mod derive_app_context;
mod derive_into_element;
mod derive_path_static_str;
mod derive_render;
mod derive_visual_context;
mod register_action;
mod styles;
mod test;

use proc_macro::TokenStream;
use syn::{DeriveInput, Ident};

/// register_action! can be used to register an action with the GPUI runtime.
/// You should typically use `gpui::actions!` or `gpui::impl_actions!` instead,
/// but this can be used for fine grained customization.
#[proc_macro]
pub fn register_action(ident: TokenStream) -> TokenStream {
    register_action::register_action_macro(ident)
}

/// #[derive(IntoElement)] is used to create a Component out of anything that implements
/// the `RenderOnce` trait.
#[proc_macro_derive(IntoElement)]
pub fn derive_into_element(input: TokenStream) -> TokenStream {
    derive_into_element::derive_into_element(input)
}

#[proc_macro_derive(Render)]
#[doc(hidden)]
pub fn derive_render(input: TokenStream) -> TokenStream {
    derive_render::derive_render(input)
}

#[proc_macro_derive(PathStaticStr)]
#[doc(hidden)]
pub fn derive_path_static_str(input: TokenStream) -> TokenStream {
    derive_path_static_str::derive_path_static_str(input)
}

/// #[derive(AppContext)] is used to create a context out of anything that holds a `&mut App`
/// Note that a `#[app]` attribute is required to identify the variable holding the &mut App.
///
/// Failure to add the attribute causes a compile error:
///
/// ```compile_fail
/// # #[macro_use] extern crate gpui_macros;
/// # #[macro_use] extern crate gpui;
/// #[derive(AppContext)]
/// struct MyContext<'a> {
///     app: &'a mut gpui::App
/// }
/// ```
#[proc_macro_derive(AppContext, attributes(app))]
pub fn derive_app_context(input: TokenStream) -> TokenStream {
    derive_app_context::derive_app_context(input)
}

/// #[derive(VisualContext)] is used to create a visual context out of anything that holds a `&mut Window` and
/// implements `AppContext`
/// Note that a `#[app]` and a `#[window]` attribute are required to identify the variables holding the &mut App,
/// and &mut Window respectively.
///
/// Failure to add both attributes causes a compile error:
///
/// ```compile_fail
/// # #[macro_use] extern crate gpui_macros;
/// # #[macro_use] extern crate gpui;
/// #[derive(VisualContext)]
/// struct MyContext<'a, 'b> {
///     #[app]
///     app: &'a mut gpui::App,
///     window: &'b mut gpui::Window
/// }
/// ```
///
/// ```compile_fail
/// # #[macro_use] extern crate gpui_macros;
/// # #[macro_use] extern crate gpui;
/// #[derive(VisualContext)]
/// struct MyContext<'a, 'b> {
///     app: &'a mut gpui::App,
///     #[window]
///     window: &'b mut gpui::Window
/// }
/// ```
#[proc_macro_derive(VisualContext, attributes(window, app))]
pub fn derive_visual_context(input: TokenStream) -> TokenStream {
    derive_visual_context::derive_visual_context(input)
}

/// Used by GPUI to generate the style helpers.
#[proc_macro]
#[doc(hidden)]
pub fn style_helpers(input: TokenStream) -> TokenStream {
    styles::style_helpers(input)
}

/// Generates methods for visibility styles.
#[proc_macro]
pub fn visibility_style_methods(input: TokenStream) -> TokenStream {
    styles::visibility_style_methods(input)
}

/// Generates methods for margin styles.
#[proc_macro]
pub fn margin_style_methods(input: TokenStream) -> TokenStream {
    styles::margin_style_methods(input)
}

/// Generates methods for padding styles.
#[proc_macro]
pub fn padding_style_methods(input: TokenStream) -> TokenStream {
    styles::padding_style_methods(input)
}

/// Generates methods for position styles.
#[proc_macro]
pub fn position_style_methods(input: TokenStream) -> TokenStream {
    styles::position_style_methods(input)
}

/// Generates methods for overflow styles.
#[proc_macro]
pub fn overflow_style_methods(input: TokenStream) -> TokenStream {
    styles::overflow_style_methods(input)
}

/// Generates methods for cursor styles.
#[proc_macro]
pub fn cursor_style_methods(input: TokenStream) -> TokenStream {
    styles::cursor_style_methods(input)
}

/// Generates methods for border styles.
#[proc_macro]
pub fn border_style_methods(input: TokenStream) -> TokenStream {
    styles::border_style_methods(input)
}

/// Generates methods for box shadow styles.
#[proc_macro]
pub fn box_shadow_style_methods(input: TokenStream) -> TokenStream {
    styles::box_shadow_style_methods(input)
}

/// `#[gpui::test]` can be used to annotate test functions that run with GPUI support.
///
/// It supports both synchronous and asynchronous tests, and can provide you with
/// as many `TestAppContext` instances as you need.
/// The output contains a `#[test]` annotation so this can be used with any existing
/// test harness (`cargo test` or `cargo-nextest`).
///
/// ```
/// #[gpui::test]
/// async fn test_foo(mut cx: &TestAppContext) { }
/// ```
///
/// In addition to passing a TestAppContext, you can also ask for a `StdRnd` instance.
/// this will be seeded with the `SEED` environment variable and is used internally by
/// the ForegroundExecutor and BackgroundExecutor to run tasks deterministically in tests.
/// Using the same `StdRng` for behavior in your test will allow you to exercise a wide
/// variety of scenarios and interleavings just by changing the seed.
///
/// # Arguments
///
/// - `#[gpui::test]` with no arguments runs once with the seed `0` or `SEED` env var if set.
/// - `#[gpui::test(seed = 10)]` runs once with the seed `10`.
/// - `#[gpui::test(seeds(10, 20, 30))]` runs three times with seeds `10`, `20`, and `30`.
/// - `#[gpui::test(iterations = 5)]` runs five times, providing as seed the values in the range `0..5`.
/// - `#[gpui::test(retries = 3)]` runs up to four times if it fails to try and make it pass.
/// - `#[gpui::test(on_failure = "crate::test::report_failure")]` will call the specified function after the
///    tests fail so that you can write out more detail about the failure.
///
/// You can combine `iterations = ...` with `seeds(...)`:
/// - `#[gpui::test(iterations = 5, seed = 10)]` is equivalent to `#[gpui::test(seeds(0, 1, 2, 3, 4, 10))]`.
/// - `#[gpui::test(iterations = 5, seeds(10, 20, 30)]` is equivalent to `#[gpui::test(seeds(0, 1, 2, 3, 4, 10, 20, 30))]`.
/// - `#[gpui::test(seeds(10, 20, 30), iterations = 5]` is equivalent to `#[gpui::test(seeds(0, 1, 2, 3, 4, 10, 20, 30))]`.
///
/// # Environment Variables
///
/// - `SEED`: sets a seed for the first run
/// - `ITERATIONS`: forces the value of the `iterations` argument
#[proc_macro_attribute]
pub fn test(args: TokenStream, function: TokenStream) -> TokenStream {
    test::test(args, function)
}

pub(crate) fn get_simple_attribute_field(ast: &DeriveInput, name: &'static str) -> Option<Ident> {
    match &ast.data {
        syn::Data::Struct(data_struct) => data_struct
            .fields
            .iter()
            .find(|field| field.attrs.iter().any(|attr| attr.path.is_ident(name)))
            .map(|field| field.ident.clone().unwrap()),
        syn::Data::Enum(_) => None,
        syn::Data::Union(_) => None,
    }
}
