import _ from 'lodash';
import moment from 'moment';

/**
 * Expand Zabbix item name
 *
 * @param  {string} name item name, ie "CPU $2 time"
 * @param  {string} key  item key, ie system.cpu.util[,system,avg1]
 * @return {string}      expanded name, ie "CPU system time"
 */
export function expandItemName(name, key) {

  // extract params from key:
  // "system.cpu.util[,system,avg1]" --> ["", "system", "avg1"]
  let key_params_str = key.substring(key.indexOf('[') + 1, key.lastIndexOf(']'));
  let key_params = splitKeyParams(key_params_str);

  // replace item parameters
  for (let i = key_params.length; i >= 1; i--) {
    name = name.replace('$' + i, key_params[i - 1]);
  }
  return name;
}

export function expandItems(items) {
  _.forEach(items, item => {
    item.item = item.name;
    item.name = expandItemName(item.item, item.key_);
    return item;
  });
  return items;
}

function splitKeyParams(paramStr) {
  let params = [];
  let quoted = false;
  let in_array = false;
  let split_symbol = ',';
  let param = '';

  _.forEach(paramStr, symbol => {
    if (symbol === '"' && in_array) {
      param += symbol;
    } else if (symbol === '"' && quoted) {
      quoted = false;
    } else if (symbol === '"' && !quoted) {
      quoted = true;
    } else if (symbol === '[' && !quoted) {
      in_array  = true;
    } else if (symbol === ']' && !quoted) {
      in_array = false;
    } else if (symbol === split_symbol && !quoted && !in_array) {
      params.push(param);
      param = '';
    } else {
      param += symbol;
    }
  });

  params.push(param);
  return params;
}

const MACRO_PATTERN = /{\$[A-Z0-9_\.]+}/g;

export function containsMacro(itemName) {
  return MACRO_PATTERN.test(itemName);
}

export function replaceMacro(item, macros) {
  let itemName = item.name;
  let item_macros = itemName.match(MACRO_PATTERN);
  _.forEach(item_macros, macro => {
    let host_macros = _.filter(macros, m => {
      if (m.hostid) {
        return m.hostid === item.hostid;
      } else {
        // Add global macros
        return true;
      }
    });

    let macro_def = _.find(host_macros, { macro: macro });
    if (macro_def && macro_def.value) {
      let macro_value = macro_def.value;
      let macro_regex = new RegExp(escapeMacro(macro));
      itemName = itemName.replace(macro_regex, macro_value);
    }
  });

  return itemName;
}

function escapeMacro(macro) {
  macro = macro.replace(/\$/, '\\\$');
  return macro;
}

/**
 * Split template query to parts of zabbix entities
 * group.host.app.item -> [group, host, app, item]
 * {group}{host.com} -> [group, host.com]
 */
export function splitTemplateQuery(query) {
  let splitPattern = /\{[^\{\}]*\}|\{\/.*\/\}/g;
  let split;

  if (isContainsBraces(query)) {
    let result = query.match(splitPattern);
    split = _.map(result, part => {
      return _.trim(part, '{}');
    });
  } else {
    split = query.split('.');
  }

  return split;
}

function isContainsBraces(query) {
  let bracesPattern = /^\{.+\}$/;
  return bracesPattern.test(query);
}

// Pattern for testing regex
export const regexPattern = /^\/(.*)\/([gmi]*)$/m;

export function isRegex(str) {
  return regexPattern.test(str);
}

export function isTemplateVariable(str, templateVariables) {
  var variablePattern = /^\$\w+/;
  if (variablePattern.test(str)) {
    var variables = _.map(templateVariables, variable => {
      return '$' + variable.name;
    });
    return _.includes(variables, str);
  } else {
    return false;
  }
}

export function buildRegex(str) {
  var matches = str.match(regexPattern);
  var pattern = matches[1];
  var flags = matches[2] !== "" ? matches[2] : undefined;
  return new RegExp(pattern, flags);
}

// Need for template variables replace
// From Grafana's templateSrv.js
export function escapeRegex(value) {
  return value.replace(/[\\^$*+?.()|[\]{}\/]/g, '\\$&');
}

export function parseInterval(interval) {
  var intervalPattern = /(^[\d]+)(y|M|w|d|h|m|s)/g;
  var momentInterval = intervalPattern.exec(interval);
  return moment.duration(Number(momentInterval[1]), momentInterval[2]).valueOf();
}

export function parseTimeShiftInterval(interval) {
  let intervalPattern = /^([\+\-]*)([\d]+)(y|M|w|d|h|m|s)/g;
  let momentInterval = intervalPattern.exec(interval);
  let duration = 0;

  if (momentInterval[1] === '+') {
    duration = 0 - moment.duration(Number(momentInterval[2]), momentInterval[3]).valueOf();
  } else {
    duration = moment.duration(Number(momentInterval[2]), momentInterval[3]).valueOf();
  }

  return duration;
}

/**
 * Format acknowledges.
 *
 * @param  {array} acknowledges array of Zabbix acknowledge objects
 * @return {string} HTML-formatted table
 */
export function formatAcknowledges(acknowledges) {
  if (acknowledges.length) {
    var formatted_acknowledges = '<br><br>Acknowledges:<br><table><tr><td><b>Time</b></td>'
      + '<td><b>User</b></td><td><b>Comments</b></td></tr>';
    _.each(_.map(acknowledges, function (ack) {
      var timestamp = moment.unix(ack.clock);
      return '<tr><td><i>' + timestamp.format("DD MMM YYYY HH:mm:ss") + '</i></td><td>' + ack.alias
        + ' (' + ack.name + ' ' + ack.surname + ')' + '</td><td>' + ack.message + '</td></tr>';
    }), function (ack) {
      formatted_acknowledges = formatted_acknowledges.concat(ack);
    });
    formatted_acknowledges = formatted_acknowledges.concat('</table>');
    return formatted_acknowledges;
  } else {
    return '';
  }
}

export function convertToZabbixAPIUrl(url) {
  var zabbixAPIUrlPattern = /.*api_jsonrpc.php$/;
  var trimSlashPattern = /(.*?)[\/]*$/;
  if (url.match(zabbixAPIUrlPattern)) {
    return url;
  } else {
    return url.replace(trimSlashPattern, "$1");
  }
}

/**
 * Wrap function to prevent multiple calls
 * when waiting for result.
 */
export function callOnce(func, promiseKeeper) {
  return function() {
    if (!promiseKeeper) {
      promiseKeeper = Promise.resolve(
        func.apply(this, arguments)
        .then(result => {
          promiseKeeper = null;
          return result;
        })
      );
    }
    return promiseKeeper;
  };
}

// Fix for backward compatibility with lodash 2.4
if (!_.includes) {
  _.includes = _.contains;
}