import type { ScriptContext, ScriptCoroutineContext, ScriptGameEventHandler } from "../types";
import type { ScriptCoroutines } from "./coroutines";

export type ScriptCoroutineGameEventHandler = {
    handler: ScriptGameEventHandler;
    coroutine: ScriptCoroutineContext;
}

export class ScriptGameEventBus {
    private coroutines: ScriptCoroutines;
    private handlers: Record<string, ScriptCoroutineGameEventHandler[]> = {};

    constructor(coroutines: ScriptCoroutines) {
        this.coroutines = coroutines;
    }

    on(event: string, handler: ScriptGameEventHandler, coroutine: ScriptCoroutineContext): void {
        console.log('subscribing to ' + event, handler, coroutine);
        let set = this.handlers[event];
        if (!set) {
            set = [];
            this.handlers[event] = set;
        }

        if (!set.some((h) => h.handler === handler))
            set.push({ handler, coroutine });
    }

    off(event: string, handler: ScriptGameEventHandler): void {
        console.log('unubscribing from ' + event, handler);
        const handlers = this.handlers[event];
        if (!handlers)
            return;

        this.handlers[event] = handlers.filter((h) => h.handler !== handler);
    }

    emit(event: string, context: Omit<ScriptContext, keyof ScriptCoroutineContext>): void {
        const coroutines = this.handlers[event]
            ?.map((h) => ({
                owner: h.coroutine.thisObject.id,
                name: `${h.coroutine.thisObjectType.name}[${h.coroutine.thisObject.id}]:${event}`,
                coroutine: h.handler({ ...context, ...h.coroutine }),
            }));

        if (coroutines)
            this.coroutines.push(coroutines);
    }
}