feat(fana): C1 — núcleo del writer DAG editor (core + graph)

Primer paso de fana (prioridad alta entre las apps Fase C).

- fana-core — NarrativeAtom: id + content_hash SHA-256 + content
  Arc<String> (structural sharing: ramificar es O(1)) + semantic_vectors
  + dependencies + branch_id + CoherenceState (Valid/InConflict/
  PendingEvaluation). Invariante hash↔content verificable; set_content
  re-hashea y marca PendingEvaluation.
- fana-graph — NarrativeGraph: DAG de átomos + adjacency
  dependencia→dependientes. propagate_mutation: BFS que marca
  PendingEvaluation en cascada a todo descendiente (la "onda de choque
  lógica" de la spec), agnóstico de UI — devuelve los ids afectados.
  topological_order con detección de ciclo.

10 tests verdes. cargo check --workspace verde.
Pendiente fana: semantic (cliente verbo), store (sled), llm, render-plan,
editor-gpui.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This commit is contained in:
sergio
2026-05-20 15:41:17 +00:00
parent 05886022e0
commit 353e0bbb43
6 changed files with 376 additions and 0 deletions
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//! `fana-graph` — el grafo narrativo (DAG de `NarrativeAtom`s).
//!
//! Mantiene los átomos + una adjacency list `dependencia → dependientes`.
//! Cuando un átomo muta, [`NarrativeGraph::propagate_mutation`] marca en
//! cascada a todo descendiente como `PendingEvaluation` — la "onda de
//! choque lógica" de la spec. Agnóstico de UI: devuelve los ids
//! afectados; el front-end decide cuándo re-renderizar.
#![forbid(unsafe_code)]
use fana_core::{CoherenceState, NarrativeAtom};
use std::collections::{HashMap, HashSet, VecDeque};
use uuid::Uuid;
/// El documento como grafo dirigido acíclico de átomos narrativos.
#[derive(Debug, Default)]
pub struct NarrativeGraph {
nodes: HashMap<Uuid, NarrativeAtom>,
/// `dependencia → [átomos que dependen de ella]`.
adjacency: HashMap<Uuid, Vec<Uuid>>,
}
impl NarrativeGraph {
pub fn new() -> Self {
Self::default()
}
pub fn len(&self) -> usize {
self.nodes.len()
}
pub fn is_empty(&self) -> bool {
self.nodes.is_empty()
}
pub fn contains(&self, id: Uuid) -> bool {
self.nodes.contains_key(&id)
}
pub fn get(&self, id: Uuid) -> Option<&NarrativeAtom> {
self.nodes.get(&id)
}
pub fn get_mut(&mut self, id: Uuid) -> Option<&mut NarrativeAtom> {
self.nodes.get_mut(&id)
}
/// Inserta un átomo y conecta las aristas desde sus dependencias.
pub fn insert(&mut self, atom: NarrativeAtom) {
let id = atom.id;
for &dep in &atom.dependencies {
let children = self.adjacency.entry(dep).or_default();
if !children.contains(&id) {
children.push(id);
}
}
self.nodes.insert(id, atom);
}
/// Dependientes directos de `id`.
pub fn dependents(&self, id: Uuid) -> &[Uuid] {
self.adjacency.get(&id).map(|v| v.as_slice()).unwrap_or(&[])
}
/// Propaga una mutación: marca `PendingEvaluation` en TODO descendiente
/// transitivo de `origin` (BFS sobre la adjacency). Devuelve los ids
/// afectados — el caller (front-end) decide cuándo re-renderizar.
///
/// `origin` mismo no se marca (es la fuente; ya se sabe que cambió).
pub fn propagate_mutation(&mut self, origin: Uuid) -> Vec<Uuid> {
let mut affected = Vec::new();
let mut seen: HashSet<Uuid> = HashSet::new();
let mut queue: VecDeque<Uuid> = VecDeque::new();
queue.push_back(origin);
seen.insert(origin);
while let Some(current) = queue.pop_front() {
let children: Vec<Uuid> = self
.adjacency
.get(&current)
.cloned()
.unwrap_or_default();
for child in children {
if seen.insert(child) {
if let Some(node) = self.nodes.get_mut(&child) {
node.coherence = CoherenceState::PendingEvaluation;
}
affected.push(child);
queue.push_back(child);
}
}
}
affected
}
/// Orden topológico de los átomos (dependencias antes que dependientes).
/// `None` si el grafo tiene un ciclo (no es un DAG válido).
pub fn topological_order(&self) -> Option<Vec<Uuid>> {
let mut indeg: HashMap<Uuid, usize> = self.nodes.keys().map(|&k| (k, 0)).collect();
for atom in self.nodes.values() {
for &dep in &atom.dependencies {
if self.nodes.contains_key(&dep) {
*indeg.entry(atom.id).or_insert(0) += 1;
}
}
}
let mut queue: VecDeque<Uuid> =
indeg.iter().filter(|(_, &d)| d == 0).map(|(&k, _)| k).collect();
let mut order = Vec::with_capacity(self.nodes.len());
while let Some(u) = queue.pop_front() {
order.push(u);
for &child in self.dependents(u) {
if let Some(d) = indeg.get_mut(&child) {
*d -= 1;
if *d == 0 {
queue.push_back(child);
}
}
}
}
if order.len() == self.nodes.len() {
Some(order)
} else {
None // quedó un ciclo
}
}
}
#[cfg(test)]
mod tests {
use super::*;
/// Construye una cadena a → b → c y devuelve sus ids.
fn chain() -> (NarrativeGraph, Uuid, Uuid, Uuid) {
let mut g = NarrativeGraph::new();
let a = NarrativeAtom::new("a", "main");
let ( a_id,) = (a.id,);
let b = NarrativeAtom::new("b", "main").depends_on(a_id);
let b_id = b.id;
let c = NarrativeAtom::new("c", "main").depends_on(b_id);
let c_id = c.id;
g.insert(a);
g.insert(b);
g.insert(c);
(g, a_id, b_id, c_id)
}
#[test]
fn insert_wires_adjacency() {
let (g, a, b, c) = chain();
assert_eq!(g.len(), 3);
assert_eq!(g.dependents(a), &[b]);
assert_eq!(g.dependents(b), &[c]);
assert!(g.dependents(c).is_empty());
}
#[test]
fn propagate_marks_all_descendants_pending() {
let (mut g, a, b, c) = chain();
let affected = g.propagate_mutation(a);
assert_eq!(affected.len(), 2);
assert!(affected.contains(&b) && affected.contains(&c));
assert_eq!(g.get(b).unwrap().coherence, CoherenceState::PendingEvaluation);
assert_eq!(g.get(c).unwrap().coherence, CoherenceState::PendingEvaluation);
// El origen NO se marca.
assert_eq!(g.get(a).unwrap().coherence, CoherenceState::Valid);
}
#[test]
fn propagate_from_leaf_affects_nothing() {
let (mut g, _a, _b, c) = chain();
assert!(g.propagate_mutation(c).is_empty());
}
#[test]
fn topological_order_respects_dependencies() {
let (g, a, b, c) = chain();
let order = g.topological_order().expect("es un DAG");
let pos = |id: Uuid| order.iter().position(|&x| x == id).unwrap();
assert!(pos(a) < pos(b));
assert!(pos(b) < pos(c));
}
#[test]
fn cycle_has_no_topological_order() {
// a depende de b, b depende de a.
let mut g = NarrativeGraph::new();
let a = NarrativeAtom::new("a", "main");
let b = NarrativeAtom::new("b", "main");
let (a_id, b_id) = (a.id, b.id);
let a = a.depends_on(b_id);
let b = b.depends_on(a_id);
g.insert(a);
g.insert(b);
assert!(g.topological_order().is_none());
}
}