// Package memory provides an in memory implementation of the storage interface.
package memory

import (
	"errors"
	"sync"

	"github.com/coreos/poke/storage"
)

// New returns an in memory storage.
func New() storage.Storage {
	return &memStorage{
		clients:       make(map[string]storage.Client),
		authCodes:     make(map[string]storage.AuthCode),
		refreshTokens: make(map[string]storage.Refresh),
		authReqs:      make(map[string]storage.AuthRequest),
	}
}

type memStorage struct {
	mu sync.Mutex

	clients       map[string]storage.Client
	authCodes     map[string]storage.AuthCode
	refreshTokens map[string]storage.Refresh
	authReqs      map[string]storage.AuthRequest

	keys storage.Keys
}

func (s *memStorage) tx(f func()) {
	s.mu.Lock()
	defer s.mu.Unlock()
	f()
}

var errAlreadyExists = errors.New("already exists")

func (s *memStorage) Close() error { return nil }

func (s *memStorage) CreateClient(c storage.Client) error {
	s.tx(func() { s.clients[c.ID] = c })
	return nil
}

func (s *memStorage) CreateAuthCode(c storage.AuthCode) error {
	s.tx(func() { s.authCodes[c.ID] = c })
	return nil
}

func (s *memStorage) CreateRefresh(r storage.Refresh) error {
	s.tx(func() { s.refreshTokens[r.RefreshToken] = r })
	return nil
}

func (s *memStorage) CreateAuthRequest(a storage.AuthRequest) error {
	s.tx(func() { s.authReqs[a.ID] = a })
	return nil
}

func (s *memStorage) GetClient(id string) (client storage.Client, err error) {
	s.tx(func() {
		var ok bool
		if client, ok = s.clients[id]; !ok {
			err = storage.ErrNotFound
		}
	})
	return
}

func (s *memStorage) GetKeys() (keys storage.Keys, err error) {
	s.tx(func() { keys = s.keys })
	return
}

func (s *memStorage) GetRefresh(token string) (tok storage.Refresh, err error) {
	s.tx(func() {
		var ok bool
		if tok, ok = s.refreshTokens[token]; !ok {
			err = storage.ErrNotFound
			return
		}
	})
	return
}

func (s *memStorage) GetAuthRequest(id string) (req storage.AuthRequest, err error) {
	s.tx(func() {
		var ok bool
		if req, ok = s.authReqs[id]; !ok {
			err = storage.ErrNotFound
			return
		}
	})
	return
}

func (s *memStorage) ListClients() (clients []storage.Client, err error) {
	s.tx(func() {
		for _, client := range s.clients {
			clients = append(clients, client)
		}
	})
	return
}

func (s *memStorage) ListRefreshTokens() (tokens []storage.Refresh, err error) {
	s.tx(func() {
		for _, refresh := range s.refreshTokens {
			tokens = append(tokens, refresh)
		}
	})
	return
}

func (s *memStorage) DeleteClient(id string) (err error) {
	s.tx(func() {
		if _, ok := s.clients[id]; !ok {
			err = storage.ErrNotFound
			return
		}
		delete(s.clients, id)
	})
	return
}

func (s *memStorage) DeleteRefresh(token string) (err error) {
	s.tx(func() {
		if _, ok := s.refreshTokens[token]; !ok {
			err = storage.ErrNotFound
			return
		}
		delete(s.refreshTokens, token)
	})
	return
}

func (s *memStorage) DeleteAuthCode(id string) (err error) {
	s.tx(func() {
		if _, ok := s.authCodes[id]; !ok {
			err = storage.ErrNotFound
			return
		}
		delete(s.authCodes, id)
	})
	return
}

func (s *memStorage) DeleteAuthRequest(id string) (err error) {
	s.tx(func() {
		if _, ok := s.authReqs[id]; !ok {
			err = storage.ErrNotFound
			return
		}
		delete(s.authReqs, id)
	})
	return
}

func (s *memStorage) GetAuthCode(id string) (c storage.AuthCode, err error) {
	s.tx(func() {
		var ok bool
		if c, ok = s.authCodes[id]; !ok {
			err = storage.ErrNotFound
			return
		}
	})
	return
}

func (s *memStorage) ClaimCode(id string) (err error) {
	s.tx(func() {
		if _, ok := s.authCodes[id]; !ok {
			err = storage.ErrNotFound
			return
		}
		delete(s.authCodes, id)
	})
	return
}

func (s *memStorage) ClaimRefresh(refreshToken string) (token storage.Refresh, err error) {
	s.tx(func() {
		var ok bool
		if token, ok = s.refreshTokens[refreshToken]; !ok {
			err = storage.ErrNotFound
			return
		}
		delete(s.refreshTokens, refreshToken)
	})
	return
}

func (s *memStorage) UpdateClient(id string, updater func(old storage.Client) (storage.Client, error)) (err error) {
	s.tx(func() {
		client, ok := s.clients[id]
		if !ok {
			err = storage.ErrNotFound
			return
		}
		if client, err = updater(client); err == nil {
			s.clients[id] = client
		}
	})
	return
}

func (s *memStorage) UpdateKeys(updater func(old storage.Keys) (storage.Keys, error)) (err error) {
	s.tx(func() {
		var keys storage.Keys
		if keys, err = updater(s.keys); err == nil {
			s.keys = keys
		}
	})
	return
}

func (s *memStorage) UpdateAuthRequest(id string, updater func(old storage.AuthRequest) (storage.AuthRequest, error)) (err error) {
	s.tx(func() {
		req, ok := s.authReqs[id]
		if !ok {
			err = storage.ErrNotFound
			return
		}
		if req, err := updater(req); err == nil {
			s.authReqs[id] = req
		}
	})
	return
}