;+
;
; @file_comments
;
; @categories
;
; @param NAMEFILE
;
; @keyword GRID {default='T'}{type=scalar string}
; Used to specify on which grid type are located the data
;
; @keyword _EXTRA
; Used to pass keywords to <pro>isafile</pro>, 
; <pro>ncdf_getaxis</pro> and <pro>ncdf_gettime</pro>
;
; @returns
;
; @uses
;
; @restrictions
;
; @examples
;
; @history
;
; @version
; $Id$
;
; @todo
; seb : I don't know what to do with that...
;
;-
FUNCTION scanfile, namefile, GRID=GRID, _EXTRA=ex
;
;  liste des presupposes:
;       1) le fichier a lire est un fichier netcdf
;       2) le nom de ce fichier finit
;       par U.nc, V.nc, W.nc, T.nc ou F.nc, la lettre avant le
;       nc designant la grille a laquelle se rapporte la champ.
;       Si tel n''est pas la cas, le fichier est attribue a la grille
;       T.
;       3) ce fichier contient une dimension infinie qui doit etre
;       celle qui se rapporte au temps et au mois 2 autres dimensions
;       dont les noms sont 'x','lon...','xi_...' et 'y','lat...' ou
;       'eta_...' ou bien en majuscule.
;       4) il doit exister ds ce fichier une unique variable n''ayant
;       qu''une dimension et etant la dimension temporelle. cette
;       variable sera prise comme axe des temps. Rq: si plusieurs
;       variables verifient ces criteres on considere la premiere
;       variable
;       5) Cette variable axe des temps doit contenir l''attribut
;       'units' qui doit etre ecrit suivant la syntaxe:
;               "seconds since 0001-01-01 00:00:00"
;               "hours since 0001-01-01 00:00:00"
;               "days since 1979-01-01 00:59:59"
;               "months since 1979-01-01 00:59:59"
;               "years since 1979-01-01 00:59:59"
;
; je crois que c''est tout!
;
;        GRID='[UTVWF]' to specify the type of grid. Defaut is (1)
;        based on the name of the file if the file ends by
;        GRID[._][TUVFW].NC (not case sensible) or (2) T if case (1)
;        is not found.
;
;
  compile_opt idl2, strictarrsubs
;
@common
;------------------------------------------------------------
; filename
;------------------------------------------------------------
  fullname = isafile(filename = namefile, IODIRECTORY = iodir, _extra = ex)
  IF size(fullname, /type) NE 7 THEN return, -1
;------------------------------------------------------------
; open file
;------------------------------------------------------------
  cdfid = ncdf_open(fullname)
;------------------------------------------------------------
; What contains the file?
;------------------------------------------------------------
  inq = ncdf_inquire(cdfid)  ;
;------------------------------------------------------------
; name of all dimensions
;------------------------------------------------------------
  namedim = strarr(inq.ndims)
  for dimiq = 0, inq.ndims-1 do begin
    ncdf_diminq, cdfid, dimiq, tmpname, value
    namedim[dimiq] = strlowcase(tmpname)
  ENDFOR
;------------------------------------------------------------
; x/y dimensions id
;------------------------------------------------------------
  ncdf_getaxis, cdfid, dimidx, dimidy, _extra = ex
;------------------------------------------------------------
; name of all variables
;------------------------------------------------------------
; we keep only the variables containing at least x, y and time dimension (if existing...)
  namevar = strarr(inq.nvars)
  for varid = 0, inq.nvars-1 do begin
    varinq = ncdf_varinq(cdfid, varid) ; what contains the variable?
    if (inter(varinq.dim, dimidx))[0] NE -1 AND $
       (inter(varinq.dim, dimidy))[0] NE -1 AND $
       ((where(varinq.dim EQ inq.recdim))[0] NE -1 OR inq.recdim EQ -1) $
    THEN namevar[varid] = varinq.name
  ENDFOR
  namevar = namevar[where(namevar NE '')]
;------------------------------------------------------------
; find vargrid for each selected variable...
;------------------------------------------------------------
  listgrid = strarr(n_elements(namevar))
; default definitions
  IF keyword_set(grid) THEN vargrid = strupcase(grid) ELSE vargrid = 'T'
; look for values of vargrid for each variable
  IF finite(glamu[0]) EQ 1 AND NOT keyword_set(grid) THEN BEGIN
; for each variable, look if we in one of the case corresponding to ROMS conventions?
    FOR i = 0, n_elements(namevar)-1 do begin
      varinq = ncdf_varinq(cdfid, namevar[i])
      tmpnm = namedim[varinq.dim]
; are we in one of the case corresponding to ROMS conventions?
      CASE 1 OF
        tmpnm[2 < (varinq.ndims-1)] EQ 's_w':vargrid = 'W'
        tmpnm[0] EQ 'xi_rho' AND tmpnm[1] EQ 'eta_rho':listgrid[i] = 'T'
        tmpnm[0] EQ 'xi_u'   AND tmpnm[1] EQ 'eta_u'  :listgrid[i] = 'U'
        tmpnm[0] EQ 'xi_v'   AND tmpnm[1] EQ 'eta_v'  :listgrid[i] = 'V'
        tmpnm[0] EQ 'xi_psi' AND tmpnm[1] EQ 'eta_psi':listgrid[i] = 'F'
        tmpnm[0] EQ 'xi_rho' AND tmpnm[1] EQ 'eta_v'  :listgrid[i] = 'V'
        tmpnm[0] EQ 'xi_u'   AND tmpnm[1] EQ 'eta_rho':listgrid[i] = 'U'
        tmpnm[0] EQ 'xi_u'   AND tmpnm[1] EQ 'eta_v'  :listgrid[i] = 'F'
        ELSE:
      ENDCASE
    ENDFOR
    empty = where(listgrid EQ '')
    IF empty[0] NE -1 THEN BEGIN
; could we define the grid type from the file name??
      pattern = ['GRID.', 'GRID_', 'GRID', 'UPID_', '30ID_']
      gdtype = ['T', 'U', 'V', 'W', 'F']
      fnametest = strupcase(fullname)
      FOR i = 0, n_elements(pattern)-1 DO BEGIN
        FOR j = 0, n_elements(gdtype)-1 DO BEGIN
          substr = pattern[i]+gdtype[j]
          pos = strpos(fnametest, substr)
          IF pos NE -1 THEN $
             vargrid = strmid(fnametest, pos+strlen(substr)-1, 1)
        ENDFOR
      ENDFOR
      listgrid[empty] = vargrid
    ENDIF
  ENDIF ELSE listgrid[*] = vargrid
;------------------------------------------------------------
; time axis
;------------------------------------------------------------
  time = ncdf_gettime(fullname, cdfid, caller = 'scanfile', err = err, _extra = ex)
  IF n_elements(err) NE 0 THEN BEGIN
    dummy = report(err)
    jpt = abs(time)
    fakecal = 1
  ENDIF ELSE jpt = n_elements(time) 
; high frequency calendar: more than one element per day
  IF max(histogram([long(time-time[0])])) GT 1 THEN fakecal = 1 ELSE fakecal = 0
  date0fk = date2jul(19000101)
  IF keyword_set(fakecal) THEN time = date0fk+lindgen(1 > jpt)
;------------------------------------------------------------
  ncdf_close, cdfid
;------------------------------------------------------------
  return, {filename:fullname, time_counter:time, listvar:namevar $
           , listgrid:strupcase(listgrid), caltype:key_caltype $
           , fakecal:date0fk*fakecal}
end