/**
 * Shared input constraints for tool schemas and settings.
 *
 * Tool parameters and `hashlineEdit` settings use the same integer rules, so
 * both read them from here rather than restating bounds per call site.
 *
 * @module pi-hashline-edit/pi
 */

import type { ConstrainedSamplingConfig } from "@earendil-works/pi-ai";
import { Type, type TLiteral, type TSchemaOptions } from "typebox";

/**
 * Every tool's sampling request: providers that support it enforce the parameter schema while
 * sampling, and the rest sample as usual. Pi's strict converter rejects object and array
 * unions, so no tool schema uses them.
 */
export const STRICT_SAMPLING = {
  type: "json_schema",
  strict: "prefer",
} as const satisfies ConstrainedSamplingConfig;

/**
 * A union of string literals that keeps its static type, which TypeBox infers only from a
 * tuple. `describe` gives each choice its own description.
 */
export function literalUnion<const V extends string>(
  values: readonly V[],
  describe?: (value: V) => string,
  options?: TSchemaOptions,
) {
  return Type.Union(
    values.map((value) =>
      describe ? Type.Literal(value, { description: describe(value) }) : Type.Literal(value),
    ) as [TLiteral<V>, ...TLiteral<V>[]],
    options,
  );
}

/** The `path` parameter of the tools that take one file. */
export function filePathField() {
  return Type.String({ minLength: 1, description: "Path to the file (relative or absolute)" });
}

/** JSON Schema keywords for an integer in [minimum, maximum]; fractions are rejected, not rounded. */
export function integerRange(minimum: number, maximum: number) {
  return { minimum, multipleOf: 1, maximum };
}

/** Positive line numbers, line counts, and match limits. */
export const POSITIVE_SAFE_INTEGER = integerRange(1, Number.MAX_SAFE_INTEGER);

/** grep `context` parameter and its configured default. */
export const GREP_CONTEXT_RANGE = integerRange(0, 20);