tix-tracker 0.12.0

//! The inbox query: scope, entries, age, and counts — one snapshot, no writes.
//!
//! Contract `triage-state.md` §Queue query: "`triage list`/`triage status`
//! return ordered entries, age, and counts derived from one issue snapshot. The
//! query is read-only, deterministic for a supplied date, and uses the same
//! status/category/completion service as other surfaces. No query writes files
//! or History." Research R3 and R11, data-model §5–§6, WP02 T007–T011.
//!
//! Three claims hold the design together, and each is a property of the
//! *signatures* rather than of a comment:
//!
//! 1. **One snapshot.** [`collect`] takes `&[Issue]`. It cannot open a file,
//!    walk a directory, or call [`crate::storage::Store::list`], so there is
//!    nowhere for a second filesystem pass to live. The caller loads the issues
//!    (normally through [`crate::search::Corpus::build`]) and hands them over
//!    once.
//! 2. **Read-only.** Nothing in this module takes `&mut` of anything outside
//!    its own return value, and no type here is `Serialize`. A query cannot
//!    write what it cannot name.
//! 3. **Shared vocabulary.** Membership is a set of column *names* resolved by
//!    [`crate::workflow::active_resolution`]; acceptance and decline are
//!    categories from that same resolution, never a literal `"done"` or
//!    `"canceled"` string (C-002).
//!
//! The age source is [`crate::triage::entry_time`] — the stamp WP01 records —
//! and never `created` or `updated` (research R4). A supplied `today` makes the
//! arithmetic deterministic: no wall-clock read happens inside a query.

use crate::config::Config;
use crate::error::{Result, TixError};
use crate::model::Issue;
use crate::relationships::RelationKind;
use crate::triage::{EntryTime, entry_time};
use crate::workflow::{self, CategoryResolution, WorkflowCategory, is_completed};

/// The inbox, resolved against one board.
///
/// Built by [`scope`] and consumed by [`collect`]. Held as resolved **column
/// names** rather than as the `[triage]` section, because everything downstream
/// compares an issue's status against a column and a section is not a column:
/// the same resolution the rest of the crate uses decides what is in the inbox,
/// so the inbox cannot drift from `tix list` or from `tix mv` (research R3,
/// "scope drift → shared #183 resolver").
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct InboxScope {
    /// The board this scope was resolved against, for messages that must name it.
    pub board: String,
    /// `[triage].entry_status`: the column an issue sits in while awaiting a decision.
    pub entry_status: String,
    /// `[triage].deferred_status`, or [`Self::entry_status`] when the section
    /// names none (WP01's `effective_deferred_status`).
    pub deferred_status: String,
    /// The membership set: the two columns above, deduplicated and in **board
    /// order** so the set is a function of the board rather than of how the
    /// section happened to spell it.
    pub columns: Vec<String>,
    /// The board's category resolution, carried alongside so a caller can
    /// classify an entry without asking for the config again.
    pub resolution: CategoryResolution,
}

impl InboxScope {
    /// Whether `issue` is in the inbox.
    ///
    /// Column membership only. An issue's *age* is a separate question — a
    /// legacy issue with no `entered_at` is in the inbox and has an unknown age
    /// — and folding the two together would make "is it queued?" depend on when
    /// it was stamped.
    #[must_use]
    pub fn matches(&self, issue: &Issue) -> bool {
        self.columns.iter().any(|c| issue.status.is(c))
    }

    /// The board's columns joined for a message, in board order.
    ///
    /// Delegates rather than re-deriving, so an inbox message lists the same
    /// columns as an `unknown_column` refusal from the same board.
    #[must_use]
    pub fn column_list(&self) -> String {
        self.resolution.column_list()
    }
}

/// Resolve the inbox scope from `[triage]` and the shared category service (T007).
///
/// `Ok(None)` means this project configures no inbox at all: the section is
/// absent, which is the default and the state every legacy `tix.toml` is in.
/// Absence is not an error — it is the documented opt-out (WP01, data-model §1)
/// — and a caller that wants the inbox checks for the `None`.
///
/// A section that *is* present is validated first, through WP01's own
/// [`crate::triage::config::validate`]. That is deliberate: this function is
/// reached from a filter string a user typed (`scope:triage`), which may run
/// against a `Config` a caller built by hand rather than one that came through
/// [`Config::load_with_warning`]. Reusing the loader's validator means there is
/// one answer to "is this section valid", not one per entry point.
pub fn scope(config: &Config) -> Result<Option<InboxScope>> {
    let Some(triage) = config.triage.as_ref() else {
        return Ok(None);
    };
    crate::triage::config::validate(config)?;

    // `validate` is what makes both of these `Some`: it rejects a section that
    // names no entry status and one whose columns the board does not have,
    // before this line is reachable.
    let entry = triage
        .entry_status
        .as_deref()
        .expect("triage::config::validate requires entry_status when the section exists");
    let deferred = triage
        .effective_deferred_status()
        .expect("the fallback is entry_status, which validate just required");

    let (board, resolution) = workflow::active_resolution(config);
    let mut named: Vec<String> = vec![entry.to_string()];
    if deferred != entry {
        named.push(deferred.to_string());
    }
    // Board order, not the order the section wrote them in: two configs that
    // name the same two columns must produce the same scope, and a
    // `HashMap`-backed set would not.
    let columns = resolution
        .columns()
        .filter(|column| named.iter().any(|c| c == column))
        .map(str::to_string)
        .collect();

    Ok(Some(InboxScope {
        board,
        entry_status: entry.to_string(),
        deferred_status: deferred.to_string(),
        columns,
        resolution,
    }))
}

/// Resolve a `scope:` query token to the columns it selects (WP02 T010).
///
/// The only scope is `triage`. Both failures are **errors, not empty results**,
/// for the reason [`crate::search::resolve_parent_criterion`] documents: a user
/// who typed `scope:triage` and is told "0 issues" cannot tell a typo from a
/// project that has no inbox, and those are two different answers.
///
/// Not a new [`crate::workflow::DiagnosticKind`]: this is command-layer input
/// validation like `unknown --show value`, reported as
/// [`TixError::InvalidInput`]. The seven-name diagnostic vocabulary is the
/// workflow contract's and stays at seven.
pub fn scope_columns(config: &Config, name: &str) -> Result<Vec<String>> {
    if !name.eq_ignore_ascii_case("triage") {
        return Err(TixError::InvalidInput(format!(
            "unknown scope `{name}` — this project's scopes are: triage"
        )));
    }
    match scope(config)? {
        Some(scope) => Ok(scope.columns),
        None => Err(TixError::InvalidInput(
            "`scope:triage` needs a `[triage]` section in tix.toml, and this \
             project has none"
                .to_string(),
        )),
    }
}

/// One row of the derived inbox (data-model §5).
///
/// Borrows the issue rather than copying it: the snapshot the caller already
/// loaded is the source of truth (C-001), and a queue of 10,000 entries that
/// cloned its issues would hold a second, silently divergent copy of every title
/// and body. A consumer that wants more than these fields reads `issue`.
///
/// `last_decision` from data-model §5 is **not** here, and the reason is a
/// boundary rather than an omission: the triage History kinds that would answer
/// it are introduced by WP03 T016, and today's vocabulary has none. Deriving it
/// from the last event of *any* kind would report a `relationship_added` as the
/// queue's most recent decision.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct QueueEntry<'a> {
    /// The canonical issue this row describes.
    pub issue: &'a Issue,
    /// The stamp queue age is derived from, verbatim from WP01's
    /// [`crate::triage::entry_time`] — `Unknown` for a legacy issue, never
    /// substituted with `created` or `updated`.
    pub entered_at: EntryTime<'a>,
    /// Days between [`Self::entered_at`] and the supplied `today`; `None` when
    /// the entry has no stamp or a stamp this parser cannot read.
    ///
    /// `None`, never `0`: a missing stamp and "entered today" are different
    /// facts, and a zero that means "unknown" is how an unknown age becomes a
    /// confident one.
    pub age_days: Option<i64>,
}

/// One age bucket, in the order [`AGE_BUCKETS`] declares them.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct AgeBucket {
    /// The bucket's display label.
    pub label: &'static str,
    /// How many inbox entries fell in it.
    pub count: usize,
}

/// The age buckets, in presentation order, most recent first.
///
/// Presentation only (data-model §6: "presentation-friendly deterministic
/// data"). The boundaries are this module's choice and are not load-bearing:
/// every decision about an entry uses [`QueueEntry::age_days`], so a surface
/// that wants different buckets re-buckets the ages it already has rather than
/// asking for a second query.
pub const AGE_BUCKETS: [&str; 7] = ["today", "1-2", "3-6", "7-13", "14-29", "30+", "unknown"];

/// The bucket an age falls in, or `"unknown"` for an age nothing was recorded
/// for.
#[must_use]
pub fn age_bucket(age: Option<i64>) -> &'static str {
    match age {
        // `<= 0` rather than `== 0`: an entry stamped ahead of `today` is not
        // waiting a negative number of days, it is waiting to be looked at, and
        // splitting it into its own bucket would make the distribution depend
        // on a clock skew nobody asked about.
        Some(age) if age <= 0 => AGE_BUCKETS[0],
        Some(age) if age <= 2 => AGE_BUCKETS[1],
        Some(age) if age <= 6 => AGE_BUCKETS[2],
        Some(age) if age <= 13 => AGE_BUCKETS[3],
        Some(age) if age <= 29 => AGE_BUCKETS[4],
        Some(_) => AGE_BUCKETS[5],
        None => AGE_BUCKETS[6],
    }
}

/// The derived inbox summary (data-model §6).
///
/// Every field is a count over **one** pass of one snapshot (NFR-001): the
/// numbers agree with each other by construction because they are accumulated
/// together, not reconciled afterwards.
///
/// The counts are independent facts, not a partition. `awaiting + deferred ==
/// total` when the section names a deferred column of its own, and `2 * total`
/// when it does not — WP01 makes `deferred_status` default to `entry_status`,
/// so a project with one inbox column has one column and no status to tell the
/// two apart. Reporting `deferred == total` there is the truth; reporting `0`
/// would claim nothing is deferred when the config says everything is.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct QueueMetrics<'a> {
    /// Inbox entries — issues whose status is a configured inbox column.
    pub total: usize,
    /// Entries in the entry column: awaiting a first decision.
    pub awaiting: usize,
    /// Entries in the deferred column (see the struct note on equality).
    pub deferred: usize,
    /// Entries already in the `completed` category while still in an inbox
    /// column — accepted, but not gone.
    ///
    /// A **staleness** count, and 0 on a correctly configured board: an
    /// accepted issue leaves the inbox, so a non-zero figure reports an issue
    /// the columns disagree about. The value comes from [`is_completed`], the
    /// crate's single definition of completion, so it cannot disagree with
    /// `tix mv` (C-002).
    pub accepted: usize,
    /// Entries already in the `canceled` category while still in an inbox
    /// column: declined, but not gone. Same staleness reading as
    /// [`Self::accepted`], judged by [`WorkflowCategory::Canceled`] rather than
    /// by a column name (WP01 T004: decline *is* a move to `canceled`).
    pub declined: usize,
    /// Entries that originate a `duplicates` edge — the #169 relation vocabulary
    /// rather than a status, because duplicate is a relation and never a column
    /// (C-006).
    pub duplicated: usize,
    /// Entries with no readable [`QueueEntry::entered_at`].
    pub unknown_age: usize,
    /// The age histogram, one entry per [`AGE_BUCKETS`] label, in order.
    ///
    /// Sums to [`Self::total`] — every entry lands in exactly one bucket,
    /// `unknown` included.
    pub age_distribution: Vec<AgeBucket>,
    /// The entries themselves, in snapshot order.
    ///
    /// Not re-sorted: [`crate::storage::Store::list`] fixes the order (sorted
    /// by relative filename), so the inbox agrees with `tix list` without a
    /// second ordering rule that could disagree with it.
    pub entries: Vec<QueueEntry<'a>>,
}

/// Days between an entry stamp and `today`, or `None` when either is unreadable.
///
/// The only age arithmetic in the crate, so two surfaces cannot compute two
/// answers from one pair of dates. Date math reuses
/// [`crate::sync::date_to_epoch_days`] rather than growing a second calendar
/// parser beside `model::civil_from_days`.
///
/// `entered_at` is an RFC 3339 instant (`2026-09-30T09:12:44Z`) while `today`
/// is the `YYYY-MM-DD` [`crate::model::today`] returns, so the instant is read
/// through its date prefix. An instant written without a readable date is an
/// **unknown** age, not a zero and not `updated` (research R4): the fallback
/// discipline WP01 established for a missing stamp holds for a malformed one
/// too.
#[must_use]
pub fn age_days(entered_at: EntryTime<'_>, today: &str) -> Option<i64> {
    let EntryTime::Recorded(at) = entered_at else {
        return None;
    };
    let entered = crate::sync::date_to_epoch_days(at.get(..10)?)?;
    let today = crate::sync::date_to_epoch_days(today.trim())?;
    Some(today - entered)
}

/// Derive the inbox from one snapshot of issues (T008, T009, NFR-001).
///
/// One `for` loop, one membership test, one age computation, one category
/// lookup per member — no nested `issues × issues` pass and no second walk of
/// `issues`.
///
/// `today` is a parameter, never [`crate::model::today()`]: a query is
/// deterministic for a supplied date (contract §Queue query), which is what
/// lets a test pin an age and what keeps a long-running board from reporting
/// two different ages for one issue in one frame.
#[must_use]
pub fn collect<'a>(issues: &'a [Issue], scope: &InboxScope, today: &str) -> QueueMetrics<'a> {
    let mut metrics = QueueMetrics {
        total: 0,
        awaiting: 0,
        deferred: 0,
        accepted: 0,
        declined: 0,
        duplicated: 0,
        unknown_age: 0,
        age_distribution: Vec::new(),
        entries: Vec::new(),
    };
    for issue in issues {
        if !scope.matches(issue) {
            continue;
        }
        let entered_at = entry_time(issue);
        let age = age_days(entered_at, today);
        if age.is_none() {
            metrics.unknown_age += 1;
        }
        if issue.status.is(&scope.entry_status) {
            metrics.awaiting += 1;
        }
        if issue.status.is(&scope.deferred_status) {
            metrics.deferred += 1;
        }
        // #183's own answers, in its own vocabulary. Neither branch names a
        // column: `accepted` is "complete" as the service defines it, and
        // `declined` is the `canceled` category WP01 made decline map to. Two
        // independent `if`s rather than one `else if`, so neither count depends
        // on the other having been evaluated first.
        if is_completed(issue, &scope.resolution) {
            metrics.accepted += 1;
        }
        if workflow::category_of(issue, &scope.resolution) == Some(WorkflowCategory::Canceled) {
            metrics.declined += 1;
        }
        if issue
            .relationships
            .iter()
            .any(|r| r.kind == RelationKind::Duplicates && r.from == issue.number)
        {
            metrics.duplicated += 1;
        }
        metrics.entries.push(QueueEntry {
            issue,
            entered_at,
            age_days: age,
        });
        metrics.total += 1;
    }

    // A local first: assigning through `metrics.age_distribution = ...` while
    // the same expression reads `metrics.entries` would hold both a mutable and
    // an immutable borrow of `metrics` at once.
    let distribution = AGE_BUCKETS
        .iter()
        .map(|label| AgeBucket {
            label,
            count: metrics
                .entries
                .iter()
                .filter(|entry| age_bucket(entry.age_days) == *label)
                .count(),
        })
        .collect();
    metrics.age_distribution = distribution;
    metrics
}

#[cfg(test)]
mod tests {
    #[allow(clippy::wildcard_imports)]
    use super::*;
    use crate::triage::record_entry;

    /// A board that declares every category, so `[triage]` can name a
    /// `canceled` column (WP01 T004's requirement) and a `completed` one.
    const BOARD: &str = r#"issues_dir = "docs/issues"

[kanban.default]
columns = ["triage", "todo", "in progress", "in review", "done", "wontfix"]
done_column = "done"
category_map = { triage = "backlog", todo = "unstarted", "in progress" = "active", "in review" = "active", done = "completed", wontfix = "canceled" }
"#;

    const TRIAGE: &str = "[triage]\nentry_status = \"triage\"\ndeclined_status = \"wontfix\"\n";

    fn config_with(section: &str) -> Config {
        toml::from_str(&format!("{BOARD}{section}")).expect("fixture is a well-formed tix.toml")
    }

    fn issue(number: u32, status: &str) -> Issue {
        let mut issue = Issue::parse(&format!(
            "---\nnumber: {number}\ntitle: \"Issue {number}\"\nstatus: {status}\nlabels: []\n\
             priority: medium\nfiles: []\ncreated: 2026-01-01\nupdated: 2026-01-01\n---\n\nBody."
        ))
        .expect("the fixture parses");
        issue.filename = format!("2026-01-01-issue-{number}.md");
        issue
    }

    fn scope_of(config: &Config) -> InboxScope {
        scope(config)
            .expect("the fixture validates")
            .expect("the fixture configures a `[triage]` section")
    }

    // -- T007: resolve inbox scope ----------------------------------------

    #[test]
    fn triage_queue_scope_is_absent_without_a_triage_section() {
        // The default state of every legacy `tix.toml`: no inbox, and asking for
        // one is a named error rather than an empty board.
        let config = config_with("");
        assert_eq!(config.triage, None, "the fixture has no `[triage]`");
        assert_eq!(scope(&config).unwrap(), None);
        assert!(
            scope_columns(&config, "triage").is_err(),
            "a scope this project does not configure must be an error, not 0 rows"
        );
    }

    #[test]
    fn triage_queue_scope_resolves_entry_and_deferred_through_the_shared_resolver() {
        let config = config_with(TRIAGE);
        let scope = scope_of(&config);

        assert_eq!(scope.board, "default");
        assert_eq!(scope.entry_status, "triage");
        // WP01's default: no `deferred_status` key, so the entry column answers.
        assert_eq!(scope.deferred_status, "triage");
        assert_eq!(scope.columns, vec!["triage".to_string()]);
        assert_eq!(
            scope.resolution.resolve("triage"),
            Some(WorkflowCategory::Backlog),
            "the scope carries #183's answer, not this module's"
        );
    }

    #[test]
    fn triage_queue_scope_membership_is_column_membership() {
        let config = config_with(&format!("{TRIAGE}deferred_status = \"todo\"\n"));
        let scope = scope_of(&config);
        assert_eq!(
            scope.columns,
            vec!["triage".to_string(), "todo".to_string()],
            "both inbox columns, deduplicated, in board order"
        );

        assert!(scope.matches(&issue(1, "triage")), "entry column");
        assert!(scope.matches(&issue(2, "todo")), "deferred column");
        assert!(
            !scope.matches(&issue(3, "in review")),
            "not an inbox column"
        );
        assert!(!scope.matches(&issue(4, "wontfix")), "declined has left");
        assert!(!scope.matches(&issue(5, "done")), "accepted has left");
    }

    #[test]
    fn triage_queue_scope_unknown_name_is_refused_by_name() {
        let config = config_with(TRIAGE);
        let err = scope_columns(&config, "backlog").unwrap_err().to_string();
        assert!(err.contains("unknown scope `backlog`"), "{err}");
        assert!(
            err.contains("triage"),
            "the error names what would have worked: {err}"
        );
    }

    #[test]
    fn triage_queue_scope_of_a_hand_built_config_is_still_validated() {
        // `scope:` runs against whatever `Config` the caller holds, not only
        // against one that came through `Config::load_with_warning` — so a
        // section naming a column the board does not have is refused here too,
        // with WP01's own message rather than a second one.
        let config =
            config_with("[triage]\nentry_status = \"nope\"\ndeclined_status = \"wontfix\"\n");
        let err = scope(&config).unwrap_err().to_string();
        assert!(err.contains("unknown_column"), "{err}");
        assert!(err.contains("`[triage].entry_status`"), "{err}");
        assert!(
            err.contains("triage, todo"),
            "and the board's column list: {err}"
        );
    }

    // -- T008: one-pass entries and age ------------------------------------

    #[test]
    fn triage_queue_age_is_entry_stamp_against_the_supplied_today() {
        let mut entry = issue(1, "triage");
        record_entry(&mut entry, "2026-09-20T09:12:44Z", None);
        let scope = scope_of(&config_with(TRIAGE));

        let metrics = collect(std::slice::from_ref(&entry), &scope, "2026-09-30");
        assert_eq!(metrics.total, 1);
        assert_eq!(metrics.entries[0].age_days, Some(10), "ten days, not nine");
        assert_eq!(age_bucket(Some(10)), "7-13");
        assert_eq!(metrics.unknown_age, 0);
    }

    #[test]
    fn triage_queue_age_is_deterministic_for_the_date_it_is_given() {
        let mut entry = issue(1, "triage");
        record_entry(&mut entry, "2026-09-20T09:12:44Z", None);
        let scope = scope_of(&config_with(TRIAGE));
        let one = collect(std::slice::from_ref(&entry), &scope, "2026-09-30");
        let two = collect(std::slice::from_ref(&entry), &scope, "2026-09-30");
        let later = collect(std::slice::from_ref(&entry), &scope, "2026-10-02");

        assert_eq!(one, two, "same date, same answer — no wall-clock read");
        assert_eq!(
            later.entries[0].age_days,
            Some(12),
            "a later date, more days"
        );
    }

    #[test]
    fn triage_queue_legacy_entry_has_an_unknown_age_never_a_substitute() {
        // The fixture carries `created` and `updated` of 2026-01-01 — nine
        // months before the `today` below. Using either would report a wait the
        // issue never served (research R4).
        let legacy = issue(1, "triage");
        let scope = scope_of(&config_with(TRIAGE));

        let metrics = collect(std::slice::from_ref(&legacy), &scope, "2026-09-30");
        assert_eq!(metrics.total, 1, "a legacy issue is still in the inbox");
        assert_eq!(
            metrics.entries[0].age_days, None,
            "unknown, and specifically not the 272 days `updated` would imply"
        );
        assert_eq!(metrics.unknown_age, 1);
        assert_eq!(age_bucket(None), "unknown");
    }

    #[test]
    fn triage_queue_an_unreadable_stamp_is_unknown_rather_than_zero() {
        let mut malformed = issue(1, "triage");
        malformed.entered_at = Some("not a date".to_string());
        let scope = scope_of(&config_with(TRIAGE));

        let metrics = collect(std::slice::from_ref(&malformed), &scope, "2026-09-30");
        assert_eq!(metrics.entries[0].age_days, None, "not Some(0)");
        assert_eq!(metrics.unknown_age, 1, "and counted as unknown");
    }

    // -- T009: counts and stable order -------------------------------------

    #[test]
    fn triage_queue_counts_split_the_inbox_by_its_two_columns() {
        let config = config_with(&format!("{TRIAGE}deferred_status = \"todo\"\n"));
        let scope = scope_of(&config);
        let issues = vec![
            issue(1, "triage"),
            issue(2, "triage"),
            issue(3, "todo"),
            issue(4, "in review"),
        ];

        let metrics = collect(&issues, &scope, "2026-09-30");
        assert_eq!(metrics.total, 3, "the `in review` row is not in the inbox");
        assert_eq!(metrics.awaiting, 2, "two in the entry column");
        assert_eq!(metrics.deferred, 1, "one in the deferred column");
        assert_eq!(
            metrics.awaiting + metrics.deferred,
            metrics.total,
            "and with a distinct deferred column the two counts partition it"
        );
        assert_eq!(metrics.accepted, 0, "nobody has been decided yet");
        assert_eq!(metrics.declined, 0);
        assert_eq!(metrics.duplicated, 0);
        assert_eq!(
            metrics.unknown_age, 3,
            "no fixture issue carries an `entered_at`, so no fixture issue has an age"
        );
    }

    #[test]
    fn triage_queue_a_single_column_inbox_reports_the_same_count_twice() {
        // WP01 defaults `deferred_status` to `entry_status`, so a project that
        // names no deferred column has one column and no status to tell the two
        // facts apart. `deferred == total` is the truth; `0` would claim
        // nothing is deferred when the config says everything is.
        let config = config_with(TRIAGE);
        let scope = scope_of(&config);
        assert_eq!(scope.entry_status, scope.deferred_status);

        let issues = vec![issue(1, "triage"), issue(2, "triage")];
        let metrics = collect(&issues, &scope, "2026-09-30");
        assert_eq!(metrics.total, 2);
        assert_eq!(metrics.awaiting, 2);
        assert_eq!(metrics.deferred, 2, "one column, two descriptions of it");
    }

    #[test]
    fn triage_queue_counts_follow_the_category_mapping_not_the_column_name() {
        // The board maps `done` → `completed` and `wontfix` → `canceled`. Put
        // an inbox column on each and the counts must follow the *mapping*: a
        // literal `"done"` here would report the `wontfix` column as accepted,
        // and a literal `"declined"` column name would not exist at all.
        let accepted_scope = scope_of(&config_with(
            "[triage]\nentry_status = \"done\"\ndeclined_status = \"wontfix\"\n",
        ));
        let in_accepted = vec![issue(1, "done")];
        let metrics = collect(&in_accepted, &accepted_scope, "2026-09-30");
        assert_eq!(metrics.total, 1);
        assert_eq!(metrics.accepted, 1, "`done` is complete, via #183");
        assert_eq!(metrics.declined, 0, "complete is not canceled");

        let declined_scope = scope_of(&config_with(
            "[triage]\nentry_status = \"wontfix\"\ndeclined_status = \"wontfix\"\n",
        ));
        let in_declined = vec![issue(2, "wontfix")];
        let metrics = collect(&in_declined, &declined_scope, "2026-09-30");
        assert_eq!(metrics.total, 1);
        assert_eq!(metrics.declined, 1, "canceled, via #183");
        assert_eq!(
            metrics.accepted, 0,
            "canceled is terminal and never complete (C-003)"
        );
    }

    #[test]
    fn triage_queue_duplicate_is_counted_from_the_relation_vocabulary() {
        let config = config_with(TRIAGE);
        let scope = scope_of(&config);

        let mut duplicate = issue(1, "triage");
        duplicate
            .relationships
            .push(crate::relationships::Relationship::new(
                1,
                99,
                RelationKind::Duplicates,
                "Canonical",
            ));
        let mut blocked = issue(2, "triage");
        blocked
            .relationships
            .push(crate::relationships::Relationship::new(
                2,
                98,
                RelationKind::Blocks,
                "Something else",
            ));
        let plain = issue(3, "triage");
        let all = [duplicate, blocked, plain];

        let metrics = collect(&all, &scope, "2026-09-30");
        assert_eq!(metrics.total, 3, "relations do not change membership");
        assert_eq!(
            metrics.duplicated, 1,
            "only the `duplicates` edge counts, and only from its origin"
        );
    }

    #[test]
    fn triage_queue_entries_keep_the_snapshot_order() {
        // `Store::list` sorts by filename; `collect` must not re-sort, or the
        // inbox and `tix list` would disagree about which row is first.
        let issues: Vec<Issue> = [3, 1, 2].iter().map(|n| issue(*n, "triage")).collect();
        let scope = scope_of(&config_with(TRIAGE));
        let metrics = collect(&issues, &scope, "2026-09-30");

        assert_eq!(
            metrics
                .entries
                .iter()
                .map(|e| e.issue.number)
                .collect::<Vec<_>>(),
            vec![3, 1, 2],
            "input order, unchanged"
        );
    }

    #[test]
    fn triage_queue_age_distribution_sums_to_the_total() {
        // Anti-vacuity: a histogram of zeros would satisfy any per-bucket
        // assertion, so the invariant checked is the one that cannot hold if an
        // entry were dropped on the way in.
        let scope = scope_of(&config_with(TRIAGE));
        let mut issues = Vec::new();
        for (n, age) in [(1u32, 0i64), (2, 1), (3, 5), (4, 12), (5, 25)] {
            let mut entry = issue(n, "triage");
            record_entry(
                &mut entry,
                &format!("2026-09-{:02}T00:00:00Z", 30 - age),
                None,
            );
            issues.push(entry);
        }
        issues.push(issue(6, "triage")); // no stamp at all

        let metrics = collect(&issues, &scope, "2026-09-30");
        assert_eq!(metrics.total, 6);
        assert_eq!(metrics.unknown_age, 1);
        let sum: usize = metrics.age_distribution.iter().map(|b| b.count).sum();
        assert_eq!(
            sum, metrics.total,
            "every entry lands in exactly one bucket"
        );
        assert_eq!(
            metrics
                .age_distribution
                .iter()
                .map(|b| b.label)
                .collect::<Vec<_>>(),
            AGE_BUCKETS.to_vec(),
            "and in the declared order"
        );
        assert_eq!(metrics.age_distribution[0].count, 1, "the `today` bucket");
        assert_eq!(metrics.age_distribution[4].count, 1, "the `14-29` bucket");
        assert_eq!(metrics.age_distribution[6].count, 1, "the `unknown` bucket");
    }
}