// libraries
const fs = require("fs/promises")
const path = require("path")
const crypto = require("crypto")
const {
    sourceDir
} = require("./config.js")


class Logger {
    constructor({ name, logDebug }) {
        this.name = name
        this.debug = logDebug
    }

    _log(logType, data, method) {
        console[method](`[${this.name}] [${logType}] ${typeof data == "string" ? data : data.toString()}`)
    }

    info(data) {
        this._log("info", data, "log")
    }

    warn(data) {
        this._log("warn", data, "error")
    }

    error(data) {
        this._log("error", data, "error")
    }

    debug(data) {
        if (this.debug) {
            this._log("debug", data, "error")
        }
    }
}

async function recursiveFileSearch(dir) {
    const fileList = []
    for (const file of await fs.readdir(dir, { withFileTypes: true })) {
        let pathDir = path.resolve(dir, file.name)
        if (file.isFile()) {
            fileList.push(pathDir)
        } else if (file.isDirectory()) {
            fileList.push(...(await recursiveFileSearch(pathDir)))
        } else {
            logger.warn(`Found directory entry that is neither a file or directory (${pathDir}), ignoring!`)
        }
    }
    return fileList
}

const logger = new Logger({
    name: "launcher", 
    logDebug: process.env.DEBUG == "true"
}),
    LINE_SEPERATOR = "-----------------------------------"

if (!process.env.REPL_SLUG) {
    logger.error(LINE_SEPERATOR)
    logger.error("Repl not detected!")
    logger.error("")
    logger.error("This file is meant to be ran in a Repl")
    logger.error(LINE_SEPERATOR)
}

logger.info(LINE_SEPERATOR)
logger.info("Checking if the proxy needs to be recompiled...")
logger.info(LINE_SEPERATOR)

fs.readFile(path.join(__dirname, ".sourcehash"))
    .then(data => {
        let oldHash = data.toString()
        logger.info("Found old hash, calculating hash of source files...")
        recursiveFileSearch(sourceDir)
            .then(files => {
                Promise.all(files.map(f => fs.readFile(f)))
                    .then(data => {
                        const hash = crypto.createHash("sha256")
                        data.forEach(d => hash.update(d))
                        let sourceHash = hash.digest().toString()

                        if (sourceHash === oldHash) {
                            logger.info("Source hasn't been changed, skipping compilation...")
                            process.exit(0)
                        } else {
                            logger.info("Source has been changed, recompiling...")
                            fs.writeFile(path.join(__dirname, ".sourcehash"), sourceHash)
                                .then(() => {
                                    process.exit(2)
                                })
                                .catch(err => {
                                    logger.error(`Could not write new hash to disk!\n${err.stack}`)
                                    process.exit(1)
                                })
                        }
                    })
            })
            .catch(err => {
                logger.error(`Could not calculate file hashes for files in directory ${sourceDir}!\n${err.stack}`)
                process.exit(1)
            })
    })
    .catch(err => {
        if (err.code == "ENOENT") {
            logger.warn("Previous source hash not found! Assuming a clean install is being used.")
            logger.info("Calculating hash...")
            recursiveFileSearch(sourceDir)
                .then(files => {
                    Promise.all(files.map(f => fs.readFile(f)))
                        .then(data => {
                            const hash = crypto.createHash("sha256")
                            data.forEach(d => hash.update(d))
                            let sourceHash = hash.digest().toString()
                            fs.writeFile(path.join(__dirname, ".sourcehash"), sourceHash)
                                .then(() => {
                                    logger.info("Saved hash to disk.")
                                    process.exit(2)
                                })
                                .catch(err => {
                                    logger.error(`Could not write new hash to disk!\n${err.stack}`)
                                    process.exit(1)
                                })
                        })
                })
                .catch(err => {
                    logger.error(`Could not calculate file hashes for files in directory ${sourceDir}!\n${err.stack}`)
                    process.exit(1)
                })
        } else {
            logger.error(`Could not read .sourcehash file in ${path.join(__dirname, ".sourcehash")} due to an unknown error! Try again with a clean repl?\n${err.stack}`)
            process.exit(1)
        }
    })