; docformat = 'rst'
;
; NAME:
;    getCameraCoords
; PURPOSE:
;    Retrieve sky coordinates afrom FITS header
;
;+
; :Description:
;    Retrieve sky coordinates afrom FITS header
;
; :Categories:
;    FITS, Camera
;
; :Returns: A structure with sky coordinates. Fields are::
;    If fails, return codes are::
;
; :Params:
;    head: in, required, type=string
;        A FITS header from the telescope
;    tel: in, optional, type=string
;        The ID of the telescope (from getTelescopeID)
;    cam: in, optional, type=string
;        The ID of the camera (from getCameraID)
;
; :Keywords:
;    empty: in, optional, type=boolean, default=0
;      If set, return an empty structure
;
; :Uses:
;    sxpar, lxpar, getTelescopeID, getCameraID
;
; :Author:
;    B.Carry (OCA)
;
; :History:
;    Change History::
;      Written in July 2017, B. Carry (OCA)
;      2023 Dec.: B.Carry (OCA) - Added LBTO
;-
function getCameraCoords, head, tel, cam, empty=empty
  COMPILE_OPT hidden, idl2
;-----------------------------------------------------------------------------------------------;
;-----------------------------------------------------------------------------------------------;
;---  TAG ---    I -- Initialization And Input Verification              -----------------------;
;-----------------------------------------------------------------------------------------------;
;-----------------------------------------------------------------------------------------------;
 ;--I.1-- Syntax Verification  -----------------------------------------------------------------;
  if n_params() lt 1 then begin
    message, 'Syntax : filter = getCameraCoords(head, [tel, cam])'
    return, -1
  endif

 ;--I.2-- Coordinates Structure  ---------------------------------------------------------------;
  coords = {ra:0., dec:0., alt:0., az:0., airmass:0. }
  if keyword_set(empty) then return, coords


 ;--I.3-- Telescope and Camera ID  -------------------------------------------------------------;
  if not keyword_set(tel) then tel=getTelescopeID(head)
  if not keyword_set(cam) then cam=getCameraID(head)




;-----------------------------------------------------------------------------------------------;
;-----------------------------------------------------------------------------------------------;
;---  TAG ---   II -- Header Parsing and Extract Coordinates             -----------------------;
;-----------------------------------------------------------------------------------------------;
;-----------------------------------------------------------------------------------------------;
  case tel of

    ;--II.1-- ESO-VLT Telescopes  --------------------------------------------------------------;
    'ESO-VLT': begin
       coords.RA  = sxPar(head, 'RA')
       coords.Dec = sxPar(head, 'DEC')
       coords.Alt = sxPar(head, 'EL')
       coords.Az  = sxPar(head, 'AZ')
       coords.airmass= sxPar(head, 'AIRMASS')
     end


    ;--II.2-- ESO-LSO Telescopes  --------------------------------------------------------------;
    'ESO-LSO': begin
       coords.RA  = sxPar(head, 'RA')
       coords.Dec = sxPar(head, 'DEC')
       coords.Alt = sxPar(head, 'EL')
       coords.Az  = sxPar(head, 'AZ')
       coords.airmass= sxPar(head, 'AIRMASS')
     end


    ;--II.3-- Keck Observatory  ----------------------------------------------------------------;
    'KeckII': begin
       coords.RA  = sxPar(head, 'RA')
       coords.Dec = sxPar(head, 'DEC')
       coords.Alt = sxPar(head, 'EL')
       coords.Az  = sxPar(head, 'AZ')
       coords.airmass= sxPar(head, 'AIRMASS')
     end


    ;--II.4-- Gemini Observatory  --------------------------------------------------------------;
     'Gem-S': begin
       coords.RA  = sxPar(head, 'RA')
       coords.Dec = sxPar(head, 'DEC')
       coords.Alt = sxPar(head, 'EL')
       coords.Az  = sxPar(head, 'AZ')
       coords.airmass= sxPar(head, 'AIRMASS')
     end
     'Gem-N': begin
       coords.RA  = sxPar(head, 'RA')
       coords.Dec = sxPar(head, 'DEC')
       coords.Alt = sxPar(head, 'EL')
       coords.Az  = sxPar(head, 'AZ')
       coords.airmass= sxPar(head, 'AIRMASS')
     end

    ;--II.5-- LBT Observatory  -----------------------------------------------------------------;
     'LBTO': begin
       coords.RA  = sxPar(head, 'RA_AC')
       coords.Dec = sxPar(head, 'DEC_AC')
       coords.Alt = sxPar(head, 'EL')/3600
       coords.Az  = sxPar(head, 'AZ')/3600
       coords.airmass= 1/cos( coords.Alt / !RADEG )
     end


    ;--II.x-- Unknown  -------------------------------------------------------------------------;
     else: begin
       message, 'getCameraCoords: Telescope not known'
       return, -3
     end

  endcase


 ;--III.X-- Return Filter Structure  -----------------------------------------------------------;
  return, coords

end