import { Logger } from "../Logger.js";
import type { NamedParameterValues } from "../types.js";
import { interpolatePositionalParameterReferences } from "./interpolatePositionalParameterReferences.js";
import type { ValueExpression } from "@slonik/sql-tag";
import { InvalidInputError } from "slonik";
import type { FragmentSqlToken } from "slonik";

const log = Logger.child({
  namespace: "interpolateNamedParameterReferences",
});

const difference = (a: string[], b: string[]) => {
  return a.filter((value) => !b.includes(value));
};

/**
 * @see https://regex101.com/r/KrEe8i/2
 */
const namedPlaceholderRegex = /[\s(,]:([_a-z]+)/gu;

/**
 * @see https://github.com/mysqljs/sqlstring/blob/f946198800a8d7f198fcf98d8bb80620595d01ec/lib/SqlString.js#L73
 */
export const interpolateNamedParameterReferences = (
  inputSql: string,
  inputValues: NamedParameterValues = {},
): FragmentSqlToken => {
  const resultValues: ValueExpression[] = [];
  const parameterNames = Object.keys(inputValues);

  for (const parameterName of parameterNames) {
    const parameterValue = inputValues[parameterName];

    resultValues.push(parameterValue);
  }

  const usedParameterNames = [] as string[];

  const resultSql = inputSql.replaceAll(namedPlaceholderRegex, (match, g1) => {
    if (!parameterNames.includes(g1)) {
      throw new InvalidInputError("Named parameter reference does not have a matching value.");
    }

    usedParameterNames.push(g1);

    const parameterIndex = parameterNames.indexOf(g1) + 1;

    return match.slice(0, -g1.length - 1) + `$slonik_${parameterIndex}`;
  });

  const unusedParameterNames = difference(parameterNames, usedParameterNames);

  if (unusedParameterNames.length > 0) {
    log.warn(
      {
        unusedParameterNames,
      },
      "unused parameter names",
    );

    throw new InvalidInputError(
      "Values object contains value(s) not present as named parameter references in the query.",
    );
  }

  return interpolatePositionalParameterReferences(resultSql, resultValues);
};