return typeof value === "number" && Number.isFinite(value) && value >= 0 ? value : undefined;

}

function resolveLatestCompactionCheckpoint(

type SessionCompactionCheckpointEntry = NonNullable<SessionEntry["compactionCheckpoints"]>[number];

function isProjectableCompactionCheckpoint(

value: unknown,

): value is SessionCompactionCheckpointEntry {

if (!value || typeof value !== "object" || Array.isArray(value)) {

return false;

}

const checkpoint = value as {

checkpointId?: unknown;

createdAt?: unknown;

reason?: unknown;

};

return (

Boolean(normalizeOptionalString(checkpoint.checkpointId)) &&

typeof checkpoint.createdAt === "number" &&

Number.isFinite(checkpoint.createdAt) &&

(checkpoint.reason === "manual" ||

checkpoint.reason === "auto-threshold" ||

checkpoint.reason === "overflow-retry" ||

checkpoint.reason === "timeout-retry")

);

}

function resolveProjectableCompactionCheckpoints(

entry?: Pick<SessionEntry, "compactionCheckpoints"> | null,

): NonNullable<SessionEntry["compactionCheckpoints"]>[number] | undefined {

): SessionCompactionCheckpointEntry[] {

const checkpoints = entry?.compactionCheckpoints;

if (!Array.isArray(checkpoints) || checkpoints.length === 0) {

return undefined;

return [];

}

return checkpoints.reduce((latest, checkpoint) =>

!latest || checkpoint.createdAt > latest.createdAt ? checkpoint : latest,

return checkpoints.filter(isProjectableCompactionCheckpoint);

}

function resolveLatestCompactionCheckpoint(

checkpoints: readonly SessionCompactionCheckpointEntry[],

): SessionCompactionCheckpointEntry | undefined {

return checkpoints.reduce<SessionCompactionCheckpointEntry | undefined>(

(latest, checkpoint) =>

!latest || checkpoint.createdAt > latest.createdAt ? checkpoint : latest,

undefined,

);

}

function buildCompactionCheckpointPreview(

checkpoint: NonNullable<SessionEntry["compactionCheckpoints"]>[number] | undefined,

checkpoint: SessionCompactionCheckpointEntry | undefined,

): GatewaySessionRow["latestCompactionCheckpoint"] {

if (!checkpoint) {

return undefined;

params.storeChildSessionsByKey.get(key),

)

: resolveChildSessionKeys(key, store, now, rowContext?.subagentRuns);

const compactionCheckpoints = resolveProjectableCompactionCheckpoints(entry);

const compactionCheckpointCount = Array.isArray(entry?.compactionCheckpoints)

? compactionCheckpoints.length

: undefined;

const latestCompactionCheckpoint = buildCompactionCheckpointPreview(

resolveLatestCompactionCheckpoint(entry),

resolveLatestCompactionCheckpoint(compactionCheckpoints),

);

const selectedOrRuntimeModelProvider = selectedModel?.provider ?? modelProvider;

const selectedOrRuntimeModel = selectedModel?.model ?? model;

lastTo: deliveryFields.lastTo ?? entry?.lastTo,

lastAccountId: deliveryFields.lastAccountId ?? entry?.lastAccountId,

lastThreadId: deliveryFields.lastThreadId ?? entry?.lastThreadId,

compactionCheckpointCount: entry?.compactionCheckpoints?.length,

compactionCheckpointCount,

latestCompactionCheckpoint,

pluginExtensions: pluginExtensions.length > 0 ? pluginExtensions : undefined,

};