// This program processes queries about the MP3 files available on various computers.  
// Each computer is identified by a unique id (a string).  Information about the computer, 
// including connection speed and a list of MP3's are stored in the computer class object.

#include <algorithm>
#include <iostream>
#include <list>
#include <map>
#include <string>
#include <cctype>
#include "mp3.h"
#include "computer.h"

typedef map<string, Computer> MP3_map;    // since the names of maps tend to be rather long.

void add_computer(MP3_map& mp3_system);   // prototypes of helper functions
void print_mp3s_on_computer(const MP3_map& mp3_system);
void find_song(const MP3_map& mp3_system);
void find_songs_by_artist(const MP3_map& mp3_system);

int main() {
  // the mp3 database
  MP3_map mp3_system;
  bool quit = false;
  // process the input
  char option;
  while (cin >> option) {
    switch (option) {
    case 'a':  add_computer(mp3_system); break;
    case 'p':  print_mp3s_on_computer(mp3_system); break;
    case 'f':  find_song(mp3_system); break;
    case 'F':  find_songs_by_artist(mp3_system); break;
    case 'q':  return 1; break;
    default:
      cout << "Error: " << option << " is not a valid command" << endl;;
      break;
    }
  }
}

// Add a computer to the map of MP3's
void add_computer(MP3_map& mp3_system) {
  string computer_id, line;
  double speed;
  // read id & speed
  cin >> computer_id >> speed;
  getline(cin, line); // read the rest of that line

  // Create a new computer & read its MP3's
  Computer new_computer(speed);
  do {
    string artist,title;
    getline(cin, artist);
    if (artist == "") break;
    getline(cin, title);
    new_computer.add_mp3(artist, title);
  } while (true);

  // Try to add the computer using the map insert function.
  pair<MP3_map::iterator, bool> result_pair = mp3_system.insert(make_pair(computer_id, new_computer));
  // make sure the computer isn't already there!
  assert(result_pair.second);
  cout << "Computer " << computer_id << " added." << endl;
}

// Print the MP3's for a given computer.
void print_mp3s_on_computer(const MP3_map& mp3_system) {
  string computer_id, line;
  // read id
  cin >> computer_id;
  getline(cin, line); 

  // Find the computer
  MP3_map::const_iterator c_itr = mp3_system.find(computer_id);
  if (c_itr == mp3_system.end()) {
    cout << "Computer " << computer_id << " is not in the system." << endl;
  } else {
    cout << "Songs found on " << computer_id << ":\n";
    c_itr->second.print_mp3s();
  }
}

// Find all computers with a particular song.
void find_song(const MP3_map& mp3_system) {
  string line, artist, title;
  getline(cin, line); // read the rest of request line
  // get the artist & title 
  getline(cin, artist); 
  getline(cin, title);

  // Iterate through the map, looking for the song.
  bool found = false;
  string computer_id;
  double speed;

  MP3_map::const_iterator c_itr;
  for (c_itr = mp3_system.begin(); c_itr != mp3_system.end(); c_itr++) {
    MP3 request;
    if (c_itr->second.has_song(artist, title, request)) {
      if (!found || c_itr->second.getSpeed() > speed) {
        found = true;
        computer_id = c_itr->first;
        speed = c_itr->second.getSpeed();
      }
    }
  }

  if (found)
    cout << "Fastest download for \"" << title << "\" by " << artist << " from " << computer_id << endl;
  else 
    cout << "No computer found with \"" << title << "\" by " << artist << endl;
}

// Find and output information about all songs by a given artist.
void find_songs_by_artist(const MP3_map& mp3_system) {
  string line, artist;
  getline(cin, line); // read the rest of request line
  // Get the artist.
  getline(cin, artist);

  // you need to write this for lab






}