// src/lisp/primitives/higher-order.ts
// Higher-Order Function Primitives: map, filter, reduce, compose, partial, etc.

import type { SExpr } from '../SExpr';
import type { ILambdaClosure } from '../ILambdaClosure';
import type { IPrimitiveDefinition } from './mccarthy';

/**
 * MAP - Apply function to each element
 * (map (lambda (x) (* x x)) '(1 2 3)) → (1 4 9)
 *
 * Note: map requires applyLambda to be injected by the interpreter
 */
export const map: IPrimitiveDefinition = {
  name: 'map',
  handler: async (args, evaluate) => {
    // This is a placeholder - the interpreter handles this specially
    // because it needs access to the lambda application mechanism
    throw new Error('map must be handled by interpreter with lambda support');
  },
};

/**
 * FILTER - Keep elements where predicate is true
 * (filter (lambda (x) (> x 2)) '(1 2 3 4)) → (3 4)
 */
export const filter: IPrimitiveDefinition = {
  name: 'filter',
  handler: async (args, evaluate) => {
    throw new Error('filter must be handled by interpreter with lambda support');
  },
};

/**
 * REDUCE - Fold a list with a function
 * (reduce + 0 '(1 2 3 4)) → 10
 */
export const reduce: IPrimitiveDefinition = {
  name: 'reduce',
  aliases: ['fold', 'foldl'],
  handler: async (args, evaluate) => {
    throw new Error('reduce must be handled by interpreter with lambda support');
  },
};

/**
 * FIND - Find first matching element
 * (find (lambda (x) (> x 2)) '(1 2 3 4)) → 3
 */
export const find: IPrimitiveDefinition = {
  name: 'find',
  handler: async (args, evaluate) => {
    throw new Error('find must be handled by interpreter with lambda support');
  },
};

/**
 * EVERY - Check if all elements satisfy predicate
 * (every (lambda (x) (> x 0)) '(1 2 3)) → true
 */
export const every: IPrimitiveDefinition = {
  name: 'every',
  aliases: ['all?'],
  handler: async (args, evaluate) => {
    throw new Error('every must be handled by interpreter with lambda support');
  },
};

/**
 * SOME - Check if any element satisfies predicate
 * (some (lambda (x) (> x 2)) '(1 2 3)) → true
 */
export const some: IPrimitiveDefinition = {
  name: 'some',
  aliases: ['any?'],
  handler: async (args, evaluate) => {
    throw new Error('some must be handled by interpreter with lambda support');
  },
};

/**
 * COMPOSE - Function composition
 * ((compose f g) x) = (f (g x))
 */
export const compose: IPrimitiveDefinition = {
  name: 'compose',
  handler: async (args, evaluate) => {
    throw new Error('compose must be handled by interpreter with lambda support');
  },
};

/**
 * PARTIAL - Partial application
 * ((partial + 1) 2) → 3
 */
export const partial: IPrimitiveDefinition = {
  name: 'partial',
  handler: async (args, evaluate) => {
    throw new Error('partial must be handled by interpreter with lambda support');
  },
};

/**
 * CURRY - Currying
 * ((curry + 1) 2) → 3
 */
export const curry: IPrimitiveDefinition = {
  name: 'curry',
  handler: async (args, evaluate) => {
    throw new Error('curry must be handled by interpreter with lambda support');
  },
};

/**
 * JUXT - Apply multiple functions, return list of results
 * ((juxt inc dec) 5) → (6 4)
 */
export const juxt: IPrimitiveDefinition = {
  name: 'juxt',
  handler: async (args, evaluate) => {
    throw new Error('juxt must be handled by interpreter with lambda support');
  },
};

/**
 * COMPLEMENT - Negate a predicate
 * ((complement even?) 3) → true
 */
export const complement: IPrimitiveDefinition = {
  name: 'complement',
  handler: async (args, evaluate) => {
    throw new Error('complement must be handled by interpreter with lambda support');
  },
};

/**
 * IDENTITY - Return argument unchanged
 * (identity 42) → 42
 */
export const identity: IPrimitiveDefinition = {
  name: 'identity',
  handler: async (args, evaluate) => {
    return await evaluate(args[0]);
  },
};

/**
 * CONSTANTLY - Return a function that always returns the same value
 * ((constantly 42) anything) → 42
 */
export const constantly: IPrimitiveDefinition = {
  name: 'constantly',
  handler: async (args, evaluate) => {
    throw new Error('constantly must be handled by interpreter with lambda support');
  },
};

/**
 * All higher-order primitives
 * Note: Most require interpreter support for lambda handling
 */
export const higherOrderPrimitives: IPrimitiveDefinition[] = [
  map,
  filter,
  reduce,
  find,
  every,
  some,
  compose,
  partial,
  curry,
  juxt,
  complement,
  identity,
  constantly,
];
