package org.shedlang.compiler.parser;

import org.junit.jupiter.api.Test;

import static org.shedlang.compiler.ast.untyped.UntypedNodeMatchers.*;
import static org.shedlang.compiler.parser.ParserTesting.parseString;
import static org.zwobble.precisely.AssertThat.assertThat;
import static org.zwobble.precisely.Matchers.isSequence;

public class ParserIfTests {
    @Test
    public void canParseIfWithSingleConditionalBranchAndNoElse() {
        var source = "if (a) { 1; }";

        var node = parseString(source, Parser::parseTopLevelExpression);

        assertThat(node, isUntypedIfNode(
            isSequence(
                isUntypedConditionalBranchNode(
                    isUntypedReferenceNode("a"),
                    isUntypedBlockNode(isSequence(
                        isUntypedExpressionStatementNode(isUntypedIntLiteralNode(1))
                    ))
                )
            ),
            isUntypedBlockNode(isSequence())
        ));
    }

    @Test
    public void canParseIfWithSingleConditionalBranchAndElse() {
        var source = "if (a) { 1; } else { 2; }";

        var node = parseString(source, Parser::parseTopLevelExpression);

        assertThat(node, isUntypedIfNode(
            isSequence(
                isUntypedConditionalBranchNode(
                    isUntypedReferenceNode("a"),
                    isUntypedBlockNode(isSequence(
                        isUntypedExpressionStatementNode(isUntypedIntLiteralNode(1))
                    ))
                )
            ),
            isUntypedBlockNode(isSequence(
                isUntypedExpressionStatementNode(isUntypedIntLiteralNode(2))
            ))
        ));
    }

    @Test
    public void canParseIfWithManyConditionalBranchesAndNoElse() {
        var source = "if (a) { 1; } else if (b) { 2; }";

        var node = parseString(source, Parser::parseTopLevelExpression);

        assertThat(node, isUntypedIfNode(
            isSequence(
                isUntypedConditionalBranchNode(
                    isUntypedReferenceNode("a"),
                    isUntypedBlockNode(isSequence(
                        isUntypedExpressionStatementNode(isUntypedIntLiteralNode(1))
                    ))
                ),
                isUntypedConditionalBranchNode(
                    isUntypedReferenceNode("b"),
                    isUntypedBlockNode(isSequence(
                        isUntypedExpressionStatementNode(isUntypedIntLiteralNode(2))
                    ))
                )
            ),
            isUntypedBlockNode(isSequence())
        ));
    }

    @Test
    public void canParseIfWithManyConditionalBranchesAndElse() {
        var source = "if (a) { 1; } else if (b) { 2; } else { 3; }";

        var node = parseString(source, Parser::parseTopLevelExpression);

        assertThat(node, isUntypedIfNode(
            isSequence(
                isUntypedConditionalBranchNode(
                    isUntypedReferenceNode("a"),
                    isUntypedBlockNode(isSequence(
                        isUntypedExpressionStatementNode(isUntypedIntLiteralNode(1))
                    ))
                ),
                isUntypedConditionalBranchNode(
                    isUntypedReferenceNode("b"),
                    isUntypedBlockNode(isSequence(
                        isUntypedExpressionStatementNode(isUntypedIntLiteralNode(2))
                    ))
                )
            ),
            isUntypedBlockNode(isSequence(
                isUntypedExpressionStatementNode(isUntypedIntLiteralNode(3))
            ))
        ));
    }
}