bookmark-manager-r4/Classes/IconDatabase.cs

using Microsoft.Data.Sqlite;
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

namespace BookmarkManager
{
    public class IconDatabase
    {
        protected string dbFilename = null;
        protected SqliteConnection dbConnection = null;


        public IconDatabase(string filename)
        {
            if (string.IsNullOrWhiteSpace(filename)) return;

            dbFilename = filename;

            bool isNew = !File.Exists(dbFilename);

            SqliteConnectionStringBuilder builder = new SqliteConnectionStringBuilder();
            builder.DataSource = dbFilename;
            builder.Cache = SqliteCacheMode.Private;
            builder.Mode = SqliteOpenMode.ReadWriteCreate;

            dbConnection = new SqliteConnection(builder.ToString());
            dbConnection.Open();

            if (isNew) Initialise();




            //if (File.Exists(filename))
            //{
            //    File.Delete("test.db3");
            //}

        }

        public bool AddIcon(string id, Image image)
        {
            if (dbConnection == null) return false;
            if (string.IsNullOrWhiteSpace(id)) return false;

            if (image == null) return DeleteIcon(id);
            if (HasIcon(id)) return UpdateIcon(id, image);

            SqliteCommand command = new SqliteCommand();
            command.Connection = dbConnection;
            command.CommandText = "INSERT INTO icons (id, content) VALUES (@id, @content)";
            command.Parameters.Add("@id", SqliteType.Text).Value = id;
            command.Parameters.Add("@content", SqliteType.Blob, 20).Value = ImageToBytes(image);

            try
            {
                command.ExecuteNonQuery();
            }
            catch (Exception)
            {
                return false;
            }

            return true;
        }

        public void Close()
        {
            if (dbConnection == null) return;

            dbConnection.Close();
            dbConnection.Dispose();
            dbConnection = null;
        }

        public bool DeleteIcon(string id)
        {
            if (dbConnection == null) return false;
            if (string.IsNullOrWhiteSpace(id)) return false;

            SqliteCommand command = new SqliteCommand();
            command.Connection = dbConnection;
            command.CommandText = "DELETE FROM icons WHERE id = @id";
            command.Parameters.Add("@id", SqliteType.Text).Value = id;

            try
            {
                command.ExecuteNonQuery();
            }
            catch (Exception)
            {
                return false;
            }

            return true;
        }


        public Image FindIcon(string id)
        {
            if (dbConnection == null) return null;
            if (string.IsNullOrWhiteSpace(id)) return null;

            byte[] iconBytes = null;

            SqliteCommand command = new SqliteCommand();
            command.Connection = dbConnection;
            command.CommandText = "SELECT content FROM icons WHERE @id";
            command.Parameters.Add("@id", SqliteType.Text).Value = id;

            try
            {
                using (var reader = command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        if (reader["content"] != null && !Convert.IsDBNull(reader["content"]))
                        {
                            iconBytes = (byte[])reader["content"];
                        }
                    }
                }

                command.Dispose();
            }
            catch (Exception)
            {
                return null;
            }

            if (iconBytes == null)
            {
                return null;
            }

            Image img = null;

            try
            {
                img = Image.FromStream(new MemoryStream(iconBytes));
            }
            catch (Exception)
            {
                return null;
            }

            return new Bitmap(img, 16, 16);
        }

        public bool HasIcon(string id)
        {
            if (dbConnection == null) return false;
            if (string.IsNullOrWhiteSpace(id)) return false;

            int rv = 0;

            SqliteCommand command = new SqliteCommand();
            command.Connection = dbConnection;
            command.CommandText = "SELECT COUNT(1) AS count FROM icons WHERE @id";
            command.Parameters.Add("@id", SqliteType.Text).Value = id;

            try
            {
                using (var reader = command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        if (reader["count"] != null && !Convert.IsDBNull(reader["count"]))
                        {
                            rv = (int)reader["count"];
                        }
                    }
                }

                command.Dispose();
            }
            catch (Exception)
            {
                return false;
            }

            return (rv > 0);
        }

        public bool UpdateIcon(string id, Image image)
        {
            if (dbConnection == null) return false;
            if (string.IsNullOrWhiteSpace(id)) return false;

            if (image == null) return DeleteIcon(id);
            if (!HasIcon(id)) return AddIcon(id, image);

            SqliteCommand command = new SqliteCommand();
            command.Connection = dbConnection;
            command.CommandText = "UPDATE icons SET content = @content WHERE id = @id";
            command.Parameters.Add("@id", SqliteType.Text).Value = id;
            command.Parameters.Add("@content", SqliteType.Blob, 20).Value = ImageToBytes(image);

            try
            {
                command.ExecuteNonQuery();
            }
            catch (Exception)
            {
                return false;
            }

            return true;
        }


        protected bool Initialise()
        {
            if (dbConnection == null) return false;

            try
            {
                SqliteCommand command = new SqliteCommand("CREATE TABLE icons (id TEXT PRIMARY KEY, content BLOB)", dbConnection);
                command.ExecuteNonQuery();
                command.Dispose();
            }
            catch (Exception)
            {
                return false;
            }

            return true;
        }

        protected byte[] ImageToBytes(Image image)
        {
            MemoryStream stream = new MemoryStream();
            //image.Save(stream, ((image.RawFormat == null) ? ImageFormat.Bmp : new ImageFormat(image.RawFormat.Guid)));
            image.Save(stream, ImageFormat.Bmp);
            stream.Close();

            return stream.ToArray();
        }


    }
}