//! Copy and paste of timeline features. Pasted features are independent copies: sketches get
//! their own dimension parameters, feature inputs their own names, and references inside the
//! copied set point at the copies.

use std::collections::BTreeMap;

use serde_json::{Value, json};
use solvecraft_doc::{FeatureKind, PlaneRef};

use super::CommandSpec;
use crate::params::{bad, string_list, vec3};
use crate::{Result, Session};

pub static COMMANDS: &[CommandSpec] = &[
    CommandSpec::new("timeline.copy", "Copy Features", copy).noundo().params("features: [ids or names] (in timeline order on paste)"),
    CommandSpec::new("timeline.paste", "Paste Features", paste)
        .params("translate?: [x,y,z] (moves the copies' geometry); the copies go at the marker"),
];

fn copy(s: &mut Session, p: &Value) -> Result<Value> {
    let cmd = "timeline.copy";
    let mut keys = string_list(p, "features");
    if let Some(Value::Array(a)) = p.get("features") {
        keys.extend(a.iter().filter_map(Value::as_u64).map(|n| n.to_string()));
    }
    if keys.is_empty() || keys.len() > 1000 {
        return Err(bad(cmd, "`features` must list 1…1000 features"));
    }
    let mut ids = Vec::new();
    for k in &keys {
        ids.push(s.doc.find_feature(k).map(|f| f.id).ok_or_else(|| bad(cmd, format!("no feature `{k}`")))?);
    }
    // Keep timeline order so sketches come before the features that use them.
    let copied: Vec<solvecraft_doc::Feature> = s.doc.features.iter().filter(|f| ids.contains(&f.id)).cloned().collect();
    let names: Vec<String> = copied.iter().map(|f| f.name.clone()).collect();
    s.clipboard = copied;
    Ok(json!({"copied": names}))
}

/// Origin planes become explicit planes so a translation can move them.
fn explicit_planes(p: &mut PlaneRef) {
    match p {
        PlaneRef::Origin { name } => {
            if let Some(plane) = solvecraft_geom::Plane::named(name) {
                *p = PlaneRef::Custom { plane };
            }
        }
        PlaneRef::Offset { base, .. } | PlaneRef::AtAngle { base, .. } => explicit_planes(base),
        _ => {}
    }
}

fn paste(s: &mut Session, p: &Value) -> Result<Value> {
    let cmd = "timeline.paste";
    if s.clipboard.is_empty() {
        return Err(bad(cmd, "nothing copied (timeline.copy first)"));
    }
    let translate = match p.get("translate") {
        Some(v) => Some(vec3(v).ok_or_else(|| bad(cmd, "`translate` must be [x, y, z]"))?),
        None => None,
    };
    let feats = s.clipboard.clone();
    let comp = s.active_component;
    let mut sketches: BTreeMap<u64, u64> = BTreeMap::new();
    let mut names: BTreeMap<String, String> = BTreeMap::new();
    let mut made = Vec::new();
    for f in feats {
        let mut kind = f.kind.clone();
        kind.remap_refs(&sketches, &names);
        let doc = s.doc_mut();
        if let FeatureKind::Sketch { sketch, .. } = &mut kind {
            // Each dimension of the copy gets its own parameter, with the same expression.
            for c in &mut sketch.constraints {
                if let Some(pn) = c.param.clone() {
                    let (e, u) = doc.param(&pn).map(|x| (x.expr.clone(), x.unit.clone())).unwrap_or_else(|| (pn.clone(), "mm".into()));
                    c.param = Some(doc.new_model_param(&e, &u));
                }
            }
        }
        if let Some(t) = translate {
            if let FeatureKind::Sketch { plane, .. } | FeatureKind::ConstructionPlane { plane } = &mut kind {
                explicit_planes(plane);
            }
            let mut m = solvecraft_doc::IDENTITY;
            m[3][0] = t.x;
            m[3][1] = t.y;
            m[3][2] = t.z;
            kind.transform_geometry(&m);
        }
        let id = doc.add_feature(kind, None)?;
        if let Some(nf) = doc.feature_mut(id) {
            nf.component = comp;
            nf.body_names = f.body_names.iter().map(|b| format!("{b} (copy)")).collect();
        }
        let new_name = doc.feature(id).map(|x| x.name.clone()).unwrap_or_default();
        if matches!(f.kind, FeatureKind::Sketch { .. }) {
            sketches.insert(f.id, id);
        }
        names.insert(f.name.clone(), new_name.clone());
        made.push(json!({"id": id, "name": new_name, "from": f.name}));
    }
    s.refresh();
    let errors: Vec<Value> = made
        .iter()
        .filter_map(|m| m["id"].as_u64())
        .filter_map(|id| s.model.result(id).and_then(|r| r.error.clone()).map(|e| json!({"feature": id, "error": e})))
        .collect();
    Ok(json!({"pasted": made, "errors": errors}))
}

#[cfg(test)]
mod tests {
    use serde_json::json;

    use crate::Session;

    fn run(s: &mut Session, id: &str, p: serde_json::Value) -> serde_json::Value {
        match s.execute(id, &p) {
            Ok(v) => v,
            Err(e) => panic!("{id} {p}: {e}"),
        }
    }

    fn volume(s: &mut Session) -> f64 {
        run(s, "MeasureCommand", json!({}))["total"]["volume_mm3"].as_f64().unwrap_or(f64::NAN)
    }

    #[test]
    fn copy_paste_sketch_and_extrude() {
        let mut s = Session::default();
        run(&mut s, "ChangeParameterCommand", json!({"name": "w", "expression": "10 mm"}));
        run(&mut s, "SketchCreate", json!({"plane": "XY", "name": "S"}));
        run(&mut s, "ShapeRectangleTwoPoint", json!({"p0": [0, 0], "p1": [10, 10]}));
        run(&mut s, "ConstraintCoincident", json!({"a": "p1", "b": "origin"}));
        run(&mut s, "SketchDimension", json!({"entities": ["l1"], "value": "w"}));
        run(&mut s, "SketchDimension", json!({"entities": ["l2"], "value": 10}));
        run(&mut s, "SketchStop", json!({}));
        run(&mut s, "Extrude", json!({"sketch": "S", "distance": 5}));
        assert!((volume(&mut s) - 500.0).abs() < 1e-6);
        run(&mut s, "timeline.copy", json!({"features": ["S", "Extrude1"]}));
        let r = run(&mut s, "timeline.paste", json!({"translate": [30, 0, 0]}));
        assert_eq!(r["errors"].as_array().map(Vec::len), Some(0), "{r}");
        assert_eq!(run(&mut s, "MeasureCommand", json!({}))["body_count"], 2);
        assert!((volume(&mut s) - 1000.0).abs() < 1e-6);
        // The copy's dimensions are its own, still driven by the user parameter.
        run(&mut s, "ChangeParameterCommand", json!({"name": "w", "expression": "20 mm"}));
        assert!((volume(&mut s) - 2000.0).abs() < 1e-6);
        let pasted_extrude = r["pasted"][1]["name"].as_str().unwrap_or_default().to_string();
        let d = s.doc.find_feature(&pasted_extrude).and_then(|f| f.param_names.first().cloned()).unwrap_or_default();
        run(&mut s, "ChangeParameterCommand", json!({"name": d, "expression": "10"}));
        assert!((volume(&mut s) - 3000.0).abs() < 1e-6, "only the copy got thicker");
        assert!(s.execute("timeline.paste", &json!({"translate": "x"})).is_err());
        let mut t = Session::default();
        assert!(t.execute("timeline.paste", &json!({})).is_err());
    }
}