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Gaia    = require("upon").Home
which   = require("which")
_       = require("massagist")._
Massage = require("massagist").Massage
points  = require("./points")
phase   = require("./phase")

class Ephemeris

The defaults-overriding options will become part of the help command, the man-pages / docs and the gh-pages. For example the -o that overrides @settings.out can be:

  • points (phase is based on it)
  • phase (your CLI Formatting Friend)
  • points,table (raw cliff output of points)
  • json (the precious json)
  • json,codedown (markdown code block html)
  • print (python's print)
  • pprint (python's pretty-substitutes swe labels)
  • inspect (the pretty eyes thing)
  • see Massage for more options...
    "root": "#{__dirname}/../"
    "out": "json"
    "time": null
    "geo": {"lat": null, "lon": null}
    "stuff": [ [0, 1, 2, 3]
             , [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 15, 17, 18, 19, 20]
             , [5145, 7066, 20000, 28978, 38628, 50000, 90377, 90482, 136108, 136199, 136472]
    "houses": "W"

Configure ephemeris specifics, this is valid precious input.

  configure: (specifics, cb) ->
    @specifics = specifics if specifics?
    @settings = _.allFurther @defaults, @specifics

    unless @settings.data?.match /^\//

If not absolute, then relative (to eden) ephemeris data path.

      @settings.data = "#{@settings.root}#{@settings.data}"

The @settings.ut and @settings.geo - being reset.

    @gaia = new Gaia @settings["geo"], @settings["time"]
    @settings.geo = {}
    @settings.geo.lat = @gaia.lat
    @settings.geo.lon = @gaia.lon
    @settings.ut = @gaia.ut

The @ephemeris is a function that implements precious json - input & output conforming to the spec. It is optional, as we may just want to use this class for generating ephemeris input - the output results being deferred for later perhaps. It's only set once, as it isn't expected to change.

    unless @ephemeris?
      if _.isString @settings.precious
        @ephemeris = require(@settings.precious).ephemeris

This can be called in various contexts. Example: the callback can be used when the ephemeris paths are not immediately known (a global precious). It's passed via the @constructor / @preciousPaths - see the following sections...

    cb() if cb?

Because precious is not a dependency, nor is gravity, get the paths from a global precious install.

  preciousPaths: (cb) ->
    which "precious", (er, thing) =>
      if er?

TODO: handle precious not installed

        @defaults.precious = null
        apath = thing.substring 0, thing.lastIndexOf '/'
        apath += '/../lib/node_modules/precious/'
        @defaults.data = apath + 'node_modules/gravity/data/'
        @defaults.prep = apath + 'bin/'
        @defaults.precious = apath + 'index.js'

Pass a callback if you need to call @run immediately, or something...

  constructor: (specifics = {}, cb) ->
    switch specifics.precious

We don't want to call precious and don't care where may be installed. Nothing special to do here. This is how we use eden to get json input configuration for perhaps later calling precious with.

      when false then ;

Precious manually installed locally in ./node_modules. Takes one's specifics word for it, without checking. This may be how things will be done in the future - by default if precious becomes a dependency.

      when true
        apath = './node_modules/'
        @defaults.data = 'precious/node_modules/gravity/data/'
        @defaults.prep = '.bin/'
        @defaults.precious = 'precious/index.js'
        specifics.precious = undefined # so that the default takes

Undefined may become null. Unknown what the paths are. Expecting a global precious install. There may be none, which is null. Null is bad - because undefined implies intent to use precious.

      when undefined
        return @preciousPaths => @configure specifics, cb

Unless all the paths have been given as specifics, throw an error. Of-course, it's assumed that the paths are valid. More about completeness than intended use.

        unless _.isString specifics.precious
          throw "Invalid precious specifics!"

    return @configure specifics, cb

A way to change just the output format, with possible method-chaining.

  out: (treats) ->
    @settings.out = treats

Just for processing points output as json (at this point). It also sets up the points json for phase.

  pre: (stream) ->
    process = true
    the_points = "points"
    becoming = "json"

This is so that the_points can be passed as JSON to Massage further.

    if _.isArray(@settings.out) and @settings.out[0] is the_points
      [process, @settings.out[0]] = [the_points, becoming]

Only the data changes for the following, @settings.out remains as is.

    else if _.include [the_points, "phase"], @settings.out
      process = the_points

Specific processing (e.g. points), or else return the same stream without changing anything at all.

    if process is the_points
      points stream

This is the reason Ephemeris exists, though running it sometimes just gets the @settings, so that the precious ephemeris can perhaps later be invoked conveniently with - or else simply for whatever reason - besides any bugs...

  run: (stream) ->

However, Ephemeris can't always be @run nor it is necessarily desirable.

    if @settings.precious is false

Note: this isn't fit for rerun as @settings are being changed...

      if _.isString(@settings.out) and @settings.out isnt "json"
        @settings.out = ["json", @settings.out]

Clean-up the @settings for later use.

      delete @settings[key] for key in ['root', 'data', 'precious']
      if _.isArray @settings.out
        massage = new Massage @settings.out
        massage.write   JSON.stringify(@settings), stream
      else stream.write JSON.stringify(@settings)
    else unless _.isFunction @ephemeris
      throw "No ephemeris to run!"
      ephemeris = @ephemeris @settings

An array of massage steps. Expected to be something valid that Massage can handle. The eden (cli) sets up an Array if --out is a comma-delimited sequence.

    if _.isArray @settings.out
      streamin = @pre ephemeris
      massage = new Massage @settings.out
      massage.pipe streamin, stream

The rest of these are special cases or else straight output of whatever precious returns.

These are the non-array single massage steps for which json is assumed being implied for a starting point. Basically a list of valid, single massage steps for a more readable json output.

    else if _.include ["inspect", "indent"], @settings.out
      massage = new Massage ["json", @settings.out]
      massage.pipe ephemeris, stream

The most readable output of eden and the default in the context of cli usage.

    else if @settings.out is "phase"
      phase (@pre ephemeris), stream

Unprocessed - straight from precious, whatever didn't get caught above. For example eden -o pprint. Unless @pre modifies the data (points).

    else @pre(ephemeris).pipe stream

Special (error) cases.

    ephemeris.on "error", (data) -> console.log data.toString()

Know when all the data has been got. Useful for post-formatting with trailing \n by the cli, for example.

    ephemeris.on "end", -> stream.emit "end"

module.exports = Ephemeris