ljos 0.41.1

//! Origin-bound admission.
//!
//! Every memory a seat writes is stored at once and labelled with whose it
//! is. `origin` on a live atom is `user-declared` (a person),
//! `agent-derived` (this seat's own agent), `tool-echo` (tool output),
//! `external` or `peer` (another seat), and `source.basis` is `person` or
//! `agent`. A 400 that names `origin` as unknown is retried once without
//! the field.
//!
//! Packset's memory levels are `explicit` and `derived`. `derived` is L0.
//! An agent's lesson from `ljos finish`, tool output and another seat are
//! stored there, and [`accept`] raises one to `explicit` and records the
//! review. Search reads neither label, so it finds the claim at once.
//!
//! A writer that holds agent writes answers 400 `held as proposal <id>`.
//! `POST /v1/proposals/accept` with `{"workspace","id"}` stores it there
//! and then, so nothing waits for a person.
//!
//! An older ljos kept such lessons as proposals in
//! `$XDG_STATE_HOME/ljos/proposals.jsonl` and stored one only on `ljos
//! accept`. [`import_open`] stores each open one once, labelled as it was
//! filed.

use std::collections::BTreeMap;
use std::path::PathBuf;
use std::sync::Mutex;

use crate::quoted_yes::Yes;
use crate::PacksetClient;
use anyhow::{bail, Context, Result};
use serde::{Deserialize, Serialize};
use serde_json::Value;

pub const ORIGIN_USER: &str = "user-declared";
pub const ORIGIN_AGENT: &str = "agent-derived";
pub const ORIGIN_TOOL: &str = "tool-echo";
pub const ORIGIN_PEER: &str = "peer";

/// Packset's lower memory level (`packset_core::record::LEVELS`). L0.
pub const LEVEL_L0: &str = "derived";
/// Packset's level for a claim a person stood behind.
pub const LEVEL_EXPLICIT: &str = "explicit";

/// The level an origin is stored at.
///
/// A person's words are `explicit`. An agent's lesson, tool output and
/// another seat start at L0 until [`accept`].
#[must_use]
pub fn admission_level(origin: &str) -> &'static str {
    match origin {
        ORIGIN_USER => LEVEL_EXPLICIT,
        _ => LEVEL_L0,
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct Record {
    id: String,
    /// `open`, `stored`, `refused`, `accepted` or `satisfied`.
    status: String,
    remote: bool,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    remote_id: Option<String>,
    /// The live atom this row was stored as.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    stored: Option<String>,
    text: String,
    kind: String,
    /// `user-declared`, `agent-derived`, `tool-echo` or `peer`.
    #[serde(default, skip_serializing_if = "String::is_empty")]
    origin: String,
    /// The person's words this acceptance rests on, where a seat carried
    /// them instead of the person typing in a terminal of their own.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    grant: Option<Yes>,
    /// The seat that filed the proposal. Empty on a row written before
    /// seats were recorded.
    #[serde(default, skip_serializing_if = "String::is_empty")]
    seat: String,
    /// When the latest outcome was written, RFC 3339.
    #[serde(default, skip_serializing_if = "String::is_empty")]
    at: String,
    /// The pack's reason, when the outcome is `refused`.
    #[serde(default, skip_serializing_if = "String::is_empty")]
    reason: String,
    /// A revised text. The original `text` stays. Absent until
    /// `ljos proposals amend`.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    amendment: Option<Amendment>,
    atom: Value,
}

/// A revised proposal text, who wrote it, and when.
#[derive(Debug, Clone, Serialize, Deserialize)]
struct Amendment {
    text: String,
    seat: String,
    at: String,
}

fn gate() -> std::sync::MutexGuard<'static, ()> {
    static GATE: Mutex<()> = Mutex::new(());
    GATE.lock().unwrap_or_else(|e| e.into_inner())
}

fn origin_cache() -> &'static Mutex<BTreeMap<String, bool>> {
    static KEPT: std::sync::OnceLock<Mutex<BTreeMap<String, bool>>> = std::sync::OnceLock::new();
    KEPT.get_or_init(|| Mutex::new(BTreeMap::new()))
}

fn proposals_path() -> PathBuf {
    std::env::var_os("XDG_STATE_HOME")
        .map(PathBuf::from)
        .or_else(|| std::env::var_os("HOME").map(|h| PathBuf::from(h).join(".local/state")))
        .unwrap_or_else(|| PathBuf::from(".local/state"))
        .join("ljos")
        .join("proposals.jsonl")
}

/// The marker that says no proposal is left open to import.
fn imported_path() -> PathBuf {
    proposals_path().with_file_name("proposals-imported")
}

fn http_timeout() -> std::time::Duration {
    std::env::var("PACKSET_TIMEOUT_MS")
        .ok()
        .and_then(|v| v.trim().parse::<u64>().ok())
        .filter(|ms| *ms > 0)
        .map_or(
            std::time::Duration::from_secs(30),
            std::time::Duration::from_millis,
        )
}

pub fn stamp_origin(atom: &mut Value, origin: &str) {
    if let Some(map) = atom.as_object_mut() {
        map.insert("origin".into(), Value::String(origin.to_string()));
    }
}

/// Mark `atom` as the person's: origin `user-declared` and `source.basis`
/// `person`. Only a person-path writer calls this; the readers take the
/// basis, not the origin alone, as the person standing behind a claim.
pub fn stamp_person(atom: &mut Value) {
    stamp_origin(atom, ORIGIN_USER);
    atom["source"]["basis"] = Value::String(crate::Basis::Person.as_str().into());
}

fn strip_origin(atom: &mut Value) {
    if let Some(map) = atom.as_object_mut() {
        map.remove("origin");
    }
}

fn origin_rejected(text: &str) -> bool {
    let lower = text.to_lowercase();
    lower.contains("origin")
        && (lower.contains("unknown")
            || lower.contains("unexpected")
            || lower.contains("not a field")
            || lower.contains("unrecognized"))
}

/// POST an atom. When this writer refuses `origin`, the field is dropped
/// and the post is tried once more. The answer is remembered per base URL.
pub fn post_kept(client: &PacksetClient, atom: &Value) -> Result<Value> {
    let base = client.base().to_string();
    let mut body = atom.clone();
    let known = origin_cache()
        .lock()
        .unwrap_or_else(|e| e.into_inner())
        .get(&base)
        .copied();
    if known == Some(false) {
        strip_origin(&mut body);
    }
    match client.post_atom(&body) {
        Ok(v) => {
            if body.get("origin").is_some() {
                origin_cache()
                    .lock()
                    .unwrap_or_else(|e| e.into_inner())
                    .insert(base, true);
            }
            Ok(v)
        }
        Err(e) => {
            let text = e.to_string();
            if body.get("origin").is_some() && origin_rejected(&text) {
                origin_cache()
                    .lock()
                    .unwrap_or_else(|err| err.into_inner())
                    .insert(base, false);
                strip_origin(&mut body);
                return client.post_atom(&body).map_err(anyhow::Error::from);
            }
            Err(anyhow::Error::from(e))
        }
    }
}

fn read_latest() -> BTreeMap<String, Record> {
    let bytes = crate::read_state_file(&proposals_path()).unwrap_or_default();
    crate::complete_rows::<Record>(&bytes)
        .into_iter()
        .map(|rec| (rec.id.clone(), rec))
        .collect()
}

fn append(rec: &Record) -> Result<()> {
    let path = proposals_path();
    if let Some(dir) = path.parent() {
        std::fs::create_dir_all(dir)?;
    }
    let mut line = serde_json::to_string(rec)?;
    line.push('\n');
    crate::append_locked_row(&path, line.as_bytes(), crate::Durability::Durable)
        .with_context(|| format!("admit: cannot write {}", path.display()))
}

/// The id in `held as proposal <id>`.
fn held_proposal_id(text: &str) -> Option<String> {
    let marker = "held as proposal ";
    let rest = text.get(text.find(marker)? + marker.len()..)?;
    let id: String = rest.chars().take_while(|c| c.is_ascii_hexdigit()).collect();
    (id.len() == 32).then_some(id)
}

/// Write `atom` as an agent's own memory, live at once, with origin
/// `agent-derived`. Nothing waits for a person. A text the pack's prose
/// gate would turn away is stored as typed, with the gate's reason as a
/// label ([`write_fitted`]).
///
/// # Errors
///
/// An empty text, or the pack refusing the claim for a reason that is not
/// the prose gate: a secret, an instruction to the model, an unknown kind.
pub fn write_agent(client: &PacksetClient, atom: Value) -> Result<Value> {
    write_fitted(client, atom, true, write_agent_one)
}

/// Post `atom` with `post`, text unchanged. The pack holds an agent's and
/// a hook's claim (`held`) to its sentence, grade and adverb limits and
/// keeps any other with a warning. A limit is a warning, not a rewrite:
/// the stored text is the text that was typed. When the pack refuses that
/// prose, one local record keeps it and search shows that one row. A
/// `note` is not held to the gate.
fn write_fitted(
    client: &PacksetClient,
    atom: Value,
    held: bool,
    post: fn(&PacksetClient, Value) -> Result<Value>,
) -> Result<Value> {
    let text = atom["text"].as_str().unwrap_or("").trim().to_string();
    if text.is_empty() {
        crate::memory_port::keep_empty("lesson");
        return Err(crate::policy_label::labelled(
            "empty-input",
            "remember: empty text is not a claim",
        ));
    }
    let refused = (held && atom["kind"].as_str() != Some(packset_core::record::NOTE_KIND))
        .then(|| crate::pack_copy::gate_refusal(&text))
        .flatten();
    if crate::pack_copy::reject_unsafe(&text).is_err() {
        return post(client, atom);
    }
    if let Some(why) = refused.as_deref() {
        let kind = atom["kind"].as_str().unwrap_or("lesson");
        crate::memory_port::keep_prose(&text, kind, why);
    }
    match post(client, atom.clone()) {
        Ok(mut posted) => {
            label_prose(&mut posted, refused.as_deref());
            Ok(posted)
        }
        Err(e) if refused.is_some() && !crate::note_can_wait(&e) => {
            crate::verbatim::keep(&atom, refused.as_deref().unwrap_or(""))
        }
        Err(e) => Err(e),
    }
}

/// Put `warning` on `posted` when the pack did not already name one.
fn label_prose(posted: &mut Value, warning: Option<&str>) {
    let Some(why) = warning.filter(|why| !why.is_empty()) else {
        return;
    };
    let Some(map) = posted.as_object_mut() else {
        return;
    };
    let prose = map
        .entry("prose".to_string())
        .or_insert_with(|| Value::Object(Default::default()));
    let Some(fields) = prose.as_object_mut() else {
        return;
    };
    if fields
        .get("warning")
        .and_then(Value::as_str)
        .is_some_and(|have| !have.is_empty())
    {
        return;
    }
    fields.insert("warning".into(), Value::String(why.to_string()));
}

/// One agent atom, with no further split.
///
/// Always origin `agent-derived` and `source.basis` `agent`, whatever the
/// prose. The pack keeps a person's long or hard sentence with a warning
/// and refuses an agent's; filing the agent's as the person's to get it
/// kept would hand it to every reader as the person's words.
pub(crate) fn write_agent_one(client: &PacksetClient, mut atom: Value) -> Result<Value> {
    let text = atom["text"].as_str().unwrap_or("").trim();
    if text.is_empty() {
        crate::memory_port::keep_empty("lesson");
        return Err(crate::policy_label::labelled(
            "empty-input",
            "remember: empty text is not a claim",
        ));
    }
    stamp_origin(&mut atom, ORIGIN_AGENT);
    atom["source"]["basis"] = Value::String(crate::Basis::Agent.as_str().into());
    if atom["source"]["seat"]
        .as_str()
        .unwrap_or("")
        .trim()
        .is_empty()
    {
        let seat = proposing_seat();
        if !seat.is_empty() {
            atom["source"]["seat"] = Value::String(seat);
        }
    }
    post_live(client, atom)
}

/// Post `atom` as it is labelled. A writer that holds the write answers
/// `held as proposal ID`; that proposal is accepted on the spot, so the
/// claim is live there too, and the origin `atom` carries is put back.
fn post_live(client: &PacksetClient, atom: Value) -> Result<Value> {
    match post_kept(client, &atom) {
        Ok(posted) => Ok(posted),
        Err(e) => {
            let text = format!("{e:#}");
            let Some(id) = held_proposal_id(&text) else {
                return Err(e);
            };
            let workspace = atom
                .get("workspace")
                .and_then(Value::as_str)
                .filter(|w| !w.is_empty())
                .map_or_else(|| client.workspace(), str::to_string);
            let accepted = accept_on_writer(client, &workspace, &id)?;
            let origin = atom["origin"].as_str().unwrap_or(ORIGIN_AGENT);
            relabel(client, &workspace, accepted, origin)
        }
    }
}

/// Store `atom` at once, as its labels say: a known origin is kept, any
/// other is `agent-derived`, a claim that is not the person's has
/// `source.basis` `agent`, and the level is [`admission_level`]. `ljos
/// finish --lesson`, `ljos findings --remember` and the correction hook
/// write this way. Search finds the claim at once; [`accept`] raises it.
///
/// # Errors
///
/// An empty text, or the pack refusing the claim for a reason other than
/// its prose gate.
pub fn store_labelled(client: &PacksetClient, mut atom: Value) -> Result<Value> {
    if atom["text"].as_str().unwrap_or("").trim().is_empty() {
        crate::memory_port::keep_empty("lesson");
        return Err(crate::policy_label::labelled(
            "empty-input",
            "store: empty text is not a claim",
        ));
    }
    if atom
        .get("workspace")
        .and_then(Value::as_str)
        .unwrap_or("")
        .is_empty()
    {
        atom["workspace"] = Value::String(client.workspace());
    }
    if !packset_core::atom::known_origin(atom["origin"].as_str().unwrap_or("")) {
        stamp_origin(&mut atom, ORIGIN_AGENT);
    }
    let origin = atom["origin"].as_str().unwrap_or(ORIGIN_AGENT).to_string();
    if origin != ORIGIN_USER && atom["source"]["basis"].as_str().is_none() {
        atom["source"]["basis"] = Value::String(crate::Basis::Agent.as_str().into());
    }
    atom["level"] = Value::String(admission_level(&origin).to_string());
    // The pack's `validate` asks with the hold on: its prose gate is for
    // what an agent or a hook writes, whether the writer holds or not.
    // Packset used to export this as `needs_accept(origin, hook, hold)`
    // with the hold forced on. A hook write and an agent-derived write
    // are the ones the prose gate reads before the post.
    let held = atom["hook"] == Value::Bool(true) || origin == ORIGIN_AGENT;
    write_fitted(client, atom, held, post_live)
}

/// How long one hook call spends storing the proposals an older ljos left
/// open. The prompt's search after it must keep its fused pool, which
/// waits up to [`crate::HOOK_RERANK_BUDGET_MS`], or recall is lost. The
/// rest of [`crate::HOOK_WALL_BUDGET_MS`] is split evenly with the
/// cross-encoder stage. Each can be cut without harm: the rows left go
/// on the next call, and a cut rerank answers with the fused pool.
pub const IMPORT_SLICE_MS: u64 = (crate::HOOK_WALL_BUDGET_MS - crate::HOOK_RERANK_BUDGET_MS) / 2;

/// What one [`import_open`] did.
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
pub struct Imported {
    /// Rows stored as live memories.
    pub stored: usize,
    /// Rows still open for a later call.
    pub left: usize,
}

/// Store each proposal an older ljos left open, once, as the labelled
/// memory its row holds ([`store_labelled`]), and mark the row `stored`
/// with the atom's id. A row the pack turns away is marked `refused` and
/// keeps its atom, so `ljos accept` can try it again; no row is dropped.
/// No post starts once `budget_ms` is spent, and a pack that does not
/// answer ends the call; the rows left stay open for the next one. Once
/// none is left, a marker beside the file spares later calls the read.
pub fn import_open(budget_ms: u64) -> Imported {
    let _deadline = crate::pack_link::CommandDeadline::enter(crate::IMPORT_ADMISSION);
    let marker = imported_path();
    if marker.exists() || !proposals_path().exists() {
        return Imported::default();
    }
    let _g = gate();
    let open: Vec<Record> = read_latest()
        .into_values()
        .filter(|rec| rec.status == "open")
        .collect();
    let started = std::time::Instant::now();
    let budget = std::time::Duration::from_millis(budget_ms);
    let mut client = crate::pack().ok();
    let mut out = Imported::default();
    for mut rec in open {
        let Some(live) = client.as_ref().filter(|_| started.elapsed() < budget) else {
            out.left += 1;
            continue;
        };
        let stored = if rec.remote {
            import_held(live, &rec)
        } else {
            store_labelled(live, rec.atom.clone())
        };
        match stored {
            Ok(posted) => {
                rec.status = "stored".into();
                rec.stored = posted["id"].as_str().map(str::to_string);
            }
            Err(e) if crate::note_can_wait(&e) => {
                client = None;
                out.left += 1;
                continue;
            }
            Err(err) => {
                let text = rec.atom["text"].as_str().unwrap_or("");
                let kind = rec.atom["kind"].as_str().unwrap_or("lesson");
                crate::memory_port::keep_prose(text, kind, &format!("legacy proposal: {err:#}"));
                rec.status = "refused".into();
            }
        }
        match append(&rec) {
            Ok(()) if rec.status == "stored" => out.stored += 1,
            Ok(()) => {}
            Err(_) => out.left += 1,
        }
    }
    if out.left == 0 {
        let _ = std::fs::write(&marker, format!("{}\n", crate::now_utc()));
    }
    out
}

/// A row whose atom a writer holds is accepted there, then given back the
/// origin and level it was filed under. A writer that no longer holds it
/// is posted the row's atom.
fn import_held(client: &PacksetClient, rec: &Record) -> Result<Value> {
    let workspace = workspace_of(client, rec);
    let remote_id = rec.remote_id.as_deref().unwrap_or(&rec.id);
    let accepted = match accept_on_writer(client, &workspace, remote_id) {
        Ok(accepted) => accepted,
        Err(e) if crate::note_can_wait(&e) => return Err(e),
        Err(_) => return store_labelled(client, rec.atom.clone()),
    };
    let origin = if rec.origin.is_empty() {
        ORIGIN_AGENT
    } else {
        rec.origin.as_str()
    };
    let Some(id) = accepted["id"].as_str().filter(|id| !id.is_empty()) else {
        bail!("import: the writer stored {remote_id} without an id");
    };
    update_fields(
        client,
        &workspace,
        id,
        serde_json::json!({"origin": origin, "level": admission_level(origin)}),
    )
}

/// Raise a proposal's memory level from L0 to `explicit`.
fn promote_level(atom: &mut Value) {
    if let Some(map) = atom.as_object_mut() {
        map.insert("level".into(), Value::String(LEVEL_EXPLICIT.to_string()));
    }
}

/// Make `atom` a standing explicit claim. The origin is left as stored,
/// so a reader can still see where it came from. Accept is what the
/// prompt hook reads as promotion: the horizon tag, and the keep verdict
/// the caller records.
fn stand_for_prompt(atom: &mut Value) {
    promote_level(atom);
    let mut entities = atom
        .get("entities")
        .and_then(Value::as_array)
        .cloned()
        .unwrap_or_default();
    let standing = entities
        .iter()
        .any(|entity| entity.as_str() == Some("horizon:standing"));
    entities.retain(|entity| entity.as_str() != Some("horizon:transient"));
    if !standing {
        entities.push(Value::String("horizon:standing".to_string()));
    }
    atom["entities"] = Value::Array(entities);
}

/// Fields [`stand_for_prompt`] changes on `before`, or an empty object
/// when the claim is already standing and explicit.
fn prompt_fields(before: &Value) -> Value {
    let mut after = before.clone();
    stand_for_prompt(&mut after);
    let mut fields = serde_json::Map::new();
    if after.get("level") != before.get("level") {
        if let Some(level) = after.get("level") {
            fields.insert("level".to_string(), level.clone());
        }
    }
    if after.get("entities") != before.get("entities") {
        if let Some(entities) = after.get("entities") {
            fields.insert("entities".to_string(), entities.clone());
        }
    }
    Value::Object(fields)
}

/// The person's own text wrote the claim. An open proposal of those words
/// is satisfied, so a later accept does not post a second atom.
pub fn satisfy_text(text: &str) {
    let _g = gate();
    let text = text.trim();
    if text.is_empty() {
        return;
    }
    let open: Vec<Record> = read_latest()
        .into_values()
        .filter(|rec| rec.status == "open" && rec.text.trim() == text)
        .collect();
    for mut rec in open {
        rec.status = "satisfied".into();
        // A satisfied row that is not written leaves the proposal open, so a
        // later `ljos accept` reposts it. Name the log and the error, not the
        // proposal's text, which a row could carry a secret in.
        if let Err(e) = append(&rec) {
            eprintln!(
                "ljos: a satisfied proposal was not recorded in {}: {e:#}",
                proposals_path().display()
            );
        }
        close_remote(&rec);
    }
}

fn workspace_of(client: &PacksetClient, rec: &Record) -> String {
    let workspace = rec
        .atom
        .get("workspace")
        .and_then(Value::as_str)
        .unwrap_or("");
    if workspace.is_empty() {
        client.workspace()
    } else {
        workspace.to_string()
    }
}

/// Close a held proposal whose text is already a live claim. The writer's
/// duplicate rule keeps one atom when the text and kind match.
fn close_remote(rec: &Record) {
    if !rec.remote {
        return;
    }
    let Some(remote_id) = rec.remote_id.as_deref() else {
        return;
    };
    let Ok(client) = crate::pack() else {
        return;
    };
    let workspace = workspace_of(&client, rec);
    let _ = accept_on_writer(&client, &workspace, remote_id);
}

fn accepted_line(rec: &Record, posted: &Value) -> String {
    let origin = posted
        .get("origin")
        .and_then(Value::as_str)
        .filter(|origin| !origin.is_empty())
        .unwrap_or(ORIGIN_AGENT);
    format!(
        "accepted {} as {} origin {origin}{}\n{}",
        rec.id,
        rec.kind,
        crate::revision_note(posted),
        rec.grant.as_ref().map(Yes::line).unwrap_or_default()
    )
}

/// Accept on a writer that held the write stores it as `user-declared`.
/// Put back the origin it was written with, or the memory list and every
/// reader that goes by origin would take it for the person's. One update,
/// on an atom just stored.
fn relabel(
    client: &PacksetClient,
    workspace: &str,
    accepted: Value,
    origin: &str,
) -> Result<Value> {
    let stored = accepted.get("origin").and_then(Value::as_str).unwrap_or("");
    if stored == origin {
        return Ok(accepted);
    }
    let Some(id) = accepted
        .get("id")
        .and_then(Value::as_str)
        .filter(|id| !id.is_empty())
    else {
        bail!("accept stored the claim without an id, so its origin could not be put back to {origin}");
    };
    update_fields(client, workspace, id, serde_json::json!({"origin": origin})).with_context(|| {
        format!("the claim {id} was stored as {stored}; putting the origin back to {origin} failed")
    })
}

/// `POST /v1/atoms/update` of `fields` on atom `id`. The pack's answer.
fn update_fields(
    client: &PacksetClient,
    workspace: &str,
    id: &str,
    fields: Value,
) -> Result<Value> {
    let body = serde_json::json!({"workspace": workspace, "id": id, "fields": fields});
    let bytes = serde_json::to_vec(&body).unwrap_or_default();
    match client.roundtrip(
        "POST",
        "/v1/atoms/update",
        &[],
        Some(&bytes),
        true,
        http_timeout(),
    ) {
        Ok(answer) if (200..300).contains(&answer.status) => {
            serde_json::from_str(&answer.body).context("update: the pack's answer was not json")
        }
        Ok(answer) => bail!("update: {}: {}", answer.status, answer.body),
        Err(e) => bail!("update: {e}"),
    }
}

fn accept_on_writer(client: &PacksetClient, workspace: &str, id: &str) -> Result<Value> {
    let body = serde_json::json!({"workspace": workspace, "id": id});
    let bytes = serde_json::to_vec(&body).unwrap_or_default();
    match client.roundtrip(
        "POST",
        "/v1/proposals/accept",
        &[],
        Some(&bytes),
        true,
        http_timeout(),
    ) {
        Ok(answer) if (200..300).contains(&answer.status) => {
            serde_json::from_str(&answer.body).context("accept: the pack's answer was not json")
        }
        Ok(answer) => {
            bail!(
                "accept: POST /v1/proposals/accept failed: {}: {}",
                answer.status,
                answer.body
            )
        }
        Err(e) => bail!("accept: POST /v1/proposals/accept failed: {e}"),
    }
}

/// Every acceptance that rests on a person's words a seat carried, by
/// proposal id. An audit reads these to see which lessons went in on a
/// quoted yes rather than from a terminal of the person's own.
#[must_use]
pub fn granted() -> Vec<(String, Yes)> {
    let mut out: Vec<(String, Yes)> = read_latest()
        .into_values()
        .filter(|rec| rec.status == "accepted")
        .filter_map(|rec| rec.grant.map(|yes| (rec.id, yes)))
        .collect();
    out.sort_by(|a, b| a.1.at.cmp(&b.1.at).then_with(|| a.0.cmp(&b.0)));
    out
}

/// Accept a stored memory, or a proposal an older ljos filed. See
/// [`accept_on`].
pub fn accept(id: &str) -> Result<String> {
    accept_on(id, None)
}

/// Accept each id or prefix. One result line per id: `accepted`,
/// `already in pack`, `not found`, or `refused` with the pack's reason.
/// A refusal names the measured value and the limit. One id does not
/// stop the rest.
#[must_use]
pub fn accept_ids(ids: &[String], yes: Option<&crate::quoted_yes::Yes>) -> String {
    let mut out = String::new();
    for id in ids {
        let line = match accept_on(id, yes) {
            Ok(line) => line,
            Err(err) => format!("refused {}: {err:#}\n", id.trim()),
        };
        if line.ends_with('\n') {
            out.push_str(&line);
        } else {
            out.push_str(&line);
            out.push('\n');
        }
    }
    out
}

/// File an open proposal from this seat. The row names the seat, so a
/// later list can count proposals per seat.
///
/// # Errors
///
/// The text is empty, or the proposal log cannot be written.
pub fn file_open(text: &str, kind: &str) -> Result<String> {
    let text = text.trim();
    if text.is_empty() {
        bail!("proposals: empty text is not a proposal");
    }
    let kind = if kind.trim().is_empty() {
        "lesson"
    } else {
        kind.trim()
    };
    let seat = proposing_seat();
    let id = proposal_id(text, &seat);
    let rec = Record {
        id: id.clone(),
        status: "open".into(),
        remote: false,
        remote_id: None,
        stored: None,
        text: text.to_string(),
        kind: kind.to_string(),
        origin: ORIGIN_AGENT.into(),
        grant: None,
        seat: seat.clone(),
        at: crate::now_utc(),
        reason: String::new(),
        amendment: None,
        atom: serde_json::json!({
            "kind": kind,
            "text": text,
            "origin": ORIGIN_AGENT,
            "level": LEVEL_L0,
            "source": {"seat": &seat, "basis": "agent"},
        }),
    };
    append(&rec)?;
    Ok(format!("{id}\n"))
}

/// The seat filing this proposal: the one this call resolved, not a
/// placeholder and not an empty name. Empty when nothing resolved, which
/// the listing prints as `seat unknown`.
fn proposing_seat() -> String {
    let seat = crate::seat_name();
    if seat.is_empty() || crate::omitted_actor_name(&seat) {
        String::new()
    } else {
        seat
    }
}

fn proposal_id(text: &str, seat: &str) -> String {
    use sha2::{Digest, Sha256};
    let digest = Sha256::digest(format!("{seat}\n{text}").as_bytes());
    digest.iter().map(|b| format!("{b:02x}")).take(16).collect()
}

/// Record a revised text on proposal `id` and run the readability check
/// accept uses. The original text stays on the row. Nothing is accepted.
///
/// # Errors
///
/// The text is empty, or the proposal log cannot be written.
pub fn amend_proposal(id: &str, text: &str) -> Result<String> {
    let text = text.trim();
    if text.is_empty() {
        bail!("proposals: empty text is not an amendment");
    }
    let _g = gate();
    let id = id.trim();
    if id.is_empty() {
        bail!("proposals: an id is required");
    }
    let rows = read_latest();
    let known: Vec<String> = rows.keys().cloned().collect();
    let id = match crate::resolve_short_id("proposals", id, &known) {
        Ok(id) => id,
        Err(err) => return Ok(format!("not found {id}: {err:#}\n")),
    };
    let id = id.as_str();
    let Some(mut rec) = rows.get(id).cloned() else {
        return Ok(format!("not found {id}\n"));
    };
    if !matches!(rec.status.as_str(), "open" | "proposed" | "refused") {
        return Ok(format!("already in pack {id}\n"));
    }
    rec.amendment = Some(Amendment {
        text: text.to_string(),
        seat: crate::seat_name(),
        at: crate::now_utc(),
    });
    rec.atom["text"] = Value::String(text.to_string());
    if let Some(why) = crate::pack_copy::gate_refusal(text) {
        rec.status = "refused".to_string();
        rec.reason = why.clone();
        rec.at = crate::now_utc();
        append(&rec)?;
        return Ok(amend_refusal(id, text, &why));
    }
    rec.status = "open".to_string();
    rec.reason.clear();
    rec.at = crate::now_utc();
    append(&rec)?;
    Ok(format!("ok {id}: passes (ready for ljos accept)\n"))
}

/// `refused <id>: <reason>; <value> vs limit <limit>: "<sentence>"`.
fn amend_refusal(id: &str, text: &str, why: &str) -> String {
    let quote = trim_quote(&offending_sentence(text, why));
    let (reason, value, limit) = measured(why);
    match (value, limit) {
        (Some(value), Some(limit)) if !quote.is_empty() => {
            format!("refused {id}: {reason}; {value} vs limit {limit}: \"{quote}\"\n")
        }
        _ if !quote.is_empty() => format!("refused {id}: {why}: \"{quote}\"\n"),
        _ => format!("refused {id}: {why}\n"),
    }
}

fn measured(why: &str) -> (String, Option<String>, Option<String>) {
    if let Some((words, limit)) = word_limit(why) {
        return (
            format!("sentence has {words} words"),
            Some(words.to_string()),
            Some(limit.to_string()),
        );
    }
    if let Some(rest) = why.split("readability grade ").nth(1) {
        let mut parts = rest.split_whitespace();
        let grade = parts.next().unwrap_or("");
        if parts.next() == Some("exceeds") {
            let limit = parts
                .next()
                .unwrap_or("")
                .trim_end_matches(|c: char| !c.is_ascii_digit() && c != '.');
            if !grade.is_empty() && !limit.is_empty() {
                return (
                    format!("readability grade {grade} exceeds {limit}"),
                    Some(grade.to_string()),
                    Some(limit.to_string()),
                );
            }
        }
    }
    if let (Some(n), Some(limit)) = (
        number_before(why, " sentences"),
        number_after(why, "at most "),
    ) {
        return (
            format!("atom has {n} sentences"),
            Some(n.to_string()),
            Some(limit.to_string()),
        );
    }
    if let Some(rest) = why.split("adverb ratio ").nth(1) {
        let mut parts = rest.split_whitespace();
        let ratio = parts.next().unwrap_or("");
        if parts.next() == Some("exceeds") {
            let limit = parts
                .next()
                .unwrap_or("")
                .trim_end_matches(|c: char| !c.is_ascii_digit() && c != '.');
            if !ratio.is_empty() && !limit.is_empty() {
                return (
                    format!("adverb ratio {ratio} exceeds {limit}"),
                    Some(ratio.to_string()),
                    Some(limit.to_string()),
                );
            }
        }
    }
    (why.to_string(), None, None)
}

/// The latest proposal per id, filtered by seat and status. A row that
/// names no seat is `seat unknown`. With no status, open rows the pack
/// does not already hold come first, then refused rows, then one count
/// line. `--status in-pack` lists the rows the pack already holds.
#[must_use]
pub fn list_proposals(seat: Option<&str>, status: Option<&str>) -> String {
    let held = live_atoms().unwrap_or_default();
    let want_seat = seat.map(str::trim).filter(|s| !s.is_empty());
    let want_status = status.map(str::trim).filter(|s| !s.is_empty());
    let mut rows: Vec<Record> = read_latest().into_values().collect();
    rows.retain(|rec| want_seat.is_none_or(|seat| seat_matches(rec, seat)));
    rows.sort_by(|a, b| a.id.cmp(&b.id));
    if rows.is_empty() {
        return "no proposals\n".to_string();
    }
    if let Some(status) = want_status {
        let mut out = String::new();
        for rec in &rows {
            if !status_selected(rec, status, &held) {
                continue;
            }
            out.push_str(&proposal_line(rec, &held));
        }
        if out.is_empty() {
            out.push_str("no proposals\n");
        }
        return out;
    }
    let mut fresh = String::new();
    let mut refused = String::new();
    let mut open_n = 0usize;
    let mut new_n = 0usize;
    let mut pack_n = 0usize;
    for rec in &rows {
        let open = matches!(rec.status.as_str(), "open" | "proposed");
        if open {
            open_n += 1;
            if atom_in_pack(rec, &held) {
                pack_n += 1;
            } else {
                new_n += 1;
                fresh.push_str(&proposal_line(rec, &held));
            }
        } else if rec.status == "refused" {
            refused.push_str(&proposal_line(rec, &held));
        }
    }
    let mut out = fresh;
    out.push_str(&refused);
    out.push_str(&format!(
        "{open_n} open: {new_n} new, {pack_n} already in pack (`--status in-pack` to list them)\n"
    ));
    out
}

/// Write `already-in-pack` and the time on each open row whose atom is
/// already a pack entry. A row already settled is left as it is. Nothing
/// is deleted. One line per id that changed, then the count.
///
/// # Errors
///
/// The proposals log could not be written.
pub fn settle_proposals(seat: Option<&str>) -> Result<String> {
    let held = live_atoms().unwrap_or_default();
    let want_seat = seat.map(str::trim).filter(|s| !s.is_empty());
    let _g = gate();
    let mut rows: Vec<Record> = read_latest().into_values().collect();
    rows.retain(|rec| want_seat.is_none_or(|seat| seat_matches(rec, seat)));
    rows.sort_by(|a, b| a.id.cmp(&b.id));
    let mut lines = Vec::new();
    for mut rec in rows {
        if !matches!(rec.status.as_str(), "open" | "proposed") || !atom_in_pack(&rec, &held) {
            continue;
        }
        let id = rec.id.clone();
        note_outcome(&mut rec, "already-in-pack", "")?;
        lines.push(format!("already in pack {id}"));
    }
    let n = lines.len();
    lines.push(format!("settled {n}"));
    Ok(format!("{}\n", lines.join("\n")))
}

/// Live atoms, when the pack answers. `None` is a pack that does not, so a
/// list still prints and does not pretend a row is already held.
fn live_atoms() -> Option<Vec<Value>> {
    let client = crate::pack().ok()?;
    crate::atoms_lean(&client, &client.workspace()).ok()
}

fn proposal_kind(rec: &Record) -> String {
    if !rec.kind.trim().is_empty() {
        return rec.kind.trim().to_string();
    }
    rec.atom["kind"]
        .as_str()
        .unwrap_or("lesson")
        .trim()
        .to_string()
}

fn proposal_text(rec: &Record) -> String {
    if let Some(text) = rec
        .amendment
        .as_ref()
        .map(|amendment| amendment.text.trim())
        .filter(|text| !text.is_empty())
    {
        return text.to_string();
    }
    let text = rec.text.trim();
    if !text.is_empty() {
        return text.to_string();
    }
    rec.atom["text"].as_str().unwrap_or("").trim().to_string()
}

/// Put the text accept will store onto the atom. An amended proposal
/// carries `provenance:amended`, which a reader of the pack can see.
fn stamp_current(rec: &mut Record) {
    let text = proposal_text(rec);
    rec.atom["text"] = Value::String(text);
    if rec.amendment.is_some() {
        crate::add_entities(&mut rec.atom, ["provenance:amended".to_string()]);
    }
}

/// Whether an amendment was written after the refusal. A refusal of that
/// same amendment is not a newer one.
fn amended_since_refusal(rec: &Record) -> bool {
    rec.amendment
        .as_ref()
        .is_some_and(|amendment| amendment.at > rec.at)
}

/// The writer's duplicate rule: one atom when the folded text and the kind
/// match. Accept reports that row as already in pack, and so does the list.
fn atom_in_pack(rec: &Record, held: &[Value]) -> bool {
    let kind = proposal_kind(rec);
    let text = proposal_text(rec);
    if text.is_empty() || kind.is_empty() {
        return false;
    }
    let key = crate::memories::lesson_key(&kind, &text);
    held.iter().any(|atom| {
        let held_kind = atom["kind"].as_str().unwrap_or("").trim();
        if held_kind != kind {
            return false;
        }
        let same = |words: &str| crate::memories::lesson_key(held_kind, words) == key;
        same(atom["text"].as_str().unwrap_or(""))
            || atom["aliases"]
                .as_array()
                .is_some_and(|aliases| aliases.iter().filter_map(Value::as_str).any(same))
    })
}

fn seat_matches(rec: &Record, seat: &str) -> bool {
    if seat == "unknown" || seat == "seat unknown" {
        rec.seat.trim().is_empty()
    } else {
        rec.seat == seat
    }
}

fn wants_in_pack(status: &str) -> bool {
    status == "in-pack" || status == "already in pack"
}

fn status_selected(rec: &Record, status: &str, held: &[Value]) -> bool {
    if wants_in_pack(status) {
        return rec.status == "already-in-pack"
            || (matches!(rec.status.as_str(), "open" | "proposed") && atom_in_pack(rec, held));
    }
    rec.status == status
}

fn display_status(rec: &Record, held: &[Value]) -> String {
    if rec.status == "already-in-pack"
        || (matches!(rec.status.as_str(), "open" | "proposed") && atom_in_pack(rec, held))
    {
        "already in pack".to_string()
    } else {
        rec.status.clone()
    }
}

fn proposal_seat(rec: &Record) -> String {
    let filed = rec.seat.trim();
    if !filed.is_empty() {
        return filed.to_string();
    }
    rec.atom["source"]["seat"]
        .as_str()
        .unwrap_or("")
        .trim()
        .to_string()
}

fn proposal_line(rec: &Record, held: &[Value]) -> String {
    let named = proposal_seat(rec);
    let seat = if named.is_empty() {
        "seat unknown".to_string()
    } else {
        format!("seat {named}")
    };
    let text = if rec.status == "refused" && !rec.reason.is_empty() {
        format!(
            "{}  amend it with ljos proposals amend",
            refusal_clause(&proposal_text(rec), &rec.reason)
        )
    } else {
        proposal_text(rec).replace('\n', " ")
    };
    format!(
        "{}  {}  {seat}  {text}\n",
        rec.id,
        display_status(rec, held)
    )
}

/// How many characters of the offending sentence a refusal quotes.
const QUOTE_CHARS: usize = 80;

/// The refusal a person can act on. A sentence past the word limit names
/// the count, the limit and the sentence, trimmed to about 80 characters.
fn refusal_clause(text: &str, why: &str) -> String {
    let quote = trim_quote(&offending_sentence(text, why));
    if quote.is_empty() {
        return why.to_string();
    }
    if let Some((words, limit)) = word_limit(why) {
        format!("sentence has {words} words; limit {limit}: \"{quote}\"")
    } else {
        format!("{why}: \"{quote}\"")
    }
}

fn word_limit(why: &str) -> Option<(usize, usize)> {
    let words = number_before(why, " words")?;
    let limit = number_after(why, "the limit is ")?;
    Some((words, limit))
}

fn offending_sentence(text: &str, why: &str) -> String {
    let parts = packset_core::prose::sentences(text);
    if let Some(n) = number_after(why, "atom sentence ") {
        if let Some(sentence) = n.checked_sub(1).and_then(|i| parts.get(i)) {
            return sentence.trim().to_string();
        }
    }
    if parts.len() == 1 {
        return parts[0].trim().to_string();
    }
    text.trim().to_string()
}

fn trim_quote(text: &str) -> String {
    let text = text.trim();
    if text.chars().count() <= QUOTE_CHARS {
        return text.to_string();
    }
    let keep = QUOTE_CHARS - 3;
    let mut out: String = text.chars().take(keep).collect();
    if let Some(space) = out.rfind(' ') {
        if space > keep / 2 {
            out.truncate(space);
        }
    }
    out.push_str("...");
    out
}

fn number_before(text: &str, marker: &str) -> Option<usize> {
    let at = text.find(marker)?;
    let head = text[..at].trim_end();
    let digits: String = head
        .chars()
        .rev()
        .take_while(|c| c.is_ascii_digit())
        .collect();
    digits.chars().rev().collect::<String>().parse().ok()
}

fn number_after(text: &str, marker: &str) -> Option<usize> {
    let rest = text.split(marker).nth(1)?;
    let digits: String = rest.chars().take_while(|c| c.is_ascii_digit()).collect();
    digits.parse().ok()
}

/// [`accept`], recording the person's words the acceptance rests on.
///
/// `id` names a live memory, or a proposal row: an open one is stored
/// now at `explicit`, a stored one is accepted as the memory it became.
/// A satisfied or accepted row is already in the pack.
///
/// `yes` is a yes a seat carried from chat, see [`crate::quoted_yes`]. It
/// is kept on the accepted row, beside the acceptance it stands for, and
/// said back on the line the caller prints. `None` is the terminal path,
/// where the person ran the accept themselves.
///
/// # Errors
///
/// No proposal or memory has that id, a short id starts several, or the
/// pack or the state directory refuses the write.
pub fn accept_on(id: &str, yes: Option<&crate::quoted_yes::Yes>) -> Result<String> {
    let _g = gate();
    let id = id.trim();
    if id.is_empty() {
        bail!("accept: an id is required");
    }
    let rows = read_latest();
    let known: Vec<String> = rows.keys().cloned().collect();
    let id = match crate::resolve_short_id("accept", id, &known) {
        Ok(id) => id,
        Err(err) => return Ok(format!("not found {id}: {err:#}\n")),
    };
    let id = id.as_str();
    let Some(mut rec) = rows.get(id).cloned() else {
        return match accept_memory(id, None, yes) {
            Ok(line) => Ok(line),
            Err(err) if err.to_string().contains("no memory") => Ok(format!("not found {id}\n")),
            Err(err) => Err(err),
        };
    };
    rec.grant = yes.cloned();
    match rec.status.as_str() {
        "satisfied" => {
            close_remote(&rec);
            note_outcome(&mut rec, "already-in-pack", "")?;
            return Ok(format!("already in pack {id}\n"));
        }
        "accepted" | "already-in-pack" => return Ok(format!("already in pack {id}\n")),
        "stored" => {
            let stored = rec.stored.clone().unwrap_or_default();
            return accept_memory(&stored, Some(rec), yes);
        }
        "refused" if !amended_since_refusal(&rec) => {
            let when = if rec.at.is_empty() {
                "unknown"
            } else {
                rec.at.as_str()
            };
            return Ok(format!(
                "refused {id}: unchanged since last refusal at {when}; amend it with ljos proposals amend\n"
            ));
        }
        "open" | "proposed" | "refused" => {
            stamp_current(&mut rec);
            if matches!(rec.status.as_str(), "open" | "proposed") {
                if let Some(held) = live_atoms() {
                    if atom_in_pack(&rec, &held) {
                        note_outcome(&mut rec, "already-in-pack", "")?;
                        return Ok(format!("already in pack {id}\n"));
                    }
                }
            }
        }
        _ => return Ok(format!("not found {id}\n")),
    }
    let text = proposal_text(&rec);
    if let Some(why) = crate::pack_copy::gate_refusal(&text) {
        if rec.status != "refused" || rec.reason != why {
            rec.reason.clone_from(&why);
            note_outcome(&mut rec, "refused", &why)?;
        }
        return Ok(format!("refused {id}: {}\n", refusal_clause(&text, &why)));
    }
    let client = crate::pack()?;
    if rec.remote {
        let remote_id = rec.remote_id.clone().unwrap_or_else(|| rec.id.clone());
        let workspace = workspace_of(&client, &rec);
        let posted = accept_on_writer(&client, &workspace, &remote_id)?;
        note_outcome(&mut rec, "accepted", "")?;
        return Ok(accepted_line(&rec, &posted));
    }
    // A person accepting the proposal is the promotion off L0. The origin
    // stays, so a reader can still see where the claim came from. The
    // horizon becomes standing, which is what the prompt hook reads.
    stand_for_prompt(&mut rec.atom);
    match post_kept(&client, &rec.atom) {
        Ok(posted) => {
            rec.stored = posted["id"].as_str().map(str::to_string);
            note_outcome(&mut rec, "accepted", "")?;
            Ok(accepted_line(&rec, &posted))
        }
        Err(e) => {
            let err_text = e.to_string();
            let Some(remote_id) = held_proposal_id(&err_text) else {
                if !crate::note_can_wait(&e) {
                    let why =
                        crate::server_reason(&format!("{e:#}")).unwrap_or_else(|| format!("{e:#}"));
                    note_outcome(&mut rec, "refused", &why)?;
                    return Ok(format!(
                        "refused {id}: {}\n",
                        refusal_clause(&proposal_text(&rec), &why)
                    ));
                }
                return Err(e).with_context(|| format!("accept: POST /v1/atoms failed for {id}"));
            };
            // Filed while this writer was not holding, or the post is the
            // filing. Accept that proposal. Do not leave it open.
            let workspace = workspace_of(&client, &rec);
            let posted = accept_on_writer(&client, &workspace, &remote_id)?;
            rec.remote = true;
            rec.remote_id = Some(remote_id);
            note_outcome(&mut rec, "accepted", "")?;
            Ok(accepted_line(&rec, &posted))
        }
    }
}

/// Record `status` on `rec` and the time, when it changed. A repeat of the
/// same outcome writes nothing.
fn note_outcome(rec: &mut Record, status: &str, reason: &str) -> Result<()> {
    if rec.status == status && rec.reason == reason && !rec.at.is_empty() {
        return Ok(());
    }
    rec.status = status.to_string();
    rec.reason = reason.to_string();
    rec.at = crate::now_utc();
    append(rec)
}

/// Accept live memory `id`, a whole id or the start of one: raise its level
/// to `explicit`, record a `keep` verdict for `ljos memories review`, and
/// keep the acceptance and the yes it rests on as a row. `rec` is the
/// proposal row an import stored it from.
fn accept_memory(id: &str, rec: Option<Record>, yes: Option<&Yes>) -> Result<String> {
    let client = crate::pack()?;
    let workspace = client.workspace();
    let atoms = crate::atoms_lean(&client, &workspace).context("accept: GET /v1/atoms failed")?;
    let all: Vec<crate::memories::Memory> = atoms
        .iter()
        .filter_map(crate::memories::Memory::of)
        .collect();
    let full = match crate::memories::resolve(id, &all) {
        Ok(full) => full,
        Err(err) if err.to_string().contains("no memory starts with") => {
            bail!("no memory {id}")
        }
        Err(err) => return Err(err).context(format!("accept: no open proposal or memory {id}")),
    };
    let atom = atoms
        .iter()
        .find(|a| a["id"].as_str() == Some(full.as_str()))
        .cloned()
        .unwrap_or_default();
    let fields = prompt_fields(&atom);
    let posted = if fields.as_object().is_some_and(|map| !map.is_empty()) {
        update_fields(&client, &workspace, &full, fields)?
    } else {
        atom.clone()
    };
    crate::memories::record(&full, "keep", None)?;
    let mut rec = rec.unwrap_or_else(|| Record {
        id: full.clone(),
        status: String::new(),
        remote: false,
        remote_id: None,
        stored: None,
        text: atom["text"].as_str().unwrap_or("").to_string(),
        kind: atom["kind"].as_str().unwrap_or("lesson").to_string(),
        origin: atom["origin"].as_str().unwrap_or("").to_string(),
        grant: None,
        seat: atom["source"]["seat"]
            .as_str()
            .unwrap_or("")
            .trim()
            .to_string(),
        at: String::new(),
        reason: String::new(),
        amendment: None,
        atom,
    });
    rec.stored = Some(full);
    rec.grant = yes.cloned();
    note_outcome(&mut rec, "accepted", "")?;
    Ok(accepted_line(&rec, &posted))
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::os::unix::fs::PermissionsExt;

    fn record(id: String) -> Record {
        Record {
            id,
            status: "proposed".into(),
            remote: false,
            remote_id: None,
            stored: None,
            text: "use uv for python envs".into(),
            kind: "lesson".into(),
            origin: ORIGIN_AGENT.into(),
            grant: None,
            seat: String::new(),
            at: String::new(),
            reason: String::new(),
            amendment: None,
            atom: serde_json::json!({"text": "use uv for python envs"}),
        }
    }

    /// The seat that filed a proposal is on the row and in the listing.
    #[test]
    fn a_proposal_names_the_seat_that_filed_it() {
        let _g = crate::test_env_lock();
        let dir = tempfile::tempdir().unwrap();
        unsafe {
            std::env::set_var("XDG_STATE_HOME", dir.path());
            std::env::set_var("LJOS_SEAT", "saddle");
            std::env::remove_var("PACKSET_URL");
        }
        let filed = file_open("Fire the kiln only after the shelf is cool.", "lesson").unwrap();
        assert!(!filed.trim().is_empty(), "{filed}");
        let listed = list_proposals(None, None);
        assert!(listed.contains("seat saddle"), "{listed}");
        assert!(!listed.contains("seat unknown"), "{listed}");
        let row = read_latest().into_values().next().unwrap();
        assert_eq!(row.seat, "saddle");
        assert_eq!(row.atom["source"]["seat"], "saddle");
    }

    /// A held proposal carries the whole atom, so its row is private and
    /// written whole, like the other state logs.
    #[test]
    fn concurrent_proposal_rows_each_parse_and_stay_private() {
        let _g = crate::test_env_lock();
        let dir = tempfile::tempdir().unwrap();
        unsafe { std::env::set_var("XDG_STATE_HOME", dir.path()) };
        const THREADS: usize = 16;
        const EACH: usize = 8;
        let handles: Vec<_> = (0..THREADS)
            .map(|thread| {
                std::thread::spawn(move || {
                    for n in 0..EACH {
                        append(&record(format!("{thread}-{n}"))).unwrap();
                    }
                })
            })
            .collect();
        for handle in handles {
            handle.join().expect("proposal writer");
        }
        let path = proposals_path();
        let text = std::fs::read_to_string(&path).unwrap();
        for line in text.lines() {
            serde_json::from_str::<Record>(line)
                .unwrap_or_else(|err| panic!("proposal row does not parse ({err}): {line}"));
        }
        assert_eq!(read_latest().len(), THREADS * EACH, "{text}");
        let mode = std::fs::symlink_metadata(&path)
            .unwrap()
            .permissions()
            .mode()
            & 0o777;
        assert_eq!(mode, 0o600, "proposals mode {mode:o}");
    }

    /// A proposal still being appended is not yet held; the proposals
    /// before it are.
    #[test]
    fn a_torn_last_proposal_leaves_the_others() {
        let _g = crate::test_env_lock();
        let dir = tempfile::tempdir().unwrap();
        unsafe { std::env::set_var("XDG_STATE_HOME", dir.path()) };
        append(&record("a".into())).unwrap();
        let path = proposals_path();
        let mut bytes = std::fs::read(&path).unwrap();
        bytes.extend_from_slice(b"{\"id\":\"b\",\"text\":\"caf\xc3");
        std::fs::write(&path, bytes).unwrap();
        let ids: Vec<String> = read_latest().into_keys().collect();
        assert_eq!(ids, ["a"]);
    }

    /// A proposals file swapped for a symlink is not written through.
    #[test]
    fn a_symlinked_proposals_file_is_refused() {
        let _g = crate::test_env_lock();
        let dir = tempfile::tempdir().unwrap();
        unsafe { std::env::set_var("XDG_STATE_HOME", dir.path()) };
        let path = proposals_path();
        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
        let outside = dir.path().join("outside");
        std::fs::write(&outside, "kept\n").unwrap();
        std::os::unix::fs::symlink(&outside, &path).unwrap();
        assert!(append(&record("a".into())).is_err());
        assert_eq!(std::fs::read_to_string(&outside).unwrap(), "kept\n");
    }
}