/*
 * Copyright (c) Microsoft Corporation. All rights reserved.
 * Licensed under the MIT License.
 */

import { INetworkModule, Logger } from "@azure/msal-common";
import { ManagedIdentityRequestParameters } from "../../config/ManagedIdentityRequestParameters";
import { BaseManagedIdentitySource } from "./BaseManagedIdentitySource";
import { NodeStorage } from "../../cache/NodeStorage";
import { CryptoProvider } from "../../crypto/CryptoProvider";
import {
    HttpMethod,
    METADATA_HEADER_NAME,
    ManagedIdentityEnvironmentVariableNames,
    ManagedIdentityIdType,
    ManagedIdentitySourceNames,
    RESOURCE_BODY_OR_QUERY_PARAMETER_NAME,
} from "../../utils/Constants";
import {
    ManagedIdentityErrorCodes,
    createManagedIdentityError,
} from "../../error/ManagedIdentityError";
import { ManagedIdentityId } from "../../config/ManagedIdentityId";

/**
 * Original source of code: https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/identity/Azure.Identity/src/CloudShellManagedIdentitySource.cs
 */
export class CloudShell extends BaseManagedIdentitySource {
    private msiEndpoint: string;

    constructor(
        logger: Logger,
        nodeStorage: NodeStorage,
        networkClient: INetworkModule,
        cryptoProvider: CryptoProvider,
        msiEndpoint: string
    ) {
        super(logger, nodeStorage, networkClient, cryptoProvider);

        this.msiEndpoint = msiEndpoint;
    }

    public static getEnvironmentVariables(): Array<string | undefined> {
        const msiEndpoint: string | undefined =
            process.env[ManagedIdentityEnvironmentVariableNames.MSI_ENDPOINT];

        return [msiEndpoint];
    }

    public static tryCreate(
        logger: Logger,
        nodeStorage: NodeStorage,
        networkClient: INetworkModule,
        cryptoProvider: CryptoProvider,
        managedIdentityId: ManagedIdentityId
    ): CloudShell | null {
        const [msiEndpoint] = CloudShell.getEnvironmentVariables();

        // if the msi endpoint environment variable is undefined, this MSI provider is unavailable.
        if (!msiEndpoint) {
            logger.info(
                `[Managed Identity] ${ManagedIdentitySourceNames.CLOUD_SHELL} managed identity is unavailable because the '${ManagedIdentityEnvironmentVariableNames.MSI_ENDPOINT} environment variable is not defined.`
            );
            return null;
        }

        const validatedMsiEndpoint: string =
            CloudShell.getValidatedEnvVariableUrlString(
                ManagedIdentityEnvironmentVariableNames.MSI_ENDPOINT,
                msiEndpoint,
                ManagedIdentitySourceNames.CLOUD_SHELL,
                logger
            );

        logger.info(
            `[Managed Identity] Environment variable validation passed for ${ManagedIdentitySourceNames.CLOUD_SHELL} managed identity. Endpoint URI: ${validatedMsiEndpoint}. Creating ${ManagedIdentitySourceNames.CLOUD_SHELL} managed identity.`
        );

        if (
            managedIdentityId.idType !== ManagedIdentityIdType.SYSTEM_ASSIGNED
        ) {
            throw createManagedIdentityError(
                ManagedIdentityErrorCodes.unableToCreateCloudShell
            );
        }

        return new CloudShell(
            logger,
            nodeStorage,
            networkClient,
            cryptoProvider,
            msiEndpoint
        );
    }

    public createRequest(resource: string): ManagedIdentityRequestParameters {
        const request: ManagedIdentityRequestParameters =
            new ManagedIdentityRequestParameters(
                HttpMethod.POST,
                this.msiEndpoint
            );

        request.headers[METADATA_HEADER_NAME] = "true";

        request.bodyParameters[RESOURCE_BODY_OR_QUERY_PARAMETER_NAME] =
            resource;

        return request;
    }
}
