const mariadb = require("mariadb")
const logger = require("./logger")
const fs = require("fs/promises")
const path = require("path")

const dbConfig = {
    host: process.env.DATABASE_HOST,
    user: process.env.DATABASE_USER,
    password: process.env.DATABASE_PASSWORD,
    database: process.env.DATABASE_NAME,
    acquireTimeout: 20000,
    connectTimeout: 20000,
    bigIntAsNumber: true,
    insertIdAsNumber: true,
    decimalAsNumber: true
}

const pool = mariadb.createPool({
    ...dbConfig,
    connectionLimit: Number(process.env.DATABASE_CONNECTION_LIMIT) || 10
})

async function runDDL() {
    let rootConn
    let ddlConn

    try {
        rootConn = await mariadb.createConnection({
            host: dbConfig.host,
            user: dbConfig.user,
            password: dbConfig.password,
            connectTimeout: dbConfig.connectTimeout
        })

        await rootConn.query(
            `CREATE DATABASE IF NOT EXISTS \`${dbConfig.database}\` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;`
        )
        logger.log(`Base de données '${dbConfig.database}' vérifiée.`, ["MariaDB", "yellow"])
        await rootConn.end()
        rootConn = null

        ddlConn = await mariadb.createConnection({
            ...dbConfig,
            multipleStatements: true
        })

        logger.log("Checking and synchronising the schema...", ["MariaDB", "yellow"])

        const ddlDir = path.join(process.cwd(), "data", "ddl")
        const files = await fs.readdir(ddlDir)

        const sqlFiles = files
            .filter(file => file.endsWith(".sql"))
            .sort()

        for (const file of sqlFiles) {
            const filePath = path.join(ddlDir, file)
            const sql = await fs.readFile(filePath, "utf-8")

            if (sql.trim()) {
                logger.log(`Execution of ${file.bold || file}`, ["DDL", "yellow"])
                await ddlConn.query(sql)
            }
        }

        logger.log("MariaDB database successfully initialised!", ["MariaDB", "yellow"])
    } catch (error) {
        if (error?.fatal) {
            logger.error("Critical error during DB initialisation: " + error.message, ["MariaDB", "yellow"])
            logger.error(error)
            throw error
        } else {
            logger.warn("Minimal error during DB initialisation: " + error.message, ["MariaDB", "yellow"])
        }

    } finally {
        if (rootConn) {
            await rootConn.end()
        }
        if (ddlConn) {
            await ddlConn.end()
        }
    }
}

module.exports = {
    pool,
    runDDL
}