package main

import (
	"bufio"
	"database/sql"
	"fmt"
	"os"
	"strconv"

	_ "github.com/lib/pq"
)

type db interface {
	Create()
	Count()
	ListAll()
}

type contact struct {
	id        int    `db:"id"`
	age       int    `db:"age"`
	firstName string `db:"first_name"`
	lastName  string `db:"last_name"`
	email     string `db:"email"`
}

func main() {
	db := connectDB()

	for opt := buildOptions(); opt != 0; {

		switch opt {
		case 0:
			fmt.Println("Quitting")
			return
		case 1:
			c := buildContact()
			c.addNewUser(db)
			fmt.Println("User Added With ID ", c.id)
			break
		case 2:
			fmt.Println("List All Users")
			listAllUsers(db)
		case 3:
			fmt.Println("Edit a user")
		case 4:
			fmt.Println("Remove a user")
		case 5:
			fmt.Println("Find Contact")
			buildFindUser(db)
		}

		opt = buildOptions()
	}
}

func connectDB() *sql.DB {
	const (
		host     = "localhost"
		port     = 5432
		user     = "golang"
		password = "golang_password"
		dbName   = "storekeeper"
	)

	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable", host, port, user, password, dbName)
	db, err := sql.Open("postgres", dsn)
	if err != nil {
		panic(err)
	}

	err = db.Ping()
	if err != nil {
		panic(err)
	}

	fmt.Println("Connection established")
	return db
}

func buildOptions() int {
	defer recover()
	fmt.Printf("Welcome to Your Personal Organizer\n***Options***\nNew Contact (1)\tAll Contacts (2)\tEdit Contact (3)\tRemove Contact (4)\tFind User (5)\n")
	r := bufio.NewScanner(os.Stdin)
	opCode := 0

	if r.Scan() {
		opt, err := strconv.Atoi(r.Text())
		if err != nil {
			panic(err)
		}
		opCode = opt
	}
	return opCode
}

func buildContact() *contact {
	defer recover()
	var c contact
	r := bufio.NewScanner(os.Stdin)
	fmt.Println("Enter Firstname")
	if r.Scan() {
		c.firstName = r.Text()
	}

	fmt.Println("Enter Lastname")
	if r.Scan() {
		c.lastName = r.Text()
	}
	fmt.Println("Enter Email")
	if r.Scan() {
		c.email = r.Text()
	}

	fmt.Println("Enter Age:")
	if r.Scan() {
		age, err := strconv.Atoi(r.Text())
		if err != nil {
			panic(err)
		}
		c.age = age
	}

	return &c
}

func buildFindUser(db *sql.DB) {
	r := bufio.NewScanner(os.Stdin)
	fmt.Println("How do you want to find The User?")
	var id int
	if r.Scan() {
		i, err := strconv.Atoi(r.Text())
		if err != nil {
			panic(err)
		}
		id = i
	}

	findAUser(id, db)

}

func (c *contact) addNewUser(db *sql.DB) {
	//create user at this point.
	stmt := "INSERT INTO users (first_name,last_name,email,age) VALUES($1,$2,$3,$4)"
	res, err := db.Exec(stmt, c.firstName, c.lastName, c.email, c.age)
	if err != nil {
		panic(err)
	}
	lastID, err := res.LastInsertId()
	if err != nil {
		panic(err)
	}
	c.id = int(lastID)
	fmt.Println("User Added Successfully.")
}

func listAllUsers(db *sql.DB) {
	stmt := "SELECT id,first_name,last_name,email,age FROM users"
	res, err := db.Query(stmt)
	if err != nil {
		panic(err)
	}

	for res.Next() {
		var c contact
		res.Scan(&c.id, &c.firstName, &c.lastName, &c.email, &c.age)
		fmt.Printf("Fullname: %s\t Email: %s\tAge: %d\n", c.firstName+" "+c.lastName, c.email, c.age)
	}
}

func findAUser(id int, db *sql.DB) {
	var c contact
	stmt := "SELECT id,first_name,last_name,email,age FROM users WHERE ID=$1"
	row := db.QueryRow(stmt, id)
	switch err := row.Scan(&c.id, &c.firstName, &c.lastName, &c.email, &c.age); err {
	case sql.ErrNoRows:
		fmt.Println("No User found with the provided ID.")
	case nil:
		fmt.Printf("User Found Name: %s \tEmail: %s\tAge:%d\n", c.firstName+" "+c.lastName, c.email, c.age)
	default:
		panic(err)
	}
}