package db

import (
	"JISQueueing/common"
	"database/sql"
	"errors"
)

//ErrVisitorNotFound indicates that the email does not belong to an existing visitor (new account).
var ErrVisitorNotFound = errors.New("visitor email does not exist")

//GetAllVisitors returns a list of all visitors in our record.
func GetAllVisitors() []common.Visitor {
	rows, _ := db.Query("SELECT * FROM clients")
	defer rows.Close()

	return convertIntoVisitors(rows)
}

//GetVisitor retrieves the visitor with the specified ID in the form of  `common.Visitor`.
func GetVisitor(email string) (common.Visitor, error) {
	rows, _ := db.Query("SELECT * FROM clients WHERE email=? COLLATE NOCASE", email)
	defer rows.Close()
	visitors := convertIntoVisitors(rows)
	if len(visitors) == 0 {
		return common.Visitor{}, ErrVisitorNotFound
	}
	return visitors[0], nil
}

//NewVisitor saves the provided visitor and returns whether the email is new (first time) or already used (old, and update name).
func NewVisitor(visitor common.Visitor) (bool, common.Visitor) {
	exists, editVisitor := EditVisitor(visitor)
	if exists {
		return false, editVisitor
	}

	result, _ := db.Exec("INSERT INTO clients (email, name, first_ticket) VALUES (?, ?, ?)", visitor.Email, visitor.Name, -1)
	rowsAffected, _ := result.RowsAffected()
	return rowsAffected > 0, visitor
}

//EditVisitor updates the provided visitor with the new name associated with the email.
func EditVisitor(visitor common.Visitor) (bool, common.Visitor) {
	result, _ := db.Exec("UPDATE clients SET name=? WHERE email=? COLLATE NOCASE", visitor.Name, visitor.Email)
	rowsAffected, _ := result.RowsAffected()

	updated, _ := GetVisitor(visitor.Email)
	return rowsAffected > 0, updated
}

//SetFirstTicket updates the first ticket column for the provided visitor
func SetFirstTicket(visitor common.Visitor) bool {
	result, _ := db.Exec("UPDATE clients SET first_ticket=? WHERE email=? COLLATE NOCASE", visitor.FirstTicket, visitor.Email)
	rowsAffected, _ := result.RowsAffected()

	return rowsAffected > 0
}

//convertIntoVisitors converts the result set from a sql query of a rows of visitors into a []common.Visitor.
func convertIntoVisitors(rows *sql.Rows) []common.Visitor {
	visitors := make([]common.Visitor, 0)
	for rows.Next() {
		var email string
		var name string
		var firstTicket int
		rows.Scan(&email, &name, &firstTicket)

		visitor := common.Visitor{
			Email:       email,
			Name:        name,
			FirstTicket: firstTicket,
		}
		visitors = append(visitors, visitor)
	}
	return visitors
}