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

import { ConsoleLogger } from "../extension/log/ConsoleLogger";
import { ILogger } from "../extension/log/LogHelper";
import { ErrorHelper } from "./error/errorHelper";
import { InternalError } from "./error/internalError";
import { TelemetryHelper, ICommandTelemetryProperties } from "./telemetryHelper";
import { TelemetryGenerator } from "./telemetryGenerators";
import { Telemetry } from "./telemetry";

export enum ProcessType {
    Extension,
    Debugee,
    Debugger,
}

/* This class should we used for each entry point of the code, so we handle telemetry and error reporting properly */
export class EntryPointHandler {
    private processType: ProcessType;

    constructor(processType: ProcessType, private logger: ILogger = new ConsoleLogger()) {
        this.processType = processType;
    }

    /* This method should wrap any async entry points to the code, so we handle telemetry and error reporting properly */
    public runFunction(
        taskName: string,
        error: InternalError,
        codeToRun: (telemetry: TelemetryGenerator) => Promise<void> | void,
        errorsAreFatal: boolean = false,
        extProps?: ICommandTelemetryProperties,
    ): Promise<void> {
        return this.runFunctionWExtProps(
            taskName,
            extProps || {},
            error,
            codeToRun,
            errorsAreFatal,
        );
    }

    public runFunctionWExtProps(
        taskName: string,
        extProps: ICommandTelemetryProperties,
        error: InternalError,
        codeToRun: (telemetry: TelemetryGenerator) => Promise<void> | void,
        errorsAreFatal: boolean = false,
    ): Promise<void> {
        return this.handleErrors(
            error,
            TelemetryHelper.generate(taskName, extProps, codeToRun),
            errorsAreFatal,
        );
    }

    // This method should wrap the entry point of the whole app, so we handle telemetry and error reporting properly
    public runApp(
        appName: string,
        appVersion: string,
        error: InternalError,
        reporter: Telemetry.ITelemetryReporter,
        codeToRun: () => Promise<void> | void,
        extProps?: ICommandTelemetryProperties,
    ): Promise<void> {
        try {
            Telemetry.init(appName, appVersion, reporter);
            return this.runFunction(appName, error, codeToRun, true, extProps);
        } catch (error) {
            this.logger.error(error);
            throw error;
        }
    }

    private handleErrors(
        error: InternalError,
        resultOfCode: Promise<void>,
        errorsAreFatal: boolean,
    ): Promise<void> {
        resultOfCode.catch(reason => {
            const isDebugeeProcess = this.processType === ProcessType.Debugee;
            const shouldLogStack = !errorsAreFatal || isDebugeeProcess;
            this.logger.error(error.message, ErrorHelper.wrapError(error, reason), shouldLogStack);
            // For the debugee process we don't want to throw an exception because the debugger
            // will appear to the user if he turned on the VS Code uncaught exceptions feature.
            if (errorsAreFatal) {
                if (isDebugeeProcess) {
                    process.exit(1);
                } else {
                    throw reason;
                }
            }
        });

        return resultOfCode;
    }
}
