use googletest::matchers::eq;
use googletest::{expect_that, gtest};
use xatu::{PathStep, Resolution, ResolutionPath, ScopeGraph};

#[gtest]
fn resolves_a_local_declaration() {
    let mut graph = ScopeGraph::new();
    let scope = graph.root_scope();
    let declaration = graph.add_declaration(scope, "value");
    let reference = graph.add_reference(scope, "value");

    let expected = vec![resolution(declaration, vec![PathStep::Declaration(declaration)])];
    expect_that!(graph.resolve(reference), eq(&expected));
}

#[gtest]
fn resolves_a_parent_declaration() {
    let mut graph = ScopeGraph::new();
    let parent = graph.root_scope();
    let declaration = graph.add_declaration(parent, "value");
    let child = graph.add_scope(parent);
    let reference = graph.add_reference(child, "value");

    let expected = vec![resolution(
        declaration,
        vec![PathStep::Parent, PathStep::Declaration(declaration)],
    )];
    expect_that!(graph.resolve(reference), eq(&expected));
}

#[gtest]
fn local_declarations_shadow_parent_declarations() {
    let mut graph = ScopeGraph::new();
    let parent = graph.root_scope();
    graph.add_declaration(parent, "value");
    let child = graph.add_scope(parent);
    let declaration = graph.add_declaration(child, "value");
    let reference = graph.add_reference(child, "value");

    let expected = vec![resolution(declaration, vec![PathStep::Declaration(declaration)])];
    expect_that!(graph.resolve(reference), eq(&expected));
}

#[gtest]
fn preserves_ambiguous_local_declarations() {
    let mut graph = ScopeGraph::new();
    let scope = graph.root_scope();
    let first = graph.add_declaration(scope, "value");
    let second = graph.add_declaration(scope, "value");
    let reference = graph.add_reference(scope, "value");

    let expected = vec![
        resolution(first, vec![PathStep::Declaration(first)]),
        resolution(second, vec![PathStep::Declaration(second)]),
    ];
    expect_that!(graph.resolve(reference), eq(&expected));
}

#[gtest]
fn leaves_unresolved_references_without_resolutions() {
    let mut graph = ScopeGraph::new();
    let reference = graph.add_reference(graph.root_scope(), "value");

    let expected = Vec::<Resolution>::new();
    expect_that!(graph.resolve(reference), eq(&expected));
}

fn resolution(
    declaration: xatu::DeclarationId,
    steps: Vec<PathStep>,
) -> Resolution {
    Resolution {
        declaration,
        path: ResolutionPath { steps },
    }
}