// Purpose. Mediator design pattern lab
//
// Discussion. In this design, each user "knows" its groups, and each group
// "knows" its users. The many-to-many mapping between the User class and the
// Group class couples them together. If we "objectified" this mapping rela-
// tionship several benefits would result: the two classes are no longer
// coupled, many mappings could be supported simply by creating many "mediator"
// instances, and the "mediator" abstraction could be refined through
// inheritance.
//
// Assignment.
// o The new main() and the Mediator implementation are provided.
// o Create a Mediator declaration. It's state will include: array of 10 ptrs
// to Group, array of 10 ptrs to User, totalGroups int, totalUsers int, 10x10
// matrix of int for the "mapping". It's behavior will include:
// addUser(User*), addGroup(Group*), map(User*,Group*), reportUsers(Group*),
// reportGroups(User*)
// o User::addGroup() and Group::addUser() have been moved to Mediator
// o User::groups_ and Group::users_ have been moved to Mediator
// o User and Group ctors need to accept a reference to the Mediator instance
// o User::reportGroups() and Group::reportUsers() now delegate to the Mediator

#include <iostream.h>
#include <string.h>

class Group;

class User {
public:
User( char* );
const char* getName();
void addGroup( Group* );
void reportGroups();
private:
char name_[15];
Group* groups_[10];
int total_;
};

class Group {
public:
Group( char* );
const char* getName();
void addUser( User* );
void reportUsers();
private:
char name_[15];
User* users_[10];
int total_;
};

User::User( char* name ) {
strcpy( name_, name );
total_ = 0;
}
const char* User::getName() { return name_; }
void User::addGroup( Group* group ) { groups_[total_++] = group; }
void User::reportGroups() {
cout << " " << name_ << ": ";
for (int i=0; i < total_; i++)
cout << ((i == 0) ? "" : ", ") << groups_[i]->getName();
cout << endl;
}


Group::Group( char* name ) {
strcpy( name_, name );
total_ = 0;
}
const char* Group::getName() { return name_; }
void Group::addUser( User* user ) { users_[total_++] = user; }
void Group::reportUsers() {
cout << " " << name_ << ": ";
for (int i=0; i < total_; i++)
cout << ((i == 0) ? "" : ", ") << users_[i]->getName();
cout << endl;
}

void main( void ) {
User* users[4];
Group* groups[4];
users[0] = new User( "Kermit" );
users[1] = new User( "Gonzo" );
users[2] = new User( "Fozzy" );
users[3] = new User( "Piggy" );
groups[0] = new Group( "Green" );
groups[1] = new Group( "ColdBlooded" );
groups[2] = new Group( "Male" );
groups[3] = new Group( "Muppets" );

for (int i=0; i < 4; i++)
for (int j=0; j <= i; j++) {
groups[i]->addUser( users[j] );
users[j]->addGroup( groups[i] ); }

cout << "Groups:" << endl;
for (i=0; i < 4; i++) groups[i]->reportUsers();

cout << "Users:" << endl;
for (i=0; i < 4; i++) users[i]->reportGroups();

for (i=0; i < 4; i++) { delete users[i]; delete groups[i]; }
}

// Groups:
// Green: Kermit
// ColdBlooded: Kermit, Gonzo
// Male: Kermit, Gonzo, Fozzy
// Muppets: Kermit, Gonzo, Fozzy, Piggy
// Users:
// Kermit: Green, ColdBlooded, Male, Muppets
// Gonzo: ColdBlooded, Male, Muppets
// Fozzy: Male, Muppets
// Piggy: Muppets

#if 0
Mediator::Mediator() {
totalGroups_ = 0;
totalUsers_ = 0;
for (int i=0; i < 10; i++)
for (int j=0; j < 10; j++)
mappings_[i][j] = 0;
}
void Mediator::addUser( User* user ) {
users_[totalUsers_++] = user;
}
void Mediator::addGroup( Group* group ) {
groups_[totalGroups_++] = group;
}

void Mediator::map( User* user, Group* group ) {
int i, j;
for (i=0; i < totalGroups_; i++)
if ( ! strcmp( groups_[i]->getName(), group->getName() ) )
break;
for (j=0; j < totalUsers_; j++)
if ( ! strcmp( users_[j]->getName(), user->getName() ) )
break;
mappings_[i][j] = 1;
}
void Mediator::reportUsers( Group* g ) {
int i, j, first;
for (i=0; i < totalGroups_; i++)
if ( ! strcmp( groups_[i]->getName(), g->getName()))
break;
for (j=0, first=1; j < totalUsers_; j++)
if (mappings_[i][j]) {
cout << ((first) ? "" : ", ") << users_[j]->getName();
first = 0;
}
cout << endl;
}
void Mediator::reportGroups( User* u ) {
int i, j, first;
for (j=0; j < totalUsers_; j++)
if ( ! strcmp( users_[j]->getName(), u->getName()))
break;
for (i=0, first=1; i < totalGroups_; i++)
if (mappings_[i][j]) {
cout << ((first) ? "" : ", ") << groups_[i]->getName();
first = 0;
}
cout << endl;
}

void main( void ) {
User* users[4];
Group* groups[4];
Mediator mapping;
users[0] = new User( "Kermit", mapping );
users[1] = new User( "Gonzo", mapping );
users[2] = new User( "Fozzy", mapping );
users[3] = new User( "Piggy", mapping );
groups[0] = new Group( "Green", mapping );
groups[1] = new Group( "ColdBlooded", mapping );
groups[2] = new Group( "Male", mapping );
groups[3] = new Group( "Muppets", mapping );

for (int i=0; i < 4; i++) {
mapping.addUser( users[i] );
mapping.addGroup( groups[i] ); }

for (i=0; i < 4; i++)
for (int j=0; j <= i; j++)
mapping.map( users[j], groups[i] );

cout << "Groups:" << endl;
for (i=0; i < 4; i++) groups[i]->reportUsers();

cout << "Users:" << endl;
for (i=0; i < 4; i++) users[i]->reportGroups();

for (i=0; i < 4; i++) { delete users[i]; delete groups[i]; }
}
#endif