const bunyan = require("bunyan");
const request = require("request");

Logger = module.exports = {
  initialize(name) {
    this.isProduction =
      (process.env["NODE_ENV"] || "").toLowerCase() === "production";
    this.defaultLevel =
      process.env["LOG_LEVEL"] || (this.isProduction ? "warn" : "debug");
    this.loggerName = name;
    this.ringBuffer = new bunyan.RingBuffer({
      limit: process.env["LOG_RING_BUFFER_SIZE"] || 30
    });
    this.logger = bunyan.createLogger({
      name,
      serializers: bunyan.stdSerializers,
      streams: [
        {
          level: this.defaultLevel,
          stream: process.stdout
        },
        {
          level: "trace",
          type: "raw",
          stream: this.ringBuffer
        }
      ]
    });
    if (this.isProduction) {
      // clear interval if already set
      if (this.checkInterval) {
        clearInterval(this.checkInterval);
      }
      // check for log level override on startup
      this.checkLogLevel();
      // re-check log level every minute
      const checkLogLevel = () => this.checkLogLevel();
      this.checkInterval = setInterval(checkLogLevel, 1000 * 60);
    }
    return this;
  },

  checkLogLevel() {
    const options = {
      headers: {
        "Metadata-Flavor": "Google"
      },
      uri: `http://metadata.google.internal/computeMetadata/v1/project/attributes/${
        this.loggerName
      }-setLogLevelEndTime`
    };
    request(options, (err, response, body) => {
      if (parseInt(body) > Date.now()) {
        this.logger.level("trace");
      } else {
        this.logger.level(this.defaultLevel);
      }
    });
  },

  initializeErrorReporting(sentry_dsn, options) {
    const raven = require("raven");
    this.raven = new raven.Client(sentry_dsn, options);
    this.lastErrorTimeStamp = 0; // for rate limiting on sentry reporting
    this.lastErrorCount = 0;
  },

  captureException(attributes, message, level) {
    // handle case of logger.error "message"
    let key, value;
    if (typeof attributes === "string") {
      attributes = { err: new Error(attributes) };
    }
    // extract any error object
    let error = attributes.err || attributes.error;
    // avoid reporting errors twice
    for (key in attributes) {
      value = attributes[key];
      if (value instanceof Error && value.reportedToSentry) {
        return;
      }
    }
    // include our log message in the error report
    if (error == null) {
      if (typeof message === "string") {
        error = { message };
      }
    } else if (message != null) {
      attributes.description = message;
    }
    // report the error
    if (error != null) {
      // capture attributes and use *_id objects as tags
      const tags = {};
      const extra = {};
      for (key in attributes) {
        value = attributes[key];
        if (key.match(/_id/) && typeof value === "string") {
          tags[key] = value;
        }
        extra[key] = value;
      }
      // capture req object if available
      const { req } = attributes;
      if (req != null) {
        extra.req = {
          method: req.method,
          url: req.originalUrl,
          query: req.query,
          headers: req.headers,
          ip: req.ip
        };
      }
      // recreate error objects that have been converted to a normal object
      if (!(error instanceof Error) && typeof error === "object") {
        const newError = new Error(error.message);
        for (key of Object.keys(error || {})) {
          value = error[key];
          newError[key] = value;
        }
        error = newError;
      }
      // filter paths from the message to avoid duplicate errors in sentry
      // (e.g. errors from `fs` methods which have a path attribute)
      try {
        if (error.path) {
          error.message = error.message.replace(` '${error.path}'`, "");
        }
      } catch (error1) {}
      // send the error to sentry
      try {
        this.raven.captureException(error, { tags, extra, level });
        // put a flag on the errors to avoid reporting them multiple times
        return (() => {
          const result = [];
          for (key in attributes) {
            value = attributes[key];
            if (value instanceof Error) {
              result.push((value.reportedToSentry = true));
            } else {
              result.push(undefined);
            }
          }
          return result;
        })();
      } catch (error2) {
        return;
      }
    }
  },

  debug() {
    return this.logger.debug.apply(this.logger, arguments);
  },

  info() {
    return this.logger.info.apply(this.logger, arguments);
  },

  log() {
    return this.logger.info.apply(this.logger, arguments);
  },

  error(attributes, message, ...args) {
    if (this.isProduction) {
      attributes.logBuffer = this.ringBuffer.records;
    }
    this.logger.error(attributes, message, ...Array.from(args));
    if (this.raven != null) {
      const MAX_ERRORS = 5; // maximum number of errors in 1 minute
      const now = new Date();
      // have we recently reported an error?
      const recentSentryReport = now - this.lastErrorTimeStamp < 60 * 1000;
      // if so, increment the error count
      if (recentSentryReport) {
        this.lastErrorCount++;
      } else {
        this.lastErrorCount = 0;
        this.lastErrorTimeStamp = now;
      }
      // only report 5 errors every minute to avoid overload
      if (this.lastErrorCount < MAX_ERRORS) {
        // add a note if the rate limit has been hit
        const note =
          this.lastErrorCount + 1 === MAX_ERRORS ? "(rate limited)" : "";
        // report the exception
        return this.captureException(attributes, message, `error${note}`);
      }
    }
  },

  err() {
    return this.error.apply(this, arguments);
  },

  warn() {
    return this.logger.warn.apply(this.logger, arguments);
  },

  fatal(attributes, message, callback) {
    if (callback == null) {
      callback = function() {};
    }
    this.logger.fatal(attributes, message);
    if (this.raven != null) {
      var cb = function(e) {
        // call the callback once after 'logged' or 'error' event
        callback();
        return (cb = function() {});
      };
      this.captureException(attributes, message, "fatal");
      this.raven.once("logged", cb);
      return this.raven.once("error", cb);
    } else {
      return callback();
    }
  }
};

Logger.initialize("default-sharelatex");