closeErr := database.Close()
		if closeErr != nil {
			t.Logf("close db: %v", closeErr)
		}
	})

	return database
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	sessionID, _, token, err := database.CreateSession(
		ctx, "alice",
	)
	if err != nil {
		t.Fatal(err)
	}

	if sessionID == 0 || token == "" {
		t.Fatal("expected valid id and token")
	}

	_, _, dupToken, dupErr := database.CreateSession(
		ctx, "alice",
	)
	if dupErr == nil {
		t.Fatal("expected error for duplicate nick")
	}

	_ = dupToken
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	_, _, token, err := database.CreateSession(ctx, "bob")
	if err != nil {
		t.Fatal(err)
	}

	sessionID, clientID, nick, err :=
		database.GetSessionByToken(ctx, token)
	if err != nil {
		t.Fatal(err)
	}

	if nick != "bob" || sessionID == 0 || clientID == 0 {
		t.Fatalf("expected bob, got %s", nick)
	}

	badSID, badCID, badNick, badErr :=
		database.GetSessionByToken(ctx, "badtoken")
	if badErr == nil {
		t.Fatal("expected error for bad token")
	}

	if badSID != 0 || badCID != 0 || badNick != "" {
		t.Fatal("expected zero values on error")
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	charlieID, charlieClientID, charlieToken, err :=
		database.CreateSession(ctx, "charlie")
	if err != nil {
		t.Fatal(err)
	}

	if charlieID == 0 || charlieClientID == 0 {
		t.Fatal("expected valid session/client IDs")
	}

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

	id, err := database.GetSessionByNick(ctx, "charlie")
	if err != nil || id == 0 {
		t.Fatal("expected to find charlie")
	}

	_, err = database.GetSessionByNick(ctx, "nobody")
	if err == nil {
		t.Fatal("expected error for unknown nick")
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	chID, err := database.GetOrCreateChannel(ctx, "#test")
	if err != nil || chID == 0 {
		t.Fatal("expected channel id")
	}

	chID2, err := database.GetOrCreateChannel(ctx, "#test")
	if err != nil || chID2 != chID {
		t.Fatal("expected same channel id")
	}

	chID3, err := database.GetChannelByName(ctx, "#test")
	if err != nil || chID3 != chID {
		t.Fatal("expected same channel id")
	}

	_, err = database.GetChannelByName(ctx, "#nope")
	if err == nil {
		t.Fatal("expected error for nonexistent channel")
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	sid, _, _, err := database.CreateSession(ctx, "user1")
	if err != nil {
		t.Fatal(err)
	}

	chID, err := database.GetOrCreateChannel(ctx, "#chan")
	if err != nil {
		t.Fatal(err)
	}

	err = database.JoinChannel(ctx, chID, sid)
	if err != nil {
		t.Fatal(err)
	}

	ids, err := database.GetChannelMemberIDs(ctx, chID)
	if err != nil || len(ids) != 1 || ids[0] != sid {
		t.Fatal("expected session in channel")
	}

	err = database.JoinChannel(ctx, chID, sid)
	if err != nil {
		t.Fatal(err)
	}

	err = database.PartChannel(ctx, chID, sid)
	if err != nil {
		t.Fatal(err)
	}

	ids, _ = database.GetChannelMemberIDs(ctx, chID)
	if len(ids) != 0 {
		t.Fatal("expected empty channel")
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	chID, err := database.GetOrCreateChannel(
		ctx, "#empty",
	)
	if err != nil {
		t.Fatal(err)
	}

	sid, _, _, err := database.CreateSession(ctx, "temp")
	if err != nil {
		t.Fatal(err)
	}

	err = database.JoinChannel(ctx, chID, sid)
	if err != nil {
		t.Fatal(err)
	}

	err = database.PartChannel(ctx, chID, sid)
	if err != nil {
		t.Fatal(err)
	}

	err = database.DeleteChannelIfEmpty(ctx, chID)
	if err != nil {
		t.Fatal(err)
	}

	_, err = database.GetChannelByName(ctx, "#empty")
	if err == nil {
		t.Fatal("expected channel to be deleted")
	}
}

func createSessionWithChannels(
	t *testing.T,
	database *db.Database,
	nick, ch1Name, ch2Name string,
) (int64, int64, int64) {
	t.Helper()

	ctx := t.Context()

	sid, _, _, err := database.CreateSession(ctx, nick)
	if err != nil {
		t.Fatal(err)
	}

	ch1, err := database.GetOrCreateChannel(
		ctx, ch1Name,
	)
	if err != nil {
		t.Fatal(err)
	}

	ch2, err := database.GetOrCreateChannel(
		ctx, ch2Name,
	)
	if err != nil {
		t.Fatal(err)
	}

	err = database.JoinChannel(ctx, ch1, sid)
	if err != nil {
		t.Fatal(err)
	}

	err = database.JoinChannel(ctx, ch2, sid)
	if err != nil {
		t.Fatal(err)
	}

	return sid, ch1, ch2
}

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

	database := setupTestDB(t)
	sid, _, _ := createSessionWithChannels(
		t, database, "lister", "#a", "#b",
	)

	channels, err := database.ListChannels(
		t.Context(), sid,
	)
	if err != nil || len(channels) != 2 {
		t.Fatalf(
			"expected 2 channels, got %d",
			len(channels),
		)
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	_, err := database.GetOrCreateChannel(ctx, "#x")
	if err != nil {
		t.Fatal(err)
	}

	_, err = database.GetOrCreateChannel(ctx, "#y")
	if err != nil {
		t.Fatal(err)
	}

	channels, err := database.ListAllChannels(ctx)
	if err != nil || len(channels) < 2 {
		t.Fatalf(
			"expected >= 2 channels, got %d",
			len(channels),
		)
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	sid, _, token, err := database.CreateSession(
		ctx, "old",
	)
	if err != nil {
		t.Fatal(err)
	}

	err = database.ChangeNick(ctx, sid, "new")
	if err != nil {
		t.Fatal(err)
	}

	_, _, nick, err := database.GetSessionByToken(
		ctx, token,
	)
	if err != nil {
		t.Fatal(err)
	}

	if nick != "new" {
		t.Fatalf("expected new, got %s", nick)
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	_, err := database.GetOrCreateChannel(
		ctx, "#topictest",
	)
	if err != nil {
		t.Fatal(err)
	}

	err = database.SetTopic(ctx, "#topictest", "Hello")
	if err != nil {
		t.Fatal(err)
	}

	channels, err := database.ListAllChannels(ctx)
	if err != nil {
		t.Fatal(err)
	}

	for _, ch := range channels {
		if ch.Name == "#topictest" &&
			ch.Topic != "Hello" {
			t.Fatalf(
				"expected topic Hello, got %s",
				ch.Topic,
			)
		}
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	body := json.RawMessage(`["hello"]`)

	dbID, msgUUID, err := database.InsertMessage(
		ctx, "PRIVMSG", "poller", "#test", body, nil,
	)
	if err != nil {
		t.Fatal(err)
	}

	if dbID == 0 || msgUUID == "" {
		t.Fatal("expected valid id and uuid")
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	sid, _, token, err := database.CreateSession(
		ctx, "poller",
	)
	if err != nil {
		t.Fatal(err)
	}

	_, clientID, _, err := database.GetSessionByToken(
		ctx, token,
	)
	if err != nil {
		t.Fatal(err)
	}

	body := json.RawMessage(`["hello"]`)

	dbID, _, err := database.InsertMessage(
		ctx, "PRIVMSG", "poller", "#test", body, nil,
	)
	if err != nil {
		t.Fatal(err)
	}

	err = database.EnqueueToSession(ctx, sid, dbID)
	if err != nil {
		t.Fatal(err)
	}

	const batchSize = 10

	msgs, lastQID, err := database.PollMessages(
		ctx, clientID, 0, batchSize,
	)
	if err != nil {
		t.Fatal(err)
	}

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

	if msgs[0].Command != "PRIVMSG" {
		t.Fatalf(
			"expected PRIVMSG, got %s", msgs[0].Command,
		)
	}

	if lastQID == 0 {
		t.Fatal("expected nonzero lastQID")
	}

	msgs, _, _ = database.PollMessages(
		ctx, clientID, lastQID, batchSize,
	)

	if len(msgs) != 0 {
		t.Fatalf(
			"expected 0 messages, got %d", len(msgs),
		)
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	const msgCount = 10

	for range msgCount {
		_, _, err := database.InsertMessage(
			ctx, "PRIVMSG", "user", "#hist",
			json.RawMessage(`["msg"]`), nil,
		)
		if err != nil {
			t.Fatal(err)
		}
	}

	const histLimit = 5

	msgs, err := database.GetHistory(
		ctx, "#hist", 0, histLimit,
	)
	if err != nil {
		t.Fatal(err)
	}

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

	if msgs[0].DBID > msgs[histLimit-1].DBID {
		t.Fatal("expected ascending order")
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	sid, _, _, err := database.CreateSession(
		ctx, "deleteme",
	)
	if err != nil {
		t.Fatal(err)
	}

	chID, err := database.GetOrCreateChannel(
		ctx, "#delchan",
	)
	if err != nil {
		t.Fatal(err)
	}

	err = database.JoinChannel(ctx, chID, sid)
	if err != nil {
		t.Fatal(err)
	}

	err = database.DeleteSession(ctx, sid)
	if err != nil {
		t.Fatal(err)
	}

	_, err = database.GetSessionByNick(ctx, "deleteme")
	if err == nil {
		t.Fatal("session should be deleted")
	}

	ids, _ := database.GetChannelMemberIDs(ctx, chID)
	if len(ids) != 0 {
		t.Fatal("expected no members after deletion")
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	sid1, _, _, err := database.CreateSession(ctx, "m1")
	if err != nil {
		t.Fatal(err)
	}

	sid2, _, _, err := database.CreateSession(ctx, "m2")
	if err != nil {
		t.Fatal(err)
	}

	chID, err := database.GetOrCreateChannel(
		ctx, "#members",
	)
	if err != nil {
		t.Fatal(err)
	}

	err = database.JoinChannel(ctx, chID, sid1)
	if err != nil {
		t.Fatal(err)
	}

	err = database.JoinChannel(ctx, chID, sid2)
	if err != nil {
		t.Fatal(err)
	}

	members, err := database.ChannelMembers(ctx, chID)
	if err != nil || len(members) != 2 {
		t.Fatalf(
			"expected 2 members, got %d",
			len(members),
		)
	}
}

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

	database := setupTestDB(t)
	sid, _, _ := createSessionWithChannels(
		t, database, "multi", "#m1", "#m2",
	)

	channels, err :=
		database.GetSessionChannels(
			t.Context(), sid,
		)
	if err != nil || len(channels) != 2 {
		t.Fatalf(
			"expected 2 channels, got %d",
			len(channels),
		)
	}
}

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

	database := setupTestDB(t)
	ctx := t.Context()

	_, _, token, err := database.CreateSession(
		ctx, "enqclient",
	)
	if err != nil {
		t.Fatal(err)
	}

	_, clientID, _, err := database.GetSessionByToken(
		ctx, token,
	)
	if err != nil {
		t.Fatal(err)
	}

	body := json.RawMessage(`["test"]`)

	dbID, _, err := database.InsertMessage(
		ctx, "PRIVMSG", "sender", "#ch", body, nil,
	)
	if err != nil {
		t.Fatal(err)
	}

	err = database.EnqueueToClient(ctx, clientID, dbID)
	if err != nil {
		t.Fatal(err)
	}

	const batchSize = 10

	msgs, _, err := database.PollMessages(
		ctx, clientID, 0, batchSize,
	)
	if err != nil {
		t.Fatal(err)
	}

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