import type { BaseHandler } from 'redweb';

/** Structural Standard Schema v1 support; use an existing compatible validator library. */
export interface SocketSchema<Input = unknown, Output = Input> {
    readonly '~standard': {
        readonly version: 1;
        readonly validate: (input: unknown) =>
            { readonly value: Output; readonly issues?: undefined } | { readonly issues: readonly unknown[] } |
            Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: readonly unknown[] }>;
        readonly types?: { readonly input: Input; readonly output: Output };
    };
}

export type SchemaInput<Schema extends SocketSchema> = NonNullable<Schema['~standard']['types']>['input'];
export type SchemaOutput<Schema extends SocketSchema> = Awaited<NonNullable<Schema['~standard']['types']>['output']>;

export interface HandlerSchema<Name extends string = string, Schema extends SocketSchema = SocketSchema> {
    readonly name: Name;
    readonly schema: Schema;
}

export type RedwebSchemas<Schemas extends Record<string, SocketSchema>> = {
    readonly [Name in keyof Schemas & string]: HandlerSchema<Name, Schemas[Name]>;
};

export type MessageOf<Definition extends HandlerSchema> =
    SchemaOutput<Definition['schema']>;
export type HandlerMessage<Definition extends HandlerSchema> = MessageOf<Definition>;
export type HandlerInput<Definition extends HandlerSchema> =
    SchemaInput<Definition['schema']>;

declare const socketActionBrand: unique symbol;
export interface SocketAction { readonly [socketActionBrand]: true; }

export interface SocketHandler<Input> {
    new (): BaseHandler;
    with(payload: Input): SocketAction;
}

export function defineHandlerSchema<const Name extends string, const Schema extends SocketSchema>(
    name: Name,
    schema: Schema,
): HandlerSchema<Name, Schema>;

/** Names each schema from its object key so handlers can select SCHEMAS.join, etc. */
export function defineRedwebSchemas<const Schemas extends Record<string, SocketSchema>>(
    schemas: Schemas,
): RedwebSchemas<Schemas>;