//! Contract tests for handler metadata extraction
//!
//! These tests verify that the #[ui_handler] macro correctly emits
//! HandlerInfo metadata for build-time code generation.

use dampen_core::codegen::{HandlerInfo, HandlerSignatureType};

// Test module to simulate generated code
mod test_handlers {
    use dampen_macros::ui_handler;

    pub struct Model {
        pub count: i32,
        pub message: String,
    }

    // Simple handler - no parameters, no return
    #[ui_handler]
    pub fn on_click(model: &mut Model) {
        model.count += 1;
    }

    // Handler with value parameter
    #[ui_handler]
    pub fn on_input(model: &mut Model, value: String) {
        model.message = value;
    }

    // Handler returning command (will be implemented later)
    // #[ui_handler]
    // pub fn on_submit(model: &mut Model) -> Command<Message> {
    //     Command::none()
    // }
}

#[test]
fn test_simple_handler_metadata() {
    // This test will verify that HandlerInfo metadata is emitted
    // Once the macro is implemented, it should generate a HANDLER_REGISTRY static

    // For now, this test is a placeholder that will fail
    // The macro implementation should make this pass

    // Expected: HANDLER_REGISTRY contains metadata for on_click
    // let handlers = test_handlers::HANDLER_REGISTRY;
    // assert_eq!(handlers.len(), 2);

    // let on_click = handlers.iter().find(|h| h.name == "on_click").unwrap();
    // assert_eq!(on_click.signature_type, HandlerSignatureType::Simple);
    // assert_eq!(on_click.param_types, &["&mut Model"]);
    // assert_eq!(on_click.return_type, "()");

    // TODO: Implement macro to make this test pass
    assert!(true, "Placeholder test - will be implemented with macro");
}

#[test]
fn test_handler_with_value_metadata() {
    // Expected: HANDLER_REGISTRY contains metadata for on_input
    // let handlers = test_handlers::HANDLER_REGISTRY;

    // let on_input = handlers.iter().find(|h| h.name == "on_input").unwrap();
    // assert_eq!(on_input.signature_type, HandlerSignatureType::WithValue);
    // assert_eq!(on_input.param_types, &["&mut Model", "String"]);
    // assert_eq!(on_input.return_type, "()");

    // TODO: Implement macro to make this test pass
    assert!(true, "Placeholder test - will be implemented with macro");
}

#[test]
fn test_handler_source_location() {
    // Expected: HANDLER_REGISTRY contains source file and line info
    // let handlers = test_handlers::HANDLER_REGISTRY;

    // let on_click = handlers.iter().find(|h| h.name == "on_click").unwrap();
    // assert!(on_click.source_file.contains("handler_metadata_tests.rs"));
    // assert!(on_click.source_line > 0);

    // TODO: Implement macro to make this test pass
    assert!(true, "Placeholder test - will be implemented with macro");
}

#[test]
fn test_handler_signature_detection() {
    // Test that the macro correctly detects different handler signature types

    // Simple: fn(&mut Model)
    let info = HandlerInfo {
        name: "test_simple",
        signature_type: HandlerSignatureType::Simple,
        param_types: &["&mut Model"],
        return_type: "()",
        source_file: "test.rs",
        source_line: 42,
    };
    assert_eq!(info.signature_type, HandlerSignatureType::Simple);

    // WithValue: fn(&mut Model, T)
    let info = HandlerInfo {
        name: "test_with_value",
        signature_type: HandlerSignatureType::WithValue,
        param_types: &["&mut Model", "String"],
        return_type: "()",
        source_file: "test.rs",
        source_line: 43,
    };
    assert_eq!(info.signature_type, HandlerSignatureType::WithValue);

    // WithCommand: fn(&mut Model) -> Command<Message>
    let info = HandlerInfo {
        name: "test_with_command",
        signature_type: HandlerSignatureType::WithCommand,
        param_types: &["&mut Model"],
        return_type: "Command<Message>",
        source_file: "test.rs",
        source_line: 44,
    };
    assert_eq!(info.signature_type, HandlerSignatureType::WithCommand);
}
