const fs = require("fs")
const util = require("util")

const logger = require("logplease").create("state")
const state = new Map()

function replacer(key, value) {
    if(value instanceof Map) {
        return {
            data_type: "Map",
            value: Array.from(value.entries()),
        }
    } else {
        return value
    }
}
  
function reviver(key, value) {
    if(typeof value === "object" && value !== null) {
        if (value.data_type === "Map") {
            return new Map(value.value)
        }
    }
    return value
}
  

module.exports = {
    state,
    async load(data_file){
        if(fs.exists_sync(data_file)){
            logger.info("Loading state from file")
            var content = await util.promisify(fs.read_file)(data_file)
            var obj = JSON.parse(content.toString(), reviver);
            [...obj.keys()].forEach(k => state.set(k, obj.get(k)))
        }else{
            logger.info("Creating new statefile")
            state.set("repositories", new Map().set("offical", "https://repo.pistonee.org/index.yaml"))
        }
    },
    async save(data_file){
        logger.info("Saving state to disk")
        await util.promisify(fs.write_file)(data_file, JSON.stringify(state, replacer))
    }
}