using System;

using System.Collections.ObjectModel;

using System.Data;

using GeoAPI;

using GeoAPI.Geometries;

using SharpMap.Base;

namespace SharpMap.Data.Providers

{

/// <summary>

/// Abstract base provider that handles geometry factory based on SRID

/// </summary>

[Serializable]

public abstract class BaseProvider : DisposableObject, IProvider

{

static BaseProvider()

{

Map.Configure();

}

private int _srid;

private bool _isOpen;

/// <summary>

/// Event raised when <see cref="SRID"/> has changed

/// </summary>

public event EventHandler SridChanged;

/// <summary>

/// Gets or sets the factory to create geometries.

/// </summary>

public IGeometryFactory Factory { get; protected set; }

/// <summary>

/// Creates an instance of this class. The <see cref="ConnectionID"/> is set to <see cref="String.Empty"/>,

/// the spatial reference id to <c>0</c> and an appropriate factory is chosen.

/// </summary>

protected BaseProvider()

:this(0)

{

}

/// <summary>

/// Creates an instance of this class. The <see cref="ConnectionID"/> is set to <see cref="String.Empty"/>,

/// the spatial reference id to <paramref name="srid"/> and an appropriate factory is chosen.

/// </summary>

/// <param name="srid">The spatial reference id</param>

protected BaseProvider(int srid)

{

ConnectionID = string.Empty;

SRID = srid;

Factory = GeometryServiceProvider.Instance.CreateGeometryFactory(SRID);

}

/// <summary>

/// Releases all managed resources

/// </summary>

protected override void ReleaseManagedResources()

{

Factory = null;

base.ReleaseManagedResources();

}

#region Implementation of IProvider

/// <summary>

/// Gets the connection ID of the datasource

/// </summary>

/// <remarks>

/// <para>The ConnectionID should be unique to the datasource (for instance the filename or the

/// connectionstring), and is meant to be used for connection pooling.</para>

/// <para>If connection pooling doesn't apply to this datasource, the ConnectionID should return String.Empty</para>

/// </remarks>

public string ConnectionID { get; protected set; }

/// <summary>

/// Returns true if the datasource is currently open

/// </summary>

public virtual bool IsOpen { get { return _isOpen; } }

/// <summary>

/// The spatial reference ID (CRS)

/// </summary>

public int SRID

{

get { return _srid; }

set

{

if (value != _srid)

{

_srid = value;

OnSridChanged(EventArgs.Empty);

}

}

}

/// <summary>

/// Handler method to handle changes of <see cref="SRID"/>.

/// </summary>

/// <param name="eventArgs">Event arguments.</param>

protected virtual void OnSridChanged(EventArgs eventArgs)

{

Factory = GeometryServiceProvider.Instance.CreateGeometryFactory(SRID);

if (SridChanged != null)

SridChanged(this, eventArgs);

}

/// <summary>

/// Gets the features within the specified <see cref="GeoAPI.Geometries.Envelope"/>

/// </summary>

/// <param name="bbox"></param>

/// <returns>Features within the specified <see cref="GeoAPI.Geometries.Envelope"/></returns>

public abstract Collection<IGeometry> GetGeometriesInView(Envelope bbox);

/// <summary>

/// Returns all objects whose <see cref="GeoAPI.Geometries.Envelope"/> intersects 'bbox'.

/// </summary>

/// <remarks>

/// This method is usually much faster than the QueryFeatures method, because intersection tests

/// are performed on objects simplified by their <see cref="GeoAPI.Geometries.Envelope"/>, and using the Spatial Index

/// </remarks>

/// <param name="bbox">Box that objects should intersect</param>

/// <returns></returns>

public abstract Collection<uint> GetObjectIDsInView(Envelope bbox);

/// <summary>

/// Returns the geometry corresponding to the Object ID

/// </summary>

/// <param name="oid">Object ID</param>

/// <returns>geometry</returns>

public abstract IGeometry GetGeometryByID(uint oid);

/// <summary>

/// Returns the data associated with all the geometries that are intersected by 'geom'

/// </summary>

/// <param name="geom">Geometry to intersect with</param>

/// <param name="ds">FeatureDataSet to fill data into</param>

public void ExecuteIntersectionQuery(IGeometry geom, FeatureDataSet ds)

{

OnBeginExecuteIntersectionQuery(geom);

OnExecuteIntersectionQuery(geom, ds);

OnEndExecuteIntersectionQuery();

}

/// <summary>

/// Method to perform preparatory things for executing an intersection query against the data source

/// </summary>

/// <param name="geom">The geometry to use as filter.</param>

protected virtual void OnBeginExecuteIntersectionQuery(IGeometry geom)

{

}

/// <summary>

/// Method to perform the intersection query against the data source

/// </summary>

/// <param name="geom">The geometry to use as filter</param>

/// <param name="ds">The feature data set to store the results in</param>

protected abstract void OnExecuteIntersectionQuery(IGeometry geom, FeatureDataSet ds);

/// <summary>

/// Method to do cleanup work after having performed the intersection query against the data source

/// </summary>

protected virtual void OnEndExecuteIntersectionQuery()

{

}

/// <summary>

/// Returns the data associated with all the geometries that are intersected by 'geom'

/// </summary>

/// <param name="box">Geometry to intersect with</param>

/// <param name="ds">FeatureDataSet to fill data into</param>

public abstract void ExecuteIntersectionQuery(Envelope box, FeatureDataSet ds);

/// <summary>

/// Function to return the total number of features in the dataset

/// </summary>

/// <returns>The number of features</returns>

public abstract int GetFeatureCount();

/// <summary>

/// Function to return a <see cref="SharpMap.Data.FeatureDataRow"/> based on <paramref name="rowId">RowID</paramref>

/// </summary>

/// <param name="rowId">The unique identifier of the row</param>

/// <returns>datarow</returns>

public abstract FeatureDataRow GetFeature(uint rowId);

/// <summary>

/// Function to return the <see cref="Envelope"/> of dataset

/// </summary>

/// <returns>The extent of the dataset</returns>

public abstract Envelope GetExtents();

/// <summary>

/// Opens the datasource

/// </summary>

public virtual void Open()

{

_isOpen = true;

}

/// <summary>

/// Closes the datasource

/// </summary>

public virtual void Close()

{

_isOpen = false;

}

#endregion

/// <summary>

/// Method to clone the feature data tables schema.

/// </summary>

/// <param name="baseTable">The feature data table</param>

/// <returns>An empty feature data table, having the same schema as <paramref name="baseTable"/></returns>

protected static FeatureDataTable CloneTableStructure(FeatureDataTable baseTable)

{

var res = new FeatureDataTable(baseTable);

var cols = res.Columns;

foreach (DataColumn column in baseTable.Columns)

{

cols.Add(new DataColumn(column.ColumnName, column.DataType, column.Expression, column.ColumnMapping)

/*{AllowDBNull = column.AllowDBNull, AutoIncrement = column.AutoIncrement, AutoIncrementSeed = column.AutoIncrementSeed,

AutoIncrementStep = column.AutoIncrementStep, Caption = column.Caption}*/);

}

/*

var constraints = res.Constraints;

foreach (var constraint in baseTable.Constraints)

{

var uc = constraint as UniqueConstraint;

if (uc != null)

{

}

}

*/

return res;

}

}

/// <summary>

/// Abstract base provider that handles geometry factory based on SRID

/// </summary>

[Serializable]

public abstract class BaseProvider<TOid> : DisposableObject, IProvider<TOid>

where TOid: IComparable<TOid>

{

static BaseProvider()

{

Map.Configure();

}

private int _srid;

private bool _isOpen;

/// <summary>

/// Event raised when <see cref="SRID"/> has changed

/// </summary>

public event EventHandler SridChanged;

/// <summary>

/// Gets or sets the factory to create geometries.

/// </summary>

public IGeometryFactory Factory { get; protected set; }

/// <summary>

/// Creates an instance of this class. The <see cref="ConnectionID"/> is set to <see cref="String.Empty"/>,

/// the spatial reference id to <c>0</c> and an appropriate factory is chosen.

/// </summary>

protected BaseProvider()

: this(0)

{

}

/// <summary>

/// Creates an instance of this class. The <see cref="ConnectionID"/> is set to <see cref="String.Empty"/>,

/// the spatial reference id to <paramref name="srid"/> and an appropriate factory is chosen.

/// </summary>

/// <param name="srid">The spatial reference id</param>

protected BaseProvider(int srid)

{

ConnectionID = string.Empty;

SRID = srid;

Factory = GeometryServiceProvider.Instance.CreateGeometryFactory(SRID);

}

/// <summary>

/// Releases all managed resources

/// </summary>

protected override void ReleaseManagedResources()

{

Factory = null;

base.ReleaseManagedResources();

}

#region Implementation of IProvider

/// <summary>

/// Gets the connection ID of the datasource

/// </summary>

/// <remarks>

/// <para>The ConnectionID should be unique to the datasource (for instance the filename or the

/// connectionstring), and is meant to be used for connection pooling.</para>

/// <para>If connection pooling doesn't apply to this datasource, the ConnectionID should return String.Empty</para>

/// </remarks>

public string ConnectionID { get; protected set; }

/// <summary>

/// Returns true if the datasource is currently open

/// </summary>

public virtual bool IsOpen { get { return _isOpen; } }

/// <summary>

/// The spatial reference ID (CRS)

/// </summary>

public int SRID

{

get { return _srid; }

set

{

if (value != _srid)

{

_srid = value;

OnSridChanged(EventArgs.Empty);

}

}

}

/// <summary>

/// Handler method to handle changes of <see cref="SRID"/>.

/// </summary>

/// <param name="eventArgs">Event arguments.</param>

protected virtual void OnSridChanged(EventArgs eventArgs)

{

Factory = GeometryServiceProvider.Instance.CreateGeometryFactory(SRID);

if (SridChanged != null)

SridChanged(this, eventArgs);

}

/// <summary>

/// Gets the features within the specified <see cref="GeoAPI.Geometries.Envelope"/>

/// </summary>

/// <param name="bbox"></param>

/// <returns>Features within the specified <see cref="GeoAPI.Geometries.Envelope"/></returns>

public abstract Collection<IGeometry> GetGeometriesInView(Envelope bbox);

/// <summary>

/// Returns all objects whose <see cref="GeoAPI.Geometries.Envelope"/> intersects 'bbox'.

/// </summary>

/// <remarks>

/// This method is usually much faster than the QueryFeatures method, because intersection tests

/// are performed on objects simplified by their <see cref="GeoAPI.Geometries.Envelope"/>, and using the Spatial Index

/// </remarks>

/// <param name="bbox">Box that objects should intersect</param>

/// <returns></returns>

public abstract Collection<TOid> GetObjectIDsInView(Envelope bbox);

/// <summary>

/// Returns the geometry corresponding to the Object ID

/// </summary>

/// <param name="oid">Object ID</param>

/// <returns>geometry</returns>

public abstract IGeometry GetGeometryByID(TOid oid);

/// <summary>

/// Returns the data associated with all the geometries that are intersected by 'geom'

/// </summary>

/// <param name="geom">Geometry to intersect with</param>

/// <param name="ds">FeatureDataSet to fill data into</param>

public void ExecuteIntersectionQuery(IGeometry geom, FeatureDataSet ds)

{

OnBeginExecuteIntersectionQuery(geom);

OnExecuteIntersectionQuery(geom, ds);

OnEndExecuteIntersectionQuery();

}

/// <summary>

/// Method to perform preparatory things for executing an intersection query against the data source

/// </summary>

/// <param name="geom">The geometry to use as filter.</param>

protected virtual void OnBeginExecuteIntersectionQuery(IGeometry geom)

{

}

/// <summary>

/// Method to perform the intersection query against the data source

/// </summary>

/// <param name="geom">The geometry to use as filter</param>

/// <param name="ds">The feature data set to store the results in</param>

protected abstract void OnExecuteIntersectionQuery(IGeometry geom, FeatureDataSet ds);

/// <summary>

/// Method to do cleanup work after having performed the intersection query against the data source

/// </summary>

protected virtual void OnEndExecuteIntersectionQuery()

{

}

/// <summary>

/// Returns the data associated with all the geometries that are intersected by 'geom'

/// </summary>

/// <param name="box">Geometry to intersect with</param>

/// <param name="ds">FeatureDataSet to fill data into</param>

public abstract void ExecuteIntersectionQuery(Envelope box, FeatureDataSet ds);

/// <summary>

/// Function to return the total number of features in the dataset

/// </summary>

/// <returns>The number of features</returns>

public abstract int GetFeatureCount();

/// <summary>

/// Function to return a <see cref="SharpMap.Data.FeatureDataRow"/> based on <paramref name="rowId">RowID</paramref>

/// </summary>

/// <param name="rowId">The unique identifier of the row</param>

/// <returns>datarow</returns>

public abstract FeatureDataRow GetFeature(TOid rowId);

/// <summary>

/// Function to return the <see cref="Envelope"/> of dataset

/// </summary>

/// <returns>The extent of the dataset</returns>

public abstract Envelope GetExtents();

/// <summary>

/// Opens the datasource

/// </summary>

public virtual void Open()

{

_isOpen = true;

}

/// <summary>

/// Closes the datasource

/// </summary>

public virtual void Close()

{

_isOpen = false;

}

#endregion

/// <summary>

/// Method to clone the feature data tables schema.

/// </summary>

/// <param name="baseTable">The feature data table</param>

/// <returns>An empty feature data table, having the same schema as <paramref name="baseTable"/></returns>

protected static FeatureDataTable CloneTableStructure(FeatureDataTable baseTable)

{

var res = new FeatureDataTable(baseTable);

var cols = res.Columns;

foreach (DataColumn column in baseTable.Columns)

{

cols.Add(new DataColumn(column.ColumnName, column.DataType, column.Expression, column.ColumnMapping)

/*{AllowDBNull = column.AllowDBNull, AutoIncrement = column.AutoIncrement, AutoIncrementSeed = column.AutoIncrementSeed,

AutoIncrementStep = column.AutoIncrementStep, Caption = column.Caption}*/);

}

/*

var constraints = res.Constraints;

foreach (var constraint in baseTable.Constraints)

{

var uc = constraint as UniqueConstraint;

if (uc != null)

{

}

}

*/

return res;

}

}

}