/*
Copyright 2018 New Vector Ltd

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import React from 'react';

import sdk from '../../../index';
import MatrixClientPeg from '../../../MatrixClientPeg';
import { _t } from '../../../languageHandler';
import Modal from '../../../Modal';

export default class KeyBackupPanel extends React.PureComponent {
    constructor(props) {
        super(props);

        this._startNewBackup = this._startNewBackup.bind(this);
        this._deleteBackup = this._deleteBackup.bind(this);
        this._onKeyBackupSessionsRemaining =
            this._onKeyBackupSessionsRemaining.bind(this);
        this._onKeyBackupStatus = this._onKeyBackupStatus.bind(this);
        this._restoreBackup = this._restoreBackup.bind(this);

        this._unmounted = false;
        this.state = {
            loading: true,
            error: null,
            backupInfo: null,
            sessionsRemaining: 0,
        };
    }

    componentWillMount() {
        this._loadBackupStatus();

        MatrixClientPeg.get().on('crypto.keyBackupStatus', this._onKeyBackupStatus);
        MatrixClientPeg.get().on(
            'crypto.keyBackupSessionsRemaining',
            this._onKeyBackupSessionsRemaining,
        );
    }

    componentWillUnmount() {
        this._unmounted = true;

        if (MatrixClientPeg.get()) {
            MatrixClientPeg.get().removeListener('crypto.keyBackupStatus', this._onKeyBackupStatus);
            MatrixClientPeg.get().removeListener(
                'crypto.keyBackupSessionsRemaining',
                this._onKeyBackupSessionsRemaining,
            );
        }
    }

    _onKeyBackupSessionsRemaining(sessionsRemaining) {
        this.setState({
            sessionsRemaining,
        });
    }

    _onKeyBackupStatus() {
        this._loadBackupStatus();
    }

    async _loadBackupStatus() {
        this.setState({loading: true});
        try {
            const backupInfo = await MatrixClientPeg.get().getKeyBackupVersion();
            const backupSigStatus = await MatrixClientPeg.get().isKeyBackupTrusted(backupInfo);
            if (this._unmounted) return;
            this.setState({
                backupInfo,
                backupSigStatus,
                loading: false,
            });
        } catch (e) {
            console.log("Unable to fetch key backup status", e);
            if (this._unmounted) return;
            this.setState({
                error: e,
                loading: false,
            });
            return;
        }
    }

    _startNewBackup() {
        Modal.createTrackedDialogAsync('Key Backup', 'Key Backup',
            import('../../../async-components/views/dialogs/keybackup/CreateKeyBackupDialog'),
            {
                onFinished: () => {
                    this._loadBackupStatus();
                },
            },
        );
    }

    _deleteBackup() {
        const QuestionDialog = sdk.getComponent('dialogs.QuestionDialog');
        Modal.createTrackedDialog('Delete Backup', '', QuestionDialog, {
            title: _t('Delete Backup'),
            description: _t(
                "Are you sure? You will lose your encrypted messages if your " + 
                "keys are not backed up properly."
            ),
            button: _t('Delete Backup'),
            danger: true,
            onFinished: (proceed) => {
                if (!proceed) return;
                this.setState({loading: true});
                MatrixClientPeg.get().deleteKeyBackupVersion(this.state.backupInfo.version).then(() => {
                    this._loadBackupStatus();
                });
            },
        });
    }

    _restoreBackup() {
        const RestoreKeyBackupDialog = sdk.getComponent('dialogs.keybackup.RestoreKeyBackupDialog');
        Modal.createTrackedDialog('Restore Backup', '', RestoreKeyBackupDialog, {
        });
    }

    render() {
        const Spinner = sdk.getComponent("elements.Spinner");
        const AccessibleButton = sdk.getComponent("elements.AccessibleButton");
        const encryptedMessageAreEncrypted = _t(
            "Encrypted messages are secured with end-to-end encryption. " +
            "Only you and the recipient(s) have the keys to read these messages.",
        );

        if (this.state.error) {
            return (
                <div className="error">
                    {_t("Unable to load key backup status")}
                </div>
            );
        } else if (this.state.loading) {
            return <Spinner />;
        } else if (this.state.backupInfo) {
            let clientBackupStatus;
            let buttons;

            if (MatrixClientPeg.get().getKeyBackupEnabled()) {
                clientBackupStatus = <div>
                    <p>{encryptedMessageAreEncrypted}</p>
                    <p>{_t("This device is backing up your keys. ✅")}</p>
                </div>;
                buttons = <p>
                    <AccessibleButton kind="primary" onClick={this._restoreBackup}>
                        { _t("Restore from Backup") }
                    </AccessibleButton>&nbsp;&nbsp;&nbsp;
                    <AccessibleButton kind="danger" onClick={this._deleteBackup}>
                        { _t("Delete Backup") }
                    </AccessibleButton>
                </p>;
            } else {
                clientBackupStatus = <div>
                    <p>{encryptedMessageAreEncrypted}</p>
                    <p>{_t(
                        "This device is <b>not backing up your keys</b>.", {},
                        {b: x => <b>{x}</b>},
                    )}</p>
                    <p>{_t("Back up your keys before signing out to avoid losing them.")}</p>
                </div>;
                buttons = <p>
                    <AccessibleButton kind="primary" onClick={this._restoreBackup}>
                        { _t("Use Key Backup") }
                    </AccessibleButton>
                </p>;
            }

            let uploadStatus;
            const { sessionsRemaining } = this.state;
            if (!MatrixClientPeg.get().getKeyBackupEnabled()) {
                // No upload status to show when backup disabled.
                uploadStatus = "";
            } else if (sessionsRemaining > 0) {
                uploadStatus = <div>
                    {_t("Backing up %(sessionsRemaining)s keys...", { sessionsRemaining })} <br />
                </div>;
            } else {
                uploadStatus = <div>
                    {_t("All keys backed up")} <br />
                </div>;
            }

            let backupSigStatuses = this.state.backupSigStatus.sigs.map((sig, i) => {
                const deviceName = sig.device ? (sig.device.getDisplayName() || sig.device.deviceId) : null;
                const validity = sub =>
                    <span className={sig.valid ? 'mx_KeyBackupPanel_sigValid' : 'mx_KeyBackupPanel_sigInvalid'}>
                        {sub}
                    </span>;
                const verify = sub =>
                    <span className={sig.device && sig.device.isVerified() ? 'mx_KeyBackupPanel_deviceVerified' : 'mx_KeyBackupPanel_deviceNotVerified'}>
                        {sub}
                    </span>;
                const device = sub => <span className="mx_KeyBackupPanel_deviceName">{deviceName}</span>;
                let sigStatus;
                if (!sig.device) {
                    sigStatus = _t(
                        "Backup has a signature from <verify>unknown</verify> device with ID %(deviceId)s.",
                        { deviceId: sig.deviceId }, { verify },
                    );
                } else if (sig.device.getFingerprint() === MatrixClientPeg.get().getDeviceEd25519Key()) {
                    sigStatus = _t(
                        "Backup has a <validity>valid</validity> signature from this device",
                        {}, { validity },
                    );
                } else if (sig.valid && sig.device.isVerified()) {
                    sigStatus = _t(
                        "Backup has a <validity>valid</validity> signature from " +
                        "<verify>verified</verify> device <device></device>",
                        {}, { validity, verify, device },
                    );
                } else if (sig.valid && !sig.device.isVerified()) {
                    sigStatus = _t(
                        "Backup has a <validity>valid</validity> signature from " +
                        "<verify>unverified</verify> device <device></device>",
                        {}, { validity, verify, device },
                    );
                } else if (!sig.valid && sig.device.isVerified()) {
                    sigStatus = _t(
                        "Backup has an <validity>invalid</validity> signature from " +
                        "<verify>verified</verify> device <device></device>",
                        {}, { validity, verify, device },
                    );
                } else if (!sig.valid && !sig.device.isVerified()) {
                    sigStatus = _t(
                        "Backup has an <validity>invalid</validity> signature from " +
                        "<verify>unverified</verify> device <device></device>",
                        {}, { validity, verify, device },
                    );
                }

                return <div key={i}>
                    {sigStatus}
                </div>;
            });
            if (this.state.backupSigStatus.sigs.length === 0) {
                backupSigStatuses = _t("Backup is not signed by any of your devices");
            }

            let trustedLocally;
            if (this.state.backupSigStatus.trusted_locally) {
                trustedLocally = _t("This backup is trusted because it has been restored on this device");
            }

            return <div>
                <div>{clientBackupStatus}</div>
                <details>
                    <summary>{_t("Advanced")}</summary>
                    <div>{_t("Backup version: ")}{this.state.backupInfo.version}</div>
                    <div>{_t("Algorithm: ")}{this.state.backupInfo.algorithm}</div>
                    {uploadStatus}
                    <div>{backupSigStatuses}</div>
                    <div>{trustedLocally}</div>
                </details>
                {buttons}
            </div>;
        } else {
            return <div>
                <div>
                    <p>{_t(
                        "Your keys are <b>not being backed up from this device</b>.", {},
                        {b: x => <b>{x}</b>},
                    )}</p>
                    <p>{encryptedMessageAreEncrypted}</p>
                    <p>{_t("Back up your keys before signing out to avoid losing them.")}</p>
                </div>
                <AccessibleButton kind="primary" onClick={this._startNewBackup}>
                    { _t("Start using Key Backup") }
                </AccessibleButton>
            </div>;
        }
    }
}