cad-editor/src/app/automation.rs

//! Headless automation server (`OpenCADStudio --serve`).
//!
//! Drives the app without a GUI over a line-based JSON protocol: one request
//! object per line on stdin, one response object per line on stdout. State (the
//! active document) persists across requests, so an external process — a script
//! or an AI agent — can act, observe, and act again.
//!
//! Operations:
//! - `{"op":"new"}`                          — start an empty document
//! - `{"op":"open","path":"file.dwg"}`       — load a drawing
//! - `{"op":"run","cmd":"LAYER Walls"}`      — run a command (the same dispatcher
//!                                             the GUI command line uses)
//! - `{"op":"entities"}`                     — summary count by entity type
//! - `{"op":"save","path":"out.dwg"}`        — write the document (path optional
//!                                             once opened/saved)

use std::io::{BufRead, Write};
use std::path::PathBuf;

use serde_json::{json, Value};

use super::OpenCADStudio;

/// Run the headless JSON server until stdin closes.
pub fn serve() {
    let mut app = OpenCADStudio::new();
    let stdin = std::io::stdin();
    let stdout = std::io::stdout();

    emit(
        &stdout,
        json!({"ok": true, "ready": true, "version": env!("CARGO_PKG_VERSION")}),
    );

    for line in stdin.lock().lines() {
        let Ok(line) = line else { break };
        let line = line.trim();
        if line.is_empty() {
            continue;
        }
        let resp = app.automation_op(line);
        emit(&stdout, resp);
    }
}

fn emit(stdout: &std::io::Stdout, value: Value) {
    let mut o = stdout.lock();
    let _ = writeln!(o, "{value}");
    let _ = o.flush();
}

fn err(msg: impl std::fmt::Display) -> Value {
    json!({ "ok": false, "error": msg.to_string() })
}

fn v3(v: acadrust::types::Vector3) -> Value {
    json!([v.x, v.y, v.z])
}

/// One entity as JSON: handle, type, layer, plus basic geometry for the common
/// types (others carry only the common fields).
fn entity_json(e: &acadrust::EntityType) -> Value {
    use acadrust::EntityType as E;
    let c = e.common();
    let mut obj = json!({
        "handle": format!("{:X}", c.handle.value()),
        "type": crate::entities::names::ui_name(e),
        "layer": c.layer,
    });
    let map = obj.as_object_mut().expect("json object");
    match e {
        E::Line(l) => {
            map.insert("start".into(), v3(l.start));
            map.insert("end".into(), v3(l.end));
        }
        E::Circle(cc) => {
            map.insert("center".into(), v3(cc.center));
            map.insert("radius".into(), json!(cc.radius));
        }
        E::Arc(a) => {
            map.insert("center".into(), v3(a.center));
            map.insert("radius".into(), json!(a.radius));
            map.insert("start_angle".into(), json!(a.start_angle));
            map.insert("end_angle".into(), json!(a.end_angle));
        }
        E::Point(p) => {
            map.insert("location".into(), v3(p.location));
        }
        _ => {}
    }
    obj
}

impl OpenCADStudio {
    /// Handle one JSON request line and return the JSON response.
    pub(crate) fn automation_op(&mut self, line: &str) -> Value {
        let req: Value = match serde_json::from_str(line) {
            Ok(v) => v,
            Err(e) => return err(format!("invalid JSON: {e}")),
        };
        match req["op"].as_str().unwrap_or("") {
            "new" => {
                let i = self.active_tab;
                self.tabs[i].scene.document = acadrust::CadDocument::new();
                self.tabs[i].current_path = None;
                // The headless session starts on the welcome (Start) tab, which
                // blocks drawing commands; turn it into a real drawing.
                self.tabs[i].is_start = false;
                self.tabs[i].scene.bump_geometry();
                self.entity_summary()
            }
            "open" => {
                let Some(path) = req["path"].as_str() else {
                    return err("open: missing \"path\"");
                };
                let bytes = match std::fs::read(path) {
                    Ok(b) => b,
                    Err(e) => return err(format!("open: {e}")),
                };
                let name = PathBuf::from(path)
                    .file_name()
                    .map(|n| n.to_string_lossy().into_owned())
                    .unwrap_or_else(|| path.to_string());
                match crate::io::load_bytes(&name, bytes) {
                    Ok(doc) => {
                        let i = self.active_tab;
                        self.tabs[i].scene.document = doc;
                        self.tabs[i].current_path = Some(PathBuf::from(path));
                        self.tabs[i].is_start = false;
                        self.tabs[i].scene.bump_geometry();
                        self.entity_summary()
                    }
                    Err(e) => err(format!("open: {e}")),
                }
            }
            "run" => {
                let cmd = req["cmd"].as_str().unwrap_or("").to_string();
                if cmd.is_empty() {
                    return err("run: missing \"cmd\"");
                }
                let i = self.active_tab;
                let before = self.tabs[i].scene.document.entities().count();
                self.run_headless(&cmd);
                let after = self.tabs[i].scene.document.entities().count();
                json!({
                    "ok": true,
                    "cmd": cmd,
                    "entities": after,
                    "added": after as i64 - before as i64,
                })
            }
            "entities" => self.entity_summary(),
            "query" => self.entity_query(&req),
            "select" => {
                let i = self.active_tab;
                self.tabs[i].scene.deselect_all();
                if req["clear"].as_bool() != Some(true) {
                    // By explicit handles (hex, as returned by `query`).
                    if let Some(arr) = req["handles"].as_array() {
                        for h in arr.iter().filter_map(|h| h.as_str()) {
                            if let Ok(v) = u64::from_str_radix(h.trim_start_matches("0x"), 16) {
                                self.tabs[i].scene.select_entity(acadrust::Handle::new(v), false);
                            }
                        }
                    }
                    // Or by type / layer.
                    let type_filter = req["type"].as_str();
                    let layer_filter = req["layer"].as_str();
                    if type_filter.is_some() || layer_filter.is_some() {
                        let handles: Vec<acadrust::Handle> = self.tabs[i]
                            .scene
                            .document
                            .entities()
                            .filter(|e| {
                                type_filter.is_none_or(|t| {
                                    crate::entities::names::ui_name(e).eq_ignore_ascii_case(t)
                                })
                            })
                            .filter(|e| layer_filter.is_none_or(|l| e.common().layer == l))
                            .map(|e| e.common().handle)
                            .collect();
                        for h in handles {
                            self.tabs[i].scene.select_entity(h, false);
                        }
                    }
                }
                json!({ "ok": true, "selected": self.tabs[i].scene.selected_entities().len() })
            }
            "save" => {
                let i = self.active_tab;
                let path = req["path"]
                    .as_str()
                    .map(PathBuf::from)
                    .or_else(|| self.tabs[i].current_path.clone());
                let Some(path) = path else {
                    return err("save: no \"path\" and the document has none");
                };
                match crate::io::save(&self.tabs[i].scene.document, &path) {
                    Ok(()) => {
                        self.tabs[i].current_path = Some(path.clone());
                        json!({ "ok": true, "saved": path.to_string_lossy() })
                    }
                    Err(e) => err(format!("save: {e}")),
                }
            }
            "" => err("missing \"op\""),
            other => err(format!("unknown op: {other}")),
        }
    }

    /// Run a command headlessly. Single-word and inline-argument commands
    /// (`PDMODE 3`, `LAYER Walls`) dispatch as-is. For an interactive tool with
    /// coordinate arguments (`LINE 0,0 10,10`) the first word starts the tool
    /// and the remaining tokens are fed as points / option keywords, then the
    /// command is terminated as if Enter were pressed.
    fn run_headless(&mut self, cmd: &str) {
        let i = self.active_tab;
        let tokens: Vec<&str> = cmd.split_whitespace().collect();
        if tokens.len() <= 1 {
            let _ = self.dispatch_command(cmd);
            return;
        }
        let _ = self.dispatch_command(tokens[0]);
        if self.tabs[i].active_cmd.is_none() {
            // Not an interactive tool — an inline-argument command.
            let _ = self.dispatch_command(cmd);
            return;
        }
        self.last_point = None;
        for tok in &tokens[1..] {
            if self.tabs[i].active_cmd.is_none() {
                break;
            }
            self.feed_active_cmd(tok);
        }
        // Terminate a still-open command (LINE / PLINE finish on Enter).
        if self.tabs[i].active_cmd.is_some() {
            if let Some(r) = self.tabs[i].active_cmd.as_mut().map(|c| c.on_enter()) {
                let _ = self.apply_cmd_result(r);
            }
        }
    }

    /// Feed one token to the active command: a coordinate becomes a point, any
    /// other token an option keyword.
    fn feed_active_cmd(&mut self, token: &str) {
        let i = self.active_tab;
        if let Some((mut pt, kind)) = super::helpers::parse_coord(token) {
            if matches!(kind, super::helpers::CoordKind::Relative) {
                if let Some(base) = self.last_point {
                    pt += base;
                }
            }
            self.last_point = Some(pt);
            if let Some(r) = self.tabs[i].active_cmd.as_mut().map(|c| c.on_point(pt)) {
                let _ = self.apply_cmd_result(r);
            }
        } else if let Some(r) = self.tabs[i]
            .active_cmd
            .as_mut()
            .and_then(|c| c.on_text_input(token))
        {
            let _ = self.apply_cmd_result(r);
        }
    }

    /// List entities (handle, type, layer, basic geometry), optionally filtered
    /// by `type` and/or `layer`, capped by `limit` (default 1000).
    fn entity_query(&self, req: &Value) -> Value {
        let i = self.active_tab;
        let type_filter = req["type"].as_str();
        let layer_filter = req["layer"].as_str();
        let limit = req["limit"].as_u64().unwrap_or(1000) as usize;

        let mut entities = Vec::new();
        let mut matched = 0u64;
        for e in self.tabs[i].scene.document.entities() {
            if let Some(tf) = type_filter {
                if !crate::entities::names::ui_name(e).eq_ignore_ascii_case(tf) {
                    continue;
                }
            }
            if let Some(lf) = layer_filter {
                if e.common().layer != lf {
                    continue;
                }
            }
            matched += 1;
            if entities.len() < limit {
                entities.push(entity_json(e));
            }
        }
        json!({
            "ok": true,
            "count": matched,
            "returned": entities.len(),
            "entities": entities,
        })
    }

    /// Count of entities in the active document, total and by type.
    fn entity_summary(&self) -> Value {
        let i = self.active_tab;
        let mut by_type: std::collections::BTreeMap<String, u64> = Default::default();
        let mut total = 0u64;
        for e in self.tabs[i].scene.document.entities() {
            *by_type
                .entry(crate::entities::names::ui_name(e).to_string())
                .or_default() += 1;
            total += 1;
        }
        json!({ "ok": true, "total": total, "by_type": by_type })
    }
}

#[cfg(test)]
mod tests {
    use crate::app::OpenCADStudio;

    #[test]
    fn automation_ops_round_trip() {
        let mut app = OpenCADStudio::new_for_test();

        let r = app.automation_op(r#"{"op":"new"}"#);
        assert_eq!(r["ok"], true);
        assert_eq!(r["total"], 0);

        // A synchronous command runs through the real dispatcher.
        let r = app.automation_op(r#"{"op":"run","cmd":"PDMODE 3"}"#);
        assert_eq!(r["ok"], true);
        assert_eq!(r["cmd"], "PDMODE 3");

        // A draw command with coordinates creates real geometry.
        let r = app.automation_op(r#"{"op":"run","cmd":"LINE 0,0 10,10 10,20"}"#);
        assert_eq!(r["ok"], true);
        assert_eq!(r["added"], 2); // two segments → two Line entities
        let r = app.automation_op(r#"{"op":"run","cmd":"CIRCLE 5,5 3"}"#);
        assert_eq!(r["added"], 1);

        let r = app.automation_op(r#"{"op":"entities"}"#);
        assert_eq!(r["ok"], true);
        assert_eq!(r["total"], 3);
        assert_eq!(r["by_type"]["Line"], 2);
        assert_eq!(r["by_type"]["Circle"], 1);

        // query returns per-entity detail and honours a type filter.
        let r = app.automation_op(r#"{"op":"query","type":"Circle"}"#);
        assert_eq!(r["count"], 1);
        assert_eq!(r["entities"][0]["type"], "Circle");
        assert_eq!(r["entities"][0]["radius"], 3.0);

        // select by type, then a selection command acts on it.
        let r = app.automation_op(r#"{"op":"select","type":"Line"}"#);
        assert_eq!(r["selected"], 2);
        app.automation_op(r#"{"op":"run","cmd":"ERASE"}"#);
        let r = app.automation_op(r#"{"op":"entities"}"#);
        assert_eq!(r["total"], 1); // only the Circle remains

        // Errors are reported, never panics.
        assert_eq!(app.automation_op(r#"{"op":"bogus"}"#)["ok"], false);
        assert_eq!(app.automation_op("not json")["ok"], false);
        assert_eq!(app.automation_op(r#"{"op":"run"}"#)["ok"], false);
    }

    #[test]
    fn save_then_open_round_trips() {
        let mut app = OpenCADStudio::new_for_test();
        let path = std::env::temp_dir().join("ocs_automation_test.dxf");
        let p = path.to_string_lossy();
        app.automation_op(r#"{"op":"new"}"#);
        assert_eq!(
            app.automation_op(&format!(r#"{{"op":"save","path":"{p}"}}"#))["ok"],
            true
        );
        assert_eq!(
            app.automation_op(&format!(r#"{{"op":"open","path":"{p}"}}"#))["ok"],
            true
        );
        let _ = std::fs::remove_file(&path);
    }
}