package de.pointedears.converter.app;

import java.text.DateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map.Entry;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
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.ConversionData;
import de.pointedears.converter.db.CurrenciesDatabase;
import de.pointedears.converter.helpers.Notifier;
import de.pointedears.converter.helpers.UpdateService;

/**
 * Activity that implements currency conversion
 * 
 * @author pelinux
 */
public class CurrenciesActivity extends Activity
{
  /**
   * String to use to indicate that an exchange rate has never been updated
   */
  private String TEXT_NEVER;

  /*
   * Constants for mapping value strings
   * 
   * @todo: Use resource IDs
   */
  /**
   * Database field/spinner value for Swiss Francs
   */
  public static String VALUE_CHF;

  /**
   * Database field/spinner value for Euros
   */
  public static String VALUE_EUR;

  /**
   * Database field/spinner value for US Dollars
   */
  public static String VALUE_USD;

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

  private static HashMap<String, ConversionData> conversionRates;

  private static String EXCHANGE_RATES_UPDATED_TO;

  private final static DateFormat dateFormatter = DateFormat
    .getDateInstance(DateFormat.SHORT);

  /**
   * Receiver for intent broadcasts, registered in
   * {@link CurrenciesActivity#onCreate(Bundle)}
   */
  public class UpdateBroadcastReceiver extends BroadcastReceiver
  {
    /**
     * Notification message template
     */

    /*
     * (non-Javadoc)
     * 
     * @see android.content.BroadcastReceiver#onReceive(android.content.Context,
     * android.content.Intent)
     */
    @Override
    public void onReceive(Context context, Intent intent)
    {
      if (intent.getAction().equals(UpdateService.ACTION_UPDATE))
      {
        CurrenciesActivity.this.fillTableRates();

        Bundle extras = intent.getExtras();
        Notifier.sendMessage(
          CurrenciesActivity.this,
          extras.get(UpdateService.EXTRA_NUM_RATES)
            + CurrenciesActivity.EXCHANGE_RATES_UPDATED_TO
            + CurrenciesActivity.dateFormatter.format(extras
              .get(UpdateService.EXTRA_DATE)));
      }
    }
  }

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    this.setContentView(R.layout.activity_currencies);

    this.TEXT_NEVER =
      this.getString(R.string.currencies_never_updated);

    CurrenciesActivity.VALUE_CHF = this.getString(R.string.currencies_CHF);
    CurrenciesActivity.VALUE_EUR = this.getString(R.string.currencies_EUR);
    CurrenciesActivity.VALUE_USD = this.getString(R.string.currencies_USD);

    CurrenciesActivity.EXCHANGE_RATES_UPDATED_TO =
      this.getString(R.string.currencies_notification);

    UpdateBroadcastReceiver br = new UpdateBroadcastReceiver();
    this.registerReceiver(br, new IntentFilter(UpdateService.ACTION_UPDATE));

    /* Set up currency database, and retrieve conversion rates */
    CurrenciesActivity.database = new CurrenciesDatabase(this);
    this.setConversionRates(CurrenciesActivity.database
      .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
   */
  public void fillTableRates()
  {
    TableLayout tableRates =
      (TableLayout) this.findViewById(R.id.currencies_table_rates);

    /* Remove any pre-existing currency rows */
    while (tableRates.getChildCount() > 3)
    {
      tableRates.removeViewAt(3);
    }

    for (Entry<String, ConversionData> factorEntry : CurrenciesActivity
      .getConversionRates()
      .entrySet())
    {
      TableRow row = new TableRow(this);

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

      TextView columnRate = new TextView(this);
      final ConversionData conversionData = factorEntry.getValue();
      columnRate.setText(conversionData.getRate().toString());
      row.addView(columnRate);

      TextView columnUpdated = new TextView(this);
      Date updated = conversionData.getUpdated();
      if (updated.getTime() > 0)
      {
        columnUpdated.setText(CurrenciesActivity.dateFormatter.format(updated));
      }
      else
      {
        columnUpdated.setText(this.TEXT_NEVER);
      }

      row.addView(columnUpdated);

      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;

    /*
     * NOTE: Had to do it the complicated way because somehow the Android SDK
     * won't get it another way
     */
    ConversionData conversionData1 = null;
    Double factorToEuro = 1.0;
    if (selectedItemValue1 != null)
    {
      conversionData1 =
        CurrenciesActivity.getConversionRates().get(selectedItemValue1);
      if (conversionData1 != null)
      {
        factorToEuro = conversionData1.getRate();
      }
    }

    ConversionData conversionData2 = null;
    Double factorFromEuro = 1.0;
    if (selectedItemValue2 != null)
    {
      conversionData2 =
        CurrenciesActivity.getConversionRates().get(selectedItemValue2);
      if (conversionData2 != null)
      {
        factorFromEuro = conversionData2.getRate();
      }
    }

    newValue = newValue / factorToEuro * factorFromEuro;

    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:
        /*
         * Request the update service to run a thread to fetch the rates from
         * the Web (project requirement)
         */
        Intent intent = new Intent(this, UpdateService.class);
        intent.setAction(UpdateService.ACTION_UPDATE);
        this.startService(intent);
        return true;

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

  /**
   * @return the conversionRates
   */
  public static HashMap<String, ConversionData> getConversionRates()
  {
    return CurrenciesActivity.conversionRates;
  }

  /**
   * @param conversionRates
   *          the conversionRates to set
   */
  public void setConversionRates(HashMap<String, ConversionData> conversionRates)
  {
    CurrenciesActivity.conversionRates = conversionRates;
  }

  /**
   * @return the database
   */
  public static CurrenciesDatabase getDatabase()
  {
    return CurrenciesActivity.database;
  }
}