;+
;FUNCTION: time_struct(time)
;NAME:
;  time_struct
;PURPOSE:
; A fast, vectorized routine that returns a time structure.
;INPUT:  input can be any of the following types:
;  double(s)      seconds since 1970
;  string(s)      format:  YYYY-MM-DD/hh:mm:ss
;  structure(s)   similar to format below.
;
;OUTPUT:
;  structure with the following format:
;** Structure TIME_STRUCT, 11 tags, length=40:
;   YEAR            INT           1970            ; year    (0-14699)
;   MONTH           INT              1            ; month   (1-12)
;   DATE            INT              1            ; date    (1-31)
;   HOUR            INT              0            ; hours   (0-23)
;   MIN             INT              0            ; minutes (0-59)
;   SEC             INT              0            ; seconds (0-59)
;   FSEC            DOUBLE           0.0000000    ; fractional seconds (0-.999999)
;   DAYNUM          LONG            719162        ; days since 0 AD  (subject to change)
;   DOY             INT              0            ; day of year (1-366)
;   DOW             INT              3            ; day of week  (subject to change)
;   SOD             DOUBLE           0.0000000    ; seconds of day
;   DST        =    INT      = 0                  ; Daylight saving time flag
;   TZONE      =    INT      = 0                  ; Timezone  (Pacific time is -8)
;   TDIFF      =    INT      = 0                  ; Hours from UTC
;
;KEYWORDS:
;
;  TFORMAT: Specify a custom format for string to struct conversion:
;      Format string such as "YYYY-MM-DD/hh:mm:ss" (Default)
;          the following tokens are recognized:
;            YYYY  - 4 digit year
;            yy    - 2 digit year (00-69 assumed to be 2000-2069, 70-99 assumed to be 1970-1999)
;            MM    - 2 digit month
;            DD    - 2 digit date
;            hh    - 2 digit hour
;            mm    - 2 digit minute
;            ss    - 2 digit seconds
;            .fff   - fractional seconds (can be repeated, e.g. .f,.ff,.fff,.ffff, etc... are all acceptable codes)
;            MTH   - 3 character month
;            DOY   - 3 character Day of Year
;            TDIFF - 5 character, +hhmm or -hhmm different from UTC (sign required)
;         tformat is case sensitive!
;
;See Also:  "time_double", "time_string", "time_epoch", "time_pb5", "time_zone_offset","time_parse"
;
;NOTE:
;  This routine works on vectors and is designed to be fast.
;  Output will have the same dimensions as the input
;
;CREATED BY:    Davin Larson  Oct 1996
;
; $LastChangedBy: egrimes $
; $LastChangedDate: 2018-10-17 12:47:15 -0700 (Wed, 17 Oct 2018) $
; $LastChangedRevision: 25991 $
; $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/tags/spedas_5_0/general/misc/time/time_struct.pro $
;-
function time_struct,time,epoch=epoch,no_clean=no_clean,$
   MMDDYYYY=MMDDYYYY, $ ;string conversion from format listed in month date year format, instead of default year month date
   timezone=timezone,  $
   local_time=local_time, $
   is_local_time=is_local_time,$     ; this keyword is not yet working correctly
   tformat=tformat,$
   tdiff=tdiff
   
;dprint,dlevel=9,time[0]
dt = size(/type,time)
if keyword_set(timezone) then begin
   local_time=1
   tzone = timezone
endif
;tzone = keyword_set(timezone) ? timezone : 0

tst0 = {time_structr,year:0,month:0,date:0,hour:0,min:0,sec:0, $
        fsec:!values.d_nan, daynum:0l,doy:0,dow:0,sod:!values.d_nan, $
        dst:0,tzone:0,tdiff:0}
dim =   size(/dimension,time)
ndim =  size(/n_dimen,time)


if dt eq 7 then begin         ; input is a string

  ;parsing abstracted in separate routine
  tsts = time_parse(time,tformat=tformat,MMDDYYYY=MMDDYYYY)
  
  if keyword_set(no_clean) then return,tsts $
  else begin
     t = time_double(tsts)
     if keyword_set(is_local_time) then begin
;dprint,dlevel=9,'is_local_time'
        dst = isdaylightsavingtime(t,tzone)
        t -= (dst+tzone)*3600
     endif
     return,time_struct(t,timezone=tzone,local_time=local_time)
  endelse
endif

if ndim eq 0 then tsts =tst0 else tsts = make_array(value=tst0,dim=dim)

if keyword_set(epoch) then return,time_struct(time_double(time,epoch=epoch),timezone=timezone)


if dt eq 5 or dt eq 4 or dt eq 3 or dt eq 14 then begin         ; input is a double or integer
    good = where(finite(time),ngood)
    if  ngood gt 0 then begin
        ltime = time[good]
        if keyword_set(local_time)  then begin
           dst = isdaylightsavingtime(time[good],tzone)
           ltime += (tzone+dst) * 3600l
           tsts[good].dst = dst
           tsts[good].tzone = tzone
           tsts[good].tdiff = tzone+dst
        endif
        dn1970 = 719162l        ; day number of 1970-1-1
        dn = floor(ltime/3600.d/24.d)
        sod = ltime - dn*3600.d*24.d
        daynum = dn + dn1970
        hour = floor(sod/3600.d)
        fsec = sod - hour*3600.d
        min  = floor(fsec/60.d)
        fsec  = fsec - min*60
        sec  = floor(fsec)
        fsec = fsec - sec
        day_to_year_doy,daynum,year,doy
        doy_to_month_date,year,doy,month,date
        tsts[good].month= month
        tsts[good].date = date
        tsts[good].year = year
        tsts[good].doy  = doy
        tsts[good].hour = hour
        tsts[good].min  = min
        tsts[good].sec  = sec
        tsts[good].fsec = round(fsec*1d9)/1d9
        tsts[good].sod  = sod
        tsts[good].daynum = daynum
        tsts[good].dow = daynum mod 7
    endif
    return,tsts
endif

if dt eq 8 then  $             ;input is a structure
   return,time_struct(time_double(time),timezone=timezone)

if dt eq 0 then  $             ;input is undefined
   return,time_struct(time_string(time,prec=6))

message,/info,'Improper time input'

end