function oi = roms_read_ocean_in(fn)
% roms_read_ocean_in - Read a ROMS .in file and returns parameters
% oi = roms_read_ocean_in( fn )
%
% Input
%   fn - filename, optional; default = 'ocean.in', but it can also read
%    sediment.in
%
% Return
%   oi - structure with all info found in .in file
%    For convenience, the values of some important ones are
%    stored under their name in the structure. The rest are in an array of
%    structures oi.data, with fields:
%       oi.data(i).keyword
%                 .numval
%                 .strval
%    These have to be parsed appropriately. Examples at end of script.

% csherwood@usgs.gov

if(exist('fn','var')~=1), fn='ocean.in'; end

fid = fopen( fn, 'r' );
if(fid == -1)
   fprintf(1,'Could not open %s\n',fn)
   error('punt');
end

i=0; % counter for oi.data(i) structure
while ~feof(fid)
   % get a line from the file, use strtrim to remove "insignificant" white space 
   tline = strtrim( fgetl( fid ) );
   if( ~isempty(tline) && ~strcmp(tline(1),'!') )
      % has content and does not start w/ comment char, so process
      % first, truncate at first comment character
      k =strfind(tline,'!');
      if( ~isempty(k) )
         tline = tline(1:k-1);
      end
      % now look for equal signs. Note: there may be two.
      k = strfind(tline,'=');
      if( ~isempty(k) )% has '=' or '=='; looks like valid keyword
         i=i+1;
         % read the first part of the line as a keyword, removing blanks:
         oid(i).keyword = strtrim( tline(1:k(1)-1) );
         % Try to read the remainder as numbers (danger here, because the 
         % ROMS files use nnndn format, but sscanf expects nnnen format, so
         % real numbers may be truncated, and multiple numbers wont be
         % recognized. Try to handle this here.
         temp = strtrim(tline(k(end)+1:end));
         kk = strfind(temp,'d');
         if(~isempty(kk)), temp(kk)='e'; end
         oid(i).numval = sscanf(temp,'%g' );
         % and also, try to read the remainder as strings, but first
         % check to see if there is a continuation character
         more_continuation = 1;
         temp = tline(k(end)+1:end);
         while more_continuation
            m = strfind(temp,'\'); % look for continuation line
            if( isempty(m) ) % no continuation line
               kk =strfind(temp,'!');
               if(~isempty(kk)) % trim line at comment
                  temp = temp(1:kk-1);
               end
               t1 = temp;
               if(exist('tt','var')) % concatenate with previous line
                  tt = [tt,' ',t1];
               else
                  tt = t1;
               end
               more_continuation = 0;
            else % found continuation char, read another line
               t1 = temp(1:m-1);
               if(exist('tt','var')) % concatenate with previous line
                  tt = [tt,' ',t1];
               else
                  tt = t1;
               end
               temp = fgetl(fid);
               more_continuation = 1;
            end
         end
         oid(i).strval = tt;
         clear tt;
      else % not a comment, not a continuation, no '=', what is it?
         fprintf(1,'Dont know how to handle this:\n%s\n',tline)
      end
   end
end
fclose(fid);
if(i==0),error('did not find any keywords'), end

% store structure array in return structure
oi.data = oid;

% extract a few keywords inportant for initialization
% and duplicate them in the return structure for convenience
% (also serves as an example of how to find others)
% following assume we are reading ocean.in
for j=1:i,
   if( strcmpi( oid(j).keyword, 'TITLE' )), oi.TITLE = strtrim(oi.data(j).strval); end
   if( strcmpi( oid(j).keyword, 'MyAppCPP' )), oi.MyAppCPP = strtrim(oi.data(j).strval); end
   if( strcmpi( oid(j).keyword, 'VARNAME' )), oi.VARNAME = strtrim(oi.data(j).strval); end
   if( strcmpi( oid(j).keyword, 'GRDNAME' )), oi.GRDNAME = strtrim(oi.data(j).strval); end
   if( strcmpi( oid(j).keyword, 'ININAME' )), oi.ININAME = strtrim(oi.data(j).strval); end
   if( strcmpi( oid(j).keyword, 'Lm' )), oi.Lm = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'Mm' )), oi.Mm = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'N' )), oi.N = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'Nbed' )), oi.Nbed = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'NAT' )), oi.NAT = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'NPT' )), oi.NPT = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'NCS' )), oi.NCS = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'NNS' )), oi.NNS = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'THETA_S' )), oi.THETA_S = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'THETA_B' )), oi.THETA_B = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'TCLINE' )), oi.TCLINE = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'NFFILES' )), oi.NFFILES = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'FRCNAME' )), oi.FRCNAME = oi.data(j).strval; end
end
%% following assume that we are reading sediment.in
for j=1:i,
   if( strcmpi( oid(j).keyword, 'MUD_SD50' )),oi.MUD_SD50 = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'MUD_SRHO' )),oi.MUD_SRHO = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'MUD_WSED' )),oi.MUD_WSED = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'MUD_TAU_CE' )),oi.MUD_TAU_CE = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'MUD_ERATE' )),oi.MUD_ERATE = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'SAND_SD50' )),oi.SAND_SD50 = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'SAND_SRHO' )),oi.SAND_SRHO = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'SAND_WSED' )),oi.SAND_WSED = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'SAND_TAU_CE' )),oi.SAND_TAU_CE = oi.data(j).numval; end
   if( strcmpi( oid(j).keyword, 'SAND_ERATE' )),oi.SAND_ERATE = oi.data(j).numval; end
end