// /**
//  * @swagger
//  * /api/documents/download/{id}:
//  *   get:
//  *     tags:
//  *      - Documents
//  *     description: Get document
//  *     parameters:
//  *      - name: id
//  *        in: path
//  *        description: iShare ID
//  *        type: string
//  *        required: true
//  *        default: A41567436
//  *      - name: hash
//  *        in: query
//  *        description: Hash string
//  *        default: e0a1c9cd2817826a25bca67e60b807eae747cbed769e3ec42cf997541c32be71
//  *     responses:
//  *       200:
//  *         description: Success
//  */

// import axios from "axios";
// import CryptoJS from "crypto-js";

// const WORDKEY = process.env.HASHKEY;
// const accessTokenEndpoint = process.env.ACCESS_TOKEN_ENDPOINT;
// const tenantId = process.env.TENANT;

// const WEBAPI_URL =
//     process.env.RELAY_ROOT ||
//     "https://dev-pedw-ns.servicebus.windows.net/dev-pedw-hc/";

// const hashAPIPath = (queryPath) => {
//     var hashlink = CryptoJS.HmacSHA256(
//         queryPath,
//         CryptoJS.enc.Hex.parse(WORDKEY)
//     );
//     hashlink = hashlink.toString(CryptoJS.enc.Hex);

//     //return "&hash=" + hashlink;

//     return (queryPath.indexOf("?") > -1 ? "&hash=" : "?hash=") + hashlink;
// };

// const azureHeadersPaged = (access_token) => {
//     return {
//         headers: {
//             "OData-MaxVersion": "4.0",
//             "OData-Version": "4.0",
//             "Accept": "application/json;odata.metadata=none",
//             "Prefer":
//                 'odata.include-annotations="*",return=representation, odata.maxpagesize=10',
//             "Content-Type": "application/json",
//             "Authorization": "Bearer " + access_token,
//         },
//     };
// };

// export default async function ApiProxy(req, res) {
//     var token = await getToken();

//     var docRef = req.query;

//     var queryUrl = "documents/download/" + docRef.id + "?hash=" + docRef.hash;

//     const configDocument = (access_token) => {
//         return {
//             headers: {
//                 "OData-MaxVersion": "4.0",
//                 "OData-Version": "4.0",
//                 "Accept": "application/json",
//                 "Prefer": 'odata.include-annotations="*",return=representation',
//                 "Content-Type": "application/json",
//                 "Authorization": "Bearer " + access_token,
//             },
//             responseType: "arraybuffer",
//         };
//     };

//     return axios
//         .get(
//             WEBAPI_URL + queryUrl, // + hashAPIPath(queryUrl),
//             configDocument(token.access_token)
//         )
//         .then((response) => {
//             const bytes = response.data.byteLength;
//             console.log(bytes);

//             res.setHeader(
//                 "content-disposition",
//                 "attachment; filename=" +
//                     response.headers["content-disposition"].split(
//                         "filename="
//                     )[1]
//             );
//             return res.status(200).send(response.data);
//         })
//         .then(() => {
//             console.log(docRef.id + "has downloaded");

//             return "downloadComplete";
//         })
//         .catch((error) => {
//             consoleLogger(error);
//             res.redirect("/filenotavailable");
//         });
// }

import axios from "axios";
import { getToken } from "../../../../actions/core/token";
import { consoleLogger } from "../../../../actions/core/logger";

const WEBAPI_URL =
    process.env.RELAY_ROOT ||
    "https://dev-pedw-ns.servicebus.windows.net/dev-pedw-hc/";

const FILE_NOT_AVAILABLE_PATH = "/filenotavailable";

// Retry utility with logging
async function retry(fn, retries = 3, delay = 1000) {
    for (let attempt = 1; attempt <= retries; attempt++) {
        try {
            return { response: await fn(), attempts: attempt };
        } catch (err) {
            if (attempt === retries) throw err;
            console.log(`Retry ${attempt} failed, retrying in ${delay}ms...`);
            await new Promise((res) => setTimeout(res, delay));
            delay *= 2; // exponential backoff
        }
    }
}

const ApiProxy = async (req, res) => {
    const docRef = req.query;

    if (
        typeof docRef?.id !== "string" ||
        docRef.id.length === 0 ||
        typeof docRef?.hash !== "string" ||
        docRef.hash.length === 0
    ) {
        if (!res.headersSent) {
            res.redirect(FILE_NOT_AVAILABLE_PATH);
        }
        return;
    }

    try {
        const token = await getToken();
        const startTime = Date.now();

        const fetchStream = async () => {
            const queryUrl =
                "documents/download/" + docRef.id + "?hash=" + docRef.hash;

            return axios.get(WEBAPI_URL + queryUrl, {
                headers: {
                    "OData-MaxVersion": "4.0",
                    "OData-Version": "4.0",
                    "Accept": "application/json",
                    "Prefer":
                        'odata.include-annotations="*",return=representation',
                    "Content-Type": "application/json",
                    "Authorization": "Bearer " + token.access_token
                },
                responseType: "stream"
            });
        };

        const { response, attempts } = await retry(fetchStream, 3, 1000);

        // Extract filename
        const contentDisposition = response.headers["content-disposition"];
        const filename = contentDisposition
            ? contentDisposition.split("filename=")[1]
            : docRef.id;

        res.setHeader(
            "Content-Disposition",
            `attachment; filename=${filename}`
        );
        res.setHeader("Content-Type", "application/octet-stream");

        let totalBytes = 0;

        response.data.on("data", (chunk) => {
            totalBytes += chunk.length;
        });

        response.data.pipe(res);

        response.data.on("end", () => {
            const durationMs = Date.now() - startTime;
            console.log(
                `[Download Complete] Document: ${filename}, ID: ${docRef.id}, Size: ${totalBytes} bytes, Duration: ${durationMs}ms, Attempts: ${attempts}`
            );
        });

        response.data.on("error", (err) => {
            consoleLogger(err);
            if (!res.headersSent) res.redirect(FILE_NOT_AVAILABLE_PATH);
        });
    } catch (error) {
        consoleLogger(error);
        if (!res.headersSent) res.redirect(FILE_NOT_AVAILABLE_PATH);
    }
};

export const config = {
    api: {
        responseLimit: false
    }
};

export default ApiProxy;