'use strict';

var configResolver = require('@smithy/config-resolver');
var nodeConfigProvider = require('@smithy/node-config-provider');
var propertyProvider = require('@smithy/property-provider');

const AWS_EXECUTION_ENV = "AWS_EXECUTION_ENV";
const AWS_REGION_ENV = "AWS_REGION";
const AWS_DEFAULT_REGION_ENV = "AWS_DEFAULT_REGION";
const ENV_IMDS_DISABLED = "AWS_EC2_METADATA_DISABLED";
const DEFAULTS_MODE_OPTIONS = ["in-region", "cross-region", "mobile", "standard", "legacy"];
const IMDS_REGION_PATH = "/latest/meta-data/placement/region";

const AWS_DEFAULTS_MODE_ENV = "AWS_DEFAULTS_MODE";
const AWS_DEFAULTS_MODE_CONFIG = "defaults_mode";
const NODE_DEFAULTS_MODE_CONFIG_OPTIONS = {
    environmentVariableSelector: (env) => {
        return env[AWS_DEFAULTS_MODE_ENV];
    },
    configFileSelector: (profile) => {
        return profile[AWS_DEFAULTS_MODE_CONFIG];
    },
    default: "legacy",
};

const resolveDefaultsModeConfig = ({ region = nodeConfigProvider.loadConfig(configResolver.NODE_REGION_CONFIG_OPTIONS), defaultsMode = nodeConfigProvider.loadConfig(NODE_DEFAULTS_MODE_CONFIG_OPTIONS), } = {}) => propertyProvider.memoize(async () => {
    const mode = typeof defaultsMode === "function" ? await defaultsMode() : defaultsMode;
    switch (mode?.toLowerCase()) {
        case "auto":
            return resolveNodeDefaultsModeAuto(region);
        case "in-region":
        case "cross-region":
        case "mobile":
        case "standard":
        case "legacy":
            return Promise.resolve(mode?.toLocaleLowerCase());
        case undefined:
            return Promise.resolve("legacy");
        default:
            throw new Error(`Invalid parameter for "defaultsMode", expect ${DEFAULTS_MODE_OPTIONS.join(", ")}, got ${mode}`);
    }
});
const resolveNodeDefaultsModeAuto = async (clientRegion) => {
    if (clientRegion) {
        const resolvedRegion = typeof clientRegion === "function" ? await clientRegion() : clientRegion;
        const inferredRegion = await inferPhysicalRegion();
        if (!inferredRegion) {
            return "standard";
        }
        if (resolvedRegion === inferredRegion) {
            return "in-region";
        }
        else {
            return "cross-region";
        }
    }
    return "standard";
};
const inferPhysicalRegion = async () => {
    if (process.env[AWS_EXECUTION_ENV] && (process.env[AWS_REGION_ENV] || process.env[AWS_DEFAULT_REGION_ENV])) {
        return process.env[AWS_REGION_ENV] ?? process.env[AWS_DEFAULT_REGION_ENV];
    }
    if (!process.env[ENV_IMDS_DISABLED]) {
        try {
            const { getInstanceMetadataEndpoint, httpRequest } = await import('@smithy/credential-provider-imds');
            const endpoint = await getInstanceMetadataEndpoint();
            return (await httpRequest({ ...endpoint, path: IMDS_REGION_PATH })).toString();
        }
        catch (e) {
        }
    }
};

exports.resolveDefaultsModeConfig = resolveDefaultsModeConfig;