package api

import (
	"errors"
	"fmt"
	"github.com/google/uuid"
	"go-nkode/models"
)

type NKodeAPI struct {
	Customers      map[uuid.UUID]Customer
	SignupSessions map[uuid.UUID]UserSignSession
}

func NewNKodeAPI() NKodeAPI {
	return NKodeAPI{
		Customers:      make(map[uuid.UUID]Customer),
		SignupSessions: make(map[uuid.UUID]UserSignSession),
	}
}

func (n *NKodeAPI) CreateNewCustomer(keypadSize models.KeypadSize, nkodePolicy models.NKodePolicy) (*uuid.UUID, error) {
	newCustomer, err := NewCustomer(keypadSize, nkodePolicy)
	if err != nil {
		return nil, err
	}
	n.Customers[newCustomer.CustomerId] = *newCustomer
	return &newCustomer.CustomerId, nil
}

func (n *NKodeAPI) GenerateSignupInterface(customerId uuid.UUID) (*uuid.UUID, []int, error) {
	customer, exists := n.Customers[customerId]
	if !exists {
		return nil, nil, errors.New(fmt.Sprintf("customer doesnt exists: %s", customerId.String()))
	}

	signupSession, err := NewSignupSession(customer.Attributes.KeypadSize, customer.CustomerId)
	if err != nil {
		return nil, nil, err
	}
	n.SignupSessions[signupSession.SessionId] = *signupSession
	return &signupSession.SessionId, signupSession.SetInterface, nil
}

func (n *NKodeAPI) SetNKode(username string, customerId uuid.UUID, keySelection []int, sessionId uuid.UUID) ([]int, error) {
	_, exists := n.Customers[customerId]
	if !exists {
		return nil, errors.New(fmt.Sprintf("set nkode customer id does not exist %s", customerId.String()))
	}

	session, exists := n.SignupSessions[sessionId]
	if !exists {
		return nil, errors.New(fmt.Sprintf("session id does not exist %s", sessionId.String()))
	}
	confirmInterface, err := session.SetUserNKode(username, keySelection)
	if err != nil {
		return nil, err
	}
	n.SignupSessions[sessionId] = session
	return confirmInterface, nil
}

func (n *NKodeAPI) ConfirmNKode(customerId uuid.UUID, keySelection []int, sessionId uuid.UUID) error {
	session, exists := n.SignupSessions[sessionId]
	if !exists {
		return errors.New(fmt.Sprintf("session id does not exist %s", sessionId.String()))
	}
	customer, exists := n.Customers[customerId]
	passcode, err := session.DeducePasscode(keySelection)
	if err != nil {
		return err
	}
	err = customer.IsValidNKode(passcode)
	if err != nil {
		return err
	}
	err = customer.AddNewUser(session.Username, passcode, session.LoginInterface)
	if err != nil {
		return err
	}
	delete(n.SignupSessions, session.SessionId)
	n.Customers[customerId] = customer
	return nil
}

func (n *NKodeAPI) GetLoginInterface(username string, customerId uuid.UUID) ([]int, error) {
	err := n.customerUserExists(username, customerId)
	if err != nil {
		return nil, err
	}
	user := n.Customers[customerId].Users[username]
	err = user.Interface.PartialInterfaceShuffle()
	if err != nil {
		return nil, err
	}
	n.Customers[customerId].Users[username] = user
	return user.Interface.IdxInterface, nil
}

func (n *NKodeAPI) Login(customerId uuid.UUID, username string, keySelection []int) error {
	customer, exists := n.Customers[customerId]
	if !exists {
		return errors.New(fmt.Sprintf("customer %s does not exist", customerId.String()))
	}
	user, exists := customer.Users[username]
	if !exists {
		return errors.New(fmt.Sprintf("user dne %s", username))
	}
	passcode, err := customer.ValidKeyEntry(username, keySelection)
	if err != nil {
		return err
	}
	if user.Renew {
		err = user.RefreshPasscode(passcode, customer.Attributes)
		if err != nil {
			return err
		}
	}
	return nil
}

func (n *NKodeAPI) customerUserExists(username string, customerId uuid.UUID) error {
	customer, exists := n.Customers[customerId]
	if !exists {
		return errors.New(fmt.Sprintf("customer %s does not exist", customerId.String()))
	}
	_, exists = customer.Users[username]
	if !exists {
		return errors.New(fmt.Sprintf("user dne %s", username))
	}
	return nil
}

func (n *NKodeAPI) RenewAttributes(customerId uuid.UUID) error {
	customer, exists := n.Customers[customerId]
	if !exists {
		return errors.New(fmt.Sprintf("customer %s does not exist", customerId.String()))
	}
	return customer.RenewKeys()
}