// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.plugins.opendata.core.io.tabular;

import static org.openstreetmap.josm.tools.I18n.tr;

import java.awt.Component;
import java.awt.GraphicsEnvironment;
import java.io.IOException;
import java.io.InputStream;
import java.text.NumberFormat;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.data.coor.EastNorth;
import org.openstreetmap.josm.data.osm.DataSet;
import org.openstreetmap.josm.data.osm.Node;
import org.openstreetmap.josm.data.projection.Projection;
import org.openstreetmap.josm.gui.progress.ProgressMonitor;
import org.openstreetmap.josm.gui.util.GuiHelper;
import org.openstreetmap.josm.io.AbstractReader;
import org.openstreetmap.josm.plugins.opendata.core.OdConstants;
import org.openstreetmap.josm.plugins.opendata.core.io.ProjectionChooser;
import org.openstreetmap.josm.plugins.opendata.core.io.ProjectionPatterns;

public abstract class SpreadSheetReader extends AbstractReader {
	
	private static final NumberFormat formatFrance = NumberFormat.getInstance(Locale.FRANCE);
	private static final NumberFormat formatUK = NumberFormat.getInstance(Locale.UK);
	
	protected final SpreadSheetHandler handler;

	public SpreadSheetReader(SpreadSheetHandler handler) {
		this.handler = handler;
	}

	protected static double parseDouble(String value) throws ParseException {
		if (value.contains(",")) { 
			return formatFrance.parse(value.replace(" ", "")).doubleValue();
		} else {
			return formatUK.parse(value.replace(" ", "")).doubleValue();
		}
	}
	
	protected abstract void initResources(InputStream in, ProgressMonitor progressMonitor) throws IOException;
	
	protected abstract String[] readLine(ProgressMonitor progressMonitor) throws IOException;
	
	protected final int getSheetNumber() {
		return handler != null && handler.getSheetNumber() > -1 ? handler.getSheetNumber() : 0;
	}
	
	protected final int getLineNumber() {
		return handler != null ? handler.getLineNumber() : -1;
	}
	
	public static class CoordinateColumns {
        public Projection proj = null;
		public int xCol = -1;
		public int yCol = -1;
		public final boolean isOk() {
			return xCol > -1 && yCol > -1;
		}
        @Override
        public String toString() {
            return "CoordinateColumns [proj=" + proj + ", xCol=" + xCol + ", yCol=" + yCol + "]";
        }
	}
	
	private final CoordinateColumns addCoorColIfNeeded(List<CoordinateColumns> columns, CoordinateColumns col) {
        if (col == null || col.isOk()) {
            columns.add(col = new CoordinateColumns());
        }
        return col;
	}
	
	private class ChooserLauncher implements Runnable {

	    public Projection proj = null;
        private final ProgressMonitor progressMonitor;
	    
        public ChooserLauncher(ProgressMonitor progressMonitor) {
            this.progressMonitor = progressMonitor;
        }

        @Override
        public void run() {
            Component parent = progressMonitor == null ? Main.parent : progressMonitor.getWindowParent();
            ProjectionChooser dialog = (ProjectionChooser) new ProjectionChooser(parent).showDialog();
            if (dialog.getValue() == 1) {
                proj = dialog.getProjection();
            }
        }
	}
	
	public DataSet doParse(String[] header, ProgressMonitor progressMonitor) throws IOException {
		Main.info("Header: "+Arrays.toString(header));
		
		Map<ProjectionPatterns, List<CoordinateColumns>> projColumns = new HashMap<>();
		
		for (int i = 0; i<header.length; i++) {
			for (ProjectionPatterns pp : OdConstants.PROJECTIONS) {
			    List<CoordinateColumns> columns = projColumns.get(pp);
			    if (columns == null) {
			        projColumns.put(pp, columns = new ArrayList<>());
			    }
				CoordinateColumns col = columns.isEmpty() ? null : columns.get(columns.size()-1);
				if (pp.getXPattern().matcher(header[i]).matches()) {
				    addCoorColIfNeeded(columns, col).xCol = i;
					break;
				} else if (pp.getYPattern().matcher(header[i]).matches()) {
				    addCoorColIfNeeded(columns, col).yCol = i;
					break;
				}
			}
		}

		final List<CoordinateColumns> columns = new ArrayList<>();
		
		for (ProjectionPatterns pp : projColumns.keySet()) {
		    for (CoordinateColumns col : projColumns.get(pp)) {
	            if (col.isOk()) {
                    columns.add(col);
	                if (col.proj == null) {
	                    col.proj = pp.getProjection(header[col.xCol], header[col.yCol]);
	                }
	            }
		    }
		}

		final boolean handlerOK = handler != null && handler.handlesProjection();

		boolean projFound = false;
		
		for (CoordinateColumns c : columns) {
		    if (c.proj != null) {
		        projFound = true;
		        break;
		    }
		}
		
		if (projFound) {
			// projection identified, do nothing
		} else if (!columns.isEmpty()) {
			if (!handlerOK) {
                if (GraphicsEnvironment.isHeadless()) {
                    throw new IllegalArgumentException("No valid coordinates have been found and cannot prompt user in headless mode.");
			    }
				// TODO: filter proposed projections with min/max values ?
			    ChooserLauncher launcher = new ChooserLauncher(progressMonitor);
			    GuiHelper.runInEDTAndWait(launcher);
				if (launcher.proj == null) {
					return null; // User clicked Cancel
				}
		        for (CoordinateColumns c : columns) {
		            c.proj = launcher.proj;
		        }
			}
			
		} else {
			throw new IllegalArgumentException(tr("No valid coordinates have been found."));
		}

		String message = "";
		for (CoordinateColumns c : columns) {
		    if (!message.isEmpty()) {
		        message += "; ";
		    }
		    message += c.proj + "("+header[c.xCol]+", "+header[c.yCol]+")";
		}
		
		Main.info("Loading data using projections "+message);
		
		final DataSet ds = new DataSet();
		int lineNumber = 1;
		
		String[] fields;
		while ((fields = readLine(progressMonitor)) != null) {
			lineNumber++;
			if (handler != null) {
				handler.setXCol(-1);
				handler.setYCol(-1);
			}
			
            final Map<CoordinateColumns, EastNorth> ens = new HashMap<>();
			final Map<CoordinateColumns, Node> nodes = new HashMap<>();
			for (CoordinateColumns c : columns) {
			    nodes.put(c, new Node());
			    ens.put(c, new EastNorth(Double.NaN, Double.NaN));
			}
			
			if (fields.length > header.length) {
			    Main.warn(tr("Invalid file. Bad length on line {0}. Expected {1} columns, got {2}.", lineNumber, header.length, fields.length));
			    Main.warn(Arrays.toString(fields));
			}
			
			for (int i = 0; i<Math.min(fields.length, header.length); i++) {
				try {
				    boolean coordinate = false;
				    for (CoordinateColumns c : columns) {
				        EastNorth en = ens.get(c);
                        if (i == c.xCol) {
                            coordinate = true;
                            ens.put(c, new EastNorth(parseDouble(fields[i]), en.north()));
                            if (handler != null) {
                                handler.setXCol(i);
                            }
                        } else if (i == c.yCol) {
                            coordinate = true;
                            ens.put(c, new EastNorth(en.east(), parseDouble(fields[i])));
                            if (handler != null) {
                                handler.setYCol(i);
                            }
                        }					        
				    }
                    if (!coordinate) {
                        if (!fields[i].isEmpty()) {
                            nodes.values().iterator().next().put(header[i], fields[i]);
                        }
                    }
				} catch (ParseException e) {
					System.err.println("Warning: Parsing error on line "+lineNumber+": "+e.getMessage());
				}
			}
			Node firstNode = null;
			for (CoordinateColumns c : columns) {
			    Node n = nodes.get(c);
			    EastNorth en = ens.get(c);
    			if (en.isValid()) {
    				n.setCoor(c.proj != null && !handlerOK ? c.proj.eastNorth2latlon(en) : handler.getCoor(en, fields));
    			} else {
    				System.err.println("Warning: Skipping line "+lineNumber+" because no valid coordinates have been found at columns "+c);
    			}
    			if (n.getCoor() != null) {
    			    if (firstNode == null) {
    			        firstNode = n;
    			    }
    			    if (n == firstNode || n.getCoor().greatCircleDistance(firstNode.getCoor()) > Main.pref.getDouble(OdConstants.PREF_TOLERANCE, OdConstants.DEFAULT_TOLERANCE)) {
    			        ds.addPrimitive(n);
    			    } else {
    			        nodes.remove(c);
    			    }
    			}
			}
			if (handler != null && !Main.pref.getBoolean(OdConstants.PREF_RAWDATA)) {
			    handler.nodesAdded(ds, nodes, header, lineNumber);
			}
		}
		
		return ds;
	}
	
	public final DataSet parse(InputStream in, ProgressMonitor progressMonitor) throws IOException {
		
		initResources(in, progressMonitor);
		
		String[] header = null;
		int length = 0;
		int n = 0;
		
		while (header == null || length == 0) {
			n++;
			header = readLine(progressMonitor);
			length = 0;
			if (header == null && n > getLineNumber()) {
				return null;
			} else if (header != null && (getLineNumber() == -1 || getLineNumber() == n)) {
				for (String field : header) {
					length += field.length();
				}
			}
		}
		
		return doParse(header, progressMonitor);
	}
}
