//! LOFT command/history integration. Geometry and validation live in the kernel.

use acadrust::entities::{EmbeddedEntity, Point, Surface, SurfaceData, SurfaceKind};
use acadrust::objects::{SolidHistoryLoft, SolidHistoryLoftParameters, SolidHistoryNodeBase};
use acadrust::{EntityType, Handle};
use cadkernel::brep::Body;
use crate::command::{ExtrudeMode, LoftOptions, LoftSectionSelection};
use super::sweep_model::embedded_path;

fn embedded_section(entity: &EntityType) -> Option<EmbeddedEntity> {
    match entity {
        EntityType::Region(region) => Some(EmbeddedEntity::Region(region.clone())),
        EntityType::Point(point) => Some(EmbeddedEntity::Point(point.clone())),
        _ => embedded_path(entity),
    }
}

pub fn is_section(entity: &EntityType) -> bool {
    embedded_section(entity).is_some_and(|entity|
        cadkernel::acis::loft_section_geometry(&[entity]).is_ok())
}

pub fn is_guide_or_path(entity: &EntityType) -> bool {
    embedded_path(entity).is_some_and(|entity| cadkernel::acis::loft_path_geometry(&entity).is_ok())
}

pub fn record(
    sections: &[LoftSectionSelection], guides: &[Handle], path: Option<Handle>,
    available: &[(Handle, EntityType)], mode: ExtrudeMode, options: LoftOptions,
) -> Result<SolidHistoryLoft, String> {
    let find = |handle| available.iter().find(|(candidate, _)| *candidate == handle)
        .map(|(_, entity)| entity).ok_or_else(|| "A selected loft source no longer exists.".to_string());
    let mut cross_sections = Vec::new();
    let mut section_counts = Vec::new();
    let mut surface = mode == ExtrudeMode::Surface;
    for section in sections {
        let members = match section {
            LoftSectionSelection::Entity(handle) => vec![embedded_section(find(*handle)?)
                .ok_or("Unsupported loft section.")?],
            LoftSectionSelection::Point(point) => vec![EmbeddedEntity::Point(Point::from_coords(point.x, point.y, point.z))],
            LoftSectionSelection::Join(handles) => handles.iter().map(|handle| {
                embedded_section(find(*handle)?).ok_or_else(|| "Unsupported joined loft edge.".to_string())
            }).collect::<Result<Vec<_>, _>>()?,
        };
        if let cadkernel::brep::LoftSection::Profile { closed, .. } = cadkernel::acis::loft_section_geometry(&members)? {
            surface |= !closed;
        }
        section_counts.push(members.len());
        cross_sections.extend(members);
    }
    let guides = guides.iter().map(|handle| embedded_path(find(*handle)?)
        .ok_or_else(|| "Unsupported loft guide.".to_string())).collect::<Result<Vec<_>, _>>()?;
    let path_entity = path.map(|handle| embedded_path(find(handle)?)
        .ok_or_else(|| "Unsupported loft path.".to_string())).transpose()?;
    Ok(SolidHistoryLoft {
        base: SolidHistoryNodeBase::new(1), operation_major: 1,
        cross_sections, guides,
        parameters: Some(SolidHistoryLoftParameters {
            path_entity, normals: options.normals,
            start_draft_angle: options.start_draft_angle, end_draft_angle: options.end_draft_angle,
            start_magnitude: options.start_magnitude, end_magnitude: options.end_magnitude,
            start_continuity: options.start_continuity, end_continuity: options.end_continuity,
            start_bulge: options.start_bulge, end_bulge: options.end_bulge,
            closed: options.closed, periodic: options.periodic, surface, align_direction: options.align_direction, section_counts,
        }),
        ..SolidHistoryLoft::default()
    })
}

pub fn build_body(
    sections: &[LoftSectionSelection], guides: &[Handle], path: Option<Handle>,
    available: &[(Handle, EntityType)], mode: ExtrudeMode, options: LoftOptions,
) -> Result<Body, String> {
    cadkernel::acis::rebuild_loft_with_options(&record(sections, guides, path, available, mode, options)?)
}

pub fn surface_entity(record: &SolidHistoryLoft) -> EntityType {
    let settings = record.parameters.clone().unwrap_or_else(|| SolidHistoryLoftParameters {
        normals: 0, ..Default::default()
    });
    let mut surface = Surface::new(SurfaceKind::Lofted);
    surface.surface_data = SurfaceData::Lofted {
        loft_transform: record.base.transform,
        cross_section_entities: record.cross_sections.clone(), guide_entities: record.guides.clone(),
        path_entity: settings.path_entity,
        plane_normal_lofting_type: settings.normals,
        start_draft_angle: settings.start_draft_angle, end_draft_angle: settings.end_draft_angle,
        start_draft_magnitude: settings.start_magnitude, end_draft_magnitude: settings.end_magnitude,
        arc_length_parameterization: true, no_twist: true, align_direction: settings.align_direction,
        simple_surfaces: true, closed_surfaces: settings.closed, solid: false,
        ruled_surface: settings.normals == 0, virtual_guide: false,
        cross_sections: Vec::new(), guide_curves: Vec::new(), path_curve: None,
    };
    EntityType::Surface(surface)
}