import {
  ArrayToken,
  BinaryToken,
  ComparisonPredicateToken,
  DateToken,
  FragmentToken,
  IdentifierToken,
  IntervalToken,
  JsonBinaryToken,
  JsonToken,
  ListToken,
  QueryToken,
  TimestampToken,
  UnnestToken,
  UuidToken,
} from "../tokens.js";
import type { SqlToken as SqlTokenType } from "../types.js";
import { hasOwnProperty } from "./hasOwnProperty.js";
import { UnexpectedStateError } from "@slonik/errors";

const Tokens = [
  ArrayToken,
  BinaryToken,
  ComparisonPredicateToken,
  DateToken,
  FragmentToken,
  IdentifierToken,
  IntervalToken,
  JsonBinaryToken,
  JsonToken,
  ListToken,
  QueryToken,
  TimestampToken,
  UnnestToken,
  UuidToken,
] as const;

const tokenNames = new Set(
  Tokens.map((token) => {
    const tokenTypeName = Symbol.keyFor(token);

    if (typeof tokenTypeName !== "string") {
      throw new UnexpectedStateError("Expected token type be a symbol with inferrable key");
    }

    return tokenTypeName;
  }),
);

export const isSqlToken = (subject: unknown): subject is SqlTokenType => {
  if (typeof subject !== "object" || subject === null) {
    return false;
  }

  if (!hasOwnProperty(subject, "type")) {
    return false;
  }

  const tokenType = subject.type;

  if (typeof tokenType !== "symbol") {
    return false;
  }

  const tokenTypeName = Symbol.keyFor(tokenType);

  if (typeof tokenTypeName !== "string") {
    return false;
  }

  // It is worth clarifying that we don't care if symbols match.
  // However, we do care that:
  // 1) the type is a symbol; and
  // 2) we can recognize the key
  //
  // The reason we care that the type is a symbol,
  // is because it makes it impossible to inject
  // it from outside of the codebase, e.g. through JSON.
  //
  // The reason we don't try to match instance of an object
  // is because there is because it makes it difficult
  // to version Slonik plugins that are used to
  // construct custom SQL fragments.
  return tokenNames.has(tokenTypeName);
};