import { test, expect } from "bun:test"
import { toBytecode } from "#bytecode"
import { VM } from "#vm"

test("MAKE_FUNCTION - creates function with captured scope", async () => {
  const bytecode = toBytecode(`
    MAKE_FUNCTION () #999
  `)

  const result = await new VM(bytecode).run()
  expect(result.type).toBe('function')
  if (result.type === 'function') {
    expect(result.body).toBe(999)
    expect(result.params).toEqual([])
  }
})

test("CALL and RETURN - basic function call", async () => {
  const bytecode = toBytecode(`
    MAKE_FUNCTION () #3
    CALL #0
    HALT
    PUSH 42
    RETURN
  `)

  const result = await new VM(bytecode).run()
  expect(result).toEqual({ type: 'number', value: 42 })
})

test("CALL and RETURN - function with one parameter", async () => {
  const bytecode = toBytecode(`
    MAKE_FUNCTION (x) #4
    PUSH 100
    CALL #1
    HALT
    LOAD x
    RETURN
  `)

  const result = await new VM(bytecode).run()
  expect(result).toEqual({ type: 'number', value: 100 })
})

test("CALL and RETURN - function with two parameters", async () => {
  const bytecode = toBytecode(`
    MAKE_FUNCTION (a b) #5
    PUSH 10
    PUSH 20
    CALL #2
    HALT
    LOAD a
    LOAD b
    ADD
    RETURN
  `)

  const result = await new VM(bytecode).run()
  expect(result).toEqual({ type: 'number', value: 30 })
})