<?php
// vim:filetype=php expandtab tabstop=2 softtabstop=2 shiftwidth=2 autoindent smartindent
// $Id$

function tribune_meteo_info() {
  return t('Gives weather information.');
}

function tribune_meteo_filter(&$post) {
  $answer = array(
    'info' => variable_get('tribune_meteo_name', "Meteo"),
  );

  if (variable_get('tribune_meteo_authentified', FALSE)) {
    $answer['login'] = $answer['info'];
  }

  if (preg_match(':^/'. t('weather') .' (.+)$:', $post['message'], $matches)) {
    $city = $matches[1];
    $answer['message'] = _tribune_meteo_get_weather_info($city);
    $answer['message'] = tribune_filters_print_clock($post) ." ". $answer['message'];
    return array($answer);
  }
  elseif (preg_match(':^/'. t('forecast') .'? (.+)$:', $post['message'], $matches)) {
    $city = $matches[1];
    $answer['message'] = _tribune_meteo_get_weather_forecast($city);
    $answer['message'] = tribune_filters_print_clock($post) ." ". $answer['message'];
    return array($answer);
  }
}

function tribune_meteo_help() {
  $user = array_shift(user_load_self(array()));
  $help = 'Type "/weather <em>city</em>" for weather information, "/forecast <em>city</em>" for a forecast.';
  return $help;
}

function _tribune_meteo_get_weather_info($city) {
  if (preg_match("/[A-Z]{4}[0-9]{4}/", $city)) {
    return _tribune_meteo_get_yahoo_weather_info(strtoupper($city));
  }
  else {
    return _tribune_meteo_get_google_weather_info($city);
  }
}

function _tribune_meteo_get_weather_forecast($city) {
  if (preg_match("/[A-Z]{4}[0-9]{4}/", $city)) {
    return _tribune_meteo_get_yahoo_weather_forecast(strtoupper($city));
  }
  else {
    return _tribune_meteo_get_google_weather_forecast($city);
  }
}

function _tribune_meteo_get_google_feed($city) {
  $lang = $language['language'];
  $units = variable_get('tribune_meteo_imperial', FALSE) ? 'US' : 'SI';
  $url = "http://www.google.co.uk/ig/api?hl=". $lang ."&weather=". urlencode($city);

  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
  $result = curl_exec($ch);
  try {
    $xml = new SimpleXMLElement(utf8_encode($result), LIBXML_NOERROR | LIBXML_NOWARNING);

    if ($xml->xpath("/xml_api_reply/weather/problem_cause")) {
      return array('error' => t("Unable to find weather data for <i>@city</i>", array('@city' => $city)));
    }

    return array('error' => FALSE, 'xml' => $xml, 'lang' => $lang, 'units' => $units);
  }
  catch (Exception $e) {
    return array('error' => $e->getMessage());
  }
}

function _tribune_meteo_get_google_weather_info($city) {
  $result = _tribune_meteo_get_google_feed($city);

  if ($result['error']) {
    $info = $result['error'];
  }
  else {
    $xml = $result['xml'];
    $to_units = strtolower($result['units']);
    $node = $xml->xpath("/xml_api_reply/weather/forecast_information/unit_system");
    $unit_system = $node[0]['data'];
    switch ($to_units) {
      case "us":
        $temp_unit = "F";
        $speed_unit = "mph";
        break;
      default:
        $to_units = "si";
      case "si":
        $temp_unit = "C";
        $speed_unit = "km/h";
        break;
    }

    $node = $xml->xpath("/xml_api_reply/weather/forecast_information/city");
    $city = $node[0]['data'];

    $node = $xml->xpath("/xml_api_reply/weather/current_conditions/wind_condition");
    $wind = $node[0]['data'];

    if ($to_units == "us") {
      $node = $xml->xpath("/xml_api_reply/weather/current_conditions/temp_f");
    }
    else {
      $node = $xml->xpath("/xml_api_reply/weather/current_conditions/temp_c");
    }
    $temp = $node[0]['data'];

    $node = $xml->xpath("/xml_api_reply/weather/current_conditions/condition");
    $desc = $node[0]['data'];

    $node = $xml->xpath("/xml_api_reply/weather/current_conditions/humidity");
    $humidity = preg_replace('/^[^0-9]*([0-9]*)%[^0-9]*$/', '$1', $node[0]['data']);


    $info = t("Weather in <b>@city</b>: @desc, @temp °@temp_unit, humidity: @humidity%",
      array('@city' => $city,
            '@desc' => $desc,
            '@temp' => $temp,
            '@temp_unit' => $temp_unit,
            '@humidity' => $humidity));
  }

  return $info;
}

function _tribune_meteo_get_google_weather_forecast($city) {
  $result = _tribune_meteo_get_google_feed($city);

  if ($result['error']) {
    return $result['error'];
  }
  else {
    $xml = $result['xml'];
    $to_units = strtolower($result['units']);
    $node = $xml->xpath("/xml_api_reply/weather/forecast_information/unit_system");
    $unit_system = strtolower($node[0]['data']);
    switch ($to_units) {
      case "us":
        $temp_unit = "F";
        $speed_unit = "mph";
        break;
      default:
        $to_units = "si";
      case "si":
        $temp_unit = "C";
        $speed_unit = "km/h";
        break;
    }

    $node = $xml->xpath("/xml_api_reply/weather/forecast_information/city");
    $city = $node[0]['data'];

    $conditions = array();
    $node = $xml->xpath("/xml_api_reply/weather/forecast_conditions");
    foreach ($node as $forecast) {
      $date = "";
      $high = "?";
      $low  = "?";
      $desc = "?";
      foreach ($forecast->children() as $child) {
        $value = $child['data'];
        switch ($child->getName()) {
          case 'high':
            $high = tribune_meteo_temp($value, $unit_system, $to_units);
            break;
          case 'low':
            $low = tribune_meteo_temp($value, $unit_system, $to_units);
            break;
          case 'day_of_week':
            $date = $value;
            break;
          case 'condition':
            $desc = $value;
            break;
        }
      }

      if ($date) {
        $conditions[] = array(
          'date' => $date,
          'high' => $high,
          'low'  => $low,
          'desc' => $desc,
        );
      }
    }
    $args = array();
    $info = "Forecast for <b>@city</b> ― ";
    $args['@city'] = $city;
    $args['@temp_unit'] = $temp_unit;

    foreach ($conditions as $id => $cond) {
      $info .= "@date". $id .": @low". $id ."»@high". $id ." °@temp_unit (@cond". $id ."), ";
      $args["@date". $id] = $cond['date'];
      $args["@low".  $id] = $cond['low'];
      $args["@high". $id] = $cond['high'];
      $args["@cond". $id] = $cond['desc'];
    }

    return t(substr($info, 0, -2), $args);
  }
}

function _tribune_meteo_get_yahoo_weather_info($city) {
  $info = "";

  $url = "http://weather.yahooapis.com/forecastrss?u=c&p=". $city;

  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
  $result = curl_exec($ch);
  $xml = new SimpleXMLElement($result);

  $speed_unit = "";
  $temp_unit = "";
  $node = $xml->xpath("/rss/channel/yweather:units");
  foreach ($node[0]->attributes() as $attr => $value) {
    switch ($attr) {
      case 'temperature':
        $temp_unit = $value;
        break;
      case 'speed':
        $speed_unit = $value;
        break;
    }
  }

  $city = "?";
  $node = $xml->xpath("/rss/channel/yweather:location");
  foreach ($node[0]->attributes() as $attr => $value) {
    switch ($attr) {
      case 'city':
        $city = $value;
        break;
    }
  }

  $wind = "?";
  $node = $xml->xpath("/rss/channel/yweather:wind");
  foreach ($node[0]->attributes() as $attr => $value) {
    switch ($attr) {
      case 'speed':
        $wind = $value;
        break;
    }
  }

  $temp = "?";
  $desc = "?";
  $node = $xml->xpath("/rss/channel/item/yweather:condition");
  foreach ($node[0]->attributes() as $attr => $value) {
    switch ($attr) {
      case 'temp':
        $temp = $value;
        break;
      case 'text':
        $desc = $value;
        break;
    }
  }

  $info = t("Weather in <b>@city</b>: @desc, @temp °@temp_unit",
    array('@city' => $city,
          '@desc' => $desc,
          '@temp' => $temp,
          '@temp_unit' => $temp_unit));

  return $info;
}

function _tribune_meteo_get_yahoo_weather_forecast($city) {
  $info = "";

  $url = "http://weather.yahooapis.com/forecastrss?u=c&p=". urlencode($city);

  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
  $result = curl_exec($ch);
  $xml = new SimpleXMLElement($result);

  $speed_unit = "";
  $temp_unit = "";
  $node = $xml->xpath("/rss/channel/yweather:units");
  foreach ($node[0]->attributes() as $attr => $value) {
    switch ($attr) {
      case 'temperature':
        $temp_unit = $value;
        break;
      case 'speed':
        $speed_unit = $value;
        break;
    }
  }

  $city = "?";
  $node = $xml->xpath("/rss/channel/yweather:location");
  foreach ($node[0]->attributes() as $attr => $value) {
    switch ($attr) {
      case 'city':
        $city = $value;
        break;
    }
  }

  $conditions = array();
  $node = $xml->xpath("/rss/channel/item/yweather:forecast");
  foreach ($node as $forecast) {
    $date = "";
    $high = "?";
    $low  = "?";
    $desc = "?";
    foreach ($forecast->attributes() as $attr => $value) {
      switch ($attr) {
        case 'high':
          $high = $value;
          break;
        case 'low':
          $low = $value;
          break;
        case 'date':
          $date = $value;
          break;
        case 'text':
          $desc = $value;
          break;
      }
    }

    if ($date) {
      $timestamp = strtotime($date);
      $conditions[$timestamp] = array(
        'date' => date('d/m/Y', $timestamp),
        'high' => $high,
        'low'  => $low,
        'desc' => $desc,
      );
    }
  }

  $args = array();
  $info = "Forecast for <b>@city</b> ― ";
  $args['@city'] = $city;
  $args['@temp_unit'] = $temp_unit;

  foreach ($conditions as $timestamp => $cond) {
    $info .= "@date$timestamp: @low${timestamp}»@high$timestamp °@temp_unit, ";
    $args["@date". $timestamp] = $cond['date'];
    $args["@low".  $timestamp] = $cond['low'];
    $args["@high". $timestamp] = $cond['high'];
  }

  return t(substr($info, 0, -2), $args);
}

function tribune_meteo_f2c($fahrenheit) {
  return round(($fahrenheit-32)*(5/9));
}

function tribune_meteo_c2f($celsius) {
  return round($celsius*(5/9)+32);
}

function tribune_meteo_temp($value, $from, $to) {
  $from = strtolower($from);
  $to   = strtolower($to);

  if ($from != $to) {
    switch ($to) {
      case 'si':
        return tribune_meteo_f2c($value);
      case 'us':
        return tribune_meteo_c2f($value);
      default:
        return $value;
    }
  }
  else {
    return $value;
  }
}

function tribune_meteo_settings() {
  $form = array();

  $form['tribune_meteo_name'] = array(
    '#type'           => "textfield",
    '#title'          => t("Display name"),
    '#default_value'  => variable_get('tribune_meteo_name', "Meteo"),
  );

  $form['tribune_meteo_authentified'] = array(
    '#type'           => "checkbox",
    '#title'          => t("Appear to be authentified"),
    '#default_value'  => variable_get('tribune_meteo_authentified', FALSE),
    '#description'    => t("Whether this filter will appear to be 'anonymous' or 'authentified'. Since the filter does not correspond to a real user, posting as authentified may result in 'nickname collisions'."),
  );

  $form['tribune_meteo_imperial'] = array(
    '#type'           => "checkbox",
    '#title'          => t("Use imperial system"),
    '#default_value'  => variable_get('tribune_meteo_imperial', FALSE),
    '#description'    => t("If this is enabled, the imperial system will be used, otherwise SI units will be shown."),
  );

  return system_settings_form($form);
}