/*
Copyright 2024 New Vector Ltd.
Copyright 2022-2024 The Matrix.org Foundation C.I.C.

SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/

import React, { forwardRef, ForwardRefExoticComponent, useContext } from "react";
import { MatrixEvent } from "matrix-js-sdk/src/matrix";
import { DecryptionFailureCode } from "matrix-js-sdk/src/crypto-api";

import { _t } from "../../../languageHandler";
import { IBodyProps } from "./IBodyProps";
import { LocalDeviceVerificationStateContext } from "../../../contexts/LocalDeviceVerificationStateContext";

function getErrorMessage(mxEvent: MatrixEvent, isVerified: boolean | undefined): string {
    switch (mxEvent.decryptionFailureReason) {
        case DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE:
            return _t("timeline|decryption_failure|blocked");

        case DecryptionFailureCode.HISTORICAL_MESSAGE_NO_KEY_BACKUP:
            return _t("timeline|decryption_failure|historical_event_no_key_backup");

        case DecryptionFailureCode.HISTORICAL_MESSAGE_BACKUP_UNCONFIGURED:
            if (isVerified === false) {
                // The user seems to have a key backup, so prompt them to verify in the hope that doing so will
                // mean we can restore from backup and we'll get the key for this message.
                return _t("timeline|decryption_failure|historical_event_unverified_device");
            }
            // otherwise, use the default.
            break;

        case DecryptionFailureCode.HISTORICAL_MESSAGE_USER_NOT_JOINED:
            return _t("timeline|decryption_failure|historical_event_user_not_joined");
    }
    return _t("timeline|decryption_failure|unable_to_decrypt");
}

// A placeholder element for messages that could not be decrypted
export const DecryptionFailureBody = forwardRef<HTMLDivElement, IBodyProps>(({ mxEvent }, ref): React.JSX.Element => {
    const verificationState = useContext(LocalDeviceVerificationStateContext);
    return (
        <div className="mx_DecryptionFailureBody mx_EventTile_content" ref={ref}>
            {getErrorMessage(mxEvent, verificationState)}
        </div>
    );
}) as ForwardRefExoticComponent<IBodyProps>;