// SPDX-License-Identifier: AGPL-3.0-or-later

package rpc

import (
	"context"
	"errors"

	"connectrpc.com/connect"
	"github.com/bnema/zerowrap"

	"bnema.dev/ermite/internal/domain"
)

// connectError maps an error of a use case to a Connect error with the code
// the contract documents. Errors it does not know are internal: they are
// logged here and the client only sees a generic message.
func connectError(ctx context.Context, err error) error {
	if err == nil {
		return nil
	}
	var ce *connect.Error
	if errors.As(err, &ce) {
		return err
	}
	if code, ok := codeOf(err); ok {
		return connect.NewError(code, err)
	}
	log := zerowrap.FromCtx(ctx)
	log.Error().Err(err).Msg("api request failed")
	return connect.NewError(connect.CodeInternal, errors.New("internal error"))
}

// codeOf finds the Connect code of a domain error.
func codeOf(err error) (connect.Code, bool) {
	switch {
	case errors.Is(err, context.Canceled):
		return connect.CodeCanceled, true
	case errors.Is(err, context.DeadlineExceeded):
		return connect.CodeDeadlineExceeded, true
	case errors.Is(err, domain.ErrNotFound):
		return connect.CodeNotFound, true
	case errors.Is(err, domain.ErrAlreadyExists):
		return connect.CodeAlreadyExists, true
	case errors.Is(err, domain.ErrUnauthenticated):
		return connect.CodeUnauthenticated, true
	case errors.Is(err, domain.ErrForbidden), errors.Is(err, domain.ErrRejected):
		return connect.CodePermissionDenied, true
	case errors.Is(err, domain.ErrPreconditionFailed):
		return connect.CodeFailedPrecondition, true
	case errors.Is(err, domain.ErrConflict):
		return connect.CodeAborted, true
	case errors.Is(err, domain.ErrResourceExhausted):
		return connect.CodeResourceExhausted, true
	}
	for _, invalid := range invalidErrors {
		if errors.Is(err, invalid) {
			return connect.CodeInvalidArgument, true
		}
	}
	return 0, false
}

// invalidErrors are the domain errors that mean the request was malformed.
var invalidErrors = []error{
	domain.ErrInvalid, domain.ErrInvalidName, domain.ErrInvalidVisibility,
	domain.ErrInvalidScope, domain.ErrInvalidToken,
	domain.ErrInvalidObjectID, domain.ErrInvalidRevision, domain.ErrInvalidPath,
	domain.ErrInvalidPageToken, domain.ErrInvalidPageSize, domain.ErrInvalidRefKind,
	domain.ErrNotDirectory, domain.ErrNotFile,
}