/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package com.megatim.queryadhoc.utils;

import com.megatim.queryadhoc.model.DbColumnDescription;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 *
 * @author ASUS
 */
public class FileDataReader {

    private FileDataReader() {

    }

    public static List<Map<String, Object>> readFile(List<DbColumnDescription> columnsDescription, File dataFile) throws Exception {
        List<Map<String, Object>> data = new ArrayList<>();

        //Ranger les olonnes par ordre croissant de position
        Collections.sort(columnsDescription, (DbColumnDescription c1, DbColumnDescription c2) -> Integer.valueOf(c1.getPosition()).compareTo(c2.getPosition()));

        //On détermine l'encodage du fichier
        Charset charset = CommonUtilities.getCharset(dataFile);

        try ( FileInputStream fis = new FileInputStream(dataFile);  InputStreamReader isr = new InputStreamReader(fis, charset);  BufferedReader reader = new BufferedReader(isr)) {
            String line;

            while ((line = reader.readLine()) != null) {
                LinkedHashMap<String, Object> dataLine = getLine(line, columnsDescription);
                data.add(dataLine);
            }
        }

        return data;
    }

    private static LinkedHashMap<String, Object> getLine(final String line, final List<DbColumnDescription> columnsDescription) {
        LinkedHashMap<String, Object> dataLine = new LinkedHashMap<>();
        int index = 0;

        for (DbColumnDescription c : columnsDescription) {

            //traitement des colonnes du type fichier
            String data = line.substring(index, index + c.getTaille());
            dataLine.put(c.getName(), data);

            index += c.getTaille();
        }

        return dataLine;
    }
}