const std = @import("std");
const native_sdk = @import("native_sdk");

/// Apply the state-store lookup result at the one layer that can distinguish
/// an actual restore from a fresh launch with persistence merely enabled.
pub fn applySavedWindow(window: *native_sdk.WindowOptions, saved: ?native_sdk.WindowState) bool {
    const state = saved orelse return false;
    window.default_frame = state.frame;
    window.initial_placement = .restored;
    return true;
}

/// An omitted shell field must not erase the caller's direct-SDK fallback.
pub fn applyShellRestorePolicy(fallback: native_sdk.WindowRestorePolicy, declared: ?native_sdk.WindowRestorePolicy) native_sdk.WindowRestorePolicy {
    return declared orelse fallback;
}

/// Only an authored shell origin overrides the caller's placement reason.
pub fn applyShellInitialPlacement(fallback: native_sdk.WindowInitialPlacement, has_explicit_origin: bool) native_sdk.WindowInitialPlacement {
    return if (has_explicit_origin) .explicit else fallback;
}

test "fresh default-restoring window keeps default placement on a store miss" {
    var window: native_sdk.WindowOptions = .{ .restore_state = true };
    try std.testing.expect(!applySavedWindow(&window, null));
    try std.testing.expectEqual(native_sdk.WindowInitialPlacement.default, window.initial_placement);
}

test "fresh explicitly positioned window keeps explicit placement on a store miss" {
    var window: native_sdk.WindowOptions = .{ .initial_placement = .explicit };
    try std.testing.expect(!applySavedWindow(&window, null));
    try std.testing.expectEqual(native_sdk.WindowInitialPlacement.explicit, window.initial_placement);
}

test "state-store hit replaces the frame and marks it restored" {
    var window: native_sdk.WindowOptions = .{ .initial_placement = .explicit };
    const frame = native_sdk.geometry.RectF.init(40, 60, 900, 640);
    try std.testing.expect(applySavedWindow(&window, .{ .frame = frame }));
    try std.testing.expectEqual(frame, window.default_frame);
    try std.testing.expectEqual(native_sdk.WindowInitialPlacement.restored, window.initial_placement);
}

test "omitted shell placement fields preserve direct runner fallbacks" {
    try std.testing.expectEqual(
        native_sdk.WindowRestorePolicy.center_on_primary,
        applyShellRestorePolicy(.center_on_primary, null),
    );
    try std.testing.expectEqual(
        native_sdk.WindowInitialPlacement.restored,
        applyShellInitialPlacement(.restored, false),
    );
}

test "authored shell placement fields override direct runner fallbacks" {
    try std.testing.expectEqual(
        native_sdk.WindowRestorePolicy.clamp_to_visible_screen,
        applyShellRestorePolicy(.center_on_primary, .clamp_to_visible_screen),
    );
    try std.testing.expectEqual(
        native_sdk.WindowInitialPlacement.explicit,
        applyShellInitialPlacement(.restored, true),
    );
}