/**
 * Context garbage collection.
 *
 * The whole transcript is re-sent on every turn, so a tool result that has
 * become useless keeps costing tokens for the rest of the session. This pass
 * runs on the OUTGOING message copy (via the agent's `transformContext` hook),
 * never on the persisted session, and replaces provably-dead `read` results
 * with a short stub. Nothing is lost: the persisted history is untouched and
 * the file is re-readable on demand.
 *
 * Current rule — superseded reads only (the read-then-edit / re-read pattern,
 * which dominates coding sessions):
 *
 *   A `read` result for a path P is stale once, later in the transcript, the
 *   same path is edited/written (its on-disk content changed) or read again
 *   over an overlapping line range (the newer read reflects that region's newer
 *   state). Reads of disjoint regions of the same file coexist — a later read of
 *   lines 200-260 does not evict an earlier read of lines 1-40 — so paginating
 *   through a large file never makes the model re-fetch a region it already has.
 *   A read is only evicted when a *successful* later event supersedes it — so a
 *   read whose edit failed (and which the model still needs to retry) is never
 *   touched.
 *
 * Deliberately conservative: paths are matched after `path.resolve`, so two
 * different files never collide, and any ambiguity results in NOT evicting.
 *
 * This post-hoc pass is complemented by an at-call-time guard in the `read`
 * tool (see `tools/read-dedup.ts`), which short-circuits a redundant re-read
 * before it fetches. Both share the range math in that module, and this pass
 * skips the guard's pointer results so they never supersede the read they name.
 *
 * Bash-output eviction is additionally gated on token-budget pressure
 * (`options.budgetPressure`, the fraction of the model's context window in
 * use). At 0 pressure — the default — behaviour is identical to read-only GC.
 * Bash output is not always recoverable, so it carries its own safeguards: a
 * command that looks side-effecting is never elided (re-running it, as the
 * stub invites, could repeat a destructive action), and below 80% pressure
 * only large outputs are elided.
 */
import type { AgentMessage } from "@kolisachint/hoocode-agent-core";
export interface ContextGcOptions {
    /** Working directory used to resolve relative tool path arguments. */
    cwd: string;
    /**
     * Token-budget pressure in [0, 1] — the fraction of the model's context
     * window currently in use. Absent or 0 reproduces read-only GC behaviour.
     * Bash-output eviction begins at 0.6 and becomes unconditional at 0.8.
     */
    budgetPressure?: number;
}
/**
 * Return a message array with superseded `read` results stubbed out. Returns the
 * original array reference unchanged when there is nothing to evict, so a
 * no-op turn does not needlessly perturb the outgoing context.
 */
export declare function evictSupersededReads(messages: AgentMessage[], options: ContextGcOptions): AgentMessage[];
//# sourceMappingURL=context-gc.d.ts.map