const _ = require("lodash");
const axios = require("axios");
const crypto = require("crypto");
const dns = require("dns");

function sleep(ms) {
  return new Promise((resolve) => {
    setTimeout(resolve, ms);
  });
}

function trimchar(str, ch) {
  var start = 0,
    end = str.length;

  while (start < end && str[start] === ch) ++start;

  while (end > start && str[end - 1] === ch) --end;

  return start > 0 || end < str.length ? str.substring(start, end) : str;
}

function md5(val) {
  return crypto.createHash("md5").update(val).digest("hex");
}

function crc32(val) {
  for (var a, o = [], c = 0; c < 256; c++) {
    a = c;
    for (var f = 0; f < 8; f++) a = 1 & a ? 3988292384 ^ (a >>> 1) : a >>> 1;
    o[c] = a;
  }
  for (var n = -1, t = 0; t < val.length; t++)
    n = (n >>> 8) ^ o[255 & (n ^ val.charCodeAt(t))];
  return (-1 ^ n) >>> 0;
}

const crctab16 = new Uint16Array([
  0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 0x8c48,
  0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, 0x1081, 0x0108,
  0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, 0x9cc9, 0x8d40, 0xbfdb,
  0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, 0x2102, 0x308b, 0x0210, 0x1399,
  0x6726, 0x76af, 0x4434, 0x55bd, 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e,
  0xfae7, 0xc87c, 0xd9f5, 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e,
  0x54b5, 0x453c, 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd,
  0xc974, 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
  0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, 0x5285,
  0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, 0xdecd, 0xcf44,
  0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, 0x6306, 0x728f, 0x4014,
  0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 0xef4e, 0xfec7, 0xcc5c, 0xddd5,
  0xa96a, 0xb8e3, 0x8a78, 0x9bf1, 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3,
  0x242a, 0x16b1, 0x0738, 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862,
  0x9af9, 0x8b70, 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e,
  0xf0b7, 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
  0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 0x18c1,
  0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, 0xa50a, 0xb483,
  0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, 0x2942, 0x38cb, 0x0a50,
  0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, 0xb58b, 0xa402, 0x9699, 0x8710,
  0xf3af, 0xe226, 0xd0bd, 0xc134, 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7,
  0x6e6e, 0x5cf5, 0x4d7c, 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1,
  0xa33a, 0xb2b3, 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72,
  0x3efb, 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
  0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, 0xe70e,
  0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, 0x6b46, 0x7acf,
  0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, 0xf78f, 0xe606, 0xd49d,
  0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 0x7bc7, 0x6a4e, 0x58d5, 0x495c,
  0x3de3, 0x2c6a, 0x1ef1, 0x0f78,
]);

// calculate the 16-bit CRC of data with predetermined length.
function crc16(data) {
  var res = 0x0ffff;

  for (let b of data) {
    res = ((res >> 8) & 0x0ff) ^ crctab16[(res ^ b) & 0xff];
  }

  return ~res & 0x0ffff;
}

function lockKeysFromRequest(call, serviceMethodName) {
  switch (serviceMethodName) {
    // controller
    case "CreateVolume":
      return ["create_volume_name_" + call.request.name];
    case "DeleteVolume":
    case "ControllerExpandVolume":
      return ["volume_id_" + call.request.volume_id];
    case "CreateSnapshot":
      return [
        "create_snapshot_name_" + call.request.name,
        "volume_id_" + call.request.source_volume_id,
      ];
    case "DeleteSnapshot":
      return ["snapshot_id_" + call.request.snapshot_id];

    // node
    case "NodeStageVolume":
    case "NodeUnstageVolume":
    case "NodePublishVolume":
    case "NodeUnpublishVolume":
    case "NodeExpandVolume":
      return ["volume_id_" + call.request.volume_id];

    case "NodeGetVolumeStats":
    default:
      return [];
  }
}

function getLargestNumber() {
  let number;
  for (let i = 0; i < arguments.length; i++) {
    value = Number(arguments[i]);
    if (isNaN(value)) {
      continue;
    }
    if (isNaN(number)) {
      number = value;
      continue;
    }
    number = value > number ? value : number;
  }

  return number;
}

function stripWindowsDriveLetter(path) {
  return path.replace(/^[a-zA-Z]:/, "");
}

function hasWindowsDriveLetter(path) {
  return /^[a-zA-Z]:/i.test(path);
}

/**
 * transition function to replicate `request` style requests using axios
 *
 * @param {*} options
 * @param {*} callback
 */
function axios_request(options, callback = function () {}) {
  function prep_response(res) {
    res["statusCode"] = res["status"];
    delete res["status"];

    res["body"] = res["data"];
    delete res["data"];

    return res;
  }

  axios(options)
    .then((res) => {
      res = prep_response(res);
      callback(null, res, res.body);
    })
    .catch((err) => {
      if (err.response) {
        // The request was made and the server responded with a status code
        // that falls out of the range of 2xx
        let res = prep_response(err.response);
        let senderr = false;
        if (
          options.validateStatus &&
          typeof options.validateStatus == "function"
        ) {
          senderr = true;
        }
        callback(senderr ? err : null, res, res.body);
      } else if (err.request) {
        // The request was made but no response was received
        // `error.request` is an instance of XMLHttpRequest in the browser and an instance of
        // http.ClientRequest in node.js
        callback(err, null, null);
      } else {
        // Something happened in setting up the request that triggered an Error
        callback(err, null, null);
      }
    });
}

function stringify(value) {
  const getCircularReplacer = () => {
    const seen = new WeakSet();
    return (key, value) => {
      if (typeof value === "object" && value !== null) {
        if (seen.has(value)) {
          return;
        }
        seen.add(value);
      }
      return value;
    };
  };

  return JSON.stringify(value, getCircularReplacer());
}

function default_supported_block_filesystems() {
  return ["btrfs", "exfat", "ext3", "ext4", "ext4dev", "ntfs", "vfat", "xfs"];
}

function default_supported_file_filesystems() {
  return ["nfs", "cifs"];
}

async function retry(retries, retriesDelay, code, options = {}) {
  let current_try = 0;
  let maxwait = _.get(options, "maxwait");
  let logerrors = _.get(options, "logerrors", false);
  let retryCondition = options.retryCondition;
  let executeStartTime;

  do {
    current_try++;
    try {
      executeStartTime = Date.now();
      return await code();
    } catch (err) {
      if (current_try >= retries) {
        throw err;
      }
      if (retryCondition) {
        let retry = retryCondition(err);
        if (!retry) {
          console.log(`retry - failed condition, not trying again`);
          //console.log(code.toString(), retryCondition.toString());
          throw err;
        }
      }
      if (logerrors === true) {
        console.log(`retry - err:`, err);
      }
    }

    // handle minExecutionTime
    if (options.minExecutionTime > 0) {
      let executionElapsedTIme = Date.now() - executeStartTime;
      let minExecutionDelayTime =
        options.minExecutionTime - executionElapsedTIme;
      if (minExecutionDelayTime > 0) {
        await sleep(minExecutionDelayTime);
      }
    }

    // handle delay
    let sleep_time = retriesDelay;
    if (_.get(options, "exponential", false) === true) {
      sleep_time = retriesDelay * current_try;
    }

    if (maxwait) {
      if (sleep_time > maxwait) {
        sleep_time = maxwait;
      }
    }
    if (sleep_time > 0) {
      console.log(`retry - waiting ${sleep_time}ms before trying again`);
      await sleep(sleep_time);
    }
  } while (true);
}

async function hostname_lookup(hostname) {
  return new Promise((resolve, reject) => {
    dns.lookup(hostname, function (err, result) {
      if (err) {
        return reject(err);
      }

      return resolve(result);
    });
  });
}

module.exports.sleep = sleep;
module.exports.md5 = md5;
module.exports.crc32 = crc32;
module.exports.crc16 = crc16;
module.exports.lockKeysFromRequest = lockKeysFromRequest;
module.exports.getLargestNumber = getLargestNumber;
module.exports.stringify = stringify;
module.exports.stripWindowsDriveLetter = stripWindowsDriveLetter;
module.exports.hasWindowsDriveLetter = hasWindowsDriveLetter;
module.exports.axios_request = axios_request;
module.exports.default_supported_block_filesystems =
  default_supported_block_filesystems;
module.exports.default_supported_file_filesystems =
  default_supported_file_filesystems;
module.exports.retry = retry;
module.exports.trimchar = trimchar;
module.exports.hostname_lookup = hostname_lookup;