/* Pretty handling of time axes.

Copyright (c) 2007-2014 IOLA and Ole Laursen.
Licensed under the MIT license.

Set axis.mode to "time" to enable. See the section "Time series data" in
API.txt for details.

*/

(function ($) {
  var options = {
    xaxis: {
      timezone: null, // "browser" for local to the client or timezone for timezone-js
      timeformat: null, // format string to use
      twelveHourClock: false, // 12 or 24 time in time mode
      monthNames: null, // list of names of months
    },
  };

  // round to nearby lower multiple of base

  function floorInBase(n, base) {
    return base * Math.floor(n / base);
  }

  // Returns a string with the date d formatted according to fmt.
  // A subset of the Open Group's strftime format is supported.

  function formatDate(d, fmt, monthNames, dayNames) {
    if (typeof d.strftime == "function") {
      return d.strftime(fmt);
    }

    var leftPad = function (n, pad) {
      n = "" + n;
      pad = "" + (pad == null ? "0" : pad);
      return n.length == 1 ? pad + n : n;
    };

    var r = [];
    var escape = false;
    var hours = d.getHours();
    var isAM = hours < 12;

    if (monthNames == null) {
      monthNames = [
        "Jan",
        "Feb",
        "Mar",
        "Apr",
        "May",
        "Jun",
        "Jul",
        "Aug",
        "Sep",
        "Oct",
        "Nov",
        "Dec",
      ];
    }

    if (dayNames == null) {
      dayNames = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
    }

    var hours12;

    if (hours > 12) {
      hours12 = hours - 12;
    } else if (hours == 0) {
      hours12 = 12;
    } else {
      hours12 = hours;
    }

    for (var i = 0; i < fmt.length; ++i) {
      var c = fmt.charAt(i);

      if (escape) {
        switch (c) {
          case "a":
            c = "" + dayNames[d.getDay()];
            break;
          case "b":
            c = "" + monthNames[d.getMonth()];
            break;
          case "d":
            c = leftPad(d.getDate());
            break;
          case "e":
            c = leftPad(d.getDate(), " ");
            break;
          case "h": // For back-compat with 0.7; remove in 1.0
          case "H":
            c = leftPad(hours);
            break;
          case "I":
            c = leftPad(hours12);
            break;
          case "l":
            c = leftPad(hours12, " ");
            break;
          case "m":
            c = leftPad(d.getMonth() + 1);
            break;
          case "M":
            c = leftPad(d.getMinutes());
            break;
          // quarters not in Open Group's strftime specification
          case "q":
            c = "" + (Math.floor(d.getMonth() / 3) + 1);
            break;
          case "S":
            c = leftPad(d.getSeconds());
            break;
          case "y":
            c = leftPad(d.getFullYear() % 100);
            break;
          case "Y":
            c = "" + d.getFullYear();
            break;
          case "p":
            c = isAM ? "" + "am" : "" + "pm";
            break;
          case "P":
            c = isAM ? "" + "AM" : "" + "PM";
            break;
          case "w":
            c = "" + d.getDay();
            break;
        }
        r.push(c);
        escape = false;
      } else {
        if (c == "%") {
          escape = true;
        } else {
          r.push(c);
        }
      }
    }

    return r.join("");
  }

  // To have a consistent view of time-based data independent of which time
  // zone the client happens to be in we need a date-like object independent
  // of time zones.  This is done through a wrapper that only calls the UTC
  // versions of the accessor methods.

  function makeUtcWrapper(d) {
    function addProxyMethod(sourceObj, sourceMethod, targetObj, targetMethod) {
      sourceObj[sourceMethod] = function () {
        return targetObj[targetMethod].apply(targetObj, arguments);
      };
    }

    var utc = {
      date: d,
    };

    // support strftime, if found

    if (d.strftime != undefined) {
      addProxyMethod(utc, "strftime", d, "strftime");
    }

    addProxyMethod(utc, "getTime", d, "getTime");
    addProxyMethod(utc, "setTime", d, "setTime");

    var props = [
      "Date",
      "Day",
      "FullYear",
      "Hours",
      "Milliseconds",
      "Minutes",
      "Month",
      "Seconds",
    ];

    for (var p = 0; p < props.length; p++) {
      addProxyMethod(utc, "get" + props[p], d, "getUTC" + props[p]);
      addProxyMethod(utc, "set" + props[p], d, "setUTC" + props[p]);
    }

    return utc;
  }

  // select time zone strategy.  This returns a date-like object tied to the
  // desired timezone

  function dateGenerator(ts, opts) {
    if (opts.timezone == "browser") {
      return new Date(ts);
    } else if (!opts.timezone || opts.timezone == "utc") {
      return makeUtcWrapper(new Date(ts));
    } else if (
      typeof timezoneJS != "undefined" &&
      typeof timezoneJS.Date != "undefined"
    ) {
      var d = new timezoneJS.Date();
      // timezone-js is fickle, so be sure to set the time zone before
      // setting the time.
      d.setTimezone(opts.timezone);
      d.setTime(ts);
      return d;
    } else {
      return makeUtcWrapper(new Date(ts));
    }
  }

  // map of app. size of time units in milliseconds

  var timeUnitSize = {
    second: 1000,
    minute: 60 * 1000,
    hour: 60 * 60 * 1000,
    day: 24 * 60 * 60 * 1000,
    month: 30 * 24 * 60 * 60 * 1000,
    quarter: 3 * 30 * 24 * 60 * 60 * 1000,
    year: 365.2425 * 24 * 60 * 60 * 1000,
  };

  // the allowed tick sizes, after 1 year we use
  // an integer algorithm

  var baseSpec = [
    [1, "second"],
    [2, "second"],
    [5, "second"],
    [10, "second"],
    [30, "second"],
    [1, "minute"],
    [2, "minute"],
    [5, "minute"],
    [10, "minute"],
    [30, "minute"],
    [1, "hour"],
    [2, "hour"],
    [4, "hour"],
    [8, "hour"],
    [12, "hour"],
    [1, "day"],
    [2, "day"],
    [3, "day"],
    [0.25, "month"],
    [0.5, "month"],
    [1, "month"],
    [2, "month"],
  ];

  // we don't know which variant(s) we'll need yet, but generating both is
  // cheap

  var specMonths = baseSpec.concat([
    [3, "month"],
    [6, "month"],
    [1, "year"],
  ]);
  var specQuarters = baseSpec.concat([
    [1, "quarter"],
    [2, "quarter"],
    [1, "year"],
  ]);

  function init(plot) {
    plot.hooks.processOptions.push(function (plot, options) {
      $.each(plot.getAxes(), function (axisName, axis) {
        var opts = axis.options;

        if (opts.mode == "time") {
          axis.tickGenerator = function (axis) {
            var ticks = [];
            var d = dateGenerator(axis.min, opts);
            var minSize = 0;

            // make quarter use a possibility if quarters are
            // mentioned in either of these options

            var spec =
              (opts.tickSize && opts.tickSize[1] === "quarter") ||
              (opts.minTickSize && opts.minTickSize[1] === "quarter")
                ? specQuarters
                : specMonths;

            if (opts.minTickSize != null) {
              if (typeof opts.tickSize == "number") {
                minSize = opts.tickSize;
              } else {
                minSize =
                  opts.minTickSize[0] * timeUnitSize[opts.minTickSize[1]];
              }
            }

            for (var i = 0; i < spec.length - 1; ++i) {
              if (
                axis.delta <
                  (spec[i][0] * timeUnitSize[spec[i][1]] +
                    spec[i + 1][0] * timeUnitSize[spec[i + 1][1]]) /
                    2 &&
                spec[i][0] * timeUnitSize[spec[i][1]] >= minSize
              ) {
                break;
              }
            }

            var size = spec[i][0];
            var unit = spec[i][1];

            // special-case the possibility of several years

            if (unit == "year") {
              // if given a minTickSize in years, just use it,
              // ensuring that it's an integer

              if (opts.minTickSize != null && opts.minTickSize[1] == "year") {
                size = Math.floor(opts.minTickSize[0]);
              } else {
                var magn = Math.pow(
                  10,
                  Math.floor(
                    Math.log(axis.delta / timeUnitSize.year) / Math.LN10
                  )
                );
                var norm = axis.delta / timeUnitSize.year / magn;

                if (norm < 1.5) {
                  size = 1;
                } else if (norm < 3) {
                  size = 2;
                } else if (norm < 7.5) {
                  size = 5;
                } else {
                  size = 10;
                }

                size *= magn;
              }

              // minimum size for years is 1

              if (size < 1) {
                size = 1;
              }
            }

            axis.tickSize = opts.tickSize || [size, unit];
            var tickSize = axis.tickSize[0];
            unit = axis.tickSize[1];

            var step = tickSize * timeUnitSize[unit];

            if (unit == "second") {
              d.setSeconds(floorInBase(d.getSeconds(), tickSize));
            } else if (unit == "minute") {
              d.setMinutes(floorInBase(d.getMinutes(), tickSize));
            } else if (unit == "hour") {
              d.setHours(floorInBase(d.getHours(), tickSize));
            } else if (unit == "month") {
              d.setMonth(floorInBase(d.getMonth(), tickSize));
            } else if (unit == "quarter") {
              d.setMonth(3 * floorInBase(d.getMonth() / 3, tickSize));
            } else if (unit == "year") {
              d.setFullYear(floorInBase(d.getFullYear(), tickSize));
            }

            // reset smaller components

            d.setMilliseconds(0);

            if (step >= timeUnitSize.minute) {
              d.setSeconds(0);
            }
            if (step >= timeUnitSize.hour) {
              d.setMinutes(0);
            }
            if (step >= timeUnitSize.day) {
              d.setHours(0);
            }
            if (step >= timeUnitSize.day * 4) {
              d.setDate(1);
            }
            if (step >= timeUnitSize.month * 2) {
              d.setMonth(floorInBase(d.getMonth(), 3));
            }
            if (step >= timeUnitSize.quarter * 2) {
              d.setMonth(floorInBase(d.getMonth(), 6));
            }
            if (step >= timeUnitSize.year) {
              d.setMonth(0);
            }

            var carry = 0;
            var v = Number.NaN;
            var prev;

            do {
              prev = v;
              v = d.getTime();
              ticks.push(v);

              if (unit == "month" || unit == "quarter") {
                if (tickSize < 1) {
                  // a bit complicated - we'll divide the
                  // month/quarter up but we need to take
                  // care of fractions so we don't end up in
                  // the middle of a day

                  d.setDate(1);
                  var start = d.getTime();
                  d.setMonth(d.getMonth() + (unit == "quarter" ? 3 : 1));
                  var end = d.getTime();
                  d.setTime(
                    v + carry * timeUnitSize.hour + (end - start) * tickSize
                  );
                  carry = d.getHours();
                  d.setHours(0);
                } else {
                  d.setMonth(
                    d.getMonth() + tickSize * (unit == "quarter" ? 3 : 1)
                  );
                }
              } else if (unit == "year") {
                d.setFullYear(d.getFullYear() + tickSize);
              } else {
                d.setTime(v + step);
              }
            } while (v < axis.max && v != prev);

            return ticks;
          };

          axis.tickFormatter = function (v, axis) {
            var d = dateGenerator(v, axis.options);

            // first check global format

            if (opts.timeformat != null) {
              return formatDate(
                d,
                opts.timeformat,
                opts.monthNames,
                opts.dayNames
              );
            }

            // possibly use quarters if quarters are mentioned in
            // any of these places

            var useQuarters =
              (axis.options.tickSize &&
                axis.options.tickSize[1] == "quarter") ||
              (axis.options.minTickSize &&
                axis.options.minTickSize[1] == "quarter");

            var t = axis.tickSize[0] * timeUnitSize[axis.tickSize[1]];
            var span = axis.max - axis.min;
            var suffix = opts.twelveHourClock ? " %p" : "";
            var hourCode = opts.twelveHourClock ? "%I" : "%H";
            var fmt;

            if (t < timeUnitSize.minute) {
              fmt = hourCode + ":%M:%S" + suffix;
            } else if (t < timeUnitSize.day) {
              if (span < 2 * timeUnitSize.day) {
                fmt = hourCode + ":%M" + suffix;
              } else {
                fmt = "%b %d " + hourCode + ":%M" + suffix;
              }
            } else if (t < timeUnitSize.month) {
              fmt = "%b %d";
            } else if (
              (useQuarters && t < timeUnitSize.quarter) ||
              (!useQuarters && t < timeUnitSize.year)
            ) {
              if (span < timeUnitSize.year) {
                fmt = "%b";
              } else {
                fmt = "%b %Y";
              }
            } else if (useQuarters && t < timeUnitSize.year) {
              if (span < timeUnitSize.year) {
                fmt = "Q%q";
              } else {
                fmt = "Q%q %Y";
              }
            } else {
              fmt = "%Y";
            }

            var rt = formatDate(d, fmt, opts.monthNames, opts.dayNames);

            return rt;
          };
        }
      });
    });
  }

  $.plot.plugins.push({
    init: init,
    options: options,
    name: "time",
    version: "1.0",
  });

  // Time-axis support used to be in Flot core, which exposed the
  // formatDate function on the plot object.  Various plugins depend
  // on the function, so we need to re-expose it here.

  $.plot.formatDate = formatDate;
  $.plot.dateGenerator = dateGenerator;
})(jQuery);