main.go

package main

import (
	"bufio"
	"fmt"
	badger "github.com/dgraph-io/badger/v3"
	"github.com/sarthak815/Library-Management-System/codeModules" //Importing all the code modules
	"log"
	"os"
)

var lib codeModules.Library
var db *badger.DB

func main() {

	scanner := bufio.NewScanner(os.Stdin)
	var err error
	db, err = badger.Open(badger.DefaultOptions("C:\\Users\\Sanjay\\OneDrive - Manipal Academy of Higher Education\\Documents\\GitHub\\Blockchain_Dev\\Task5-Library Management System(Persistent Version)\\tmp\\badger"))
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()
	//To keep program running for multiple operations
	for {
		fmt.Println("Enter 1.Enter Librarian Interface\n2.Enter User Interface\n3.Enter API\n4.Exit")
		var n int
		fmt.Scanln(&n) // Option choice stored
		switch n {
		// Enter Library Management System
		case 1:
			fmt.Println("Enter 1.Enter Book in LibraryDB\n2.Exit")
			var n int
			fmt.Scanln(&n)
			switch n {
			//Case 1 enters new book in library
			case 1:
				newBook := new(codeModules.Books)
				//var typeBook string
				var bookType codeModules.BookType
				fmt.Println("Enter Book Type \n1.Ebook\n2. AudioBook\n3. HardBack\n4. PaperBack\n5. Encyclopedia\n6. Magazine\n7. Comic: ")
				fmt.Scanln(&bookType) //Stores book type to identify digital or physical
				bookType--            // Indexing of enum starts at 0
				fmt.Println("Enter Name of book: ")
				scanner.Scan()
				name := scanner.Text()
				fmt.Println("Enter Author of book: ")
				scanner.Scan()
				author := scanner.Text()
				// Indicates book to be of type eBook
				if bookType <= 1 {
					var capacity int
					fmt.Println("Enter borrowing limit: ") //Total copies available to borrow for digital
					fmt.Scanln(&capacity)
					newBook.Init(bookType, name, author, capacity)
					lib.BooksAvailable = append(lib.BooksAvailable, *newBook)

				}
				//Indicates book to be of Physical type
				if bookType > 1 && bookType <= 3 {
					newBook.Init(bookType, name, author, 1) // capaccity set to 1 as physical copy can only be 1 piece
					lib.BooksAvailable = append(lib.BooksAvailable, *newBook)

				}
				//Indicates book to be of Physical and Digital
				if bookType > 3 {
					fmt.Println("Enter:\n1.Digital\n2.Physical")
					var bookt, capacity int
					capacity = 1
					fmt.Scanln(&bookt)
					if bookt == 1 {
						fmt.Println("Enter borrowing limit for digital: ")
						fmt.Scanln(&capacity)
					}

					newBook.Init(bookType, name, author, capacity) //Creating digital copy

					lib.BooksAvailable = append(lib.BooksAvailable, *newBook)
				}

			// exit clause to quit library management interface
			case 2:
				break

			}
		//Enters user interface to register/borrow/return
		case 2:
			fmt.Println("1.Enter Member Details\n2.Borrow a book\n3.Return Book\n4.Exit")
			var n int
			fmt.Scanln(&n) //stores user choice
			switch n {
			case 1: //User registration portal
				member := new(codeModules.Member) //creates new member
				fmt.Println("Enter name:")
				scanner.Scan()
				name := scanner.Text()
				b := codeModules.CheckUserNameValidity(name, lib, db) // checks if username is valid
				if !b {
					fmt.Println("Username taken! Please Enter Full Name!")
					continue
				}
				var age int
				fmt.Println("Enter age:")
				fmt.Scanln(&age)
				member.Init(name, age)

				lib.Members = append(lib.Members, *member)

			case 2: //Book borrowing portal
				var verifiedMember *codeModules.Member //used to obtain user details
				var b bool                             //checks if username is valid
				fmt.Println("Enter your name: ")
				scanner.Scan()
				name := scanner.Text()
				b, verifiedMember = codeModules.CheckUserValidity(name, &lib, db) //checks username validity and number of books that user has borrowed is below 5
				if b {                                                            //if user is valid and registered
					fmt.Println("Identity verified")
					var btype codeModules.BookType
					fmt.Println("Enter BookType: \n1.Ebook\n2. AudioBook\n3. HardBack\n4. PaperBack\n5. Encyclopedia\n6. Magazine\n7. Comic: ")
					fmt.Scanln(&btype) //checks for book type in case of book being available in both digital and physical versions
					fmt.Println("Enter Book name: ")
					scanner.Scan()
					bname := scanner.Text()                                                             //stores book name to be borrowed
					bfound, bookFound := codeModules.CheckBookValidity(bname, &lib, verifiedMember, db) //checks if book is available then stores book pointed to bookFound
					if bfound {
						if !bookFound.Borrow() { //Borrow() checks if book id available to borrow
							fmt.Println("Book Unavailable")
							continue
						}
						verifiedMember.BooksBorrowed = append(verifiedMember.BooksBorrowed, *bookFound)
						codeModules.PrintBookDetails(bookFound) //displays details of book borrowed
					}
					if !bfound { //in case book not present in struct
						fmt.Println("Book Not found/User already borrowed 5 books/Requested book borrowed!!")
					}

				} else { //in case user details not present in struct
					fmt.Println("Details not found or Already reached limit!")
				}

			case 3: //Portal for user to return book

				fmt.Println("Enter your name: ")
				scanner.Scan()
				name := scanner.Text()
				b, member := codeModules.CheckUserValidityReturn(name, &lib, db) //checks validity of user
				if b {
					fmt.Println("Identity verified")
					var btype codeModules.BookType
					fmt.Println("Enter BookType: \n1.Ebook\n2. AudioBook\n3. HardBack\n4. PaperBack\n5. Encyclopedia\n6. Magazine\n7. Comic: ")
					fmt.Scanln(&btype)
					fmt.Println("Enter Book name: ")
					scanner.Scan()
					bname := scanner.Text()
					bfound, bookFound := codeModules.CheckUserBookValidity(bname, lib, *member, db) //checks if book is available and borrowed then stores book pointed to bookFound

					if bfound {
						bookFound.Return()                                                             //modifies book borrowed value
						idx := codeModules.BookIndex(member.BooksBorrowed, *bookFound)                 //obtains index of borrowed book in user struct
						member.BooksBorrowed = codeModules.RemoveBookMember(member.BooksBorrowed, idx) //removes returned book from user struct
						fmt.Println("Book Returned")
					}
					if !bfound { //in case book not found in directory
						fmt.Println("Book Not found or not borrowed!!")
					}

				} else { //if user details not present in library
					fmt.Println("Details not found!! Please Register yourself!")
				}
			case 4: //exit clause for user portal
				break
			}
		//Sets the program to begin accepting api calls on localhost:10000
		case 3:
			handleRequests()
		//exit clause to close application
		case 4:
			//writes all data into library struct before exiting the program
			writeBooksToDB()
			writeMembersToDB()
			os.Exit(0)
		}

	}

}