fn render_frontmatter_yaml(metadata: &Metadata) -> MietteResult<String> {
let mut rendered = serde_yaml::to_string(metadata)
.map_err(|err| miette!(
help = internal_error_help(),
"failed to serialize frontmatter: {err}"
))?;
if let Some(stripped) = rendered.strip_prefix("---\n") {
rendered = stripped.to_string();
}
Ok(rendered.trim_end().to_string())
}
fn rewrite_frontmatter(raw: &str, metadata: &Metadata) -> MietteResult<String> {
let lines = raw.lines().collect::<Vec<_>>();
let header_index = lines
.iter()
.position(|line| {
let line = line.trim_start();
line.starts_with("# Rhei:") || line.starts_with("# Panta:")
})
.ok_or_else(|| {
miette!(
help = plan_authoring_help(),
"could not find a '# Rhei:' or '# Panta:' header when rewriting frontmatter"
)
})?;
let mut idx = header_index + 1;
while idx < lines.len() && lines[idx].trim().is_empty() {
idx += 1;
}
if idx < lines.len() && lines[idx].trim_start().starts_with("**States:**") {
idx += 1;
}
while idx < lines.len() && lines[idx].trim().is_empty() {
idx += 1;
}
let start = idx;
let mut end = idx;
if start < lines.len() && lines[start].trim() == "---" {
end += 1;
while end < lines.len() && lines[end].trim() != "---" {
end += 1;
}
if end == lines.len() {
return Err(miette!(
help = plan_authoring_help(),
"unterminated YAML frontmatter in plan source"
));
}
end += 1;
while end < lines.len() && lines[end].trim().is_empty() {
end += 1;
}
}
let mut result = Vec::with_capacity(lines.len() + 8);
result.extend(lines[..start].iter().map(|line| (*line).to_string()));
result.push("---".to_string());
let rendered_yaml = render_frontmatter_yaml(metadata)?;
if !rendered_yaml.is_empty() {
result.extend(rendered_yaml.lines().map(|line| line.to_string()));
}
result.push("---".to_string());
result.push(String::new());
result.extend(lines[end..].iter().map(|line| (*line).to_string()));
let mut output = result.join("\n");
if raw.ends_with('\n') || !output.is_empty() {
output.push('\n');
}
Ok(output)
}
fn ensure_mapping(parent: &mut YamlMapping, key: YamlValue) -> &mut YamlMapping {
if !matches!(parent.get(&key), Some(YamlValue::Mapping(_))) {
parent.insert(key.clone(), YamlValue::Mapping(YamlMapping::new()));
}
match parent.get_mut(&key) {
Some(YamlValue::Mapping(mapping)) => mapping,
_ => unreachable!("mapping just initialized"),
}
}
fn ensure_current_state_visit_count(
existing: Option<&Metadata>,
task_id: &TaskId,
current_state: &str,
current_state_raw: &str,
machine: &rhei_validator::StateMachine,
) -> Option<Metadata> {
state_visit_limit(machine, current_state)?;
let current =
current_state_visit_count(existing, task_id, current_state, current_state_raw, machine);
if current == task_visit_count(existing, task_id, current_state) {
return existing.cloned();
}
let mut root = existing.cloned().unwrap_or_default();
let metadata_section = ensure_mapping(&mut root, yaml_key("metadata"));
let tasks = ensure_mapping(metadata_section, yaml_key("tasks"));
let task_entry = ensure_mapping(tasks, task_id_yaml_key(task_id));
let state_visits = ensure_mapping(task_entry, yaml_key("stateVisits"));
state_visits.insert(yaml_key(current_state), yaml_u64(current));
Some(root)
}
fn update_metadata_for_transition(
existing: Option<&Metadata>,
task_id: &TaskId,
to_state: &str,
machine: &rhei_validator::StateMachine,
) -> Option<Metadata> {
state_visit_limit(machine, to_state)?;
let mut root = existing.cloned().unwrap_or_default();
let metadata_section = ensure_mapping(&mut root, yaml_key("metadata"));
let tasks = ensure_mapping(metadata_section, yaml_key("tasks"));
let task_entry = ensure_mapping(tasks, task_id_yaml_key(task_id));
let state_visits = ensure_mapping(task_entry, yaml_key("stateVisits"));
let state_key = yaml_key(to_state);
let next =
state_visits.get(&state_key).and_then(yaml_value_to_u64).map(|n| n.max(1) + 1).unwrap_or(1);
state_visits.insert(state_key, yaml_u64(next));
Some(root)
}
fn clear_runtime_state_visits(existing: Option<&Metadata>) -> Option<Metadata> {
let mut root = existing.cloned()?;
let Some(YamlValue::Mapping(metadata_section)) = root.get_mut(yaml_key("metadata")) else {
return Some(root);
};
let Some(YamlValue::Mapping(tasks)) = metadata_section.get_mut(yaml_key("tasks")) else {
return Some(root);
};
for value in tasks.values_mut() {
if let YamlValue::Mapping(task_map) = value {
task_map.remove(yaml_key("stateVisits"));
}
}
Some(root)
}
fn set_poll_next_attempt_metadata(
existing: Option<&Metadata>,
task_id: &TaskId,
state_name: &str,
next_attempt_at: u64,
next_attempt_count: u64,
) -> Metadata {
let mut root = existing.cloned().unwrap_or_default();
let metadata_section = ensure_mapping(&mut root, yaml_key("metadata"));
let tasks = ensure_mapping(metadata_section, yaml_key("tasks"));
let task_entry = ensure_mapping(tasks, task_id_yaml_key(task_id));
let poll_next = ensure_mapping(task_entry, yaml_key("pollNextAttemptAt"));
poll_next.insert(yaml_key(state_name), yaml_u64(next_attempt_at));
let state_visits = ensure_mapping(task_entry, yaml_key("stateVisits"));
state_visits.insert(yaml_key(state_name), yaml_u64(next_attempt_count.max(1)));
root
}
fn clear_poll_state_metadata(
existing: Option<&Metadata>,
task_id: &TaskId,
state_name: &str,
) -> Option<Metadata> {
let mut root = existing.cloned()?;
let Some(YamlValue::Mapping(metadata_section)) = root.get_mut(yaml_key("metadata")) else {
return Some(root);
};
let Some(YamlValue::Mapping(tasks)) = metadata_section.get_mut(yaml_key("tasks")) else {
return Some(root);
};
let Some(YamlValue::Mapping(task_entry)) = tasks.get_mut(task_id_yaml_key(task_id)) else {
return Some(root);
};
if let Some(YamlValue::Mapping(poll_next)) = task_entry.get_mut(yaml_key("pollNextAttemptAt")) {
poll_next.remove(yaml_key(state_name));
}
if task_entry
.get(yaml_key("pollNextAttemptAt"))
.and_then(YamlValue::as_mapping)
.is_some_and(YamlMapping::is_empty)
{
task_entry.remove(yaml_key("pollNextAttemptAt"));
}
if let Some(YamlValue::Mapping(state_visits)) = task_entry.get_mut(yaml_key("stateVisits")) {
state_visits.remove(yaml_key(state_name));
}
if task_entry
.get(yaml_key("stateVisits"))
.and_then(YamlValue::as_mapping)
.is_some_and(YamlMapping::is_empty)
{
task_entry.remove(yaml_key("stateVisits"));
}
Some(root)
}