type-bridge-contract 2.0.1

//! Canonical implementation-independent codec ceilings.

/// Maximum canonical artifact size: 16 MiB.
pub const MAX_CANONICAL_BYTES: usize = 16 * 1024 * 1024;
/// Maximum remote request/response envelope size: 32 MiB.
///
/// Remote envelopes embed a canonical plan plus invocation rows and framing,
/// so their owning-format budget is deliberately larger than the plan codec's
/// 16 MiB ceiling while remaining independently bounded.
pub const MAX_REMOTE_ENVELOPE_BYTES: usize = 32 * 1024 * 1024;
/// Maximum JSON nesting depth, counting the root as one.
pub const MAX_CANONICAL_DEPTH: usize = 64;
/// Maximum direct members in one array or object.
pub const MAX_CANONICAL_COLLECTION_LEN: usize = 65_536;
/// Maximum UTF-8 byte length of one string or object key: 1 MiB.
pub const MAX_CANONICAL_STRING_BYTES: usize = 1024 * 1024;

/// The complete canonical JSON structural limit set.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct CodecLimits {
    /// Maximum encoded or decoded bytes.
    pub max_bytes: usize,
    /// Maximum nested value depth.
    pub max_depth: usize,
    /// Maximum direct collection members.
    pub max_collection_len: usize,
    /// Maximum bytes in one string or key.
    pub max_string_bytes: usize,
}

impl CodecLimits {
    /// Canonical Phase 1 codec limits.
    pub const CANONICAL: Self = Self {
        max_bytes: MAX_CANONICAL_BYTES,
        max_depth: MAX_CANONICAL_DEPTH,
        max_collection_len: MAX_CANONICAL_COLLECTION_LEN,
        max_string_bytes: MAX_CANONICAL_STRING_BYTES,
    };
}

impl Default for CodecLimits {
    fn default() -> Self {
        Self::CANONICAL
    }
}

/// Canonical limits used by every contract codec consumer.
pub const CANONICAL_CODEC_LIMITS: CodecLimits = CodecLimits::CANONICAL;

/// Owning-format limits for V1 remote replies and capability advertisements.
pub const REMOTE_ENVELOPE_CODEC_LIMITS: CodecLimits = CodecLimits {
    max_bytes: MAX_REMOTE_ENVELOPE_BYTES,
    max_depth: MAX_CANONICAL_DEPTH,
    max_collection_len: MAX_CANONICAL_COLLECTION_LEN,
    max_string_bytes: MAX_CANONICAL_STRING_BYTES,
};

/// Owning-format limits for V1 remote query request envelopes.
///
/// A request embeds an independently canonical plan beneath exactly one
/// framing object. The extra level admits a standalone plan at the canonical
/// depth boundary without relaxing that plan's own revalidation or the limits
/// for replies and capability advertisements.
pub const REMOTE_REQUEST_CODEC_LIMITS: CodecLimits = CodecLimits {
    max_bytes: MAX_REMOTE_ENVELOPE_BYTES,
    max_depth: MAX_CANONICAL_DEPTH + 1,
    max_collection_len: MAX_CANONICAL_COLLECTION_LEN,
    max_string_bytes: MAX_CANONICAL_STRING_BYTES,
};

/// Maximum number of selected output slots in one typed plan.
pub const MAX_SELECTED_SLOTS: usize = 16;
/// Maximum number of bindings in one typed plan.
pub const MAX_BINDINGS: usize = 256;
/// Maximum number of nodes in one predicate tree.
pub const MAX_PREDICATE_NODES: usize = 4_096;
/// Maximum predicate nesting depth, counting a root as depth one.
pub const MAX_PREDICATE_DEPTH: usize = 64;
/// Maximum number of children in one boolean expression.
pub const MAX_BOOLEAN_TERMS: usize = 256;
/// Maximum number of explicitly allowed cross-join binding pairs.
pub const MAX_ALLOWED_CROSS_JOINS: usize = 1_024;
/// Maximum number of public row/root ordering terms.
pub const MAX_ORDER_TERMS: usize = 64;
/// Maximum number of ordering terms for one collected output slot.
pub const MAX_COLLECTION_ORDER_TERMS: usize = 64;
/// Maximum number of input rows in one typed invocation.
pub const MAX_INPUT_ROWS: usize = 4_096;
/// Maximum encoded bytes across one invocation's input-row batch: 4 MiB.
pub const MAX_INPUT_BYTES: usize = 4 * 1024 * 1024;
/// Maximum canonical bytes in one complete plan-bound query invocation.
///
/// The owning wire object adds 234 fixed bytes around the independently
/// bounded input-row batch: the `inputs` key, the longest operation spelling
/// (`exists`), and the fixed-domain query-plan fingerprint. Contract tests
/// construct an invocation whose input batch is exactly [`MAX_INPUT_BYTES`]
/// and prove that this ceiling is both attainable and one-byte tight.
pub const MAX_QUERY_INVOCATION_BYTES: usize = MAX_INPUT_BYTES + 234;
/// Maximum UTF-8 bytes in one output or query-variable name.
pub const MAX_OUTPUT_NAME_BYTES: usize = 128;
/// Maximum UTF-8 bytes in one serialized semantic identity.
pub const MAX_SEMANTIC_ID_BYTES: usize = 512;
/// Maximum bytes in one canonical serialized diagnostic.
pub const MAX_DIAGNOSTIC_BYTES: usize = 65_536;

/// Shared implementation-independent typed-plan structural ceilings.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct StructuralLimits {
    /// Selected output slots.
    pub selected_slots: usize,
    /// Plan bindings.
    pub bindings: usize,
    /// Total predicate nodes.
    pub predicate_nodes: usize,
    /// Predicate-tree depth.
    pub predicate_depth: usize,
    /// Children in one boolean expression.
    pub boolean_terms: usize,
    /// Explicitly allowed cross joins.
    pub allowed_cross_joins: usize,
    /// Public row/root ordering terms.
    pub order_terms: usize,
    /// Per-collection ordering terms.
    pub collection_order_terms: usize,
    /// Input rows in one invocation.
    pub input_rows: usize,
    /// Encoded bytes across one invocation's input rows.
    pub input_bytes: usize,
    /// Named output-slot UTF-8 bytes.
    pub output_name_bytes: usize,
    /// Semantic identity UTF-8 bytes.
    pub semantic_id_bytes: usize,
    /// Canonical diagnostic bytes.
    pub diagnostic_bytes: usize,
}

impl StructuralLimits {
    /// Canonical cross-language protocol limits.
    pub const CANONICAL: Self = Self {
        selected_slots: MAX_SELECTED_SLOTS,
        bindings: MAX_BINDINGS,
        predicate_nodes: MAX_PREDICATE_NODES,
        predicate_depth: MAX_PREDICATE_DEPTH,
        boolean_terms: MAX_BOOLEAN_TERMS,
        allowed_cross_joins: MAX_ALLOWED_CROSS_JOINS,
        order_terms: MAX_ORDER_TERMS,
        collection_order_terms: MAX_COLLECTION_ORDER_TERMS,
        input_rows: MAX_INPUT_ROWS,
        input_bytes: MAX_INPUT_BYTES,
        output_name_bytes: MAX_OUTPUT_NAME_BYTES,
        semantic_id_bytes: MAX_SEMANTIC_ID_BYTES,
        diagnostic_bytes: MAX_DIAGNOSTIC_BYTES,
    };

    /// Return whether `actual` fits the selected-slot ceiling.
    pub const fn allows_selected_slots(self, actual: usize) -> bool {
        actual <= self.selected_slots
    }

    /// Return whether `actual` fits the binding ceiling.
    pub const fn allows_bindings(self, actual: usize) -> bool {
        actual <= self.bindings
    }

    /// Return whether `actual` fits the invocation input-row ceiling.
    pub const fn allows_input_rows(self, actual: usize) -> bool {
        actual <= self.input_rows
    }

    /// Return whether `actual` fits the invocation input-byte ceiling.
    pub const fn allows_input_bytes(self, actual: usize) -> bool {
        actual <= self.input_bytes
    }

    /// Return whether `actual` fits the public ordering-term ceiling.
    pub const fn allows_order_terms(self, actual: usize) -> bool {
        actual <= self.order_terms
    }

    /// Return whether `actual` fits the predicate-node ceiling.
    pub const fn allows_predicate_nodes(self, actual: usize) -> bool {
        actual <= self.predicate_nodes
    }

    /// Return whether `actual` fits the predicate-depth ceiling.
    pub const fn allows_predicate_depth(self, actual: usize) -> bool {
        actual <= self.predicate_depth
    }

    /// Return whether `actual` fits the diagnostic-byte ceiling.
    pub const fn allows_diagnostic_bytes(self, actual: usize) -> bool {
        actual <= self.diagnostic_bytes
    }
}

impl Default for StructuralLimits {
    fn default() -> Self {
        Self::CANONICAL
    }
}

/// Canonical structural limits shared by V1 and V2 typed plans.
pub const CANONICAL_STRUCTURAL_LIMITS: StructuralLimits = StructuralLimits::CANONICAL;