package de.vanitasvitae.imi.codes;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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;

public class CodeGenerator {

    private final FileRepository repository = new FileRepository(new File(".imicodes"));

    public CodeGenerator() {

    }

    public List<SampleTubeCode> generateCodes(StudyNumber studyNumber, SampleType sampleType, int numberOfCodes)
            throws InvalidOptionException, IOException {
        List<SampleTubeCode> codes = new ArrayList<>();

        // Read the next sample code from file
        int nextSampleCode = repository.nextSampleCode(studyNumber);

        int nextTotal = nextSampleCode + numberOfCodes;
        // Check, if we'd have an overflow of sample numbers
        // We check like this to prevent integer overflows
        if (nextSampleCode > 9999 || numberOfCodes > 9999 || nextTotal - 1 > 9999) {
            throw new InvalidOptionException("Study " + studyNumber + "would have too many sample tubes" +
                    " (" + (nextTotal - 1) + "). Aborting.");
        }

        // Write back the number of the next sample number that should be generated next time
        repository.writeNextSampleCode(studyNumber, nextSampleCode + numberOfCodes);

        // Generate codes
        for (int i = 0; i < numberOfCodes; i++) {
            codes.add(new SampleTubeCode(studyNumber, sampleType, nextSampleCode + i));
        }

        return codes;
    }
}