const fs = require("node:fs")
const path = require("node:path")
const crypto = require("node:crypto")
const { DefaultError } = require("../errors/errors")
const { pipeline } = require("node:stream/promises")
const gameDataPath = path.join(process.cwd(), "data", "products")

function normalizePath($path) {
    return $path.split(path.win32.sep).join(path.posix.sep)
}

async function getFileSha1(filePath) {
    const hash = crypto.createHash("sha1")
    const readStream = fs.createReadStream(filePath)

    try {
        await pipeline(readStream, hash)
        return hash.digest("hex")
    } catch (error) {
        throw new Error(`Error when calculating SHA-1 hash: ${error.message}`);
    }
}

async function getGameFiles() {
    const files = await fs.promises.readdir(gameDataPath, { recursive: true })
    const gameFilesIndex = { root: [] }
    for (const file of files) {
        const filePath = path.join(gameDataPath, file)
        const fileMetadata = await fs.promises.stat(filePath)
        if (!fileMetadata.isDirectory()) {
            const normalizedFilePath = normalizePath(file)
            const artifact = {
                path: normalizedFilePath,
                sha1: await getFileSha1(filePath),
                size: fileMetadata.size,
                url: (process.env.BASE_POINT || "") + normalizedFilePath
            }
            const downloadObject = {
                downloads: {
                    artifact,
                },
                name: path.parse(normalizedFilePath).base
            }
            gameFilesIndex.root.push(downloadObject)
        }
    }
    return gameFilesIndex
}

async function getFile(basePath) {
    try {
        const fixedPath = path.join(gameDataPath, decodeURI(basePath))
        const fileMetadata = await fs.promises.stat(fixedPath)
        if (fileMetadata.isDirectory()) {
            throw new DefaultError(409, "Can't download a directory", "", "NotDownloadableException")
        }

        return { code: 200, path: fixedPath }
    } catch (error) {
        if (error.code == "ENOENT") {
            throw new DefaultError(404, "File not found", "", "NotFoundException")
        } else {
            throw error
        }
    }
}

module.exports = {
    getFile,
    getFileSha1,
    getGameFiles
}