function fn = address( varargin )
%ADDRESS by itself is an address book.
%  The program stores several fields such as FirstName,
%  LastName, Phone number, address, etc. for a list of 
%  people like an address book.  The list (a structure)
%  is saved to a *.mat file for storage.  The program 
%  repeatedly displays the menu until an exit character
%  is selected ('q' or 'x').  The book is automatically 
%  resorted by last name whenever it is saved.
%    To start a new address book, use the command 
%  ADDRESS('initialize').  It would be helpful to edit
%  the initialization fields to suit your own needs before
%  actually initializing the file (use 'edit address').  
%  Fields may be only be added or deleted before the 
%  initialization is performed.
%
%  Notes:
%    To run the program, either use 'run address' or 
%  just 'address' with no arguments.
%    The 'LastName' field must be present because the 
%  program sorts by last name.  Everything else is done
%  blindly, that is, only if it exists.
%    The Matlab 'clc' command can be used in the main menu 
%  to clear the screen.
%  
%  Last edit: Colin Joye, 9/9/02

% --------------- begin user definitions 1/2 --------------------
%fname = 'c:\matlab6p1\work\address_book'; % Address book file.
fname = 'address_book'; % Address book file.
% --------------- end user definitions 1/2 --------------------   

chg = 0;  % chg == 1 if the address book may have been modified.
if any(strcmp(varargin,'initialize')),
   c = 'y';
   if exist([fname '.mat'])==2, 
      c = input(['File ' fname '.mat already exists.  You can create a new ' ...
          'book by typing "edit address" and changing the "fname" variable  ' ...
          'Continue to initialize and erase existing? (y/n):' ],'s');
   end
   if strcmp(lower(c),'y'),
      
% Delete or add fields (*.X) to suit your needs below, but only 
% before the initialization is done, or else an existing 'fname' 
% file may be overwritten. 'A' is the address book structure used 
% throughout the program.  
% --------------- begin user definitions 2/2 --------------------   
      A.title     = ''           % Normally use for Dr., Prof., etc. 
      A.FirstName = 'Colin'; % FirstName should be present.
      A.LastName  = 'Joye';   % LastName must be present.
      A.email1    = 'colin.joye@villanova.edu';
      A.email2    = 'cjoye@mit.edu';
      A.email3    = 'cdanjo@aol.com';
      A.phone_home = '610-524-0296';
      A.phone_cell = '';
      A.phone_other = '';
      A.address_home = '226 Llandovery Dr., Exton, PA 19341';
      A.address_other = 'MIT, Cambridge, MA (school)';
      A.association = ''; 
      A.notes     = '';
      A.class     = '';

% --------------- end user definitions 2/2 --------------------   

      err = ''; % Error string.
      chg = 1;
      disp('> Initialization complete.');
   else
      err = ['> Initialization cancelled.'];
      disp(err);
   end
else % don't initialize, but just run the program...
   err = ''; % Error string causes program termination if used.
   try,
      load(fname); % loads the existing address book *.mat file.
   catch,
      err = ['> File ' fname '.mat does not exist.']; 
      disp(err);
      disp(['  Use ADDRESS(''initialize'') to start an ' ...
         'address book']);
   end
end

%--------- Main program loop begins here ---------------------
while strcmp(err,''),
LA = length(A);
% Menu section: displays menu for control.
disp(' ');disp(' ');disp(' ');
disp('------------------------------------');
disp('--------------- Menu ---------------');
disp('Select by typing the corresponding letter and hit enter');
disp(' A:  Add a new entry.');
disp(' C:  Count the entries.');
disp(' D:  Delete an entry.');
disp(' E:  Edit an entry.');
disp(' F:  Find by keyword.');
disp(' H:  Help and info.');
disp(' P:  Print the book to a file.');
disp(' S:  Save current address book (*.mat).');
disp(' L:  List all names in book.');
disp(' V:  View entire address book.');
disp(' Q or X:  Exit the program.');
z = input( '--- Your Choice? >> ','s');
disp(' ');
switch lower(z)
case 'a' % add a new field.
   A = add_field(A);
   chg=1; 
case 'c' % provide a count of all entries.
   count(A);
case 'clc' % clear screen.
   clc;
case 'd' % delete a field.
   A = delete_field(A);
   chg=1; 
case 'e' % edit a field.
   A = edit_field(A);
   chg=1; 
case 'f' % find a field.
   arg = input('- Find keyword: ','s');
   n = find_field(A,arg);
   format_out( A(n),n );
   disp(['> ' int2str(length(n)) ' entries found.']);
case 'h' % help and info.
   help address;
case 'p' % print the entire address book to a file.
   print_field(A);
case 's' % save entire address book.
   A = save_book(fname,A); 
   chg=0; 
case 'l' % list all names in book.
   list_names(A,[]);
case 'v' % view entire address book.
   for m=1:LA,
      format_out( A(m),m );
   end
case {'q','x'} % quit the program.
   quitting(A,fname,chg);
   break;
otherwise % invalid char.
   disp(['** Unknown Option: ''' z ''', try again.']);
end % ends switch-case.
end % ends main while-loop.
%--------- Main Program Loop Ends Here ---------------------

%--------- Subfunction Defs Begin Here ---------------------
% Add_field prompts for new information to add to the book.
% If the LastName field is blank, nothing is added.
function q = add_field(k)
disp('Add field:  ');
q = k;
Lk = length(k);
fn = fieldnames(k);
for m=1:length(fn), % Loop prompts used for input for each
   cfn = char(fn(m,:)); % field that exists in 'A' already.
   s   = ['q(Lk+1).' cfn]; 
   new = input(['- ' cfn ': '],'s');
   ss=[s '= ''' new ''';' ];
   eval(ss);
end
if isempty(q(Lk+1).LastName),
   disp('** A Last name must be entered. Try Again. **');
   q=k;
end
return;

%----------
% Delete_field finds the entry and prompts for permission 
% to delete it.
function q = delete_field(k)
arg = input('- Find keyword: ','s');
n = find_field(k,arg);
n = choose_field(k,n); % n==[] means cancel.
if ~isempty(n),
   format_out(k(n),n);
   yn = input('Delete above entry? (y/n) ','s');
   if strcmp(lower(yn),'y'), % Deletion done by the "accordion 
      Lk = length(k); % method".
      q( 1:(n-1) ) = k( 1:(n-1) );
      q( n:(Lk-1) )=k( (n+1): Lk );
      disp('   {Entry deleted}');
   else 
      q=k;
      disp('   {Entry not deleted}');
   end
else q=k; disp('   {No entries deleted}');
end
return;

%----------
% Edit_field finds the field and then prompts
% the user for any changes.  The "!<" and "!>"
% options can be used to append information to the 
% existing string for convience.
function q = edit_field(k)
disp('Edit: ');
arg = input('- Find keyword: ','s');
n = find_field(k,arg); 
n = choose_field(k,n); % n==[] means cancel.
q=k;
if ~isempty(n),
   format_out(k(n),n);
   fn=fieldnames(k);
   disp('  (!< to prepend to the existing chars, !> to postpend, !d to delete existing)');
   for m=1:length(fn),
      cfn = char(fn(m,:));
      s1  = ['q(n).' cfn]; 
      s2  = ['cur=char( k(n).' cfn ');'];
      eval(s2);
      new = '';
      new = input(['- Edit [' cfn ': ' cur ']: '],'s');
      % lookfor prepend/postpend option.
      if ~isempty(findstr('!<',new)),
         new = strrep(new,'!<','');
         new = [new cur]; % prepend.
      elseif ~isempty(findstr('!>',new)),
         new = strrep(new,'!>','');
         new = [cur new]; % postpend.
      elseif ~isempty(findstr('!d',new)),
         new='';
         s3=[s1 '= '''';' ]; % delete the existing
         eval(s3);                  % data.
      end
      if ~strcmp(new,''), % Just hitting enter on a field
         s3=[s1 '= ''' new ''';' ]; % keeps the existing
         eval(s3);                  % data.
      end
   end
else 
   disp('   {Edit cancelled}');
end
return;

%----------
% Find_options searchs a string 'in' for the 
% prepend/postpend/delete options and returns a string
% which has these options chars removed, as well as the 
% complete string.
function out = find_options( cur, new )
out='';
return;

%----------
% Find_field returns all ind(ex/ices) of 'arg' in the 
% found in the structure 'k'.  To find a substring, the
% first letters must match (ignores case).
function n = find_field(k,arg)
m=0;n=[];
K = struct2cell(k);
if ~isempty(arg),
   for m=1:size(k,2),
      if ~isempty( strmatch( lower(arg),lower( strvcat(K{:,m})) ) ),
         n = [n m];
      end
   end
end
if isempty(n),
   disp(['The string ''' arg ''' could not be found.']);
end
return;

%----------
% Count counts all of the fields and provides statistics.
function count(k)
Lk = length(k);
z=struct2cell(k);
fn = fieldnames(k);
cnt=0;
disp('Count of entries: ');
disp(['> Total number of entries: ' int2str(Lk)]);
for m=1:length(fn),
   for n=1:Lk,
      if ~cellfun('isempty',z(m,:,n)),
         cnt=cnt+1;
      end
   end
   disp(['- ' char(fn(m)) ': ' int2str(cnt)]);
   cnt=0;
end
return;

%----------
% Subfunction Choose_field prompts the user to choose a
% result if several are found..
function q = choose_field(k, n);
Ln = length(n);
if Ln>1, % then there are several results.
   flag = 0; % =1 exits when choice has been made.
   disp('---------------');
   list_names(k,n);
   disp('<x> Cancel');
   c = input(['-- ' int2str(Ln) ' results found, choose one: '],'s');
   N = valid_choice(c,Ln);% prompts user for a valid choice.
   if N==0, % cancel character.
      q = [];
      return;
   else
      q = n(N);
   end
else % there is only one result.
   q = n;
end
return;

%----------
function list_names(k,n)
% List_names lists all first and last names in the order
% dictated by vector 'n'.  If 'n' isempty, the names are 
% listed in order of entry into 'k'.
if isempty(n),
   n = 1:length(k);
end
for m = 1:length(n), % display resulting names.
   fn = []; tt = [];
   if isfield(k, 'title'),
      if ~all(isspace(k(n(m)).title)),
         tt = [k(n(m)).title ' '];
      end
   end
   if isfield(k, 'FirstName'),
      fn = k(n(m)).FirstName;
   end
   disp(['<' int2str(m) '> ' tt fn ' ' k(n(m)).LastName]);
end
return;

%----------
function print_field(k)
% Prints any or all of the fields to a file.
fn = [fieldnames(k); cellstr('all')];
disp(['Print: Make a text file containing all of the ' ... 
   'entries of any of the options.']);
for m=1:length(fn), % display resulting names.
   disp(['<' int2str(m) '> ' char(fn(m))]);
end
disp(['<x> Cancel Print request.']);
c = input('-- Select one or more (separate by SPACEBAR): ','s');
n = valid_choice(c,m+1);
if all(n~=0),
   fid = input(['-- Input a file name with an extension: '],'s');
   if ~isempty(fid),
      make_file(k,fn(n),fid);
   else
     disp('No filename was entered, try again.');
     return;
   end
end
return;

%----------
function n = valid_choice(c,Ln)
% Prompts used for a valid choice from a menu. 'n==0' means
% that 'exit' was chosen. 'c' is the input choice (char), 
% 1:Ln is the range of valid choices and 'n' is the valid 
% choice(s) (int).  'c' may also be a vector.
n=0;
while 1, % Keep prompting for choice until valid.
   v=str2num(c);
   if any(strcmp(c,'x')),
      break;
   elseif ~isempty(v) & all(v <= Ln) & all(v > 0), % valid choice.
      n = v;
      break;
   else % invalid choices
      c=input(['Unknown option: ''' c '''' ...
         ', Choose again or ''x'' to cancel: '],'s');   
   end
end
return

%----------
% Prints requested info (k.name) to file (fid).
function make_file(k,name,fid);
try
   fprintf(fid,'');
catch
   disp(['The file ''' fid ''' could not be written to.']);
   return;
end
fn = fieldnames(k);
if strcmp(name,'all'),
   w=[];
else
   w=['.' name];
end
for m=1:length(name) 
   s=['z=k(' int2str(m) ')' w ';'];
   eval(s);
end
return;

%----------
% Save_book sorts the book by LastName and saves 'A' 
% to *.mat file.
function A = save_book(fname,B)
[f,n] = sortrows(str2mat(B.LastName)); % Alphabetize.
A = B(n);
try,
   save(fname,'A');
catch,
   err = ['> Could not save file ' fname '.mat.']; 
   disp(err);
end
disp(['File saved and sorted: ' fname '.mat']);
return;

%----------
% Formats structure 'z' for displaying. 
% 'n' is the index in the book.
function format_out(z,n)
x=struct2cell(z);
for m=1:length(z),
   v=[]; % 'v' holds the indices of non-blank fields.
   for k=1:size(x,1),   % Removing blank fields...
      if ~cellfun('isempty',x(k,:,m)),
         v=[v k];
      end
   end
   f = fieldnames(z(m));
   q=cell2struct(x(v,:,m),f(v),1);
   % Print in nice format...
   X = upper(z(m).LastName(1));
   disp(['  [ ' X ' ]~~~~~~~~~~~|-' int2str(n(m)) ...
         '-|~~~~~~~~~~~~~~~~']);
   disp(' ');
   disp( q );
   disp(['  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~']);
   disp(' ');
end
return;

%----------
% Ask user for permission to save changes.
function quitting(A,fname,chg)
if chg & strcmp(lower(input('Save changes? (y/n) ','s')),'y'),
   save_book(fname,A);
end
return;


%------- End adress.m -------------