/*
 * SLD Editor - The Open Source Java SLD Editor
 *
 * Copyright (C) 2016, SCISYS UK Limited
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.sldeditor.datasource.impl;

import com.sldeditor.common.Controller;
import com.sldeditor.common.DataSourcePropertiesInterface;
import com.sldeditor.common.SLDDataInterface;
import com.sldeditor.common.console.ConsoleManager;
import com.sldeditor.datasource.DataSourceInterface;
import com.sldeditor.datasource.DataSourceUpdatedInterface;
import com.sldeditor.datasource.SLDEditorFileInterface;
import com.sldeditor.datasource.attribute.AllowedAttributeTypes;
import com.sldeditor.datasource.attribute.DataSourceAttributeData;
import com.sldeditor.datasource.attribute.DataSourceAttributeList;
import com.sldeditor.datasource.attribute.DataSourceAttributeListInterface;
import com.sldeditor.datasource.checks.CheckAttributeInterface;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.log4j.Logger;
import org.geotools.coverage.grid.io.AbstractGridCoverage2DReader;
import org.geotools.data.DataAccessFactory;
import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFactorySpi;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.FeatureSource;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.styling.UserLayer;
import org.locationtech.jts.geom.Geometry;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.feature.type.GeometryDescriptor;
import org.opengis.feature.type.Name;
import org.opengis.feature.type.PropertyDescriptor;

/**
 * Class that represents data sources for an SLD symbol. Provides functionality to read and update
 * its schema. Handles the following:
 *
 * <p>- example data
 *
 * <p>- external data (e.g shape file, tiff)
 *
 * <p>- user layer inline data
 *
 * @author Robert Ward (SCISYS)
 */
public class DataSourceImpl implements DataSourceInterface {

    /** The Constant MAX_RETRIES. */
    private static final int MAX_RETRIES = 3;

    /** The logger. */
    private static Logger logger = Logger.getLogger(DataSourceImpl.class);

    /** The listener list. */
    private List<DataSourceUpdatedInterface> listenerList = new ArrayList<>();

    /** The data source info. */
    private DataSourceInfo dataSourceInfo = new DataSourceInfo();

    /** The example data source info, used to draw the single rendered symbol. */
    private DataSourceInfo exampleDataSourceInfo = new DataSourceInfo();

    /** The user layer data source info. */
    private List<DataSourceInfo> userLayerDataSourceInfo = new ArrayList<>();

    /** The data source properties. */
    private DataSourcePropertiesInterface dataSourceProperties = null;

    /** The connected to data source flag. */
    private boolean connectedToDataSourceFlag = false;

    /** The available data stores. */
    private List<String> availableDataStoreList = new ArrayList<>();

    /** The editor file interface. */
    private SLDEditorFileInterface editorFileInterface = null;

    /** The internal data source. */
    private CreateDataSourceInterface internalDataSource = null;

    /** The external data source. */
    private CreateDataSourceInterface externalDataSource = null;

    /** The inline data source. */
    private CreateDataSourceInterface inlineDataSource = null;

    /** Default constructor. */
    public DataSourceImpl() {
        populateAvailableDataStores();
    }

    /**
     * Sets the data source creation classes.
     *
     * @param internalDataSource the internal data source
     * @param externalDataSource the external data source
     * @param inlineDataSource the inline data source
     */
    @Override
    public void setDataSourceCreation(
            CreateDataSourceInterface internalDataSource,
            CreateDataSourceInterface externalDataSource,
            CreateDataSourceInterface inlineDataSource) {
        this.internalDataSource = internalDataSource;
        this.externalDataSource = externalDataSource;
        this.inlineDataSource = inlineDataSource;
    }

    /**
     * Adds the data source updated listener.
     *
     * @param listener the listener
     */
    @Override
    public void addListener(DataSourceUpdatedInterface listener) {
        if (!listenerList.contains(listener)) {
            listenerList.add(listener);

            if (Controller.getInstance().isPopulating()) {
                if (getGeometryType() != GeometryTypeEnum.UNKNOWN) {
                    notifyDataSourceLoaded();
                }
            }
        }
    }

    /**
     * Removes the data source updated listener.
     *
     * @param listener the listener
     */
    @Override
    public void removeListener(DataSourceUpdatedInterface listener) {
        listenerList.remove(listener);
    }

    /**
     * Connect to data source.
     *
     * @param typeName the type name
     * @param editorFile the editor file
     * @param checkList the check list
     */
    @Override
    public void connect(
            String typeName,
            SLDEditorFileInterface editorFile,
            List<CheckAttributeInterface> checkList) {
        logger.debug("connect : " + typeName);
        reset();

        this.editorFileInterface = editorFile;

        if (editorFileInterface != null) {
            this.dataSourceProperties = editorFileInterface.getDataSource();

            if (this.dataSourceProperties != null) {
                if (this.dataSourceProperties.isEmpty()) {
                    openWithoutDataSource();
                } else {
                    openExternalDataSource(typeName);
                }

                // Create the example data to show in the render panel
                createExampleDataSource();

                createUserLayerDataSources();

                // Report any attributes used in SLD but not in data source
                if (checkList != null) {
                    for (CheckAttributeInterface check : checkList) {
                        check.checkAttributes(editorFile);
                    }
                }

                notifyDataSourceLoaded();
            } else {
                logger.error("dataSourceProperties is empty");
            }
        }
    }

    /** Create inline data sources. */
    private void createUserLayerDataSources() {
        logger.debug("createUserLayerDataSources");
        if (inlineDataSource == null) {
            ConsoleManager.getInstance().error(this, "No inline data source creation object set");
        } else {
            userLayerDataSourceInfo =
                    inlineDataSource.connect(null, null, this.editorFileInterface);

            if (userLayerDataSourceInfo != null) {
                for (DataSourceInfo dsInfo : userLayerDataSourceInfo) {
                    if (dsInfo.hasData()) {
                        logger.debug("User layer data sources:");
                        dsInfo.populateFieldMap();
                    }
                }
            }
        }
    }

    /**
     * Open external data source.
     *
     * @param typeName the type name
     */
    private void openExternalDataSource(String typeName) {
        logger.debug("openExternalDataSource : " + typeName);

        if (externalDataSource == null) {
            ConsoleManager.getInstance().error(this, "No external data source creation object set");
        } else {
            List<DataSourceInfo> dataSourceInfoList =
                    externalDataSource.connect(typeName, null, this.editorFileInterface);
            if ((dataSourceInfoList != null) && (dataSourceInfoList.size() == 1)) {
                dataSourceInfo = dataSourceInfoList.get(0);

                if (dataSourceInfo.hasData()) {
                    logger.debug("External data sources:");
                    dataSourceInfo.populateFieldMap();

                    connectedToDataSourceFlag = true;
                } else {
                    openWithoutDataSource();
                }
            }

            // Populate external fields
            DataSourceAttributeList attributeData = new DataSourceAttributeList();
            readAttributes(attributeData);
            SLDDataInterface sldData = this.editorFileInterface.getSLDData();

            sldData.setFieldList(attributeData.getData());
        }
    }

    /** Populates the list of available data stores that can be connected to. */
    private void populateAvailableDataStores() {
        DataAccessFactory fac = null;

        logger.debug("Available data store factories:");

        Iterator<DataStoreFactorySpi> iterator = DataStoreFinder.getAvailableDataStores();
        while (iterator.hasNext()) {
            fac = iterator.next();

            logger.debug("\t" + fac.getDisplayName());

            availableDataStoreList.add(fac.getDisplayName());
        }
    }

    /** Unload data store. */
    private void unloadDataStore() {
        if (dataSourceInfo != null) {
            // Tell any listeners that the data store is about to be disposed of
            notifyDataSourceAboutToUnloaded(dataSourceInfo.getDataStore());
            dataSourceInfo.unloadDataStore();
        }

        if (exampleDataSourceInfo != null) {
            notifyDataSourceAboutToUnloaded(exampleDataSourceInfo.getDataStore());
            exampleDataSourceInfo.unloadDataStore();
        }
    }

    /**
     * Gets the feature source.
     *
     * @return the feature source
     */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.impl.DataSourceInterface#getFeatureSource()
     */
    @Override
    public FeatureSource<SimpleFeatureType, SimpleFeature> getFeatureSource() {
        return dataSourceInfo.getFeatures();
    }

    /**
     * Gets the example feature source.
     *
     * @return the example feature source
     */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.impl.DataSourceInterface#getExampleFeatureSource()
     */
    @Override
    public FeatureSource<SimpleFeatureType, SimpleFeature> getExampleFeatureSource() {
        if (exampleDataSourceInfo != null) {
            return exampleDataSourceInfo.getFeatures();
        }
        return null;
    }

    /**
     * Gets the attributes.
     *
     * @param expectedDataType the expected data type
     * @return the attributes
     */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.impl.DataSourceInterface#getAttributes(java.lang.Class)
     */
    @Override
    public List<String> getAttributes(Class<?> expectedDataType) {
        List<String> attributeNameList = new ArrayList<>();

        Collection<PropertyDescriptor> descriptorList = getPropertyDescriptorList();

        if (descriptorList != null) {
            for (PropertyDescriptor property : descriptorList) {
                Class<?> bindingType = property.getType().getBinding();
                if (AllowedAttributeTypes.isAllowed(bindingType, expectedDataType)) {
                    attributeNameList.add(property.getName().toString());
                }
            }
        }
        return attributeNameList;
    }

    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#getAllAttributes()
     */
    @Override
    public List<String> getAllAttributes(boolean includeGeometry) {
        List<String> attributeNameList = new ArrayList<>();

        Collection<PropertyDescriptor> descriptorList = getPropertyDescriptorList();

        if (descriptorList != null) {
            for (PropertyDescriptor property : descriptorList) {
                boolean isGeometry = (property instanceof GeometryDescriptor);
                if ((isGeometry && includeGeometry) || !isGeometry) {
                    attributeNameList.add(property.getName().toString());
                }
            }
        }
        return attributeNameList;
    }

    /**
     * Gets the geometry type.
     *
     * @return the geometry type
     */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#getGeometryType()
     */
    @Override
    public GeometryTypeEnum getGeometryType() {
        return (dataSourceInfo != null)
                ? dataSourceInfo.getGeometryType()
                : GeometryTypeEnum.UNKNOWN;
    }

    /**
     * Read attributes.
     *
     * @param attributeData the attribute data
     */
    /*
     * (non-Javadoc)
     *
     * @see
     * com.sldeditor.datasource.DataSourceInterface#updateAttributes(com.sldeditor.render.iface.
     * RenderAttributeDataInterface)
     */
    @Override
    public void readAttributes(DataSourceAttributeListInterface attributeData) {
        if (attributeData == null) {
            return;
        }

        List<DataSourceAttributeData> valueMap = new ArrayList<>();

        SimpleFeatureCollection featureCollection = dataSourceInfo.getFeatureCollection();
        if (featureCollection != null) {
            SimpleFeatureIterator iterator = featureCollection.features();

            Map<Integer, Name> fieldNameMap = dataSourceInfo.getFieldNameMap();
            Map<Integer, Class<?>> fieldTypeMap = dataSourceInfo.getFieldTypeMap();

            if (iterator.hasNext()) {
                SimpleFeature feature = iterator.next();

                extractAttributes(valueMap, fieldNameMap, fieldTypeMap, feature);
            }

            iterator.close();
        }

        attributeData.setData(valueMap);
    }

    /**
     * Extract attributes.
     *
     * @param valueMap the value map
     * @param fieldNameMap the field name map
     * @param fieldTypeMap the field type map
     * @param feature the feature
     */
    private void extractAttributes(
            List<DataSourceAttributeData> valueMap,
            Map<Integer, Name> fieldNameMap,
            Map<Integer, Class<?>> fieldTypeMap,
            SimpleFeature feature) {
        List<Object> attributes = feature.getAttributes();
        for (int i = 0; i < attributes.size(); i++) {
            Name name = fieldNameMap.get(i);
            if (name != null) {
                String fieldName = name.getLocalPart();

                Class<?> fieldType = fieldTypeMap.get(i);

                if (fieldType == Geometry.class) {
                    Object value = feature.getAttribute(fieldName);

                    fieldType = value.getClass();
                }

                Object value =
                        CreateSampleData.getFieldTypeValue(
                                i, fieldName, fieldType, attributes.get(i));

                DataSourceAttributeData data =
                        new DataSourceAttributeData(fieldName, fieldType, value);

                valueMap.add(data);
            }
        }
    }

    /** Reset. */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#reset()
     */
    @Override
    public void reset() {
        unloadDataStore();

        dataSourceInfo.reset();
        dataSourceProperties = null;

        if (exampleDataSourceInfo != null) {
            exampleDataSourceInfo.reset();
            exampleDataSourceInfo = null;
        }
    }

    /** Open without data source. */
    private void openWithoutDataSource() {
        logger.debug("openWithoutDataSource");

        connectedToDataSourceFlag = false;

        if (this.editorFileInterface.getSLD() == null) {
            logger.debug("Missing StyledLayerDescriptor");
        } else {
            createInternalDataSource();
        }
    }

    /** Creates the internal data source. */
    private void createInternalDataSource() {
        logger.debug("createInternalDataSource");

        if (internalDataSource == null) {
            ConsoleManager.getInstance().error(this, "No internal data source creation object set");
        } else {
            logger.debug("Internal data sources:");
            int attempt = 0;
            boolean retry = true;
            while (retry && (attempt < MAX_RETRIES)) {
                List<DataSourceInfo> dataSourceInfoList =
                        internalDataSource.connect(
                                null,
                                dataSourceInfo.getGeometryFieldName(),
                                this.editorFileInterface);
                if ((dataSourceInfoList != null) && (dataSourceInfoList.size() == 1)) {
                    dataSourceInfo = dataSourceInfoList.get(0);
                }

                // Check that the field data types that were guessed are correct
                if (ExtractValidFieldTypes.fieldTypesUpdated()) {
                    // Field types were updated so retry
                    attempt++;
                } else {
                    // No changes made to exit
                    retry = false;
                }
            }
        }
    }

    /** Creates the example data source. */
    private void createExampleDataSource() {
        if (internalDataSource == null) {
            ConsoleManager.getInstance().error(this, "No internal data source creation object set");
        } else {
            logger.debug("Example data source:");
            List<DataSourceInfo> dataSourceInfoList =
                    internalDataSource.connect(
                            dataSourceInfo.getTypeName(),
                            dataSourceInfo.getGeometryFieldName(),
                            this.editorFileInterface);

            if ((dataSourceInfoList != null) && (dataSourceInfoList.size() == 1)) {
                exampleDataSourceInfo = dataSourceInfoList.get(0);
            }
        }
    }

    /** Notify data source loaded. */
    private void notifyDataSourceLoaded() {
        List<DataSourceUpdatedInterface> copyListenerList = new ArrayList<>(listenerList);
        GeometryTypeEnum geometryType = getGeometryType();
        for (DataSourceUpdatedInterface listener : copyListenerList) {
            listener.dataSourceLoaded(geometryType, this.connectedToDataSourceFlag);
        }
    }

    /**
     * Notify data source about to be unloaded.
     *
     * @param dataStore the data store to be unloaded
     */
    private void notifyDataSourceAboutToUnloaded(DataStore dataStore) {
        List<DataSourceUpdatedInterface> copyListenerList = new ArrayList<>(listenerList);
        for (DataSourceUpdatedInterface listener : copyListenerList) {
            listener.dataSourceAboutToUnloaded(dataStore);
        }
    }

    /**
     * Gets the data connector properties.
     *
     * @return the data connector properties
     */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#getDataConnectorProperties()
     */
    @Override
    public DataSourcePropertiesInterface getDataConnectorProperties() {
        return dataSourceProperties;
    }

    /**
     * Gets the available data store list.
     *
     * @return the available data store list
     */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#getAvailableDataStoreList()
     */
    @Override
    public List<String> getAvailableDataStoreList() {
        return availableDataStoreList;
    }

    /**
     * Update fields.
     *
     * @param attributeData the attribute data
     */
    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#updateFields(com.sldeditor.render.iface.
     * RenderAttributeDataInterface)
     */
    @Override
    public void updateFields(DataSourceAttributeListInterface attributeData) {
        if (attributeData != null) {
            List<DataSourceAttributeData> attributeDataList = attributeData.getData();

            if (this.editorFileInterface != null) {
                this.dataSourceProperties = editorFileInterface.getDataSource();
                SLDDataInterface sldData = this.editorFileInterface.getSLDData();
                if (sldData != null) {
                    sldData.setFieldList(attributeDataList);
                }
            }
            this.connectedToDataSourceFlag = false;

            createInternalDataSource();

            notifyDataSourceLoaded();
        }
    }

    /**
     * Adds the field.
     *
     * @param dataSourceField the data source field
     */
    @Override
    public void addField(DataSourceAttributeData dataSourceField) {
        if ((dataSourceField != null) && !connectedToDataSourceFlag) {
            SLDDataInterface sldData = this.editorFileInterface.getSLDData();
            List<DataSourceAttributeData> fieldList = sldData.getFieldList();

            if (fieldList == null) {
                fieldList = new ArrayList<>();
                sldData.setFieldList(fieldList);
            }
            fieldList.add(dataSourceField);

            createInternalDataSource();

            notifyDataSourceLoaded();
        }
    }

    /**
     * Gets the property descriptor list.
     *
     * @return the property descriptor list
     */
    @Override
    public Collection<PropertyDescriptor> getPropertyDescriptorList() {
        if (dataSourceInfo != null) {
            return dataSourceInfo.getPropertyDescriptorList();
        }
        return null;
    }

    /**
     * Gets the grid coverage reader.
     *
     * @return the grid coverage reader
     */
    @Override
    public AbstractGridCoverage2DReader getGridCoverageReader() {
        AbstractGridCoverage2DReader gridCoverage = null;

        if (dataSourceInfo != null) {
            gridCoverage = dataSourceInfo.getGridCoverageReader();
        }
        return gridCoverage;
    }

    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#getUserLayerFeatureSource()
     */
    @Override
    // CHECKSTYLE:OFF
    public Map<UserLayer, FeatureSource<SimpleFeatureType, SimpleFeature>>
            getUserLayerFeatureSource() {
        // CHECKSTYLE:ON
        Map<UserLayer, FeatureSource<SimpleFeatureType, SimpleFeature>> map = new HashMap<>();

        for (DataSourceInfo dsInfo : userLayerDataSourceInfo) {
            FeatureSource<SimpleFeatureType, SimpleFeature> features = dsInfo.getFeatures();
            UserLayer userLayer = dsInfo.getUserLayer();

            map.put(userLayer, features);
        }
        return map;
    }

    /** Recreate inline data sources for user layers. */
    @Override
    public void updateUserLayers() {
        createUserLayerDataSources();

        notifyDataSourceLoaded();
    }

    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#updateFieldType(java.lang.String,
     * java.lang.Class)
     */
    @Override
    public void updateFieldType(String fieldName, Class<?> dataType) {
        List<DataSourceAttributeData> fieldList =
                this.editorFileInterface.getSLDData().getFieldList();
        for (DataSourceAttributeData field : fieldList) {
            if (field.getName().compareTo(fieldName) == 0) {
                field.setType(dataType);
            }
        }
    }

    /*
     * (non-Javadoc)
     *
     * @see com.sldeditor.datasource.DataSourceInterface#getGeometryFieldName()
     */
    @Override
    public String getGeometryFieldName() {
        return dataSourceInfo.getGeometryFieldName();
    }
}