function out = readNdbcSMData(buoy,dates,opt)

%READNDBCSMDATA  Reads NDBC Standard Meterological data.
%   OUT = readNdbcSMData(BUOY,DATES) reads the Standard
%   Metorological data in file BUOY from (or between and including)
%   DATE(S).
%
%   OUT = readNdbcSMData(BUOY,DATES,OPT) if OPT=1 will only return the wave
%   data.
%
%   Input:
%     BUOY = num or 'text'; (ex. buoy=42001 | buoy='42001h.dat' |
%     buoy='../ndbc/42001q')
%     DATE(S) = yyyymmddHH | [yyyymmddHH yyyymmddHH];
%     OPT = 0 | 1
%   Output:
%     OUT = [datenum WD WSPD GST WVHT DPD APD MWD BAR ATMP WTMP DEWP VIS TIDE]
%         = [datenum WVHT(Hs) DPD(Tp) APD(Ta) MWD(Dm)]; (for OPT=1)
%   NOTE: MWD is in Nautical convention: direction from measured cw from 
%   North.
%
%   Problems encountered with this file are most likely due to NDBC
%   changing their file format... again!
%
%   out = readNdbcSMData(buoy,dates,{opt});
%
% Dave Thompson (dthompson@usgs.gov)

%% Check inputs
if ~exist('dates','var')
   dates = [0 inf];
end
if ~exist('opt','var')
   opt = 0;
end
%% Check for data file.
fname = num2str(buoy);
direc = char(regexp(fname,'.+\/|.+\\','match'));
ext = regexp(fname(length(direc)+1:end),'.+\..+','once');
if isempty(ext)
   tmp = strtrim(evalc(['dir ',fname,'h*']));
else
   tmp = strtrim(evalc(['dir ',fname]));
end
if ~isempty(findstr(tmp,'not found'))
   disp([' ',tmp,' !!'])
   out = [];
   return
end
fname = [direc,tmp];

%% Read in the data.
dat = [];

% Open the file, get the correct dateform and adjust incoming dates
% accordingly.
fid = fopen(fname,'r');
line = fgetl(fid);
% Sometimes I put location data before the orginal header.
if isempty(regexp(line,'^\D','once')) 
   out.location = str2num(line);
   line = fgetl(fid);
else
   out.location = [];
end
% I've come across different forms of these data. This attempts to account
% for that.
% Data column headers.
cols = regexp(line,'#*[A-Za-z]+','match');
if isempty(cols)
   disp([9,mfilename,' needs the header in order to determine the ',...
      'data format of this file'])
   return
else   
   if strmatch('#',cols{1})
      dnum = 16;
      dform = 'yyyymmddHHMM';
      cols = cols(6:end);
      line = fgetl(fid); % Skip down to the units line for this case.
   elseif strmatch('YY',cols{1})
      dnum = 11;
      dform = 'yymmddHH';
      cols = cols(5:end);
   elseif strmatch('mm',cols{5})
      %dates = dates*100;
      dnum = 16;
      dform = 'yyyymmddHHMM';
      cols = cols(6:end);
   else
      dnum = 13;
      dform = 'yyyymmddHH';
      cols = cols(5:end);
   end
   
   % Correct the length of the incoming dates.
   if dnum==11
      tmp = 10;
   else
      tmp = length(dform);
   end
   dates = dates*10^(tmp-length(num2str(dates(1))));
   
   % Data column headers.
   cols = [{'TIME'} cols];
   for ii=1:length(cols)
      cols{ii} = ['(',num2str(ii),')',cols{ii},' '];
   end
   out.cols = cols;
end

%% Read file line-by-line.
while 1
   line = fgetl(fid);
   
   % Break if we've reached the end of the file.
   if ~ischar(line)
      break
   end

   % Find the data of interest
   %tmp = regexp(line,'\d+\.*\d+','match');
   %fdate = str2num([tmp{1:dnum}]);
   fdate = str2num(line(isspace(line(1:dnum))==0));
   while fdate>=dates(1) && fdate<=dates(end)
      tmp = sscanf(line(dnum+1:end),'%f');
      % Replace 99, 999, 9999, etc. with NaNs
      tmp1 = tmp(2:6); tmp1(tmp1==99) = nan; tmp(2:6) = tmp1;
      tmp1 = tmp(12:end); tmp1(tmp1==99) = nan; tmp(12:end) = tmp1;
      tmp(tmp==999) = nan;
      tmp(tmp==9999) = nan;
      if opt~=0 % Only return wave data.
         tmp = tmp(4:7);
      end
      dat = [dat;[datenum(num2str(fdate),dform) tmp(1:end)']];
      line = fgetl(fid);
      % Break if we've reached the end of the file.
      if ~ischar(line)
         disp([' Reached EOF before finding last date requested in ',...
            fname,' !!'])
         break
      end
      fdate = str2num(line(isspace(line(1:dnum))==0));
   end
end
fclose(fid);

%%
if isempty(dat)
   disp(' Requested data not found in data file!')
   out = [];
   return
end
if setdiff(diff(str2num(datestr(dat(:,1),'HH'))),[1 -23])
   disp(' Did not find all dates requested !!')
end
  
out.data = dat;