package storage

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/internal/client"
	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/internal/db"
	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/internal/model"
	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/logger"
	"github.com/go-jose/go-jose/v4"
	"github.com/google/uuid"
	"github.com/zitadel/oidc/v3/pkg/oidc"
	"github.com/zitadel/oidc/v3/pkg/op"
)

func ErrNotImplemented(name string) error {
	return fmt.Errorf("%s is not implemented", name)
}

// Storage implements the Storage interface from zitadel/oidc/op
type Storage struct {
	LocalStorage        db.Storage
	InitializedBackends map[uuid.UUID]*client.OIDCClient
	Key                 *model.Key
}

/*
Auth storage interface
*/
func (s *Storage) CreateAuthRequest(ctx context.Context, req *oidc.AuthRequest, userID string) (op.AuthRequest, error) {

	// userID should normally be an empty string (to verify), we don't get it in our workflow from what I saw
	// TODO: check this is indeed not needed / never present
	logger.L.Debugf("Creating a new auth request")

	// validate that the connector is correct
	backendName, ok := stringFromCtx(ctx, "backendName")
	if !ok {
		return nil, errors.New("no backend name provided")
	}
	selectedBackend, err := s.LocalStorage.BackendStorage().GetBackendByName(ctx, backendName)
	if err != nil {
		return nil, fmt.Errorf("failed to get backend: %w", err)
	}

	var opReq model.AuthRequest
	opReq.FromOIDCAuthRequest(req, selectedBackend.ID)

	if err := s.LocalStorage.AuthRequestStorage().CreateAuthRequest(ctx, opReq); err != nil {
		return nil, fmt.Errorf("failed to save auth request: %w", err)
	}

	logger.L.Debugf("Created a new auth request for backend %s", backendName)

	return opReq, nil
}

func (s *Storage) AuthRequestByID(ctx context.Context, requestID string) (op.AuthRequest, error) {
	logger.L.Debugf("Getting auth request with ID %s", requestID)

	id, err := uuid.Parse(requestID)
	if err != nil {
		return nil, fmt.Errorf("invalid format for uuid: %w", err)
	}

	req, err := s.LocalStorage.AuthRequestStorage().GetAuthRequestByID(ctx, id)
	if err != nil {
		return nil, fmt.Errorf("failed to get auth request from DB: %w", err)
	}
	if req.UserID == "" {
		return req, nil
	}

	user, err := s.LocalStorage.UserStorage().GetUserBySubject(ctx, req.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to get user information from DB: %w", err)
	}
	req.User = user
	return req, nil
}

func (s *Storage) AuthRequestByCode(ctx context.Context, requestCode string) (op.AuthRequest, error) {
	logger.L.Debugf("Getting auth request from code %s", requestCode)

	authCode, err := s.LocalStorage.AuthCodeStorage().GetAuthCodeByCode(ctx, requestCode)
	if err != nil {
		return nil, fmt.Errorf("failed to get auth code from DB: %w", err)
	}

	req, err := s.LocalStorage.AuthRequestStorage().GetAuthRequestByID(ctx, authCode.RequestID)
	if err != nil {
		return nil, fmt.Errorf("failed to get auth request from DB: %w", err)
	}
	if req.UserID == "" {
		return req, nil
	}

	user, err := s.LocalStorage.UserStorage().GetUserBySubject(ctx, req.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to get user information from DB: %w", err)
	}
	req.User = user
	return req, nil
}

func (s *Storage) SaveAuthCode(ctx context.Context, id string, code string) error {
	logger.L.Debugf("Saving auth code %s for request %s", code, id)

	requestID, err := uuid.Parse(id)
	if err != nil {
		return fmt.Errorf("invalid requestID %s: %w", requestID, err)
	}

	codeID := uuid.New()

	savedCode := model.AuthCode{
		CodeID:    codeID,
		RequestID: requestID,
		Code:      code,
	}
	return s.LocalStorage.AuthCodeStorage().CreateAuthCode(ctx, savedCode)
}

func (s *Storage) DeleteAuthRequest(ctx context.Context, id string) error {
	reqID, err := uuid.Parse(id)
	if err != nil {
		return fmt.Errorf("invalid id format: %w", err)
	}
	return s.LocalStorage.AuthRequestStorage().DeleteAuthRequest(ctx, reqID)
}

func (s *Storage) CreateAccessToken(ctx context.Context, req op.TokenRequest) (accessTokenID string, expiration time.Time, err error) {
	accessTokenUUID := uuid.New()
	var authTime time.Time

	switch typedReq := req.(type) {
	case *model.AuthRequest:
		logger.L.Debug("Creating access token for new authentication")
		authTime = typedReq.AuthTime
	case *model.RefreshTokenRequest:
		logger.L.Debug("Handling refresh token request")
		authTime = typedReq.GetAuthTime()
	default:
		logger.L.Errorf("Unexpected type for request %v", err)
		return "", time.Time{}, errors.New("failed to parse auth request")
	}

	expiration = authTime.Add(5 * time.Minute)

	// token := model.Token{
	// 	ID:             accessTokenUUID,
	// 	RefreshTokenID: refreshTokenUUID,
	// 	Expiration:     authTime.Add(5 * time.Minute),
	// 	Subjet:         request.GetSubject(),
	// 	Audiences:      request.GetAudience(),
	// 	Scopes:         request.GetScopes(),
	// }

	return accessTokenUUID.String(), expiration, nil
}

func (s *Storage) CreateAccessAndRefreshTokens(ctx context.Context, request op.TokenRequest, currentRefreshToken string) (accessTokenID string, newRefreshTokenID string, expiration time.Time, err error) {
	accessTokenUUID := uuid.New()
	refreshTokenUUID := uuid.New()
	var authTime time.Time
	var clientID string

	switch typedReq := request.(type) {
	case *model.AuthRequest:
		logger.L.Debug("Creating access token for new authentication")
		clientID = typedReq.ClientID
		authTime = typedReq.AuthTime
	case *model.RefreshTokenRequest:
		logger.L.Debug("Handling refresh token request")
		clientID = typedReq.GetClientID()
		authTime = typedReq.GetAuthTime()
	default:
		logger.L.Errorf("Unexpected type for request %v", err)
		return "", "", time.Time{}, errors.New("failed to parse auth request")
	}

	expiration = authTime.Add(5 * time.Minute)

	// token := model.Token{
	// 	ID:             accessTokenUUID,
	// 	RefreshTokenID: refreshTokenUUID,
	// 	Expiration:     authTime.Add(5 * time.Minute),
	// 	Subjet:         request.GetSubject(),
	// 	Audiences:      request.GetAudience(),
	// 	Scopes:         request.GetScopes(),
	// }
	refreshToken := model.RefreshToken{
		ID:       refreshTokenUUID,
		ClientID: clientID,
		UserID:   request.GetSubject(),
		Scopes:   request.GetScopes(),
		AuthTime: authTime,
	}
	if err := s.LocalStorage.TokenStorage().AddRefreshToken(ctx, &refreshToken); err != nil {
		return "", "", time.Time{}, fmt.Errorf("failed to insert token in DB: %w", err)
	}

	return accessTokenUUID.String(), refreshTokenUUID.String(), expiration, nil
}

func (s *Storage) TokenRequestByRefreshToken(ctx context.Context, refreshTokenID string) (op.RefreshTokenRequest, error) {
	parsedID, err := uuid.Parse(refreshTokenID)
	if err != nil {
		return nil, fmt.Errorf("invalid format for refresh token id: %w", err)
	}

	refreshToken, err := s.LocalStorage.TokenStorage().GetRefreshTokenByID(ctx, parsedID)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, op.ErrInvalidRefreshToken
		}
		return nil, fmt.Errorf("failed to get refresh token: %w", err)
	}
	return refreshToken.Request(), nil
}

func (s *Storage) TerminateSession(ctx context.Context, userID string, clientID string) error {
	return ErrNotImplemented("TerminateSession")
}

func (s *Storage) RevokeToken(ctx context.Context, tokenOrTokenID string, userID string, clientID string) *oidc.Error {
	return nil
}

func (s *Storage) GetRefreshTokenInfo(ctx context.Context, clientID string, stoken string) (string, string, error) {
	return "", "", ErrNotImplemented("GetRefreshTokenInfo")
}

func (s *Storage) SigningKey(ctx context.Context) (op.SigningKey, error) {
	return s.Key.SigningKey(), nil
}

func (s *Storage) SignatureAlgorithms(ctx context.Context) ([]jose.SignatureAlgorithm, error) {
	return nil, ErrNotImplemented("SignatureAlgorithms")
}

func (s *Storage) KeySet(ctx context.Context) ([]op.Key, error) {
	return []op.Key{s.Key}, nil
}

/*
	OP storage
*/

func (s *Storage) getClientWithDetails(ctx context.Context, authRequestID uuid.UUID) (op.Client, error) {
	logger.L.Debug("Trying to get client details from auth request")

	authRequest, err := s.LocalStorage.AuthRequestStorage().GetAuthRequestByID(ctx, authRequestID)
	if err != nil {
		return nil, fmt.Errorf("failed to get authRequest from local storage: %w", err)
	}
	backend, err := s.LocalStorage.BackendStorage().GetBackendByID(ctx, authRequest.BackendID)
	if err != nil {
		return nil, fmt.Errorf("failed to get associated backend from local storage: %w", err)
	}
	client, err := s.LocalStorage.ClientStorage().GetClientByID(ctx, authRequest.ClientID)
	if err != nil {
		return nil, fmt.Errorf("failed to get associated client from local storage: %w", err)
	}

	// oidcClient, ok := s.InitializedBackends[backend.ID]
	// if !ok {
	// 	return nil, fmt.Errorf("no initialized backend for ID %s", backend.ID)
	// }

	authRequest.Backend = backend
	client.AuthRequest = authRequest

	return client, nil
}

// We're cheating a bit here since we're using the authrequest to get its associated client
// but a request is always associated to a backend, and we really need both, so we have no
// choice here. I'll maybe need to have a more elegant solution later, but not choice for now
func (s *Storage) GetClientByClientID(ctx context.Context, id string) (op.Client, error) {
	logger.L.Debugf("Selecting client app with ID %s", id)

	authRequestID, err := uuid.Parse(id)
	if err != nil {
		// it's not a UUID, it means this was called using client_id, we just return the client without details
		client, err := s.LocalStorage.ClientStorage().GetClientByID(ctx, id)
		if err != nil {
			return nil, fmt.Errorf("failed to get client %s from local storage: %w", id, err)
		}
		return client, nil
	}

	// we have a UUID, it means we got a requestID, so we can get all details here
	return s.getClientWithDetails(ctx, authRequestID)
}

func (s *Storage) AuthorizeClientIDSecret(ctx context.Context, clientID, clientSecret string) error {
	logger.L.Debugf("Validating client secret %s for client %s", clientSecret, clientID)

	client, err := s.LocalStorage.ClientStorage().GetClientByID(ctx, clientID)
	if err != nil {
		return err
	}

	if client.Secret != clientSecret {
		return errors.New("invalid secret")
	}

	return nil
}

func (s *Storage) SetUserinfoFromScopes(ctx context.Context, userinfo *oidc.UserInfo, userID, clientID string, scopes []string) error {
	logger.L.Debugf("Setting user info for user %s", userID)

	user, err := s.LocalStorage.UserStorage().GetUserBySubject(ctx, userID)
	if err != nil {
		return fmt.Errorf("failed to get user from DB: %w", err)
	}

	for _, s := range scopes {
		switch s {
		case "openid":
			userinfo.Subject = user.Subject
		case "profile":
			userinfo.Name = user.Name
			userinfo.FamilyName = user.FamilyName
			userinfo.GivenName = user.GivenName
			userinfo.Nickname = user.Nickname
			userinfo.Picture = user.Picture
			userinfo.UpdatedAt = oidc.FromTime(user.UpdatedAt)
		case "email":
			userinfo.Email = user.Email
			userinfo.EmailVerified = oidc.Bool(user.EmailVerified)
		}
	}

	return nil
}

func (s *Storage) SetUserinfoFromToken(ctx context.Context, userinfo *oidc.UserInfo, tokenID, subject, origin string) error {
	return ErrNotImplemented("SetUserinfoFromToken")
}

func (s *Storage) SetIntrospectionFromToken(ctx context.Context, userinfo *oidc.IntrospectionResponse, tokenID, subject, clientID string) error {
	return ErrNotImplemented("SetIntrospectionFromToken")
}

func (s *Storage) GetPrivateClaimsFromScopes(ctx context.Context, userID, clientID string, scopes []string) (map[string]interface{}, error) {
	// For now, let's just return nothing, we don't want to add any private scope
	return nil, nil
}

func (s *Storage) GetKeyByIDAndClientID(ctx context.Context, keyID, clientID string) (*jose.JSONWebKey, error) {
	return nil, ErrNotImplemented("GetKeyByIDAndClientID")
}

func (s *Storage) ValidateJWTProfileScopes(ctx context.Context, userID string, scopes []string) ([]string, error) {
	return nil, ErrNotImplemented("ValidateJWTProfileScopes")
}

func (s *Storage) Health(ctx context.Context) error {
	return ErrNotImplemented("Health")
}

func stringFromCtx(ctx context.Context, key string) (string, bool) {
	rawVal := ctx.Value(key)
	if rawVal == nil {
		return "", false
	}

	val, ok := rawVal.(string)
	return val, ok
}