import type { RPGAction, RPGActions, RPGVariables } from "../types";
import type { EvalContext, Entity } from "../core/world";

export function resolveVariables(entity: Entity): RPGVariables {
    const result: RPGVariables = {};
    for (const [key, component] of entity) {
        for (const [varKey, value] of Object.entries(component.getVariables())) {
            if (value != null) {
                if (varKey && varKey !== '.') {
                    result[`${key}.${varKey}`] = value;
                } else {
                    result[key] = value;
                }
            }
        }
    }
    return result;
}

export function resolveVariable(name: string, ctx: EvalContext): RPGVariables[string] {
    // $. prefix → world globals
    if (name.startsWith('$.')) {
        return ctx.world.globals[name.slice(2)];
    }
    // @entityId.component.variable → another entity
    if (name.startsWith('@')) {
        const dotIdx = name.indexOf('.', 1);
        if (dotIdx === -1) return undefined;
        const entityId = name.slice(1, dotIdx);
        const varName = name.slice(dotIdx + 1);
        const entity = ctx.world.getEntity(entityId);
        if (!entity) return undefined;
        return resolveVariables(entity)[varName];
    }
    // bare name → self entity
    return resolveVariables(ctx.self)[name];
}

export function resolveActions(entity: Entity): RPGActions {
    const result: RPGActions = {};
    for (const [key, component] of entity) {
        for (const [actionKey, fn] of Object.entries(component.getActions())) {
            result[`${key}.${actionKey}`] = fn;
        }
    }
    return result;
}

export async function executeAction(action: RPGAction, ctx: EvalContext): Promise<unknown> {
    let entity = ctx.self;
    let actionType = action.type;

    // @entityId.component.action → dispatch to another entity
    if (action.type.startsWith('@')) {
        const dotIdx = action.type.indexOf('.', 1);
        if (dotIdx === -1) return;
        const entityId = action.type.slice(1, dotIdx);
        const found = ctx.world.getEntity(entityId);
        if (!found) return;
        entity = found;
        actionType = action.type.slice(dotIdx + 1);
    }

    const actions = resolveActions(entity);
    return actions[actionType]?.(action.arg);
}