#!/usr/bin/env node

/*
 * This file is part of Cockpit.
 *
 * Copyright (C) 2017 Red Hat, Inc.
 *
 * Cockpit is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * Cockpit is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Cockpit; If not, see <http://www.gnu.org/licenses/>.
 */

/* chromium-cdp-driver -- A command-line JSON input/output wrapper around
 * chrome-remote-interface (Chrome Debug Protocol).
 * See https://chromedevtools.github.io/devtools-protocol/
 * This needs support for protocol version 1.3.
 *
 * Set $TEST_CDP_DEBUG environment variable to enable additional
 * frame/execution context debugging.
 */

const CDP = require('chrome-remote-interface');

let enable_debug = false;

function debug(msg) {
    if (enable_debug)
        process.stderr.write("CDP: " + msg + "\n");
}

/**
 * Format response to the client
 */

function fatal() {
    console.error.apply(console.error, arguments);
    process.exit(1);
}

function fail(err) {
    if (typeof err === 'undefined')
        err = null;
    process.stdout.write(JSON.stringify({ error: err }) + '\n');
}

function success(result) {
    if (typeof result === 'undefined')
        result = null;
    process.stdout.write(JSON.stringify({ result: result }) + '\n');
}

/**
 * Record console.*() calls and Log messages so that we can forward them to
 * stderr and dump them on test failure
 */
const messages = [];
let logPromiseResolver;
let nReportedLogMessages = 0;
const unhandledExceptions = [];

function clearExceptions() {
    unhandledExceptions.length = 0;
    return Promise.resolve();
}

function setupLogging(client) {
    client.Runtime.enable();

    client.Runtime.consoleAPICalled(info => {
        const msg = info.args.map(v => (v.value || "").toString()).join(" ");
        messages.push([info.type, msg]);
        process.stderr.write("> " + info.type + ": " + msg + "\n");

        resolveLogPromise();
    });

    client.Runtime.exceptionThrown(info => {
        const details = info.exceptionDetails;
        // don't log test timeouts, they already get handled
        if (details.exception && details.exception.className === "PhWaitCondTimeout")
            return;

        // HACK: https://github.com/cockpit-project/cockpit/issues/14871
        if (details.description && details.description.indexOf("Rendering components directly into document.body is discouraged") > -1)
            return;

        process.stderr.write(details.description || JSON.stringify(details) + "\n");

        unhandledExceptions.push(details.exception.message ||
                                 details.exception.description ||
                                 details.exception.value ||
                                 JSON.stringify(details.exception));
    });

    client.Log.enable();
    client.Log.entryAdded(entry => {
        const msg = entry.entry;
        /* Ignore unsafe-inline messages from PatternFly's usage of Emotion
         * (https://github.com/patternfly/patternfly-react/issues/2919) */
        if ((msg.text || "").indexOf("Refused to apply inline style") >= 0) {
            /* when building with --enable-debug, we have proper symbols and can reliably identify the source */
            if (msg.stackTrace && msg.stackTrace.callFrames && msg.stackTrace.callFrames[0].functionName === "makeStyleTag")
                return;
            /* further trim the output by dropping the stackTrace if it's minified */
            if (msg.stackTrace && msg.stackTrace.callFrames && msg.stackTrace.callFrames[0].functionName.length == 1)
                msg.stackTrace = "(minified)";
        }

        messages.push(["cdp", msg]);
        /* Ignore authentication failure log lines that don't denote failures */
        if (!(msg.url || "").endsWith("/login") || (msg.text || "").indexOf("401") === -1) {
            process.stderr.write("CDP: " + JSON.stringify(msg) + "\n");
        }
        resolveLogPromise();
    });
}

/**
 * Resolve the log promise created with waitLog().
 */
function resolveLogPromise() {
    if (logPromiseResolver) {
        logPromiseResolver(messages.slice(nReportedLogMessages));
        nReportedLogMessages = messages.length;
        logPromiseResolver = undefined;
    }
}

/**
 * Returns a promise that resolves when log messages are available. If there
 * are already some unreported ones in the global messages variable, resolves
 * immediately.
 *
 * Only one such promise can be active at a given time. Once the promise is
 * resolved, this function can be called again to wait for further messages.
 */
function waitLog() { // eslint-disable-line no-unused-vars
    console.assert(logPromiseResolver === undefined);

    return new Promise((resolve, reject) => {
        logPromiseResolver = resolve;

        if (nReportedLogMessages < messages.length)
            resolveLogPromise();
    });
}

/**
 * Frame tracking
 *
 * For tests to be able to select the current frame (by its name) and make
 * subsequent queries apply to that, we need to track frame name → frameId →
 * executionContextId. Frame and context IDs can even change through page
 * operations (e. g. in systemd/logs.js when reporting a crash is complete),
 * so we also need a helper function to explicitly wait for a particular frame
 * to load. This is very laborious, see this issue for discussing improvements:
 * https://github.com/ChromeDevTools/devtools-protocol/issues/72
 */
const frameIdToContextId = {};
const frameNameToFrameId = {};

let pageLoadHandler = null;

function setupFrameTracking(client) {
    client.Page.enable();

    // map frame names to frame IDs; root frame has no name, no need to track that
    client.Page.frameNavigated(info => {
        debug("frameNavigated " + JSON.stringify(info));
        frameNameToFrameId[info.frame.name || "cockpit1"] = info.frame.id;
    });

    client.Page.loadEventFired(() => {
        if (pageLoadHandler)
            pageLoadHandler();
    });

    // track execution contexts so that we can map between context and frame IDs
    client.Runtime.executionContextCreated(info => {
        debug("executionContextCreated " + JSON.stringify(info));
        frameIdToContextId[info.context.auxData.frameId] = info.context.id;
    });

    client.Runtime.executionContextDestroyed(info => {
        debug("executionContextDestroyed " + info.executionContextId);
        for (const frameId in frameIdToContextId) {
            if (frameIdToContextId[frameId] == info.executionContextId) {
                delete frameIdToContextId[frameId];
                break;
            }
        }
    });
}

function setupLocalFunctions(client) {
    client.reloadPageAndWait = (args) => {
        return new Promise((resolve, reject) => {
            pageLoadHandler = () => { pageLoadHandler = null; resolve({}) };
            client.Page.reload(args);
        });
    };
}

// helper functions for testlib.py which are too unwieldy to be poked in from Python
function getFrameExecId(frame) { // eslint-disable-line no-unused-vars
    if (frame === null)
        frame = "cockpit1";
    const frameId = frameNameToFrameId[frame];
    if (!frameId)
        return -1;
    const execId = frameIdToContextId[frameId];
    if (!execId)
        return -1;
    return execId;
}

/**
 * SSL handling
 */

// secure by default; tests can override to "continue"
// https://chromedevtools.github.io/devtools-protocol/1-3/Security/#type-CertificateErrorAction
let ssl_bad_certificate_action = "cancel";

/**
 * Change what happens when the browser opens a page with an invalid SSL certificate.
 * Defaults to "cancel", can be set to "continue".
 */
function setSSLBadCertificateAction(action) { // eslint-disable-line no-unused-vars
    ssl_bad_certificate_action = action;
    return Promise.resolve();
}

function setupSSLCertHandling(client) {
    client.Security.enable();

    client.Security.setOverrideCertificateErrors({ override: true });
    client.Security.certificateError(info => {
        process.stderr.write(`CDP: Security.certificateError ${JSON.stringify(info)}; action: ${ssl_bad_certificate_action}\n`);
        client.Security.handleCertificateError({ eventId: info.eventId, action: ssl_bad_certificate_action })
                .catch(ex => {
                // some race condition in Chromium, ok if the event is already gone
                    if (ex.response && ex.response.message && ex.response.message.indexOf("Unknown event id") >= 0)
                        debug(`setupSSLCertHandling for event ${info.eventId} failed, ignoring: ${JSON.stringify(ex.response)}`);
                    else
                        throw ex;
                });
    });
}

/**
 * Main input/process loop
 *
 * Read one line with a JS expression, eval() it, and respond with the result:
 *    success <JSON formatted return value>
 *    fail <JSON formatted error>
 * EOF shuts down the client.
 */
process.stdin.setEncoding('utf8');

if (process.env.TEST_CDP_DEBUG)
    enable_debug = true;

const options = { };
if (process.argv.length >= 3) {
    options.port = parseInt(process.argv[2]);
    if (!options.port) {
        process.stderr.write("Usage: chromium-cdp-driver.js [port]\n");
        process.exit(1);
    }
}

CDP.New(options)
        .then(target => {
            target.port = options.port;
            CDP({ target: target })
                    .then(client => {
                        setupLogging(client);
                        setupFrameTracking(client);
                        setupSSLCertHandling(client);
                        setupLocalFunctions(client);

                        let input_buf = '';
                        process.stdin
                                .on('data', chunk => {
                                    input_buf += chunk;
                                    while (true) {
                                        const i = input_buf.indexOf('\n');
                                        if (i < 0)
                                            break;
                                        const command = input_buf.slice(0, i);

                                        // run the command
                                        eval(command).then(reply => { // eslint-disable-line no-eval
                                            if (unhandledExceptions.length === 0) {
                                                success(reply);
                                            } else {
                                                const message = unhandledExceptions[0];
                                                fail(message.split("\n")[0]);
                                                clearExceptions();
                                            }
                                        }, fail);

                                        input_buf = input_buf.slice(i + 1);
                                    }
                                })
                                .on('end', () => {
                                    CDP.Close(target)
                                            .then(() => process.exit(0))
                                            .catch(fatal);
                                });
                    })
                    .catch(fatal);
        })
        .catch(fatal);
