import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;
import java.util.Map.Entry;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Collection;

public class Relation {


    String name;
    Attribute attribute1;
    Attribute attribute2;
    String tablename1;
    String tablename2;

    private String tableName;
    private String[] attributeNames;
    private String[] attributes;
    private String keyName;

    HashMap<Attribute, ArrayList<Attribute>> storage;


//could use iterable

    /**
     * Add every course into the database
     * Add the students into the array,
     * if a course is being added for the second time, we need to add the student to the end of the arraylist
     */
//must load two tables
//relation just reads the different tables
//
    public Relation(File inputFile) {

        // Set up scanner
        Scanner scanner = null;
        try {
            scanner = new Scanner(inputFile);
        } catch (FileNotFoundException fnf) {
            System.out.println("Could not find file!");
            System.exit(1);
        }

        // Read in header info
        scanner.nextLine(); // Skip the first line

        // Get table name
        this.tableName = scanner.nextLine();
        this.tableName = tableName.substring(8, tableName.length());

        // Get attribute names
        String attributeNamesStr = scanner.nextLine();
        attributeNamesStr = attributeNamesStr.substring(19, attributeNamesStr.length());
        this.attributeNames = attributeNamesStr.split(" ");

        // Get attribute types
        String attributesStr = scanner.nextLine();
        attributesStr = attributesStr.substring(19, attributesStr.length());
        this.attributes = attributesStr.split(" ");

        // Get key
        this.keyName = scanner.nextLine();
        this.keyName = keyName.substring(7, keyName.length());

        // Skip the line of hashes at end of header
        scanner.nextLine();

        // Read in data

        // Get the index of the key in the row
        int keyIndex = Arrays.asList(this.attributeNames).indexOf(this.keyName);

        // Store the data according to the format in the header
        storage = new HashMap<>();
        while (scanner.hasNext()) {
            Attribute key = null;
            ArrayList<Attribute> values = new ArrayList<>(); // might need to put somewhere else
            for (int i = 0; i < this.attributes.length; i++) {
                Attribute value = null;
                switch (this.attributes[i]) {
                    case ("INTEGER"):
                        value = new IntAttribute(scanner.nextInt());
                        break;
                    case ("STRING"):
                        value = new StringAttribute(scanner.next());
                        break;
                    case ("LINE_STRING"):
                        value = new StringAttribute(scanner.nextLine());
                        break;
                }

                values.add(value);
                if (i == keyIndex)
                    key = value;

                if (storage.get(key) != null) {
                    storage.get(key).add(value);

                }


            }
            if (storage.get(key) == null)
                storage.put(key, values);
        }

    }

}