@jupyterlab/notebook/lib/history.js

// Copyright (c) Jupyter Development Team.
// Distributed under the terms of the Modified BSD License.
import { nullTranslator } from '@jupyterlab/translation';
import { Signal } from '@lumino/signaling';
/**
 * A console history manager object.
 */
export class NotebookHistory {
    /**
     * Construct a new console history object.
     */
    constructor(options) {
        /**
         * The number of history items to increase a batch size by per subsequent request.
         */
        this._requestBatchSize = 10;
        this._cursor = 0;
        this._hasSession = false;
        this._history = [];
        this._placeholder = '';
        this._kernelSession = '';
        this._setByHistory = false;
        this._isDisposed = false;
        this._editor = null;
        this._filtered = [];
        this._kernel = null;
        this._sessionContext = options.sessionContext;
        this._trans = (options.translator || nullTranslator).load('jupyterlab');
        void this._handleKernel().then(() => {
            this._sessionContext.kernelChanged.connect(this._handleKernel, this);
        });
        this._toRequest = this._requestBatchSize;
    }
    /**
     * The current editor used by the history manager.
     */
    get editor() {
        return this._editor;
    }
    set editor(value) {
        if (this._editor === value) {
            return;
        }
        const prev = this._editor;
        if (prev) {
            prev.model.sharedModel.changed.disconnect(this.onTextChange, this);
        }
        this._editor = value;
        if (value) {
            value.model.sharedModel.changed.connect(this.onTextChange, this);
        }
    }
    /**
     * The placeholder text that a history session began with.
     */
    get placeholder() {
        return this._placeholder;
    }
    /**
     * Kernel session number for filtering
     */
    get kernelSession() {
        return this._kernelSession;
    }
    /**
     * Get whether the notebook history manager is disposed.
     */
    get isDisposed() {
        return this._isDisposed;
    }
    /**
     * Dispose of the resources held by the notebook history manager.
     */
    dispose() {
        this._isDisposed = true;
        this._history.length = 0;
        Signal.clearData(this);
    }
    /**
     * Set placeholder and editor. Start session if one is not already started.
     *
     * @param activeCell - The currently selected Cell in the notebook.
     */
    async checkSession(activeCell) {
        var _a;
        if (!this._hasSession) {
            await this._retrieveHistory();
            this._hasSession = true;
            this.editor = activeCell.editor;
            this._placeholder = ((_a = this._editor) === null || _a === void 0 ? void 0 : _a.model.sharedModel.getSource()) || '';
            // Filter the history with the placeholder string.
            this.setFilter(this._placeholder);
            this._cursor = this._filtered.length - 1;
        }
    }
    /**
     * Get the previous item in the notebook history.
     *
     * @param activeCell - The currently selected Cell in the notebook.
     *
     * @returns A Promise resolving to the historical cell content text.
     */
    async back(activeCell) {
        await this.checkSession(activeCell);
        --this._cursor;
        if (this._cursor < 0) {
            await this.fetchBatch();
        }
        this._cursor = Math.max(0, this._cursor);
        const content = this._filtered[this._cursor];
        // This shouldn't ever be undefined as `setFilter` will always be run first
        return content;
    }
    /**
     * Get the next item in the notebook history.
     *
     * @param activeCell - The currently selected Cell in the notebook.
     *
     * @returns A Promise resolving to the historical cell content text.
     */
    async forward(activeCell) {
        await this.checkSession(activeCell);
        ++this._cursor;
        this._cursor = Math.min(this._filtered.length - 1, this._cursor);
        const content = this._filtered[this._cursor];
        // This shouldn't ever be undefined as `setFilter` will always be run first
        return content;
    }
    /**
     * Update the editor of the cell with provided text content.
     *
     * @param activeCell - The currently selected Cell in the notebook.
     * @param content - the result from back or forward
     */
    updateEditor(activeCell, content) {
        var _a, _b;
        if (activeCell) {
            const model = (_a = activeCell.editor) === null || _a === void 0 ? void 0 : _a.model;
            const source = model === null || model === void 0 ? void 0 : model.sharedModel.getSource();
            if (this.isDisposed || !content) {
                return;
            }
            if (source === content) {
                return;
            }
            this._setByHistory = true;
            model === null || model === void 0 ? void 0 : model.sharedModel.setSource(content);
            let columnPos = 0;
            columnPos = content.indexOf('\n');
            if (columnPos < 0) {
                columnPos = content.length;
            }
            (_b = activeCell.editor) === null || _b === void 0 ? void 0 : _b.setCursorPosition({ line: 0, column: columnPos });
        }
    }
    /**
     * Reset the history navigation state, i.e., start a new history session.
     */
    reset() {
        this._hasSession = false;
        this._placeholder = '';
        this._toRequest = this._requestBatchSize;
    }
    /**
     * Fetches a subsequent batch of history. Updates the filtered history and cursor to correct place in history,
     * accounting for potentially new history items above it.
     */
    async fetchBatch() {
        this._toRequest += this._requestBatchSize;
        let oldFilteredReversed = this._filtered.slice().reverse();
        let oldHistory = this._history.slice();
        await this._retrieveHistory().then(() => {
            this.setFilter(this._placeholder);
            let cursorOffset = 0;
            let filteredReversed = this._filtered.slice().reverse();
            for (let i = 0; i < oldFilteredReversed.length; i++) {
                let item = oldFilteredReversed[i];
                for (let ij = i + cursorOffset; ij < filteredReversed.length; ij++) {
                    if (item === filteredReversed[ij]) {
                        break;
                    }
                    else {
                        cursorOffset += 1;
                    }
                }
            }
            this._cursor =
                this._filtered.length - (oldFilteredReversed.length + 1) - cursorOffset;
        });
        if (this._cursor < 0) {
            if (this._history.length > oldHistory.length) {
                await this.fetchBatch();
            }
        }
    }
    /**
     * Populate the history collection on history reply from a kernel.
     *
     * @param value The kernel message history reply.
     *
     * #### Notes
     * History entries have the shape:
     * [session: number, line: number, input: string]
     * Contiguous duplicates are stripped out of the API response.
     */
    onHistory(value, cell) {
        this._history.length = 0;
        let last = ['', '', ''];
        let current = ['', '', ''];
        let kernelSession = '';
        if (value.content.status === 'ok') {
            for (let i = 0; i < value.content.history.length; i++) {
                current = value.content.history[i];
                if (current !== last) {
                    kernelSession = value.content.history[i][0];
                    this._history.push((last = current));
                }
            }
            // set the kernel session for filtering
            if (!this.kernelSession) {
                if (current[2] == (cell === null || cell === void 0 ? void 0 : cell.model.sharedModel.getSource())) {
                    this._kernelSession = kernelSession;
                }
            }
        }
    }
    /**
     * Handle a text change signal from the editor.
     */
    onTextChange() {
        if (this._setByHistory) {
            this._setByHistory = false;
            return;
        }
        this.reset();
    }
    /**
     * Handle the current kernel changing.
     */
    async _handleKernel() {
        var _a;
        this._kernel = (_a = this._sessionContext.session) === null || _a === void 0 ? void 0 : _a.kernel;
        if (!this._kernel) {
            this._history.length = 0;
            return;
        }
        await this._retrieveHistory().catch();
        return;
    }
    /**
     * retrieve the history from the kernel
     *
     * @param cell - The string to use when filtering the data.
     */
    async _retrieveHistory(cell) {
        var _a;
        return await ((_a = this._kernel) === null || _a === void 0 ? void 0 : _a.requestHistory(request(this._toRequest)).then(v => {
            this.onHistory(v, cell);
        }).catch(() => {
            console.warn(this._trans.__('History was unable to be retrieved'));
        }));
    }
    /**
     * Set the filter data.
     *
     * @param filterStr - The string to use when filtering the data.
     */
    setFilter(filterStr = '') {
        // Apply the new filter and remove contiguous duplicates.
        this._filtered.length = 0;
        let last = '';
        let current = '';
        for (let i = 0; i < this._history.length; i++) {
            current = this._history[i][2];
            if (current !== last && filterStr !== current) {
                this._filtered.push((last = current));
            }
        }
        this._filtered.push(filterStr);
    }
}
function request(n) {
    return {
        output: false,
        raw: true,
        hist_access_type: 'tail',
        n: n
    };
}
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