const fs = require("node:fs");
const fsPromises = require("node:fs/promises");
const path = require("node:path");
const logger = require("../modules/logger");

const BASE_PATH = path.resolve(process.env.MAIL_STORAGE || process.cwd(), "storage")

function initialize() {
    const directories = ["", "new", "cur", "tmp"]
    for (const dir of directories) {
        const fullPath = path.join(BASE_PATH, dir)
        if (!fs.existsSync(fullPath)) {
            fs.mkdirSync(fullPath, { recursive: true })
        }
    }
    logger.log("Directories initialized", ["StorageService", "cyan"])
}

function createMailWriteStream() {
    const fileName = `${Date.now()}.${process.pid}.jawab`
    const tempPath = path.join(BASE_PATH, "tmp", fileName)
    const finalPath = path.join(BASE_PATH, "new", fileName)
    
    const writeStream = fs.createWriteStream(tempPath)

    writeStream.on("finish", async () => {
        try {
            await fsPromises.rename(tempPath, finalPath)
        } catch (err) {
            logger.log(`Rename failed: ${err.message}`, ["StorageService", "cyan"]);
        }
    })

    return { writeStream, fileName }
}

async function listNewMails() {
    try {
        const files = await fsPromises.readdir(path.join(BASE_PATH, "new"))
        return files.map(file => ({
            id: file,
            path: path.join(BASE_PATH, "new", file),
            status: "new"
        }))
    } catch (err) {
        return []
    }
}

async function getMailContent(fileName, folder = "new") {
    const fullPath = path.join(BASE_PATH, folder, fileName);
    try {
        await fsPromises.access(fullPath, fs.constants.R_OK)
        return fs.createReadStream(fullPath)
    } catch {
        return null
    }
}

module.exports = {
    initialize,
    listNewMails,
    getMailContent,
    createMailWriteStream
}