//! Provides functionality for measuring the total length of selected
//! bands in a PCB layout. It interacts with the autorouter to calculate and return
//! the length of specified band selections.

use crate::{
    board::mesadata::AccessMesadata,
    drawing::graph::PrimitiveIndex,
    geometry::{primitive::PrimitiveShape, shape::MeasureLength as MeasureLengthTrait},
    graph::MakeRef,
    router::{navcord::NavcordStepper, navmesh::Navmesh},
};

use super::{
    invoker::{GetGhosts, GetMaybeNavcord, GetMaybeNavmesh, GetObstacles},
    selection::BandSelection,
    Autorouter, AutorouterError,
};

pub struct MeasureLengthExecutionStepper {
    selection: BandSelection,
    maybe_length: Option<f64>,
}

impl MeasureLengthExecutionStepper {
    pub fn new(selection: &BandSelection) -> Result<Self, AutorouterError> {
        Ok(Self {
            selection: selection.clone(),
            maybe_length: None,
        })
    }

    pub fn doit(
        &mut self,
        autorouter: &mut Autorouter<impl AccessMesadata>,
    ) -> Result<f64, AutorouterError> {
        let length = if let Some(length) = self.maybe_length {
            length
        } else {
            let mut length = 0.0;

            for selector in self.selection.selectors() {
                let band = autorouter.board.bandname_band(&selector.band).unwrap().0;
                length += band.ref_(autorouter.board.layout().drawing()).length();
            }

            self.maybe_length = Some(length);
            length
        };

        Ok(length)
    }
}

impl GetMaybeNavmesh for MeasureLengthExecutionStepper {
    fn maybe_navmesh(&self) -> Option<&Navmesh> {
        None
    }
}

impl GetMaybeNavcord for MeasureLengthExecutionStepper {
    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
        None
    }
}

impl GetGhosts for MeasureLengthExecutionStepper {
    fn ghosts(&self) -> &[PrimitiveShape] {
        &[]
    }
}

impl GetObstacles for MeasureLengthExecutionStepper {
    fn obstacles(&self) -> &[PrimitiveIndex] {
        &[]
    }
}