const jsonata = require("jsonata");


/**
 * @typedef {Object} SecretRequest
 * @property {string} path
 * @property {string} selector
 */

/**
 * @template {SecretRequest} TRequest
 * @typedef {Object} SecretResponse
 * @property {TRequest} request
 * @property {string} value
 * @property {boolean} cachedResponse
 */

 /**
  * @template TRequest
  * @param {Array<TRequest>} secretRequests
  * @param {import('got').Got} client
  * @return {Promise<SecretResponse<TRequest>[]>}
  */
async function getSecrets(secretRequests, client) {
    const responseCache = new Map();
    const results = [];
    for (const secretRequest of secretRequests) {
        let { path, selector } = secretRequest;

        const requestPath = `v1/${path}`;
        let body;
        let cachedResponse = false;
        if (responseCache.has(requestPath)) {
            body = responseCache.get(requestPath);
            cachedResponse = true;
        } else {
            try {
                const result = await client.get(requestPath);
                body = result.body;
                responseCache.set(requestPath, body);
            } catch (error) {
                const {response} = error;
                if (response?.statusCode === 404) {
                    throw Error(`Unable to retrieve result for "${path}" because it was not found: ${response.body.trim()}`)
                }
                throw error
            }
        }
        if (!selector.match(/.*[\.].*/)) {
            selector = '"' + selector + '"'
        }
        selector = "data." + selector
        body = JSON.parse(body)
        if (body.data["data"] != undefined) {
            selector = "data." + selector
        }

        const value = await selectData(body, selector);
        results.push({
            request: secretRequest,
            value,
            cachedResponse
        });
    }
    return results;
}

/**
 * Uses a Jsonata selector retrieve a bit of data from the result
 * @param {object} data 
 * @param {string} selector 
 */
async function selectData(data, selector) {
    const ata = jsonata(selector);
    let result = JSON.stringify(await ata.evaluate(data));
    // Compat for custom engines
    if (!result && ((ata.ast().type === "path" && ata.ast()['steps'].length === 1) || ata.ast().type === "string") && selector !== 'data' && 'data' in data) {
        result = JSON.stringify(await jsonata(`data.${selector}`).evaluate(data));
    } else if (!result) {
        throw Error(`Unable to retrieve result for ${selector}. No match data was found. Double check your Key or Selector.`);
    }

    if (result.startsWith(`"`)) {
        result = JSON.parse(result);
    }
    return result;
}

module.exports = {
    getSecrets,
    selectData
}