package de.pointedears.converter.app;

import java.util.HashMap;
import java.util.Map.Entry;

import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnKeyListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import de.pointedears.converter.R;
import de.pointedears.converter.db.CurrenciesDatabase;
import de.pointedears.converter.helpers.CurrenciesUpdateThread;

/**
 * Activity that implements currency conversion
 * 
 * @author pelinux
 */
public class CurrenciesActivity extends Activity
{
  /*
   * Constants for mapping value strings
   * 
   * @todo: Use resource IDs
   */
  /**
   * Database field/spinner value for Swiss Francs
   */
  public static final String VALUE_CHF = "CHF"; //$NON-NLS-1$

  /**
   * Database field/spinner value for Euros
   */

  public static final String VALUE_EUR = "EUR"; //$NON-NLS-1$

  /**
   * Database field/spinner value for US Dollars
   */
  public static final String VALUE_USD = "USD"; //$NON-NLS-1$

  /* Unit spinners (dropdowns) */
  private Spinner spinnerUnit1;
  private Spinner spinnerUnit2;
  private CurrenciesDatabase db;

  private HashMap<String, HashMap<String, Double>> conversionRates;

  /** Called when the activity is first created. */

  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    this.setContentView(R.layout.activity_currencies);

    /* Set up currency database, and retrieve conversion rates */
    this.db = new CurrenciesDatabase(this);
    this.conversionRates = this.db.getConversionRates();
    this.fillTableRates();

    final EditText editValue1 =
      (EditText) this.findViewById(R.id.currencies_edit_value1);
    final EditText editValue2 =
      (EditText) this.findViewById(R.id.currencies_edit_value2);

    final OnKeyListener editValue1OnKey = new OnKeyListener() {
      @Override
      public boolean onKey(View v, int keyCode, KeyEvent event)
      {
        Editable editable1 = ((EditText) v).getText();

        Double value1;
        try
        {
          value1 = Double.parseDouble(editable1.toString());
        }
        catch (NumberFormatException e)
        {
          value1 = null;
        }

        String string2 = ""; //$NON-NLS-1$
        if (value1 != null)
        {
          string2 = CurrenciesActivity.this.getConvertedValue(value1, false);
        }

        editValue2.setText(string2);

        return false;
      }
    };
    editValue1.setOnKeyListener(editValue1OnKey);

    final OnKeyListener editValue2OnKey = new OnKeyListener() {
      @Override
      public boolean onKey(View v, int keyCode, KeyEvent event)
      {
        Editable editable2 = ((EditText) v).getText();

        Double value2;
        try
        {
          value2 = Double.parseDouble(editable2.toString());
        }
        catch (NumberFormatException e)
        {
          value2 = null;
        }

        String string1 = ""; //$NON-NLS-1$
        if (value2 != null)
        {
          string1 = CurrenciesActivity.this.getConvertedValue(value2, true);
        }

        editValue1.setText(string1);

        return false;
      }
    };
    editValue2.setOnKeyListener(editValue2OnKey);

    this.spinnerUnit1 =
      (Spinner) this.findViewById(R.id.currencies_spinner_unit1);
    this.spinnerUnit2 =
      (Spinner) this.findViewById(R.id.currencies_spinner_unit2);

    this.spinnerUnit1.setOnItemSelectedListener(new OnItemSelectedListener() {
      @Override
      public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
        long arg3)
      {
        /* Simulate input in second EditText so that first EditText is updated */
        editValue2OnKey.onKey(editValue2, 0, null);
      }

      @Override
      public void onNothingSelected(AdapterView<?> arg0)
      {
        /* no-op */
      }
    });

    this.spinnerUnit2.setSelection(1);
    this.spinnerUnit2.setOnItemSelectedListener(new OnItemSelectedListener() {
      @Override
      public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
        long arg3)
      {
        /* Simulate input in first EditText so that second EditText is updated */
        editValue1OnKey.onKey(editValue1, 0, null);
      }

      @Override
      public void onNothingSelected(AdapterView<?> arg0)
      {
        /* no-op */
      }
    });

    Button buttonClear =
      (Button) this.findViewById(R.id.currencies_button_clear);
    buttonClear.setOnClickListener(new OnClickListener() {

      @SuppressWarnings("nls")
      @Override
      public void onClick(View v)
      {
        editValue1.setText("");
        editValue2.setText("");
      }
    });
  }

  /**
   * Fills the table with currency conversion rates
   */
  private void fillTableRates()
  {
    TableLayout tableRates =
      (TableLayout) this.findViewById(R.id.currencies_table_rates);

    for (String key : this.conversionRates.keySet())
    {
      for (Entry<String, Double> factorEntry : this.conversionRates.get(key)
        .entrySet())
      {
        TableRow row = new TableRow(this);

        TextView columnCurrency1 = new TextView(this);
        columnCurrency1.setText(key);
        row.addView(columnCurrency1);

        TextView columnCurrency2 = new TextView(this);
        columnCurrency2.setText(factorEntry.getKey());
        row.addView(columnCurrency2);

        TextView columnRate = new TextView(this);
        columnRate.setText(factorEntry.getValue().toString());
        row.addView(columnRate);

        tableRates.addView(row);
      }
    }
  }

  /**
   * @param value
   * @return
   */
  private String getConvertedValue(double value, boolean reverse)
  {
    int selectedItemPosition1 = this.spinnerUnit1.getSelectedItemPosition();
    int selectedItemPosition2 = this.spinnerUnit2.getSelectedItemPosition();
    String[] items =
      this.getResources().getStringArray(R.array.currency_units_values);
    String selectedItemValue1 = items[selectedItemPosition1];
    String selectedItemValue2 = items[selectedItemPosition2];

    if (reverse)
    {
      String tmp = selectedItemValue1;
      selectedItemValue1 = selectedItemValue2;
      selectedItemValue2 = tmp;
    }

    Double newValue = value;

    HashMap<String, Double> mapForCurrency =
      this.conversionRates.get(selectedItemValue1);
    if (mapForCurrency != null)
    {
      Double conversionFactor = mapForCurrency.get(selectedItemValue2);
      if (conversionFactor != null)
      {
        newValue *= conversionFactor;
      }
    }

    return newValue.toString();
  }

  /*
   * (non-Javadoc)
   * 
   * @see android.app.Activity#onCreateOptionsMenu(android.view.Menu)
   */
  /*
   * (non-Javadoc)
   * 
   * @see android.app.Activity#onCreateOptionsMenu(android.view.Menu)
   */
  @Override
  public boolean onCreateOptionsMenu(Menu menu)
  {
    MenuInflater inflater = this.getMenuInflater();
    inflater.inflate(R.menu.options, menu);
    return true;
  }

  /*
   * (non-Javadoc)
   * 
   * @see android.app.Activity#onOptionsItemSelected(android.view.MenuItem)
   */
  @Override
  public boolean onOptionsItemSelected(MenuItem item)
  {
    // Handle item selection
    switch (item.getItemId())
    {
      case R.id.item_options_update:
        Thread updateThread = new CurrenciesUpdateThread();
        updateThread.start();
        return true;

      default:
        return super.onOptionsItemSelected(item);
    }
  }
}