import type { Expression, OperationNode } from "kysely";
import { sql } from "kysely";
import type { DB, Generated } from "./db";

export type IdOf<T extends keyof DB> =
  DB[T]["id"] extends Generated<infer U> ? U : DB[T]["id"];

export class JsonValue<T> implements Expression<T> {
  #value: T;

  constructor(value: T) {
    this.#value = value;
  }

  // This is a mandatory getter. You must add it and always return `undefined`.
  // The return type must always be `T | undefined`.
  get expressionType(): T | undefined {
    return undefined;
  }

  toOperationNode(): OperationNode {
    const json = JSON.stringify(this.#value);
    // Most of the time you can use the `sql` template tag to build the returned node.
    // The `sql` template tag takes care of passing the `json` string as a parameter, alongside the sql string, to the DB.
    return sql`CAST(${json} AS JSONB)`.toOperationNode();
  }
}