fusible 0.14.1

//! The reference kit data: board outline, holes, component footprints, and edge openings.

use std::collections::HashMap;

use serde::Serialize;

use super::edges::edge_contacts;
use super::spec::open_ring;
use super::{BodyError, CLEARANCE, DEFAULT_BOARD_THICKNESS, EDGE_TOLERANCE, NOTCH_MARGIN};
use crate::gerber::layers::{PcbComponentElm, PcbPoint};
use crate::gerber::PcbModel;

#[derive(Debug, Serialize)]
pub(super) struct KitHole {
    pub x: f64,
    pub y: f64,
    pub diameter: f64,
    pub plated: bool,
}

/// A component footprint: `x`, `y` is its center, `w` and `h` its size.
#[derive(Debug, Serialize)]
pub(super) struct KitComponent {
    pub name: String,
    pub layer: String,
    pub x: f64,
    pub y: f64,
    pub w: f64,
    pub h: f64,
    pub touches_edge: bool,
}

/// A wall opening: the part of a board edge a component reaches, as the generator cuts it.
///
/// `from` and `to` are points on the board edge. The cut runs outward along `normal` for
/// `notch.clearance + wall + notch.extra_depth` millimetres.
#[derive(Debug, Serialize)]
pub(super) struct KitOpening {
    pub component: String,
    pub edge: usize,
    pub side: &'static str,
    pub normal: [f64; 2],
    pub from: [f64; 2],
    pub to: [f64; 2],
}

/// The constants behind the openings, so a hand-made cut can match the generated one.
#[derive(Debug, Serialize)]
pub(super) struct KitNotch {
    pub margin: f64,
    pub edge_tolerance: f64,
    pub clearance: f64,
    pub extra_depth: f64,
}

impl KitNotch {
    fn of_the_generator() -> Self {
        Self {
            margin: NOTCH_MARGIN,
            edge_tolerance: EDGE_TOLERANCE,
            clearance: CLEARANCE,
            extra_depth: 1.0,
        }
    }
}

/// Everything a designer needs to model a part around the board, in the generator's frame.
#[derive(Debug, Serialize)]
pub(super) struct Kit {
    pub board: Option<String>,
    pub units: &'static str,
    pub frame: &'static str,
    pub outline: Vec<[f64; 2]>,
    pub thickness: f64,
    pub holes: Vec<KitHole>,
    pub components: Vec<KitComponent>,
    pub openings: Vec<KitOpening>,
    pub notch: KitNotch,
    pub warnings: Vec<String>,
}

fn component_names(json: &str) -> Result<HashMap<String, String>, BodyError> {
    let elements: Vec<serde_json::Value> =
        serde_json::from_str(json).map_err(|e| BodyError::InvalidCircuit(e.to_string()))?;
    let text = |e: &serde_json::Value, key: &str| e[key].as_str().map(str::to_string);
    Ok(elements
        .iter()
        .filter(|e| e["type"] == "source_component")
        .filter_map(|e| {
            let id = text(e, "source_component_id").or_else(|| text(e, "component_id"))?;
            Some((id.clone(), text(e, "name").unwrap_or(id)))
        })
        .collect())
}

/// The holes with a usable diameter, and how many had none and were left out.
fn holes(model: &PcbModel) -> (Vec<KitHole>, usize) {
    let plain = model
        .holes
        .iter()
        .map(|h| (h.x, h.y, h.hole_diameter.or(h.hole_width), false));
    let plated = model
        .plated_holes
        .iter()
        .map(|h| (h.x, h.y, h.hole_diameter.or(h.hole_width), true));
    let all: Vec<_> = plain.chain(plated).collect();
    let holes: Vec<KitHole> = all
        .iter()
        .filter_map(|&(x, y, d, plated)| {
            let diameter = d.filter(|d| d.is_finite() && *d > 0.0)?;
            Some(KitHole {
                x,
                y,
                diameter,
                plated,
            })
        })
        .collect();
    let skipped = all.len() - holes.len();
    (holes, skipped)
}

fn side(normal: [f64; 2]) -> &'static str {
    let horizontal = normal[0].abs() >= normal[1].abs();
    match (horizontal, normal[0] >= 0.0, normal[1] >= 0.0) {
        (true, true, _) => "+x",
        (true, false, _) => "-x",
        (false, _, true) => "+y",
        (false, _, false) => "-y",
    }
}

fn label(component: &PcbComponentElm, names: &HashMap<String, String>) -> String {
    let id = component.source_component_id.clone();
    id.as_ref()
        .and_then(|id| names.get(id).cloned())
        .or(id)
        .or_else(|| component.pcb_component_id.clone())
        .unwrap_or_else(|| "component".into())
}

/// A component's kit entry and the wall openings it needs, or `None` without a footprint.
fn entry(
    c: &PcbComponentElm,
    outline: &[PcbPoint],
    names: &HashMap<String, String>,
) -> Option<(KitComponent, Vec<KitOpening>)> {
    let (center, w, h) = (c.center?, c.width?, c.height?);
    let name = label(c, names);
    let contacts = edge_contacts(c, outline);
    let openings: Vec<KitOpening> = contacts
        .iter()
        .map(|k| KitOpening {
            component: name.clone(),
            edge: k.edge,
            side: side(k.normal),
            normal: k.normal,
            from: k.span[0],
            to: k.span[1],
        })
        .collect();
    let component = KitComponent {
        layer: c.layer.clone().unwrap_or_else(|| "top".into()),
        touches_edge: !contacts.is_empty(),
        x: center.x,
        y: center.y,
        name,
        w,
        h,
    };
    Some((component, openings))
}

/// Builds the kit of the board in `json`; `board` is the manifest name written to the file.
pub(super) fn build_kit(json: &str, board: Option<String>) -> Result<Kit, BodyError> {
    let names = component_names(json)?;
    let model = PcbModel::parse(json);
    let elm = model.boards.first().ok_or(BodyError::NoBoard)?;
    let outline = open_ring(elm.outline_points());
    if outline.len() < 3 {
        return Err(BodyError::NoBoard);
    }
    let (holes, skipped) = holes(&model);
    let entries = model
        .components
        .iter()
        .filter_map(|c| entry(c, &outline, &names));
    let (components, openings): (Vec<_>, Vec<_>) = entries.unzip();
    Ok(Kit {
        board,
        units: "mm",
        frame: "pcb coordinates, Z-up; the enclosure generator uses the same X/Y",
        outline: outline.iter().map(|p| [p.x, p.y]).collect(),
        thickness: elm.thickness.unwrap_or(DEFAULT_BOARD_THICKNESS),
        holes,
        components,
        openings: openings.into_iter().flatten().collect(),
        notch: KitNotch::of_the_generator(),
        warnings: hole_warnings(skipped),
    })
}

fn hole_warnings(skipped: usize) -> Vec<String> {
    match skipped {
        0 => Vec::new(),
        n => vec![format!(
            "{n} hole(s) have no diameter and are not in the kit"
        )],
    }
}