package org.shedlang.compiler.shid;

import org.junit.jupiter.api.Test;
import org.shedlang.compiler.ast.typed.BoundVariable;
import org.shedlang.compiler.ast.typed.Typed;
import org.shedlang.compiler.types.Types;

import java.util.List;

import static org.shedlang.compiler.shid.instructions.ShidMatchers.*;
import static org.zwobble.precisely.AssertThat.assertThat;
import static org.zwobble.precisely.Matchers.isSequence;

public class ShidCodeGenValTests {
    @Test
    public void whenValIsFunctionStatementThenExpressionIsEvaluatedAndStoredAsLocal() {
        var node = Typed.val("x", Typed.stringLiteral("hello"));
        var context = ShidCodeGen.Context.EMPTY
            .addShedVal("x");

        var result = ShidCodeGen.compileFunctionStatement(node, context);

        assertThat(result.instructions(), isSequence(
            isShidPushString("hello"),
            isShidLocalStore("x__0")
        ));
    }

    @Test
    public void whenValIsNamespaceStatementThenExpressionIsEvaluatedAndStoredAsLocal() {
        var node = Typed.val("x", Typed.stringLiteral("hello"));
        var context = ShidCodeGen.Context.EMPTY
            .addShedVal("x");

        var result = ShidCodeGen.compileNamespaceStatement(node, context);

        assertThat(result.instructions(), isSequence(
            isShidPushString("hello"),
            isShidLocalStore("x__0")
        ));
    }

    @Test
    public void valsInDifferentBlocksAssignToDifferentLocals() {
        var nodes = List.of(
            Typed.val("x", Typed.intLiteral(10)),
            Typed.expressionStatement(Typed.reference("x")),
            Typed.expressionStatement(Typed.if_(
                List.of(
                    Typed.conditionalBranch(
                        Typed.boolLiteral(true),
                        Typed.block(
                            List.of(
                                Typed.val("x", Typed.intLiteral(11)),
                                Typed.expressionStatement(Typed.reference("x"))
                            ),
                            List.of(BoundVariable.val("x"))
                        )
                    )
                ),
                Typed.block(
                    List.of(
                        Typed.val("x", Typed.intLiteral(12)),
                        Typed.expressionStatement(Typed.reference("x"))
                    ),
                    List.of(BoundVariable.val("x"))
                ),
                Types.INT
            )),
            Typed.expressionStatement(Typed.reference("x"))
        );
        var context = ShidCodeGen.Context.EMPTY
            .addShedVal("x");

        for (var node : nodes) {
            context = ShidCodeGen.compileFunctionStatement(node, context);
        }

        assertThat(context.instructions(), isSequence(
            isShidPushInt(10),
            isShidLocalStore("x__0"),
            isShidLocalLoad("x__0"),
            isShidDiscard(),
            isShidPushBool(true),
            isShidIf(
                isShidBlock(isSequence(
                    isShidPushInt(11),
                    isShidLocalStore("x__1"),
                    isShidLocalLoad("x__1"),
                    isShidDiscard(),
                    isShidPushUnit()
                )),
                isShidBlock(isSequence(
                    isShidBlock(isSequence(
                        isShidPushInt(12),
                        isShidLocalStore("x__2"),
                        isShidLocalLoad("x__2"),
                        isShidDiscard(),
                        isShidPushUnit()
                    ))
                ))
            ),
            isShidDiscard(),
            isShidLocalLoad("x__0"),
            isShidDiscard()
        ));
    }
}