using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Data.SQLite;

using SharpMap.Data.Providers.Tiles;

using SharpMap.Layers;

using SharpMap.Styles;

namespace SharpMap.Data.Providers

{

/// <summary>

/// A class wrapping a GeoPackage

/// </summary>

/// <seealso href="http://www.geopackage.org/"/>

public class GeoPackage

{

/// <summary>

/// Method to open a geopackage file

/// </summary>

/// <param name="filename">The filename of the GeoPackage</param>

/// <param name="password">The password to access the GeoPackage</param>

/// <returns></returns>

public static GeoPackage Open(string filename, string password = null)

{

try

{

GpkgUtility.CheckRequirements(filename, password);

return new GeoPackage(GpkgUtility.CreateConnectionString(filename, password));

}

catch (Exception)

{

throw new GeoPackageException(string.Format("Failed to open GeoPackage '{0}'", filename));

}

}

private readonly string _connectionString;

/// <summary>

/// Creates an instance of this class

/// </summary>

/// <param name="connectionString"></param>

private GeoPackage(string connectionString)

{

_connectionString = connectionString;

}

/// <summary>

/// Gets the <see cref="GpkgContent">Features</see> stored in the GeoPackage

/// </summary>

public ReadOnlyCollection<GpkgContent> Features

{

get

{

return new ReadOnlyCollection<GpkgContent>(ReadContents("features"));

}

}

/// <summary>

/// Gets the <see cref="GpkgContent">Tiles</see> stored in the GeoPackage

/// </summary>

public ReadOnlyCollection<GpkgContent> Tiles

{

get

{

return new ReadOnlyCollection<GpkgContent>(ReadContents("tiles"));

}

}

/// <summary>

/// Method to read the content from the 'gpkg_contents' table, filtered by <paramref name="kind"/>

/// </summary>

/// <param name="kind">The kind of content to filter for</param>

/// <returns>A list of content</returns>

private IList<GpkgContent> ReadContents(string kind)

{

var res = new List<GpkgContent>();

using (var cn = new SQLiteConnection(_connectionString))

{

cn.Open();

var cmd = new SQLiteCommand("SELECT * FROM \"gpkg_contents\" WHERE \"data_type\"='" + kind + "';", cn);

var rdr = cmd.ExecuteReader();

while (rdr.Read())

res.Add(new GpkgContent(rdr, _connectionString));

}

return res;

}

/// <summary>

/// Method to create an async tile layer

/// </summary>

/// <param name="name">The name of the layer</param>

/// <returns>A tile layer</returns>

public ILayer GetTileLayer(string name)

{

var content = FindContent(Tiles, name);

if (content == null)

throw new ArgumentException(string.Format("No tile layer named '{0}'", name));

var schema = new GpkgTileSchema(content);

return new TileLayer(new GpkgTileSource(content, schema), content.TableName);

}

/// <summary>

/// Method to create an async tile layer

/// </summary>

/// <param name="name">The name of the layer</param>

/// <returns>A tile layer</returns>

public ITileAsyncLayer GetTileAsyncLayer(string name)

{

var content = FindContent(Tiles, name);

if (content == null)

throw new ArgumentException(string.Format("No tile layer named '{0}'", name));

var schema = new GpkgTileSchema(content);

return new TileAsyncLayer(new GpkgTileSource(content, schema), content.TableName);

}

/// <summary>

/// Creates a <see cref="IProvider"/> for the <paramref name="content"/>.

/// </summary>

/// <param name="content">A content of the package</param>

/// <returns>A provider.</returns>

public IProvider GetFeatureProvider(GpkgContent content)

{

if (content == null)

throw new ArgumentNullException("content");

var p = new GpkgProvider(content);

return p;

}

/// <summary>

/// Method to get a feature layer for the given content

/// </summary>

/// <param name="content">The content</param>

/// <param name="createLayer">A delegate function to create the layer</param>

/// <returns>A layer</returns>

public ILayer GetFeatureLayer(GpkgContent content, Func<GpkgContent, IProvider, ILayer> createLayer = null)

{

if (content == null)

throw new ArgumentNullException("content");

createLayer = createLayer ?? CreateVectorLayer;

return createLayer(content, GetFeatureProvider(content));

}

#region private helper methods

private static ILayer CreateVectorLayer(GpkgContent content, IProvider provider)

{

return new VectorLayer(content.TableName, provider) { Style = VectorStyle.CreateRandomStyle() };

}

private static GpkgContent FindContent(IEnumerable<GpkgContent> contents, string contentName)

{

foreach (var content in contents)

{

if (string.Equals(content.TableName, contentName, StringComparison.CurrentCultureIgnoreCase))

return content;

}

return null;

}

#endregion

}

}