package prolog.builtins

import org.junit.jupiter.api.Assertions.assertFalse
import org.junit.jupiter.api.Assertions.assertTrue
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
import prolog.Program
import prolog.ast.logic.Fact
import prolog.ast.terms.Atom

class ControlBuiltinsTest {
    @BeforeEach
    fun setUp() {
        Program.clear()
    }

    @Test
    fun not_atom() {
        val success = Fact(Atom("a"))

        Program.load(listOf(success))

        val goal = Atom("a")
        val notGoal = Not(goal)

        val result1 = Program.query(goal)
        val result2 = Program.query(notGoal)

        assertTrue(result1.any(), "Expected query to succeed")
        assertFalse(result2.any(), "Expected query to fail")
    }

    @Test
    fun not_compound() {
        val success = Fact(Atom("f"))
        val failure = Fact(Atom("g"))

        Program.load(listOf(success, failure))

        val goal = Atom("f")
        val notGoal = Not(Atom("g"))

        val result1 = Program.query(goal)
        val result2 = Program.query(notGoal)

        assertTrue(result1.any(), "Expected query to succeed")
        assertFalse(result2.any(), "Expected query to fail")
    }

    @Test
    fun fail_should_cause_fails() {
        val success = Fact(Atom("a"))
        val failure = Fact(Atom("b"))

        Program.load(listOf(success, failure))

        val goal = Atom("a")
        val failGoal = Fail()

        val result1 = Program.query(goal)
        val result2 = Program.query(failGoal)

        assertTrue(result1.any(), "Expected query to succeed")
        assertFalse(result2.any(), "Expected query to fail")
    }
}