// Auto-split from scene/mod.rs. Pure text-move; behaviour unchanged.
use super::*;

impl Scene {
    // ── Group helpers ──────────────────────────────────────────────────────

    pub fn groups(&self) -> impl Iterator<Item = &acadrust::objects::Group> {
        self.document.objects.values().filter_map(|obj| match obj {
            ObjectType::Group(g) => Some(g),
            _ => None,
        })
    }

    /// Returns the names of all groups that contain `handle`.
    pub fn group_names_for_entity(&self, handle: Handle) -> Vec<String> {
        self.groups()
            .filter(|g| g.contains(handle))
            .map(|g| g.name.clone())
            .collect()
    }

    /// Creates a named group from the given handles and registers it in the group dictionary.
    pub fn create_group(&mut self, name: String, handles: Vec<Handle>) -> Handle {
        let group_dict_handle = self.document.header.acad_group_dict_handle;
        let mut group = acadrust::objects::Group::new(&name);
        group.handle = self.document.allocate_handle();
        group.owner = group_dict_handle;
        group.add_entities(handles);
        let gh = group.handle;
        self.document.objects.insert(gh, ObjectType::Group(group));
        if let Some(ObjectType::Dictionary(dict)) =
            self.document.objects.get_mut(&group_dict_handle)
        {
            dict.add_entry(&name, gh);
        }
        gh
    }

    /// Dissolves all groups that contain any of the given handles.
    /// Returns the number of groups removed.
    pub fn delete_groups_containing(&mut self, handles: &[Handle]) -> usize {
        let group_dict_handle = self.document.header.acad_group_dict_handle;
        let to_delete: Vec<Handle> = self
            .document
            .objects
            .values()
            .filter_map(|obj| match obj {
                ObjectType::Group(g) if handles.iter().any(|h| g.contains(*h)) => Some(g.handle),
                _ => None,
            })
            .collect();
        let count = to_delete.len();
        for gh in &to_delete {
            if let Some(ObjectType::Dictionary(dict)) =
                self.document.objects.get_mut(&group_dict_handle)
            {
                dict.entries.retain(|(_, h)| h != gh);
            }
            self.document.objects.remove(gh);
        }
        count
    }

    /// If `handle` belongs to any selectable groups, also select all other members of those groups.
    pub fn expand_selection_for_groups(&mut self, handles: &[Handle]) {
        let to_add: Vec<Handle> = self
            .document
            .objects
            .values()
            .filter_map(|obj| match obj {
                ObjectType::Group(g) if g.selectable && handles.iter().any(|h| g.contains(*h)) => {
                    Some(g.entities.clone())
                }
                _ => None,
            })
            .flatten()
            .collect();
        for h in to_add {
            self.selected.insert(h);
        }
        self.bump_selection();
    }

}