'use strict';

class ProviderError extends Error {
    name = "ProviderError";
    tryNextLink;
    constructor(message, options = true) {
        let logger;
        let tryNextLink = true;
        if (typeof options === "boolean") {
            logger = undefined;
            tryNextLink = options;
        }
        else if (options != null && typeof options === "object") {
            logger = options.logger;
            tryNextLink = options.tryNextLink ?? true;
        }
        super(message);
        this.tryNextLink = tryNextLink;
        Object.setPrototypeOf(this, ProviderError.prototype);
        logger?.debug?.(`@smithy/property-provider ${tryNextLink ? "->" : "(!)"} ${message}`);
    }
    static from(error, options = true) {
        return Object.assign(new this(error.message, options), error);
    }
}

class CredentialsProviderError extends ProviderError {
    name = "CredentialsProviderError";
    constructor(message, options = true) {
        super(message, options);
        Object.setPrototypeOf(this, CredentialsProviderError.prototype);
    }
}

class TokenProviderError extends ProviderError {
    name = "TokenProviderError";
    constructor(message, options = true) {
        super(message, options);
        Object.setPrototypeOf(this, TokenProviderError.prototype);
    }
}

const chain = (...providers) => async () => {
    if (providers.length === 0) {
        throw new ProviderError("No providers in chain");
    }
    let lastProviderError;
    for (const provider of providers) {
        try {
            const credentials = await provider();
            return credentials;
        }
        catch (err) {
            lastProviderError = err;
            if (err?.tryNextLink) {
                continue;
            }
            throw err;
        }
    }
    throw lastProviderError;
};

const fromStatic = (staticValue) => () => Promise.resolve(staticValue);

const memoize = (provider, isExpired, requiresRefresh) => {
    let resolved;
    let pending;
    let hasResult;
    let isConstant = false;
    const coalesceProvider = async () => {
        if (!pending) {
            pending = provider();
        }
        try {
            resolved = await pending;
            hasResult = true;
            isConstant = false;
        }
        finally {
            pending = undefined;
        }
        return resolved;
    };
    if (isExpired === undefined) {
        return async (options) => {
            if (!hasResult || options?.forceRefresh) {
                resolved = await coalesceProvider();
            }
            return resolved;
        };
    }
    return async (options) => {
        if (!hasResult || options?.forceRefresh) {
            resolved = await coalesceProvider();
        }
        if (isConstant) {
            return resolved;
        }
        if (requiresRefresh && !requiresRefresh(resolved)) {
            isConstant = true;
            return resolved;
        }
        if (isExpired(resolved)) {
            await coalesceProvider();
            return resolved;
        }
        return resolved;
    };
};

exports.CredentialsProviderError = CredentialsProviderError;
exports.ProviderError = ProviderError;
exports.TokenProviderError = TokenProviderError;
exports.chain = chain;
exports.fromStatic = fromStatic;
exports.memoize = memoize;