// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for details.

import {FileSystem} from "../common/node/fileSystem";
import { logger } from "vscode-chrome-debug-core";
import { ensurePackagerRunning } from "../common/packagerStatus";
import path = require("path");
import Q = require("q");
import {Request} from "../common/node/request";
import {SourceMapUtil} from "./sourceMap";
import url = require("url");
import * as semver from "semver";
import {ReactNativeProjectHelper} from "../common/reactNativeProjectHelper";
import { ErrorHelper } from "../common/error/errorHelper";
import { InternalErrorCode } from "../common/error/internalErrorCode";

export interface DownloadedScript {
    contents: string;
    filepath: string;
}

interface IStrictUrl extends url.Url {
    pathname: string;
    href: string;
}

export class ScriptImporter {
    public static DEBUGGER_WORKER_FILE_BASENAME = "debuggerWorker";
    public static DEBUGGER_WORKER_FILENAME = ScriptImporter.DEBUGGER_WORKER_FILE_BASENAME + ".js";
    private packagerAddress: string;
    private packagerPort: number;
    private sourcesStoragePath: string;
    private packagerRemoteRoot?: string;
    private packagerLocalRoot?: string;
    private sourceMapUtil: SourceMapUtil;

    constructor(packagerAddress: string, packagerPort: number, sourcesStoragePath: string, packagerRemoteRoot?: string, packagerLocalRoot?: string) {
        this.packagerAddress = packagerAddress;
        this.packagerPort = packagerPort;
        this.sourcesStoragePath = sourcesStoragePath;
        this.packagerRemoteRoot = packagerRemoteRoot;
        this.packagerLocalRoot = packagerLocalRoot;
        this.sourceMapUtil = new SourceMapUtil();
    }

    public downloadAppScript(scriptUrlString: string, projectRootPath: string): Q.Promise<DownloadedScript> {
        const parsedScriptUrl = url.parse(scriptUrlString);
        const overriddenScriptUrlString = (parsedScriptUrl.hostname === "localhost") ? this.overridePackagerPort(scriptUrlString) : scriptUrlString;
        // We'll get the source code, and store it locally to have a better debugging experience
        return Request.request(overriddenScriptUrlString, true).then(scriptBody => {
            return ReactNativeProjectHelper.getReactNativeVersion(projectRootPath).then(rnVersion => {
                // unfortunatelly Metro Bundler is broken in RN 0.54.x versions, so use this workaround unless it will be fixed
                // https://github.com/facebook/metro/issues/147
                // https://github.com/Microsoft/vscode-react-native/issues/660
                if (ReactNativeProjectHelper.getRNVersionsWithBrokenMetroBundler().indexOf(rnVersion) >= 0) {
                    let noSourceMappingUrlGenerated =  scriptBody.match(/sourceMappingURL=/g) === null;
                    if (noSourceMappingUrlGenerated) {
                        let sourceMapPathUrl = overriddenScriptUrlString.replace("bundle", "map");
                        scriptBody = this.sourceMapUtil.appendSourceMapPaths(scriptBody, sourceMapPathUrl);
                    }
                }

                // Extract sourceMappingURL from body
                let scriptUrl = <IStrictUrl>url.parse(overriddenScriptUrlString); // scriptUrl = "http://localhost:8081/index.ios.bundle?platform=ios&dev=true"
                let sourceMappingUrl = this.sourceMapUtil.getSourceMapURL(scriptUrl, scriptBody); // sourceMappingUrl = "http://localhost:8081/index.ios.map?platform=ios&dev=true"

                let waitForSourceMapping = Q<void>(void 0);
                if (sourceMappingUrl) {
                    /* handle source map - request it and store it locally */
                    waitForSourceMapping = this.writeAppSourceMap(sourceMappingUrl, scriptUrl)
                        .then(() => {
                            scriptBody = this.sourceMapUtil.updateScriptPaths(scriptBody, <IStrictUrl>sourceMappingUrl);
                        });
                }

                return waitForSourceMapping
                .then(() => this.writeAppScript(scriptBody, scriptUrl))
                .then((scriptFilePath: string) => {
                    logger.verbose(`Script ${overriddenScriptUrlString} downloaded to ${scriptFilePath}`);
                    return { contents: scriptBody, filepath: scriptFilePath };
                });
            });
        });
    }

    public downloadDebuggerWorker(sourcesStoragePath: string, projectRootPath: string, debuggerWorkerUrlPath?: string): Q.Promise<void> {
        const errPackagerNotRunning = ErrorHelper.getInternalError(InternalErrorCode.CannotAttachToPackagerCheckPackagerRunningOnPort, this.packagerPort);
        return ensurePackagerRunning(this.packagerAddress, this.packagerPort, errPackagerNotRunning)
            .then(() => {
                return ReactNativeProjectHelper.getReactNativeVersion(projectRootPath);
            })
            .then((rnVersion: string) => {
                let debuggerWorkerURL = this.prepareDebuggerWorkerURL(rnVersion, debuggerWorkerUrlPath);
                let debuggerWorkerLocalPath = path.join(sourcesStoragePath, ScriptImporter.DEBUGGER_WORKER_FILENAME);
                logger.verbose("About to download: " + debuggerWorkerURL + " to: " + debuggerWorkerLocalPath);

                return Request.request(debuggerWorkerURL, true)
                    .then((body: string) => {
                        return new FileSystem().writeFile(debuggerWorkerLocalPath, body);
                    });
            });
    }

    public prepareDebuggerWorkerURL(rnVersion: string, debuggerWorkerUrlPath?: string): string {
        let debuggerWorkerURL: string;
        // It can be empty string
        if (debuggerWorkerUrlPath !== undefined) {
            debuggerWorkerURL = `http://${this.packagerAddress}:${this.packagerPort}/${debuggerWorkerUrlPath}${ScriptImporter.DEBUGGER_WORKER_FILENAME}`;
        } else {
            let newPackager = "";
            if (!semver.valid(rnVersion) /*Custom RN implementations should support new packager*/ || (semver.gte(rnVersion, "0.50.0"))) {
                newPackager = "debugger-ui/";
            }
            debuggerWorkerURL = `http://${this.packagerAddress}:${this.packagerPort}/${newPackager}${ScriptImporter.DEBUGGER_WORKER_FILENAME}`;
        }
        return debuggerWorkerURL;
    }

    /**
     * Writes the script file to the project temporary location.
     */
    private writeAppScript(scriptBody: string, scriptUrl: IStrictUrl): Q.Promise<String> {
        let scriptFilePath = path.join(this.sourcesStoragePath, path.basename(scriptUrl.pathname)); // scriptFilePath = "$TMPDIR/index.ios.bundle"
        return new FileSystem().writeFile(scriptFilePath, scriptBody)
            .then(() => scriptFilePath);
    }

    /**
     * Writes the source map file to the project temporary location.
     */
    private writeAppSourceMap(sourceMapUrl: IStrictUrl, scriptUrl: IStrictUrl): Q.Promise<void> {
        return Request.request(sourceMapUrl.href, true)
            .then((sourceMapBody: string) => {
                let sourceMappingLocalPath = path.join(this.sourcesStoragePath, path.basename(sourceMapUrl.pathname)); // sourceMappingLocalPath = "$TMPDIR/index.ios.map"
                let scriptFileRelativePath = path.basename(scriptUrl.pathname); // scriptFileRelativePath = "index.ios.bundle"
                let updatedContent = this.sourceMapUtil.updateSourceMapFile(sourceMapBody, scriptFileRelativePath, this.sourcesStoragePath, this.packagerRemoteRoot, this.packagerLocalRoot);
                return new FileSystem().writeFile(sourceMappingLocalPath, updatedContent);
            });
    }

    /**
     * Changes the port of the url to be the one configured as this.packagerPort
     */
    private overridePackagerPort(urlToOverride: string): string {
        let components = url.parse(urlToOverride);
        components.port = this.packagerPort.toString();
        delete components.host; // We delete the host, if not the port change will be ignored
        return url.format(components);
    }
}
