import { REGIONS } from "../config/regions.js";
import { log } from "../core/log.js";
import { world } from "@minecraft/server";

const KEY = "tama.progress";
const VERSION = 1; //For updating the json in the save

/**
 * The in-memory copy of the whole save document, so we don't re-read the
 * world's dynamic properties every time something needs a value.
 * Null until load() runs. saveState() writes it back out to the world save.
 *
 * cache = {
 *     version: 1,
 *     coins: 0,
 *     gates: {
 *         lagoon:   true,
 *         farmland: false,
 *         seaside:  false,
 *         skyland:  false
 *     }
 * }
 */
let cache = null;

/**
 * Reads the save document out of the world and puts it in `cache`.
 *
 * Nothing stored under KEY yet means a brand-new world - getDynamicProperty
 * returns undefined - so build the defaults and write them straight back,
 * which is what creates the save.
 *
 * Otherwise the stored value is JSON text, so parse it back into an object.
 */
export function load(){
    const raw = world.getDynamicProperty(KEY);
    //let raw = undefined;
    //good for debugging before the value is updated
    //console.log(raw);
    
    if(raw === undefined) {
        cache = buildDefaults();
        saveState();
    } else {
        //good for debugging post update
        //console.log(raw);
        cache = JSON.parse(raw);
    }
    if(cache.version < VERSION) {
        //if(version < (VERSION) -> add attribute etc))
        log("==================================");
        log(`version: ${cache.version}, code expects ${VERSION}`);
        log("==================================");
        //if attribute === undefined -> set default value
        cache.version = VERSION;
    }
}

/**
 * Builds a fresh save document for a world that has never been played.
 *
 * `gates` is an object (not an array) filled by looping REGIONS and copying
 * each region's unlockedAtStart value, so adding a region to the config
 * automatically adds its gate here with no change to this function.
 */
function buildDefaults() {
const gates = {};
const coins = 0;
for(const id in REGIONS)
{
gates[id] = REGIONS[id].unlockedAtStart;
}
return{version: VERSION, gates: gates, coins: coins};
}

/**
 * Returns the cached save document.
 * This is the live object, not a copy - anything that mutates what comes back
 * must call saveState() afterwards, or the change is lost on world close.
 */
export function getState() {
        return cache;
}

/**
* buildDefaults returns a value, 
* using .gates returns just the 
* gates value rather than coins 
* and other default data
*/
export function resetGates() {
    cache.gates = buildDefaults().gates;
    saveState();
}
export function resetGate(id) {
    //resets the gate from the config/region config
    cache.gates[id] = REGIONS[id].unlockedAtStart;
    saveState();
}

/**
 * Sets a region's gate to T/F and persists the change.
 * e.g. updateGate("farmland", state)  ->  
 * cache.gates["farmland"] = state
 * 
 * undefined will remove a gate from the cache
 */
export function unlockGate(nKey, state) {
cache.gates[nKey] = state; 
saveState();
}

export function unlockGates() {
for(const id in REGIONS) {
cache.gates[id] = true;
}
saveState();
}

export function updateBalance(cost) {
    cache.coins += cost;
    saveState();
}

export function returnBalance(){
    const value = cache.coins;
    return value;
}

export function printGateState(){
console.log(JSON.stringify(getState().gates));
}

/**
 * Writes the cache out to the world save, where it survives the world closing.
 *
 * Returns early if nothing has been loaded yet - writing a null cache would
 * store the text "null" and corrupt the save.
 *
 * Objects are not a permitted dynamic property value (only boolean, number,
 * string and Vector3), so the document is converted to JSON text first.
 */
export function saveState() {
    if(cache === null) return;
    const text = JSON.stringify(cache);
    world.setDynamicProperty(KEY, text);
}