walltime-js/lib/walltime.coffee

A javascript library for easily translating a UTC time to a "Wall Time" for a particular time zone and back.

init = (helpers, rule, zone) ->

    class WallTime

        init: (rules = {}, zones = {}) ->
            
            @zones = {}
            @rules = {}

            @addRulesZones rules, zones
            
            @zoneSet = null
            @timeZoneName = null
            @doneInit = true

        addRulesZones: (rules = {}, zones = {}) ->
            currZone = null
            for own zoneName, zoneVals of zones
                newZones = []
                currZone = null
                for z in zoneVals
                    newZone = new zone.Zone(z.name, z._offset, z._rule, z.format, z._until, currZone)
                    newZones.push newZone
                    currZone = newZone

                @zones[zoneName] = newZones

            for own ruleName, ruleVals of rules
                newRules = (new rule.Rule(r.name, r._from, r._to, r.type, r.in, r.on, r.at, r._save, r.letter) for r in ruleVals)
                @rules[ruleName] = newRules

        setTimeZone: (name) ->
            if !@doneInit
                throw new Error "Must call init with rules and zones before setting time zone"

            if !@zones[name]
                throw new Error "Unable to find time zone named #{name || '<blank>'}"

            matches = @zones[name]
            @zoneSet = new zone.ZoneSet(matches, (ruleName) => @rules[ruleName])
            @timeZoneName = name

        Date: (y, m = 0, d = 1, h = 0, mi = 0, s = 0, ms = 0) ->
            y or= new Date().getUTCFullYear()
            
            helpers.Time.MakeDateFromParts y, m, d, h, mi, s, ms

        UTCToWallTime: (dt, zoneName = @timeZoneName) ->
            if typeof dt == "number"
                dt = new Date(dt)

            if zoneName != @timeZoneName
                @setTimeZone zoneName

            if !@zoneSet
                throw new Error "Must set the time zone before converting times"

            @zoneSet.getWallTimeForUTC dt

        WallTimeToUTC: (zoneName = @timeZoneName, y, m = 0, d = 1, h = 0, mi = 0, s = 0, ms = 0) ->
            if zoneName != @timeZoneName
                @setTimeZone zoneName

            wallTime = if typeof y == "number" then helpers.Time.MakeDateFromParts y, m, d, h, mi, s, ms else y

            @zoneSet.getUTCForWallTime wallTime

        IsAmbiguous: (zoneName = @timeZoneName, y, m, d, h, mi = 0) ->
            if zoneName != @timeZoneName
                @setTimeZone zoneName

            wallTime = if typeof y == "number" then helpers.Time.MakeDateFromParts y, m, d, h, mi else y

            @zoneSet.isAmbiguous wallTime


    # NOTE: Exporting an instantiated WallTime object.
    new WallTime

if typeof window == 'undefined'
    req_zone = require "./olson/zone"
    req_rule = require "./olson/rule"
    req_help = require "./olson/helpers"
    module.exports = init(req_help, req_rule, req_zone)
else if typeof define != 'undefined'
    # If walltime-data is not defined, automatically define so we can load
    unless require.specified 'walltime-data'
        console?.warn?("To use WallTime with requirejs please include the walltime-data.js script before requiring walltime")
        define 'walltime-data', [], ->
            null
    
    define ['olson/helpers', 'olson/rule', 'olson/zone', 'walltime-data'], (dep_help, dep_rule, dep_zone, WallTimeData) ->
        lib = init dep_help, dep_rule, dep_zone

        if WallTimeData?.zones
            lib.init WallTimeData.rules, WallTimeData.zones

        lib
else
    @WallTime or= {}

    # Some trickery here because we want a clean window.WallTime api,
    # But still have to keep the @WallTime.helpers etc.
    api = init(@WallTime.helpers, @WallTime.rule, @WallTime.zone)
    for own key,val of @WallTime
        api[key] = val

    @WallTime = api

    # Check for and initialize with the passed in data.
    if @WallTime.autoinit and @WallTime.data?.rules and @WallTime.data?.zones
        @WallTime.init @WallTime.data.rules, @WallTime.data.zones