elasticctl-api 0.2.4

//! `state push`: plan and apply, in container-then-item-then-rule order.

use super::diff::{ItemOp, ListOp};
use super::reports::{DanglingPointer, Mirror, PushReport, StackIdentity};
use crate::diff::{Change, Drift};
use crate::exceptions;
use crate::model::{ExceptionItem, ListKey, Rule};
use crate::normalize;
use crate::report::{ChangeReport, ReportEntry};
use crate::rules as api;
use elasticctl_core::{Error, ErrorKind, Result, Transport};
use serde_json::{Value, json};
use std::collections::{BTreeMap, BTreeSet};
use std::path::Path;

/// What `plan_push` computed and `apply_push` performs.
///
/// The preview fields feed the caller's guard banner; `report` is the change
/// ticket; `summary` is the JSON report.
#[derive(Debug, Clone)]
pub struct PushPlan {
    pub preview_action: String,
    pub preview_details: Vec<String>,
    pub report: ChangeReport,
    pub summary: PushReport,
    /// The exact rules the preview described, resolved once at plan time so
    /// `apply_push` never re-reads the mirror after the guard.
    desired: BTreeMap<String, Rule>,
    /// Container writes, ordered before any item or rule write.
    list_ops: Vec<ListOp>,
    /// Item creates, updates, and removals, ordered before rule writes.
    item_ops: Vec<ItemOp>,
}

/// The exception writes `apply_push` performed, folded into `PushReport`.
#[derive(Default, Clone, Copy)]
struct ExceptionCounts {
    lists_created: usize,
    lists_updated: usize,
    items_created: usize,
    items_updated: usize,
    items_removed: usize,
}

/// Compute the push preview and dry-run report without mutating the stack,
/// scoped by `source`. The `custom`/`all` default lives on the clap flag, where
/// `--help` shows it (spec 5.5).
pub async fn plan_push(
    t: &Transport,
    dir: &Path,
    selectors: &[String],
    tag: Option<&str>,
    source: crate::rules::RuleSource,
    identity: &StackIdentity,
) -> Result<PushPlan> {
    let Mirror {
        rules: local_all,
        lists,
        items,
    } = super::mirror::read_mirror(dir)?;
    // Resolve locally first because disk-only rules have no remote ID and may
    // be created by a scoped push.
    let scope = super::scope_of(t, selectors, tag, source, &local_all, "apply").await?;
    // A local file outside the `--source` scope is never a pending create
    // (spec 5.5). Selectors narrow both sides and leave the count at zero.
    let (local, out_of_scope) = if scope.is_scoped() {
        (scope.narrow(local_all), 0)
    } else {
        scope.split_by_source(local_all)
    };
    // A value-list reference is active only if its exception container is
    // reachable from a rule in this push's active closure. Reading every
    // mirror item here would let an out-of-scope rule block this preview.
    let active_list_keys = super::referenced_keys(&local);
    let value_lists = value_list_refs(&items, &active_list_keys);
    let remote = scope.remote(t).await?;
    let drift = Drift::compute(&local, &remote)?;

    let plan = super::diff::exception_plan(t, lists, items, &local, &remote).await?;
    let exceptions = plan.drift;
    let list_ops = plan.list_ops;
    let item_ops = plan.item_ops;
    let resolvable = plan.resolvable;

    let by_id = |id: &str| local.iter().find(|r| r.rule_id().ok() == Some(id)).cloned();
    let remote_by_id = |id: &str| {
        remote
            .iter()
            .find(|r| r.rule_id().ok() == Some(id))
            .cloned()
    };

    let actionable = drift.actionable();
    let actionable_ids: BTreeSet<String> =
        actionable.iter().map(|c| c.rule_id().to_string()).collect();

    // A dangling pointer is drift the normalized diff cannot see, so a rule
    // whose normalized form is unchanged still needs a write to repair it.
    // Remote-only rules are skipped: push never touches what it has no local
    // form for. Dedupe by `rule_id`: a rule referencing two wrong pointers
    // emits two `DanglingPointer`s but is one rule write.
    let mut repairs: Vec<DanglingPointer> = Vec::new();
    let mut repaired_ids: BTreeSet<String> = BTreeSet::new();
    for dangling in &exceptions.dangling {
        if actionable_ids.contains(&dangling.rule_id)
            || by_id(&dangling.rule_id).is_none()
            || !repaired_ids.insert(dangling.rule_id.clone())
        {
            continue;
        }
        repairs.push(dangling.clone());
    }

    let mut preview_details = Vec::new();

    // Name containers and items first, matching apply order.
    for op in &list_ops {
        match op {
            ListOp::Create(list) => {
                preview_details.push(format!("{}  {}  create", list.list_id()?, list.name()))
            }
            ListOp::Update { after, .. } => {
                preview_details.push(format!("{}  {}  update", after.list_id()?, after.name()))
            }
        }
    }
    for op in &item_ops {
        match op {
            ItemOp::Create(item) => {
                preview_details.push(format!("{}  {}  create", item.item_id()?, item.list_id()?))
            }
            ItemOp::Update { after, .. } => preview_details.push(format!(
                "{}  {}  update",
                after.item_id()?,
                after.list_id()?
            )),
            ItemOp::Remove { before, .. } => preview_details.push(format!(
                "{}  {}  delete",
                before.item_id()?,
                before.list_id()?
            )),
        }
    }
    for change in &actionable {
        let line = match change {
            Change::Added { rule_id, name } => format!("{rule_id}  {name}  create"),
            Change::Modified {
                rule_id,
                name,
                fields,
            } => {
                let names: Vec<&str> = fields.iter().map(|f| f.field.as_str()).collect();
                format!("{rule_id}  {name}  update ({})", names.join(", "))
            }
            _ => String::new(),
        };
        if !line.is_empty() {
            preview_details.push(line);
        }
    }
    for dangling in &repairs {
        let name = by_id(&dangling.rule_id)
            .map(|r| r.name().to_string())
            .unwrap_or_default();
        preview_details.push(format!("{}  {}  update (pointer)", dangling.rule_id, name));
    }

    // A value list is data, not configuration, and its content is not managed
    // here (spec 7.7), but a referenced value list that cannot exist must be
    // reported, never silently pushed. Absence is judged on the data streams:
    // when they are not bootstrapped, no value list can exist. The `?` refuses
    // on any failure that is not a clean "absent" 404, so an unverifiable
    // reference is a failure rather than a silent omission.
    if !value_lists.is_empty() {
        if !exceptions::value_lists_bootstrapped(t).await? {
            for value_list in &value_lists {
                preview_details.push(format!(
                    "value list \"{}\" is absent; run POST /api/lists/index to bootstrap the data streams",
                    value_list.id
                ));
            }
        } else {
            for value_list in &value_lists {
                if !exceptions::value_list_exists(t, &value_list.id).await? {
                    preview_details.push(format!("value list \"{}\" is absent", value_list.id));
                }
            }
        }
    }

    let mut entries: Vec<ReportEntry> = Vec::new();
    let mut desired: BTreeMap<String, Rule> = BTreeMap::new();

    // Record remote-only rules before applying changes, including in dry runs.
    // `actionable()` excludes them because push never deletes remote rules.
    for change in &drift.changes {
        if let Change::RemoteOnly { rule_id, name } = change {
            entries.push(ReportEntry {
                rule_id: rule_id.clone(),
                name: name.clone(),
                action: "skipped_remote_only".into(),
                before: remote_by_id(rule_id).map(|r| normalize::canonical(&r).into_value()),
                after: None,
                applied: false,
                error: None,
            });
        }
    }

    // Record every actionable change as a pending entry. The report and JSON
    // `pending` count describe proposed creates and updates.
    for change in &actionable {
        let (rule_id, name, action) = match change {
            Change::Added { rule_id, name } => (rule_id.clone(), name.clone(), "create"),
            Change::Modified { rule_id, name, .. } => (rule_id.clone(), name.clone(), "update"),
            _ => continue,
        };

        let Some(desired_rule) = by_id(&rule_id) else {
            continue;
        };
        let before = remote_by_id(&rule_id).map(|r| normalize::canonical(&r).into_value());

        desired.insert(rule_id.clone(), desired_rule.clone());

        entries.push(ReportEntry {
            rule_id,
            name,
            action: action.into(),
            before,
            after: Some(normalize::canonical(&desired_rule).into_value()),
            applied: false,
            error: None,
        });
    }

    // A repaired pointer is an update whose `before`/`after` normalization
    // cannot show the difference; the write still happens.
    for dangling in &repairs {
        let desired_rule = by_id(&dangling.rule_id).expect("repair rule was found above");
        let before = remote_by_id(&dangling.rule_id).map(|r| normalize::canonical(&r).into_value());
        desired.insert(dangling.rule_id.clone(), desired_rule.clone());
        entries.push(ReportEntry {
            rule_id: dangling.rule_id.clone(),
            name: desired_rule.name().to_string(),
            action: "update".into(),
            before,
            after: Some(normalize::canonical(&desired_rule).into_value()),
            applied: false,
            error: None,
        });
    }

    // Refuse, before any write, a rule that references a list neither on the
    // stack nor in the mirror. The ids are injected at write time against the
    // target, but resolvability is known here.
    let desired_rules: Vec<Rule> = desired.values().cloned().collect();
    let unresolved: Vec<String> = super::referenced_keys(&desired_rules)
        .into_iter()
        .filter(|key| !resolvable.contains(key))
        .map(|key| format!("\"{}\" ({})", key.list_id, key.namespace_type))
        .collect();
    if !unresolved.is_empty() {
        return Err(Error::new(
            ErrorKind::NotFound,
            format!(
                "rule(s) reference exception list(s) that do not exist on this stack and are \
                 not in the mirror: {}",
                unresolved.join(", ")
            ),
        ));
    }

    // Name the selection so a scoped preview differs from a full preview. The
    // banner names rule, list, and item counts (spec 6.1). Removals get their
    // own count: the number an operator reads before `--yes` must not read the
    // same for a run that deletes three items and one that creates three.
    let item_removals = item_ops
        .iter()
        .filter(|op| matches!(op, ItemOp::Remove { .. }))
        .count();
    let item_writes = item_ops.len() - item_removals;
    let mut preview_action = format!(
        "Push {} rule change(s), {} exception list(s) and {} item(s)",
        actionable.len() + repairs.len(),
        list_ops.len(),
        item_writes,
    );
    if item_removals > 0 {
        preview_action.push_str(&format!(", {} item deletion(s)", item_removals));
    }
    preview_action.push_str(&format!(" from {}{}", dir.display(), scope.describe()));

    let report = ChangeReport {
        profile: identity.profile.clone(),
        host: identity.host.clone(),
        space: identity.space.clone(),
        applied: false,
        entries,
    };
    let summary = push_summary(
        &report,
        scope.is_scoped().then(|| scope.selected()),
        scope.is_scoped().then_some(scope.local_total),
        out_of_scope,
        ExceptionCounts::default(),
    );

    Ok(PushPlan {
        preview_action,
        preview_details,
        report,
        summary,
        desired,
        list_ops,
        item_ops,
    })
}

/// Perform the mutations `plan_push` proposed.
///
/// The caller runs this only after its guard approves; a caller that never
/// calls it has performed a dry run by construction. It reads only from the
/// plan, never the mirror, so the preview and the apply cannot diverge.
pub async fn apply_push(t: &Transport, mut plan: PushPlan) -> Result<PushPlan> {
    // Resolve the live ids for every list a rule to write references, then
    // create or update containers, then items, then rules. The pointer is
    // injected only here, against the target stack, never at plan time.
    let desired_rules: Vec<Rule> = plan.desired.values().cloned().collect();
    let wanted: Vec<ListKey> = super::referenced_keys(&desired_rules).into_iter().collect();
    let mut resolved = exceptions::resolve_ids(t, &wanted).await?;

    let mut counts = ExceptionCounts::default();
    let mut exception_entries = Vec::with_capacity(plan.list_ops.len() + plan.item_ops.len());

    // 1. Containers. A failure records the evidence and stops: the ordering
    // invariant means later writes depend on this one.
    for op in &plan.list_ops {
        let failure = match op {
            ListOp::Create(list) => match exceptions::create_list(t, list).await {
                Ok(created) => {
                    if let Some(id) = created.as_map().get("id").and_then(Value::as_str) {
                        resolved.insert(list.key()?, id.to_string());
                    }
                    counts.lists_created += 1;
                    exception_entries.push(ReportEntry {
                        rule_id: list.list_id().unwrap_or("<unreadable>").to_string(),
                        name: list.name().to_string(),
                        action: "create_list".into(),
                        before: None,
                        after: Some(normalize::canonical_list(&created).into_value()),
                        applied: true,
                        error: None,
                    });
                    None
                }
                Err(e) => Some(ReportEntry {
                    rule_id: list.list_id().unwrap_or("<unreadable>").to_string(),
                    name: list.name().to_string(),
                    action: "create_list".into(),
                    before: None,
                    after: None,
                    applied: false,
                    error: Some(e.message),
                }),
            },
            ListOp::Update { before, after } => match exceptions::update_list(t, after).await {
                Ok(applied) => {
                    counts.lists_updated += 1;
                    exception_entries.push(ReportEntry {
                        rule_id: after.list_id().unwrap_or("<unreadable>").to_string(),
                        name: after.name().to_string(),
                        action: "update_list".into(),
                        before: Some(before.clone().into_value()),
                        after: Some(normalize::canonical_list(&applied).into_value()),
                        applied: true,
                        error: None,
                    });
                    None
                }
                Err(e) => Some(ReportEntry {
                    rule_id: after.list_id().unwrap_or("<unreadable>").to_string(),
                    name: after.name().to_string(),
                    action: "update_list".into(),
                    before: Some(before.clone().into_value()),
                    after: None,
                    applied: false,
                    error: Some(e.message),
                }),
            },
        };
        if let Some(failed_entry) = failure {
            return Ok(finish_after_exception_failure(
                plan,
                exception_entries,
                failed_entry,
                counts,
            ));
        }
    }

    // 2. Items: create, update, or delete. A failure records the evidence and
    // stops, like a container failure; a retry re-plans against the partial
    // state and re-converges.
    for op in &plan.item_ops {
        let failure = match op {
            ItemOp::Create(item) => match exceptions::create_item(t, item).await {
                Ok(applied) => {
                    counts.items_created += 1;
                    exception_entries.push(ReportEntry {
                        rule_id: item.item_id().unwrap_or("<unreadable>").to_string(),
                        name: item.list_id().unwrap_or("<unreadable>").to_string(),
                        action: "create_item".into(),
                        before: None,
                        after: Some(normalize::canonical_item(&applied).into_value()),
                        applied: true,
                        error: None,
                    });
                    None
                }
                Err(e) => Some(ReportEntry {
                    rule_id: item.item_id().unwrap_or("<unreadable>").to_string(),
                    name: item.list_id().unwrap_or("<unreadable>").to_string(),
                    action: "create_item".into(),
                    before: None,
                    after: None,
                    applied: false,
                    error: Some(e.message),
                }),
            },
            ItemOp::Update { before, after } => match exceptions::update_item(t, after).await {
                Ok(applied) => {
                    counts.items_updated += 1;
                    exception_entries.push(ReportEntry {
                        rule_id: after.item_id().unwrap_or("<unreadable>").to_string(),
                        name: after.list_id().unwrap_or("<unreadable>").to_string(),
                        action: "update_item".into(),
                        before: Some(before.clone().into_value()),
                        after: Some(normalize::canonical_item(&applied).into_value()),
                        applied: true,
                        error: None,
                    });
                    None
                }
                Err(e) => Some(ReportEntry {
                    rule_id: after.item_id().unwrap_or("<unreadable>").to_string(),
                    name: after.list_id().unwrap_or("<unreadable>").to_string(),
                    action: "update_item".into(),
                    before: Some(before.clone().into_value()),
                    after: None,
                    applied: false,
                    error: Some(e.message),
                }),
            },
            ItemOp::Remove {
                before,
                namespace_type,
            } => match exceptions::delete_item(
                t,
                before.item_id().unwrap_or("<unreadable>"),
                namespace_type,
            )
            .await
            {
                Ok(_) => {
                    counts.items_removed += 1;
                    exception_entries.push(ReportEntry {
                        rule_id: before.item_id().unwrap_or("<unreadable>").to_string(),
                        name: before.list_id().unwrap_or("<unreadable>").to_string(),
                        action: "delete_item".into(),
                        before: Some(before.clone().into_value()),
                        after: None,
                        applied: true,
                        error: None,
                    });
                    None
                }
                Err(e) => Some(ReportEntry {
                    rule_id: before.item_id().unwrap_or("<unreadable>").to_string(),
                    name: before.list_id().unwrap_or("<unreadable>").to_string(),
                    action: "delete_item".into(),
                    before: Some(before.clone().into_value()),
                    after: None,
                    applied: false,
                    error: Some(e.message),
                }),
            },
        };
        if let Some(failed_entry) = failure {
            return Ok(finish_after_exception_failure(
                plan,
                exception_entries,
                failed_entry,
                counts,
            ));
        }
    }

    // 3. Rules, injecting the resolved pointer into each.
    let mut entries = exception_entries;
    entries.reserve(plan.report.entries.len());
    for entry in plan.report.entries {
        if entry.action != "create" && entry.action != "update" {
            // `skipped_remote_only` entries pass through untouched.
            entries.push(entry);
            continue;
        }

        let Some(desired) = plan.desired.get(&entry.rule_id) else {
            // `plan_push` records a desired rule for every actionable change,
            // so this is defensive. Record the inconsistency as a failure
            // rather than dropping the planned mutation from the report.
            let missing = entry.rule_id.clone();
            entries.push(ReportEntry {
                rule_id: entry.rule_id,
                name: entry.name,
                action: entry.action,
                before: entry.before,
                after: None,
                applied: false,
                error: Some(format!("the plan has no desired rule for \"{missing}\"")),
            });
            continue;
        };

        let mut to_write = desired.clone();
        // `plan_push` verified resolvability, so a miss here is a container
        // whose live id could not be read (or a list deleted since planning).
        // Record it per-rule, like any other write failure, and continue.
        if let Err(e) = inject_list_ids(&mut to_write, &resolved) {
            entries.push(ReportEntry {
                rule_id: entry.rule_id,
                name: entry.name,
                action: entry.action,
                before: entry.before,
                after: None,
                applied: false,
                error: Some(e.message),
            });
            continue;
        }
        let before = entry.before;
        let is_create = entry.action == "create";

        // Continue after a per-rule failure so the report records every
        // outcome.
        let outcome = if is_create {
            api::create(t, &to_write).await
        } else {
            api::update(t, &to_write).await
        };

        match outcome {
            Ok(applied) => entries.push(ReportEntry {
                rule_id: entry.rule_id,
                name: entry.name,
                action: entry.action,
                before,
                after: Some(normalize::canonical(&applied).into_value()),
                applied: true,
                error: None,
            }),
            Err(e) => entries.push(ReportEntry {
                rule_id: entry.rule_id,
                name: entry.name,
                action: entry.action,
                before,
                after: None,
                applied: false,
                error: Some(e.message),
            }),
        }
    }

    let (selected, local_total, out_of_scope) = (
        plan.summary.selected,
        plan.summary.local_total,
        plan.summary.out_of_scope,
    );
    plan.report.entries = entries;
    plan.report.applied = true;
    plan.summary = push_summary(&plan.report, selected, local_total, out_of_scope, counts);
    Ok(plan)
}

/// Record a failed exception write in the change ticket and finalize the plan,
/// returning it so the caller keeps the evidence of what landed before the
/// failure.
fn finish_after_exception_failure(
    mut plan: PushPlan,
    mut exception_entries: Vec<ReportEntry>,
    failed_entry: ReportEntry,
    counts: ExceptionCounts,
) -> PushPlan {
    exception_entries.push(failed_entry);
    exception_entries.append(&mut plan.report.entries);
    plan.report.entries = exception_entries;
    plan.report.applied = true;
    let (selected, local_total, out_of_scope) = (
        plan.summary.selected,
        plan.summary.local_total,
        plan.summary.out_of_scope,
    );
    plan.summary = push_summary(&plan.report, selected, local_total, out_of_scope, counts);
    plan
}

fn push_summary(
    report: &ChangeReport,
    selected: Option<usize>,
    local_total: Option<usize>,
    out_of_scope: usize,
    counts: ExceptionCounts,
) -> PushReport {
    let (created, updated, skipped, failed) = report.counts();
    PushReport {
        applied: report.applied,
        created,
        updated,
        skipped_remote_only: skipped,
        failed,
        pending: report.pending(),
        lists_created: counts.lists_created,
        lists_updated: counts.lists_updated,
        items_created: counts.items_created,
        items_updated: counts.items_updated,
        items_removed: counts.items_removed,
        out_of_scope,
        selected,
        local_total,
    }
}

/// Inject each referenced list's live `id` into the rule.
///
/// Measured fact 3: `id` is required on create and validated by nothing, so a
/// fabricated or carried pointer would be stored silently. Resolve against this
/// stack every time. `plan_push` has already refused a list that is neither on
/// the stack nor in the mirror, so a miss here means the live id could not be
/// read, not that the list is absent.
fn inject_list_ids(rule: &mut Rule, live: &BTreeMap<ListKey, String>) -> Result<()> {
    let Some(Value::Array(refs)) = rule.as_map_mut().get_mut("exceptions_list") else {
        return Ok(());
    };
    for reference in refs.iter_mut() {
        let Value::Object(map) = reference else {
            continue;
        };
        let Some(list_id) = map.get("list_id").and_then(Value::as_str) else {
            continue;
        };
        let namespace = map
            .get("namespace_type")
            .and_then(Value::as_str)
            .unwrap_or("single");
        let key = ListKey {
            list_id: list_id.to_string(),
            namespace_type: namespace.to_string(),
        };
        match live.get(&key) {
            Some(id) => {
                map.insert("id".into(), json!(id));
            }
            None => {
                return Err(Error::new(
                    ErrorKind::NotFound,
                    format!(
                        "rule references exception list \"{list_id}\" ({namespace}), whose live \
                         id could not be resolved on this stack"
                    ),
                ));
            }
        }
    }
    Ok(())
}

/// The value-list ids an exception item's entries reference.
///
/// A `list` entry references a value list through `list.id`, a caller-supplied
/// id that is stable across stacks (spec 7.7). A `BTreeSet` keeps the preview
/// order deterministic.
fn value_list_refs(
    items: &[ExceptionItem],
    active_list_keys: &BTreeSet<ListKey>,
) -> BTreeSet<exceptions::ValueListRef> {
    let mut ids = BTreeSet::new();
    for item in items {
        let Ok(list_id) = item.list_id() else {
            continue;
        };
        let key = ListKey {
            list_id: list_id.to_string(),
            namespace_type: item.namespace_type().to_string(),
        };
        if !active_list_keys.contains(&key) {
            continue;
        }
        let Some(entries) = item.as_map().get("entries").and_then(Value::as_array) else {
            continue;
        };
        for entry in entries {
            let Some(obj) = entry.as_object() else {
                continue;
            };
            if obj.get("type").and_then(Value::as_str) != Some("list") {
                continue;
            }
            if let Some(id) = obj
                .get("list")
                .and_then(Value::as_object)
                .and_then(|l| l.get("id"))
                .and_then(Value::as_str)
            {
                ids.insert(exceptions::ValueListRef { id: id.to_string() });
            }
        }
    }
    ids
}