package db

import (
	"context"
	"time"

	"github.com/jackc/pgx/v5"
)

type VPNUser struct {
	ID                  int64
	TelegramID          *int64
	RemnawaveUUID       string
	RemnawaveUsername   string
	ExternalSquadUUID   *string
	InternalSquadUUIDs  []string
	ExpireAt            *time.Time
}

func (d *DB) UpsertTelegramUser(ctx context.Context, telegramID int64, username, firstName string) error {
	_, err := d.pool.Exec(ctx, `
		INSERT INTO telegram_users (telegram_id, username, first_name)
		VALUES ($1, $2, $3)
		ON CONFLICT (telegram_id) DO UPDATE SET
			username = EXCLUDED.username,
			first_name = EXCLUDED.first_name`,
		telegramID, nullStr(username), nullStr(firstName))
	return err
}

func (d *DB) SaveVPNUser(ctx context.Context, u VPNUser) error {
	_, err := d.pool.Exec(ctx, `
		INSERT INTO vpn_users (
			telegram_id, remnawave_uuid, remnawave_username,
			external_squad_uuid, internal_squad_uuids, expire_at
		) VALUES ($1, $2, $3, $4, $5, $6)
		ON CONFLICT (remnawave_uuid) DO UPDATE SET
			telegram_id = EXCLUDED.telegram_id,
			remnawave_username = EXCLUDED.remnawave_username,
			external_squad_uuid = EXCLUDED.external_squad_uuid,
			internal_squad_uuids = EXCLUDED.internal_squad_uuids,
			expire_at = EXCLUDED.expire_at,
			updated_at = NOW()`,
		u.TelegramID, u.RemnawaveUUID, u.RemnawaveUsername,
		u.ExternalSquadUUID, u.InternalSquadUUIDs, u.ExpireAt)
	return err
}

func (d *DB) GetVPNByTelegramID(ctx context.Context, telegramID int64) (*VPNUser, error) {
	row := d.pool.QueryRow(ctx, `
		SELECT id, telegram_id, remnawave_uuid::text, remnawave_username,
			external_squad_uuid::text, internal_squad_uuids::text[], expire_at
		FROM vpn_users
		WHERE telegram_id = $1
		ORDER BY expire_at DESC NULLS LAST
		LIMIT 1`, telegramID)

	var u VPNUser
	var ext *string
	var internal []string
	err := row.Scan(&u.ID, &u.TelegramID, &u.RemnawaveUUID, &u.RemnawaveUsername, &ext, &internal, &u.ExpireAt)
	if err == pgx.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	u.ExternalSquadUUID = ext
	u.InternalSquadUUIDs = internal
	return &u, nil
}

func (d *DB) GetVPNByUsername(ctx context.Context, username string) (*VPNUser, error) {
	row := d.pool.QueryRow(ctx, `
		SELECT id, telegram_id, remnawave_uuid::text, remnawave_username,
			external_squad_uuid::text, internal_squad_uuids::text[], expire_at
		FROM vpn_users WHERE remnawave_username = $1`, username)

	var u VPNUser
	var ext *string
	var internal []string
	err := row.Scan(&u.ID, &u.TelegramID, &u.RemnawaveUUID, &u.RemnawaveUsername, &ext, &internal, &u.ExpireAt)
	if err == pgx.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	u.ExternalSquadUUID = ext
	u.InternalSquadUUIDs = internal
	return &u, nil
}

func nullStr(s string) *string {
	if s == "" {
		return nil
	}
	return &s
}