import logger from 'log'
import fs from 'node:fs/promises'

import type {Ok} from './helpers'

const log = logger('config:read_env')
const FILE_EXT = "__FILE"

// Read from env or file
export async function read_env(key: string): Promise<Ok<string | undefined>> {
    const path = process.env[key + FILE_EXT]
    if (path !== undefined) return from_file(path)
    else return {ok: true, data: process.env[key]}
}
async function from_file(path: string): Promise<Ok<string>> {
    log.debug("Read a key from a file")
    log.trace("Path :", path)

    let content = await get_file_content(path)
    if (!content.ok) return content

    content.data = content.data.trim()

    return content
}
async function get_file_content(path: string) : Promise<Ok<string>> {
    log.debug('Read file content')
    log.trace('Path :', path)

    try {
        const data = await fs.readFile(path, {encoding: 'utf-8'})
        return {ok: true, data}
    } catch (e) {
        log.warn('Failed to read file', path)
        log.debug('Error :', e)
        return {ok: false}
    }
}