// CSE 00au HW3 main file
//
// Bookstore.cpp - the main file for the program that tracks the inventory
// at a bookstore
// 

#include <string>
#include <iostream>
#include <fstream>
#include "BookInfo.h"
#include "Inventory.h"

// The functions defined here are all helper functions for main().
// Most are called only once from main(), but they are separated out
// to make main() a small, easier-to-read function.  (I could easily
// have simply written main() as one large function full of blocks,
// each of which had its own comment.  But we never want any
// excessively long functions.)  Generally, it is undesirable in C++
// to have any functions that are not members of a class.  But all
// these functions should really be "static functions of a class",
// something we have not covered yet.  Thus, I decided to use the
// more C-like style of defining helper functions that are not part of
// a class; it's not the best C++ style, but many programmers do when
// switching from C to C++.
bool read_inventory_file(Inventory &inv, char *filename); 
bool write_inventory_file(Inventory &inv, char *filename);
string read_to_pound_sign(istream &infile);
bool deliver(Inventory &stock);
void buy(Inventory &stock, Inventory &reorder);
void list_author(Inventory &stock);
void list_genre(Inventory &stock);
book_genre genre_prompt();

// Main function of the program.
// Read an inventory file for a bookstore and process it.

// Handle transactions, then write an new inventory file and display

// re-order information when the user quits for the day.
int main() {

  Inventory stock;		// current inventory 
  Inventory reorder;	// list of books to reorder
  char filename[256];	// name of inventory file

  cout << "Please enter the filename for your inventory list." << endl;
  cin >> filename;
  if (!read_inventory_file(stock, filename)) {
    cout << "ERROR READING INVENTORY FILE" << endl;
    return 1;
  }

  bool quit = false;
  string cmd;  // input command.  Read as a string to consume following newline
  while (!quit) {
    cout << "What would you like to do now? " << endl;
    cout << "d - deliver books" << endl;
    cout << "b - buy a book (title known)" << endl;
    cout << "a - list the books in stock by a given author" << endl;
    cout << "g - list the books in stock in a given genre" << endl;
    cout << "q - close the shop and quit for the day " << endl;
    cin >> cmd;
    if (cmd == "d")
      deliver(stock);
    else if (cmd == "b")
      buy(stock, reorder);
    else if (cmd == "a")
      list_author(stock);
    else if (cmd == "g")
      list_genre(stock);
    else if (cmd == "q")
      quit = true;
    else
      cout << "Input not understood.  Please use a valid command (d, b, a, g or q). " << endl;
  }
  cout << "Please enter the filename for your new inventory list." << endl;
  cin >> filename;
  if (!write_inventory_file(stock, filename)) {
    cout << "ERROR WRITING INVENTORY FILE" << endl;
  }
    
  reorder.sort();
  int i = reorder.numBooks();
  BookInfo b;
  cout << "The "<< i << " books to reorder are:" << endl;
  while (i--) {
    reorder.getBook(i, b);
    cout << b;
  }
  return 0;
}

// Read the inventory from file with given name and store into inv
// Return true if successful, false if the inventory file can't be
// opened, or if an input error is detected.
bool read_inventory_file(Inventory &inv, char *filename) {
  ifstream infile(filename);
  string s; // temporary place-holder
  string title, author;  //info about a book
  book_genre genre;
  int copies; 
  BookInfo book; // new book being created
  if (!infile)
    return false;
  while (infile >> s) {
    if (s != "##")
      return false;

    title = read_to_pound_sign(infile);
    if (title == "")
      return false;
    author = read_to_pound_sign(infile);
    if (author == "")
      return false;

    s = read_to_pound_sign(infile);
    if (s == "CHILDRENS")
      genre = CHILD;
    else if (s == "SCI_FI_FANTASY")
      genre = SF_F;
    else if (s == "CLASSICS")
      genre = CLASS;
    else if (s == "FICTION")
      genre = FICT;
    else return false;
    
    infile >> copies;

    book.reset(title, author, genre, copies);
    inv.insert(book);
  }

  return true;
}

// Read from the infile until a pound sign is read.  Return the 
// sequence of words up to that point, separated by spaces
// Returns "" if the end of file is reached before reading a #
string read_to_pound_sign(istream &infile) {
  string s = "", temp; // the string we're creating, and temporary storage
  infile >> s;
  while (infile >> temp) {
    if (temp == "#")
      return s;
    s += " " + temp;
  }
  return "";
}
    
bool write_inventory_file(Inventory &inv, char *filename) {
  ofstream outfile(filename);	// output stream
  BookInfo b;					// pointer to the book we are now writing


  if (!outfile)
    return false;
  for (int i = 0; i < inv.numBooks(); i++) {
    inv.getBook(i, b);
    outfile << "## " << b.getTitle() << " # " << b.getAuthor();
    switch (b.getGenre()) {
    case CHILD:
      outfile << " # CHILDRENS # ";
      break;
    case SF_F:
      outfile << " # SCI_FI_FANTASY # ";
      break;
    case CLASS:
      outfile << " # CLASSICS # ";
      break;
    case FICT:
      outfile << " # FICTION # ";
      break;
    }
    outfile << b.getNumCopies() << endl;
  }
  return true;
}

// Adds copies of a new book to the inventory
//
bool deliver(Inventory &stock) {
  string title, author;		//title and author of book being delivered
  book_genre genre;			//actual genre of the book
  int copies;				//number of copies


  cout << "Please enter how many books you have to deliver:" << endl;
  cin >> copies;
  cout << "Please enter the title of the books followed by a pound sign:" << endl;
  title = read_to_pound_sign(cin); 
  cout << "Please enter the author of the books (last name, initials or first name) followed by a pound sign:" << endl;
  author = read_to_pound_sign(cin); 
  genre = genre_prompt();
  if (genre == ERROR)
    return false;
  BookInfo b(title, author, genre, copies);
  return stock.insert(b);
}
  
// Asks the customer what book they would like to buy, and if it's in
// stock, allows them to purchase it.  If they purchase the last copy,
// remove it from current stock and add it to the reorder list.
//
void buy(Inventory &stock, Inventory &reorder) {
  string title;		// title of book being purchased


  int n; // number of copies the customer wants
  cout << "Please enter the title of the book you'd like to buy followed by a pound sign." << endl;
  title = read_to_pound_sign(cin); 
  BookInfo b = stock.title_search(title);
  if (b.getGenre() == ERROR) {
    cout << "I am sorry, but we are all out of that book.  Please try back again or pick something else to read." << endl;
    return;
  }
  int numInStock = b.getNumCopies();
  cout << "We have " << numInStock <<
    " of that book.  How many would you like to buy?" << endl;
  cin >> n;
  if (n >= numInStock)
    reorder.insert(b);
  stock.sell(n, title);
}

// Asks the customer for the name of an author and prints everything
// by them.
//
void list_author(Inventory &stock) {
  string author;
  cout << "Please enter the author of the books (last name, initials or first name) followed by a pound sign:" << endl;
  author = read_to_pound_sign(cin); 
  Inventory by_author;
  stock.author_search(author, by_author);
  by_author.sort();
  by_author.print();
}

// Asks the customer for a genre and prints every such book in stock.
//
void list_genre(Inventory &stock) {
  book_genre genre = genre_prompt();
  if (genre == ERROR)
    return;
  Inventory in_genre;
  stock.genre_search(genre, in_genre);
  in_genre.sort(); 
  in_genre.print();
}

// Prompts for someone to enter a book genre.  Returns what they
// input.
book_genre genre_prompt() {
  int genre_input; // input number given for genre
  cout << "Please enter book genre: " << endl;
  cout << "1 = Sci-Fi/Fantasy, 2 = Fiction, 3 = Classics, 4 = Childrens."<< endl;
  cin >> genre_input;
  switch (genre_input) {
  case 1:
    return SF_F;
  case 2:
    return FICT;
  case 3:
    return CLASS;
  case 4:
    return CHILD;
  default:
    cout << "Invalid input." << endl;    
    return ERROR;
  }
}