package timeflow.format.file;

import timeflow.model.*;
import timeflow.data.db.*;
import timeflow.data.time.*;
import timeflow.format.field.*;

import timeflow.util.*;

import java.io.*;
import java.net.URL;
import java.util.*;

public class TimeflowFormat implements Import, Export
{

        private static final String END_OF_SCHEMA = "#TIMEFLOW\tend-metadata";
        private static final String END_OF_METADATA = "#TIMEFLOW\t====== End of Header. Data below is in tab-delimited format. =====";

        public ActDB readFile(String fileName, PrintStream messages) throws Exception
        {
                return read(new File(fileName), messages);
        }

        public static ActDB read(File file, PrintStream out) throws Exception
        {
                String text = IO.read(file.getAbsolutePath());
                DelimitedText quote = new DelimitedText('\t');
                Iterator<String[]> lines = quote.read(text).iterator();


                ActDB db = null;
                List<String> fieldNames = new ArrayList<String>();
                List<Class> fieldTypes = new ArrayList<Class>();
                List<Integer> fieldSizes = new ArrayList<Integer>();
                String source = "[unknown]", description = "";
                for (;;)
                {
                        String[] t = lines.next();

                        if (t[1].equals("field"))
                        {
                                fieldNames.add(t[2]);
                                fieldTypes.add(FieldFormatCatalog.javaClass(t[3]));
                                if (t.length > 4)
                                {
                                        fieldSizes.add(Integer.parseInt(t[4]));
                                } else
                                {
                                        fieldSizes.add(-1);
                                }
                        } else if (t[1].equals("source"))
                        {
                                source = t[2];
                        } else if (t[1].equals("description"))
                        {
                                description = t[2];

                        } else if (t[1].equals("end-metadata"))
                        {
                                break;
                        }
                }
                db = new ArrayDB((String[]) fieldNames.toArray(new String[0]),
                        (Class[]) fieldTypes.toArray(new Class[0]), source);
                db.setDescription(description);
                for (int i = 0; i < fieldNames.size(); i++)
                {
                        if (fieldSizes.get(i) > 0)
                        {
                                db.getField(fieldNames.get(i)).setRecommendedSize(fieldSizes.get(i));
                        }
                }
                for (;;)
                {
                        String[] t = lines.next();
                        if (t[1].startsWith("==="))
                        {
                                break;
                        }
                        if (t[1].equals("alias"))
                        {
                                db.setAlias(db.getField(t[3]), t[2]);
                        }
                }

                // note: in some cases headers may be in a different order than in
                // metadata section, so we will read these.
                String[] headers = lines.next();
                if (headers.length != fieldNames.size())
                {
                        throw new IllegalArgumentException("Different number of headers than fields!");
                }


                while (lines.hasNext())
                {
                        String[] t = lines.next();
                        Act a = db.createAct();
                        for (int i = 0; i < t.length; i++)
                        {
                                Field f = db.getField(headers[i]);
                                FieldFormat format = FieldFormatCatalog.getFormat(f.getType());
                                a.set(f, format.parse(t[i]));
                        }
                }

                return db;
        }

        public static void write(ActList acts, BufferedWriter bw) throws IOException
        {
                ActDB db = acts.getDB();

                PrintWriter out = new PrintWriter(bw);

                DelimitedText tab = new DelimitedText('\t');

                // Write version
                out.println("#TIMEFLOW\tformat version\t1");

                // Write source of data.
                out.println("#TIMEFLOW\tsource\t" + tab.write(db.getSource()));

                // Write description of data.
                out.println("#TIMEFLOW\tdescription\t" + tab.write(db.getDescription()));

                // Write schema.
                List<Field> fields = db.getFields();
                for (Field f : fields)
                {
                        String recSize = f.getRecommendedSize() <= 0 ? "" : "\t" + f.getRecommendedSize();
                        out.println("#TIMEFLOW\tfield\t" + tab.write(f.getName())
                                + "\t" + FieldFormatCatalog.humanName(f.getType()) + recSize);
                }

                out.println(END_OF_SCHEMA);

                // Write column mappings.
                List<String> aliases = DBUtils.getFieldAliases(db);
                for (String a : aliases)
                {
                        out.println("#TIMEFLOW\talias\t" + a + "\t" + tab.write(db.getField(a).getName()));
                }

                // Write end of header indicator
                out.println(END_OF_METADATA);

                // Write data!
                new DelimitedFormat('\t').writeDelimited(db, acts, out);

                out.flush();
                out.close();
        }

        public static void main(String[] args) throws Exception
        {
                System.out.println("Reading");
                ActDB db = read(new File("test/monet.txt"), System.out);
                System.out.println("# lines: " + db.size());
        }

        @Override
        public String getName()
        {
                return "TimeFlow Format";
        }

        @Override
        public ActDB importFile(File file) throws Exception
        {
                return read(file, System.out);
        }

        @Override
        public void export(TimeflowModel model, BufferedWriter out) throws Exception
        {
                write(model.getDB().all(), out);
        }
}