package de.vanitasvitae.imi.codes;

import java.awt.*;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.net.URI;
import java.net.URISyntaxException;
import java.sql.SQLOutput;
import java.util.List;

import de.vanitasvitae.imi.codes.input.Arguments;
import de.vanitasvitae.imi.codes.input.InputValidator;
import de.vanitasvitae.imi.codes.input.InvalidOptionException;
import de.vanitasvitae.imi.codes.persistence.FileRepository;
import de.vanitasvitae.imi.codes.types.SampleTubeCode;
import de.vanitasvitae.imi.codes.types.SampleType;
import de.vanitasvitae.imi.codes.types.StudyNumber;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;

public class Main {

    private static final String NAME_JAR = "imi.codes";
    private static final String HELP_HEADER = "Generate ID codes for sample tubes.";
    private static final String HELP_FOOTER = "\nAuthor: Paul Schaub <paul.schaub@wwu.de>";
    private static final File RECORD_DIR = new File(".imicodes");

    /**
     * Entry point to the program.
     * Any provided arguments are parsed and the behaviour of the program is modified respectively.
     * A list of available options can be displayed using "-h".
     *
     * @param args arguments
     */
    public static void main(String[] args) {
        Options options = Arguments.getCommandLineOptions();
        CommandLineParser parser = new DefaultParser();

        // Parse command line arguments
        CommandLine arguments;
        try {
            arguments = parser.parse(options, args);
        } catch (ParseException e) {
            System.out.println(e.getMessage());
            printHelp(options);
            return;
        }

        // User issues '-h', so just show help text and exit right now.
        if (arguments.hasOption(Arguments.HELP)) {
            printHelp(options);
            return;
        }

        StudyNumber studyNumber;
        SampleType sampleType;
        int numberOfCodes;
        File outputPath;
        boolean externalBrowser;

        // Validate command line arguments
        try {
            studyNumber = InputValidator.validateStudyNumber(arguments.getOptionValue(Arguments.STUDY_NUMBER));
            sampleType = InputValidator.validateSampleType(arguments.getOptionValue(Arguments.SAMPLE_TYPE));
            numberOfCodes = InputValidator.validateNumberOfCodes(arguments.getOptionValue(Arguments.NUMBER_CODES));

            if (arguments.hasOption(Arguments.OUTPUT_DESTINATION)) {
                outputPath = InputValidator.validateOutputPath(arguments.getOptionValue(Arguments.OUTPUT_DESTINATION));
            } else {
                outputPath = InputValidator.validateOutputPath("./out.html");
            }

            externalBrowser = arguments.hasOption(Arguments.EXTERNAL_BROWSER);
        } catch (InvalidOptionException e) {
            // Something is wrong with the users input, so exit.
            System.out.println(e.getMessage());
            printHelp(options);
            return;
        }

        // Store/read number of generated codes to file
        FileRepository repository = new FileRepository(RECORD_DIR);

        // Generate codes
        List<SampleTubeCode> codes;
        try {
            codes = CodeGenerator.generateCodes(repository, studyNumber, sampleType, numberOfCodes);
        } catch (InvalidOptionException e) {
            System.out.println(e.getMessage());
            return;
        } catch (IOException e) {
            System.out.println("Could not store records about already generated codes.");
            e.printStackTrace();
            return;
        }

        // Build HTML
        String html = new HtmlTableStringBuilder("IMI Sample Tube Code Generator", codes).toString();

        // Write HTML to output path
        try {
            writeHtml(html, outputPath);
        } catch (IOException e) {
            System.out.println("Could not write HTML to file " + outputPath.getAbsolutePath());
            e.printStackTrace();
            return;
        }

        // Upon users wish, open generated HTML in a browser.
        if (externalBrowser && Desktop.isDesktopSupported()) {
            try {
                Desktop.getDesktop().browse(new URI("file://" + outputPath.getAbsolutePath()));
            } catch (IOException | URISyntaxException e) {
                System.out.println("Could not open generated HTML in a browser.");
                e.printStackTrace();
            }
        }
    }

    /*
    Write HTML to a file.
     */
    private static void writeHtml(String html, File destination) throws IOException {
        try(Writer writer = new FileWriter(destination)) {
            writer.write(html);
        }
    }

    /**
     * Print a descriptive help text to the console.
     *
     * @param options {@link Options} for which we want to print a help text.
     */
    private static void printHelp(Options options) {
        HelpFormatter formatter = new HelpFormatter();

        formatter.printHelp(NAME_JAR, HELP_HEADER, options, HELP_FOOTER, true);
    }
}