package cmd

import (
	"database/sql"
	"fmt"
	"log"
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"
)

// //////////////////////////////////////////////////////////////////////////
// Check whether user exists or not in the database
// //////////////////////////////////////////////////////////////////////////
func checkUserExists(id string) bool {
	dynStmt := `SELECT id_usuario FROM usuarios WHERE id_usuario = $1`
	err := db.QueryRow(dynStmt, id).Scan()
	if err == sql.ErrNoRows {
		return false
	} else {
		return true
	}
}

// //////////////////////////////////////////////////////////////////////////
// Modify a user by its ID
// //////////////////////////////////////////////////////////////////////////
func modifyUser(c *gin.Context) {
	id := c.Param("userid")
	dynStmt := `UPDATE usuarios SET email=$1,nombre=$2,apellido1=$3,apellido2=$4,password=$5 WHERE id_usuario = $6`

	_, err := strconv.Atoi(id)
	if err != nil {
		e := fmt.Sprintf("Invalid identifier")
		c.IndentedJSON(http.StatusNotFound, setResponse(e, false))
		return
	}

	if exists := checkUserExists(id); exists != true {
		c.IndentedJSON(http.StatusNotFound, setResponse("User not found", false))
		return
	}

	user := user{}
	if err := c.BindJSON(&user); err != nil {
		e := fmt.Sprintf("Something went wrong updating the user: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}

	_, err = db.Exec(dynStmt, user.Email, user.Name, user.Surname1, user.Surname2, hashPW(user.Password), id)
	if err != nil {
		e := fmt.Sprintf("Something went wrong trying to modify the user: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}

	c.IndentedJSON(http.StatusOK, setResponse("User successfully modified", true))
}

// //////////////////////////////////////////////////////////////////////////
// Delete a user by its ID
// //////////////////////////////////////////////////////////////////////////
func deleteUser(c *gin.Context) {
	id := c.Param("userid")
	dynStmt := `DELETE FROM usuarios WHERE id_usuario = $1`

	_, err := strconv.Atoi(id)
	if err != nil {
		e := fmt.Sprintf("Invalid identifier")
		c.IndentedJSON(http.StatusNotFound, setResponse(e, false))
		return
	}

	if exists := checkUserExists(id); exists != true {
		c.IndentedJSON(http.StatusNotFound, setResponse("User not found", false))
		return
	}

	_, err = db.Exec(dynStmt, id)
	if err != nil {
		e := fmt.Sprintf("Something went wrong trying to delete the user: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}
	c.IndentedJSON(http.StatusOK, setResponse("User successfully deleted", true))
}

// //////////////////////////////////////////////////////////////////////////
// Create a new user
// //////////////////////////////////////////////////////////////////////////
func createUser(c *gin.Context) {
	newuser := user{}
	if err := c.BindJSON(&newuser); err != nil {
		e := fmt.Sprintf("Something went wrong creating the user: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}

	var dynStmt string
	if newuser.AccountType != "estudiante" && newuser.AccountType != "profesor" {
		if newuser.AccountType == "admin" {
			c.IndentedJSON(http.StatusTeapot, setResponse("Nice try (https://xkcd.com/327/)", false))
			return
		}
		c.IndentedJSON(http.StatusNotFound, setResponse("Invalid account type", false))
		return
	}
	dynStmt = `INSERT INTO usuarios(nombre, apellido1, apellido2, email, password, rol) values($1, $2, $3, $4, $5, $6)`
	_, err := db.Exec(dynStmt, newuser.Name, newuser.Surname1, newuser.Surname2, newuser.Email, hashPW(newuser.Password), newuser.AccountType)
	if err != nil {
		e := fmt.Sprintf("Something went wrong trying to create the user: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}
	e := fmt.Sprintf("User %v has been created!", newuser.Name)
	c.IndentedJSON(http.StatusOK, setResponse(e, true))
}

// //////////////////////////////////////////////////////////////////////////
// Query an individual user by its ID
// //////////////////////////////////////////////////////////////////////////
func getUser(c *gin.Context) {
	id := c.Param("userid")

	_, err := strconv.Atoi(id)
	if err != nil {
		e := fmt.Sprintf("Invalid identifier")
		c.IndentedJSON(http.StatusNotFound, setResponse(e, false))
		return
	}

	user := userNoPass{}
	dynStmt := `SELECT id_usuario,nombre,apellido1,apellido2,email,rol FROM usuarios WHERE id_usuario = $1`
	err = db.QueryRow(dynStmt, id).Scan(&user.Id, &user.Name, &user.Surname1, &user.Surname2, &user.Email, &user.AccountType)
	if err != nil {
		if err == sql.ErrNoRows {
			c.IndentedJSON(http.StatusNotFound, setResponse("User not found", false))
			return
		}
		e := fmt.Sprintf("SOMETHING BAD HAPPENED QUERYING THE DATABASE: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}
	c.IndentedJSON(http.StatusOK, setResponse(user, true))
}

// //////////////////////////////////////////////////////////////////////////
// Query all users in the database
// //////////////////////////////////////////////////////////////////////////
func getUsers(c *gin.Context) {
	users := []userNoPass{}
	rows, err := db.Query("SELECT id_usuario,nombre,apellido1,apellido2,email,rol FROM usuarios")
	if err != nil {
		e := fmt.Sprintf("SOMETHING BAD HAPPENED QUERYING THE DATABASE: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}
	defer rows.Close()
	for rows.Next() {
		user := userNoPass{}
		err = rows.Scan(&user.Id, &user.Name, &user.Surname1, &user.Surname2, &user.Email, &user.AccountType)
		if err != nil {
			e := fmt.Sprintf("SOMETHING BAD HAPPENED SCANNING THE ROWS: %v", err)
			log.Println(e)
			c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
			return
		}
		users = append(users, user)
	}
	c.IndentedJSON(http.StatusOK, setResponse(users, true))
}

// //////////////////////////////////////////////////////////////////////////
// Log into the server by comparing hashed passwords
// //////////////////////////////////////////////////////////////////////////
func userLogin(c *gin.Context) {
	u := user{}
	uDB := user{}
	if err := c.BindJSON(&u); err != nil {
		e := fmt.Sprintf("Something went wrong logging into the user: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}
	dynStmt := `SELECT password FROM usuarios WHERE email = $1`
	err := db.QueryRow(dynStmt, u.Email).Scan(&uDB.Password)
	if err != nil {
		if err == sql.ErrNoRows {
			c.IndentedJSON(http.StatusNotFound, setResponse("User not found", false))
			return
		}
		e := fmt.Sprintf("Something went REALLY wrong logging into the user: %v", err)
		log.Println(e)
		c.IndentedJSON(http.StatusInternalServerError, setResponse(e, false))
		return
	}

	if hashPW(u.Password) != uDB.Password {
		c.IndentedJSON(http.StatusUnauthorized, setResponse("INCORRECT PASSWORD", false))
	} else {
		c.IndentedJSON(http.StatusOK, setResponse("CORRECT PASSWORD :D", true))
	}
}