#![allow(clippy::too_many_arguments)]
use crate::types::{FileDescriptor, MessageIndex};
use std::cmp::min;
use std::collections::HashMap;
fn scc(
vertices: &[MessageIndex],
desc: &FileDescriptor,
u: usize,
count: &mut isize,
low: &mut [isize],
disc: &mut [isize],
stack: &mut Vec<usize>,
sccs: &mut Vec<Vec<usize>>,
ids: &HashMap<MessageIndex, usize>,
) {
disc[u] = *count;
low[u] = *count;
*count += 1;
stack.push(u);
for &v in vertices[u]
.get_message(desc)
.all_fields()
.filter(|f| !f.boxed && !f.frequency.is_repeated())
.filter_map(|f| f.typ.message())
.filter_map(|m| ids.get(m))
{
if disc[v] == -1 {
scc(vertices, desc, v, count, low, disc, stack, sccs, ids);
low[u] = min(low[u], low[v]);
} else if stack.contains(&v) {
low[u] = min(low[u], disc[v]);
}
}
if low[u] == disc[u] {
let mut scc = Vec::new();
while let Some(w) = stack.pop() {
scc.push(w);
if w == u {
break;
}
}
sccs.push(scc);
}
}
impl FileDescriptor {
fn flatten_messages(&self) -> Vec<MessageIndex> {
let mut all_msgs = self
.messages
.iter()
.map(|m| m.index.clone())
.collect::<Vec<_>>();
let mut vertices = Vec::with_capacity(all_msgs.len());
while let Some(m) = all_msgs.pop() {
all_msgs.extend(m.get_message(self).messages.iter().map(|m| m.index.clone()));
vertices.push(m);
}
vertices
}
pub fn sccs(&self) -> Vec<Vec<MessageIndex>> {
let vertices = self.flatten_messages();
let ids = vertices
.iter()
.enumerate()
.map(|(i, m)| (m.get_message(self).index.clone(), i))
.collect::<HashMap<_, _>>();
let mut low = vec![-1; vertices.len()];
let mut disc = vec![-1; vertices.len()];
let mut stack: Vec<usize> = Vec::new();
let mut count = 0isize;
let mut sccs: Vec<Vec<usize>> = Vec::new();
for u in 0..vertices.len() {
if disc[u] == -1 {
scc(
&vertices, self, u, &mut count, &mut low, &mut disc, &mut stack, &mut sccs,
&ids,
);
}
}
sccs.into_iter()
.map(|scc| scc.into_iter().map(|i| vertices[i].clone()).collect())
.collect()
}
}