import de.hsrm.compiler.Klang.ContextAnalysis;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

public class FunctionDefinitionTest {

    @Test
    void shouldNotThrowIfReturnTypeIsReferringToAnEnum() {
        // given
        var tree = Helper.prepareParser(" enum bar {A,B,C} function foo(a: int): bar { return bar.A; } foo(1);");
        var ctxAnal = new ContextAnalysis(
                Helper.getFuncs(tree),
                Helper.getStructs(tree),
                Helper.getEnums(tree)
        );

        // when / then
        assertDoesNotThrow(() -> ctxAnal.visit(tree));
    }

    @Test
    void shouldNotThrowIfParameterTypeIsReferringToAnEnum() {
        // given
        var tree = Helper.prepareParser(" enum bar {A,B,C} function foo(a: bar): int { return 1; } foo(bar.A);");
        var ctxAnal = new ContextAnalysis(
                Helper.getFuncs(tree),
                Helper.getStructs(tree),
                Helper.getEnums(tree)
        );

        // when / then
        assertDoesNotThrow(() -> ctxAnal.visit(tree));
    }

    @Test
    void shouldThrowExceptionIfParameterTypeIsNotDefined() {
        // given
        var tree = Helper.prepareParser("function foo(a: schwurbel): int { return 1; } foo();");
        var ctxAnal = new ContextAnalysis(
                Helper.getFuncs(tree),
                Helper.getStructs(tree),
                Helper.getEnums(tree)
        );

        // when / then
        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
        assertEquals("Error in line 1:14 Type schwurbel not defined.", e.getMessage());
    }

    @Test
    void shouldThrowExceptionIfReturnTypeIsNotDefined() {
        // given
        var tree = Helper.prepareParser("function foo(): schwurbel { return 1; } foo();");
        var ctxAnal = new ContextAnalysis(
                Helper.getFuncs(tree),
                Helper.getStructs(tree),
                Helper.getEnums(tree)
        );

        // when / then
        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
        assertEquals("Error in line 1:14 Type schwurbel not defined.", e.getMessage());
    }

    @Test
    void shouldThrowExceptionIfReturnStatementIsMissing() {
        // given
        var tree = Helper.prepareParser("function foo(): int { let x: int; x = 0; } foo();");
        var ctxAnal = new ContextAnalysis(
                Helper.getFuncs(tree),
                Helper.getStructs(tree),
                Helper.getEnums(tree)
        );

        // when / then
        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
        assertEquals("Error in line 1:20 Function foo has to return something of type int.", e.getMessage());
    }

    @Test
    void shouldThrowExceptionIfParameterNameMatchesEnumName() {
        // given
        var tree = Helper.prepareParser("enum Bar { A, B } function foo(Bar: int): int { return 1; } foo(1);");
        var ctxAnal = new ContextAnalysis(
                Helper.getFuncs(tree),
                Helper.getStructs(tree),
                Helper.getEnums(tree)
        );

        // when / then
        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
        assertEquals("Error in line 1:31 Parameter name Bar duplicates an enum of the same name.", e.getMessage());
    }
}