use archlens_domain::{
    CodeElement, CodeElementKind, CodeGraph, FilePath, ModuleName, Relationship, RelationshipKind,
};

fn make_element(name: &str, module: Option<&str>) -> CodeElement {
    let mut element = CodeElement::new(
        name,
        CodeElementKind::Class,
        FilePath::new(&format!("src/{name}.rs")).unwrap(),
        1,
    )
    .unwrap();

    if let Some(m) = module {
        element = element.with_module(ModuleName::new(m).unwrap());
    }

    element
}

#[test]
fn empty_graph_has_no_elements() {
    let graph = CodeGraph::new();
    assert!(graph.elements().is_empty());
    assert!(graph.relationships().is_empty());
}

#[test]
fn graph_stores_added_elements() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("OrderService", None));
    graph.add_element(make_element("Order", None));

    assert_eq!(graph.elements().len(), 2);
}

#[test]
fn graph_stores_relationships() {
    let mut graph = CodeGraph::new();
    let service = make_element("OrderService", None);
    let repo = make_element("OrderRepository", None);

    graph.add_element(service);
    graph.add_element(repo);
    graph.add_relationship(
        Relationship::new(
            "OrderService",
            "OrderRepository",
            RelationshipKind::Composition,
        )
        .unwrap(),
    );

    assert_eq!(graph.relationships().len(), 1);
    let rel = &graph.relationships()[0];
    assert_eq!(rel.source(), "OrderService");
    assert_eq!(rel.target(), "OrderRepository");
    assert_eq!(rel.kind(), RelationshipKind::Composition);
}

#[test]
fn subgraph_by_module_filters_elements() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("OrderService", Some("Orders")));
    graph.add_element(make_element("Order", Some("Orders")));
    graph.add_element(make_element("BillingService", Some("Billing")));

    let module = ModuleName::new("Orders").unwrap();
    let subgraph = graph.subgraph_by_module(&module);

    assert_eq!(subgraph.elements().len(), 2);
    assert!(
        subgraph
            .elements()
            .iter()
            .all(|e| e.module().unwrap().as_str() == "Orders")
    );
}

#[test]
fn subgraph_includes_relationships_within_module() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("OrderService", Some("Orders")));
    graph.add_element(make_element("Order", Some("Orders")));
    graph.add_element(make_element("BillingService", Some("Billing")));

    graph.add_relationship(
        Relationship::new("OrderService", "Order", RelationshipKind::Composition).unwrap(),
    );
    graph.add_relationship(
        Relationship::new(
            "OrderService",
            "BillingService",
            RelationshipKind::Composition,
        )
        .unwrap(),
    );

    let module = ModuleName::new("Orders").unwrap();
    let subgraph = graph.subgraph_by_module(&module);

    assert_eq!(subgraph.relationships().len(), 1);
    assert_eq!(subgraph.relationships()[0].target(), "Order");
}

#[test]
fn subgraph_of_nonexistent_module_is_empty() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("OrderService", Some("Orders")));

    let module = ModuleName::new("Unknown").unwrap();
    let subgraph = graph.subgraph_by_module(&module);

    assert!(subgraph.elements().is_empty());
    assert!(subgraph.relationships().is_empty());
}

#[test]
fn qualify_sets_qualified_name_on_elements_with_modules() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("DtoBaseModel", Some("Commons")));
    graph.add_element(make_element("DtoBaseModel", Some("Api")));
    graph.add_element(make_element("Orphan", None));

    let graph = graph.qualify();

    let commons_dto = graph
        .elements()
        .iter()
        .find(|e| e.module().map(|m| m.as_str()) == Some("Commons"))
        .unwrap();
    assert_eq!(commons_dto.qualified_name(), "Commons::DtoBaseModel");

    let api_dto = graph
        .elements()
        .iter()
        .find(|e| e.module().map(|m| m.as_str()) == Some("Api"))
        .unwrap();
    assert_eq!(api_dto.qualified_name(), "Api::DtoBaseModel");

    let orphan = graph
        .elements()
        .iter()
        .find(|e| e.name() == "Orphan")
        .unwrap();
    assert_eq!(orphan.qualified_name(), "Orphan");
}

#[test]
fn qualify_rewrites_unambiguous_relationship_target() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("OrderService", Some("App")));
    graph.add_element(make_element("Order", Some("Domain")));
    graph.add_relationship(
        Relationship::new("OrderService", "Order", RelationshipKind::Composition).unwrap(),
    );

    let graph = graph.qualify();

    let rel = &graph.relationships()[0];
    assert_eq!(rel.source(), "App::OrderService");
    assert_eq!(rel.target(), "Domain::Order");
}

#[test]
fn qualify_disambiguates_target_by_source_module() {
    let mut graph = CodeGraph::new();
    // DtoBaseModel exists in both Commons and Api
    graph.add_element(make_element("DtoBaseModel", Some("Commons")));
    graph.add_element(make_element("DtoBaseModel", Some("Api")));
    // GlobalAudienceDefinition inherits DtoBaseModel, and is in Commons
    graph.add_element(make_element("GlobalAudienceDefinition", Some("Commons")));

    let mut rel = Relationship::new(
        "GlobalAudienceDefinition",
        "DtoBaseModel",
        RelationshipKind::Inheritance,
    )
    .unwrap();
    // source_file is in the Commons module path
    rel = rel.with_source_file(
        archlens_domain::FilePath::new("src/commons/global_audience.rs").unwrap(),
    );
    let gad = CodeElement::new(
        "GlobalAudienceDefinition",
        archlens_domain::CodeElementKind::Class,
        archlens_domain::FilePath::new("src/commons/global_audience.rs").unwrap(),
        1,
    )
    .unwrap()
    .with_module(archlens_domain::ModuleName::new("Commons").unwrap());

    let mut graph = CodeGraph::new();
    graph.add_element(make_element("DtoBaseModel", Some("Commons")));
    graph.add_element(make_element("DtoBaseModel", Some("Api")));
    graph.add_element(gad);
    graph.add_relationship(rel);

    let graph = graph.qualify();

    let rel = &graph.relationships()[0];
    assert_eq!(rel.source(), "Commons::GlobalAudienceDefinition");
    assert_eq!(rel.target(), "Commons::DtoBaseModel");
}

#[test]
fn resolve_preserves_relationship_when_both_qualified_names_exist() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("GlobalAudienceDefinition", Some("Commons")));
    graph.add_element(make_element("DtoBaseModel", Some("Commons")));
    graph.add_element(make_element("DtoBaseModel", Some("Api")));

    graph.add_relationship(
        Relationship::new(
            "GlobalAudienceDefinition",
            "DtoBaseModel",
            RelationshipKind::Inheritance,
        )
        .unwrap(),
    );

    let graph = graph.qualify().resolve_relationships();

    // The relationship should survive — Commons::GlobalAudienceDefinition --> Commons::DtoBaseModel
    assert_eq!(graph.relationships().len(), 1);
    assert_eq!(
        graph.relationships()[0].source(),
        "Commons::GlobalAudienceDefinition"
    );
    assert_eq!(graph.relationships()[0].target(), "Commons::DtoBaseModel");
}

#[test]
fn cross_module_deps_for_returns_target_module_with_count() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("WidgetJobData", Some("aiss_worker")));
    graph.add_element(make_element("WidgetType", Some("commons")));

    graph.add_relationship(
        Relationship::new("WidgetJobData", "WidgetType", RelationshipKind::Composition).unwrap(),
    );

    let module = ModuleName::new("aiss_worker").unwrap();
    let deps = graph.cross_module_deps_for(&module);

    assert_eq!(deps.len(), 1);
    assert_eq!(deps[0].0.as_str(), "commons");
    assert_eq!(deps[0].1, 1);
}

#[test]
fn cross_module_deps_for_returns_empty_for_intra_module_only() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("OrderService", Some("Orders")));
    graph.add_element(make_element("Order", Some("Orders")));
    graph.add_relationship(
        Relationship::new("OrderService", "Order", RelationshipKind::Composition).unwrap(),
    );

    let module = ModuleName::new("Orders").unwrap();
    let deps = graph.cross_module_deps_for(&module);

    assert!(deps.is_empty());
}

#[test]
fn cross_module_deps_for_aggregates_multiple_relationships_to_same_module() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("ServiceA", Some("app")));
    graph.add_element(make_element("ServiceB", Some("app")));
    graph.add_element(make_element("DomainType1", Some("domain")));
    graph.add_element(make_element("DomainType2", Some("domain")));

    graph.add_relationship(
        Relationship::new("ServiceA", "DomainType1", RelationshipKind::Composition).unwrap(),
    );
    graph.add_relationship(
        Relationship::new("ServiceB", "DomainType2", RelationshipKind::Composition).unwrap(),
    );

    let module = ModuleName::new("app").unwrap();
    let deps = graph.cross_module_deps_for(&module);

    assert_eq!(deps.len(), 1);
    assert_eq!(deps[0].0.as_str(), "domain");
    assert_eq!(deps[0].1, 2);
}

#[test]
fn graph_lists_unique_modules() {
    let mut graph = CodeGraph::new();
    graph.add_element(make_element("OrderService", Some("Orders")));
    graph.add_element(make_element("Order", Some("Orders")));
    graph.add_element(make_element("BillingService", Some("Billing")));
    graph.add_element(make_element("Orphan", None));

    let modules = graph.modules();
    assert_eq!(modules.len(), 2);
    assert!(modules.iter().any(|m| m.as_str() == "Orders"));
    assert!(modules.iter().any(|m| m.as_str() == "Billing"));
}