fix: scope agent views to the selected machine (#3784)

* fix: scope agent views to the selected machine

refs #3732

* fix: preserve stable agent view ordering

refs #3732

---------

Co-authored-by: akbash-bot <300245827+akbash-bot@users.noreply.github.com>
Co-authored-by: JJ Liebig <jonathan.liebig@gmail.com>

1 files changed, 213 insertions, 0 deletions

diff --git a/src/agent_view_eval.rs b/src/agent_view_eval.rs
new file mode 100644
index 00000000..5d3fe844
--- /dev/null
+++ b/src/agent_view_eval.rs
@@ -0,0 +1,213 @@
+use std::borrow::Cow;
+use std::cmp::Ordering;
+
+use crate::api::schema::{
+    AgentViewBuiltinField, AgentViewBuiltinSortField, AgentViewField, AgentViewFilter,
+    AgentViewSort, AgentViewSortField, AgentViewSortOrder, AgentViewValue,
+};
+
+pub(crate) struct AgentViewContext {
+    pub(crate) scope: usize,
+    pub(crate) workspace_id: Option<String>,
+    pub(crate) tab_id: Option<String>,
+}
+
+pub(crate) trait AgentViewEntry {
+    fn scope(&self) -> usize;
+    fn status(&self) -> &'static str;
+    fn workspace_id(&self) -> Option<Cow<'_, str>>;
+    fn tab_id(&self) -> Option<Cow<'_, str>>;
+    fn pane_id(&self) -> Option<Cow<'_, str>>;
+    fn agent(&self) -> Option<&str>;
+    fn seen(&self) -> bool;
+    fn state_change_seq(&self) -> Option<u64>;
+    fn token(&self, token: &str) -> Option<&str>;
+    fn workspace_order(&self) -> Option<u64>;
+    fn tab_order(&self) -> Option<u64>;
+    fn pane_order(&self) -> Option<u64>;
+    fn attention(&self) -> u64;
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+enum EvalValue<'a> {
+    String(Cow<'a, str>),
+    ScopedId { scope: usize, value: Cow<'a, str> },
+    Bool(bool),
+    Number(u64),
+}
+
+pub(crate) fn matches_filter<E: AgentViewEntry + ?Sized>(
+    context: &AgentViewContext,
+    entry: &E,
+    filter: &AgentViewFilter,
+) -> bool {
+    match filter {
+        AgentViewFilter::All { filters } => filters
+            .iter()
+            .all(|filter| matches_filter(context, entry, filter)),
+        AgentViewFilter::Any { filters } => filters
+            .iter()
+            .any(|filter| matches_filter(context, entry, filter)),
+        AgentViewFilter::Not { filter } => !matches_filter(context, entry, filter),
+        AgentViewFilter::Eq { field, value } => {
+            field_value(entry, field) == operand_value(context, field, value)
+        }
+        AgentViewFilter::In { field, values } => {
+            let actual = field_value(entry, field);
+            values
+                .iter()
+                .any(|value| actual == operand_value(context, field, value))
+        }
+        AgentViewFilter::Exists { field } => field_value(entry, field).is_some(),
+    }
+}
+
+pub(crate) fn compare_entries<E: AgentViewEntry + ?Sized>(
+    left: &E,
+    right: &E,
+    sorts: &[AgentViewSort],
+) -> Ordering {
+    for sort in sorts {
+        let ordering = compare_optional_values(
+            sort_value(left, &sort.field),
+            sort_value(right, &sort.field),
+            sort.order,
+        );
+        if ordering != Ordering::Equal {
+            return ordering;
+        }
+    }
+    Ordering::Equal
+}
+
+fn field_value<'a, E: AgentViewEntry + ?Sized>(
+    entry: &'a E,
+    field: &AgentViewField,
+) -> Option<EvalValue<'a>> {
+    match field {
+        AgentViewField::Builtin(AgentViewBuiltinField::Status) => {
+            Some(EvalValue::String(Cow::Borrowed(entry.status())))
+        }
+        AgentViewField::Builtin(AgentViewBuiltinField::WorkspaceId) => {
+            entry.workspace_id().map(|value| EvalValue::ScopedId {
+                scope: entry.scope(),
+                value,
+            })
+        }
+        AgentViewField::Builtin(AgentViewBuiltinField::TabId) => {
+            entry.tab_id().map(|value| EvalValue::ScopedId {
+                scope: entry.scope(),
+                value,
+            })
+        }
+        AgentViewField::Builtin(AgentViewBuiltinField::PaneId) => {
+            entry.pane_id().map(|value| EvalValue::ScopedId {
+                scope: entry.scope(),
+                value,
+            })
+        }
+        AgentViewField::Builtin(AgentViewBuiltinField::Agent) => entry
+            .agent()
+            .map(|value| EvalValue::String(Cow::Borrowed(value))),
+        AgentViewField::Builtin(AgentViewBuiltinField::Seen) => Some(EvalValue::Bool(entry.seen())),
+        AgentViewField::Builtin(AgentViewBuiltinField::StateChangeSeq) => {
+            entry.state_change_seq().map(EvalValue::Number)
+        }
+        AgentViewField::Token { token } => entry
+            .token(token)
+            .map(|value| EvalValue::String(Cow::Borrowed(value))),
+    }
+}
+
+fn operand_value<'a>(
+    context: &'a AgentViewContext,
+    field: &AgentViewField,
+    value: &'a AgentViewValue,
+) -> Option<EvalValue<'a>> {
+    match value {
+        AgentViewValue::String(value) if is_id_field(field) => Some(EvalValue::ScopedId {
+            scope: context.scope,
+            value: Cow::Borrowed(value),
+        }),
+        AgentViewValue::String(value) => Some(EvalValue::String(Cow::Borrowed(value))),
+        AgentViewValue::Bool(value) => Some(EvalValue::Bool(*value)),
+        AgentViewValue::Number(value) => Some(EvalValue::Number(*value)),
+        AgentViewValue::Context {
+            context: view_context,
+        } => match view_context {
+            crate::api::schema::AgentViewContext::CurrentWorkspaceId => context
+                .workspace_id
+                .as_deref()
+                .map(|value| EvalValue::ScopedId {
+                    scope: context.scope,
+                    value: Cow::Borrowed(value),
+                }),
+            crate::api::schema::AgentViewContext::CurrentTabId => {
+                context.tab_id.as_deref().map(|value| EvalValue::ScopedId {
+                    scope: context.scope,
+                    value: Cow::Borrowed(value),
+                })
+            }
+        },
+    }
+}
+
+fn is_id_field(field: &AgentViewField) -> bool {
+    matches!(
+        field,
+        AgentViewField::Builtin(
+            AgentViewBuiltinField::WorkspaceId
+                | AgentViewBuiltinField::TabId
+                | AgentViewBuiltinField::PaneId
+        )
+    )
+}
+
+fn sort_value<'a, E: AgentViewEntry + ?Sized>(
+    entry: &'a E,
+    field: &AgentViewSortField,
+) -> Option<EvalValue<'a>> {
+    match field {
+        AgentViewSortField::Token { token } => entry
+            .token(token)
+            .map(|value| EvalValue::String(Cow::Borrowed(value))),
+        AgentViewSortField::Builtin(field) => match field {
+            AgentViewBuiltinSortField::WorkspaceOrder => {
+                entry.workspace_order().map(EvalValue::Number)
+            }
+            AgentViewBuiltinSortField::TabOrder => entry.tab_order().map(EvalValue::Number),
+            AgentViewBuiltinSortField::PaneOrder => entry.pane_order().map(EvalValue::Number),
+            AgentViewBuiltinSortField::Attention => Some(EvalValue::Number(entry.attention())),
+            AgentViewBuiltinSortField::Status => {
+                Some(EvalValue::String(Cow::Borrowed(entry.status())))
+            }
+            AgentViewBuiltinSortField::Agent => entry
+                .agent()
+                .map(|value| EvalValue::String(Cow::Borrowed(value))),
+            AgentViewBuiltinSortField::Seen => Some(EvalValue::Bool(entry.seen())),
+            AgentViewBuiltinSortField::StateChangeSeq => {
+                entry.state_change_seq().map(EvalValue::Number)
+            }
+        },
+    }
+}
+
+fn compare_optional_values(
+    left: Option<EvalValue<'_>>,
+    right: Option<EvalValue<'_>>,
+    order: AgentViewSortOrder,
+) -> Ordering {
+    match (left, right) {
+        (Some(left), Some(right)) => {
+            let ordering = left.cmp(&right);
+            if matches!(order, AgentViewSortOrder::Desc) {
+                ordering.reverse()
+            } else {
+                ordering
+            }
+        }
+        (Some(_), None) => Ordering::Less,
+        (None, Some(_)) => Ordering::Greater,
+        (None, None) => Ordering::Equal,
+    }
+}