import { sanitizeDisplayText, truncateDisplayText } from "../../shared/display-text.ts";
import { formatModelThinking } from "../../shared/formatters.ts";
import { childThinkingLevel, type ThinkingLevel } from "../../shared/model-info.ts";
import type { AsyncJobState, AsyncJobStep, HostStepFreshness, HostStepMonitorKind, HostStepNode, HostStepState, HostStepVerdict, NestedRunSummary, NestedStepSummary, SubagentRunMode, WorkflowGraphSnapshot, WorkflowPreflightLane, WorkflowPreflight } from "../../shared/types.ts";
import { HOST_STEP_MAX_COUNT, HOST_STEP_MAX_DETAIL_CHARS, HOST_STEP_MAX_LABEL_CHARS, HOST_STEP_MAX_PROVIDER_CHARS, HOST_STEP_MAX_REASON_CHARS, HOST_STEP_MAX_REF_CHARS, HOST_STEP_MAX_ROLE_CHARS, HOST_STEP_MAX_TARGET_CHARS, hostStepReportName, parseHostStepNode, validHostStepNodes } from "./host-step-status.ts";
import { workflowPreflightLaneForRuntimeKey } from "../../workflows/workflow-preflight.ts";
import { workflowGraphStageNodes } from "./workflow-graph.ts";

export const ASYNC_STATUS_SNAPSHOT_KIND = "pi-subagents.async-status-snapshot";
export const ASYNC_STATUS_SNAPSHOT_VERSION = 1;

const DEFAULT_MAX_RUNS = 20;
const DEFAULT_MAX_CHILDREN_PER_NODE = 8;
const DEFAULT_MAX_DEPTH = 3;
const DEFAULT_MAX_STRING_LENGTH = 160;
const DEFAULT_MAX_SERIALIZED_BYTES = 32 * 1024;

export type AsyncStatusSnapshotState = "queued" | "running" | "complete" | "failed" | "partial" | "paused" | "stopped" | "rejected";
export type AsyncStatusSnapshotKind = "subagent" | "workflow" | "step";

const ASYNC_STATUS_SNAPSHOT_STATES: Record<AsyncStatusSnapshotState, true> = {
	queued: true,
	running: true,
	complete: true,
	failed: true,
	partial: true,
	paused: true,
	stopped: true,
	rejected: true,
};

function isAsyncStatusSnapshotState(value: string): value is AsyncStatusSnapshotState {
	return Object.hasOwn(ASYNC_STATUS_SNAPSHOT_STATES, value);
}

export interface AsyncStatusSnapshotActivity {
	state?: string;
	currentTool?: string;
	lastActivityAt?: number;
	currentToolStartedAt?: number;
	turnCount?: number;
	toolCount?: number;
}

export interface AsyncStatusSnapshotHostStep {
	kind: HostStepMonitorKind;
	provider?: string;
	role?: string;
	state: HostStepState;
	verdict?: HostStepVerdict;
	reasonCode?: string;
	detail?: string;
	target?: string;
	stale?: boolean;
	report?: string;
}

export interface AsyncStatusSnapshotNode {
	id: string;
	kind: AsyncStatusSnapshotKind | "host-step";
	label: string;
	state: AsyncStatusSnapshotState;
	startedAt?: number;
	updatedAt?: number;
	endedAt?: number;
	activity?: AsyncStatusSnapshotActivity;
	hostStep?: AsyncStatusSnapshotHostStep;
	children?: AsyncStatusSnapshotNode[];
}

export interface AsyncStatusSnapshotCaps {
	maxRuns: number;
	maxChildrenPerNode: number;
	maxDepth: number;
	maxStringLength: number;
	maxSerializedBytes: number;
}

export interface AsyncStatusSnapshotOmitted {
	runs: number;
	children: number;
	byteLimitExceeded: boolean;
}

export interface AsyncStatusSnapshot {
	kind: typeof ASYNC_STATUS_SNAPSHOT_KIND;
	version: typeof ASYNC_STATUS_SNAPSHOT_VERSION;
	generatedAt: number;
	caps: AsyncStatusSnapshotCaps;
	omitted: AsyncStatusSnapshotOmitted;
	runs: AsyncStatusSnapshotNode[];
}

export interface AsyncStatusSnapshotOptions {
	generatedAt?: number;
	maxRuns?: number;
	maxChildrenPerNode?: number;
	maxDepth?: number;
	maxStringLength?: number;
	maxSerializedBytes?: number;
}

export interface AsyncStatusWorkflowRow {
	name: string;
	state: AsyncJobStep["status"] | HostStepState | "planned";
	/** Present only for typed host-owned monitor rows; legacy child rows omit it. */
	kind?: HostStepMonitorKind;
	context?: AsyncJobStep["context"];
	modelThinking?: string;
	/** Thinking level of the child a child row stands for. */
	thinking?: ThinkingLevel;
	activity?: string;
	startedAt?: number;
	endedAt?: number;
	durationMs?: number;
	tokens?: number;
	window?: number;
	overflow?: number;
	provider?: string;
	role?: string;
	verdict?: HostStepVerdict;
	reasonCode?: string;
	detail?: string;
	target?: string;
	freshness?: HostStepFreshness;
	reportPath?: string;
	preflight?: WorkflowPreflightLane;
}

interface ProjectionContext {
	caps: AsyncStatusSnapshotCaps;
	omitted: AsyncStatusSnapshotOmitted;
}

function validHostStepList(source: readonly HostStepNode[] | WorkflowGraphSnapshot | undefined): HostStepNode[] {
	if (source && "nodes" in source) return validHostStepNodes(source);
	const hostSteps: HostStepNode[] = [];
	for (const [index, value] of (source ?? []).slice(0, HOST_STEP_MAX_COUNT).entries()) {
		try {
			hostSteps.push(parseHostStepNode(value, `hostSteps[${index}]`));
		} catch {
			// Renderers must not turn malformed host data into a fake child row.
		}
	}
	return hostSteps;
}

function resolveCaps(options: AsyncStatusSnapshotOptions): AsyncStatusSnapshotCaps {
	return {
		maxRuns: Math.max(0, Math.floor(options.maxRuns ?? DEFAULT_MAX_RUNS)),
		maxChildrenPerNode: Math.max(0, Math.floor(options.maxChildrenPerNode ?? DEFAULT_MAX_CHILDREN_PER_NODE)),
		maxDepth: Math.max(0, Math.floor(options.maxDepth ?? DEFAULT_MAX_DEPTH)),
		maxStringLength: Math.max(0, Math.floor(options.maxStringLength ?? DEFAULT_MAX_STRING_LENGTH)),
		maxSerializedBytes: Math.max(256, Math.floor(options.maxSerializedBytes ?? DEFAULT_MAX_SERIALIZED_BYTES)),
	};
}

function publicText(value: unknown, fallback: string, maxLength: number): string {
	if (typeof value !== "string") return fallback;
	const normalized = sanitizeDisplayText(value.slice(0, Math.max(0, maxLength * 4)));
	return truncateDisplayText(normalized || fallback, maxLength);
}

function publicOptionalText(value: unknown, maxLength: number): string | undefined {
	if (typeof value !== "string") return undefined;
	const normalized = sanitizeDisplayText(value.slice(0, Math.max(0, maxLength * 4)));
	return normalized ? truncateDisplayText(normalized, maxLength) : undefined;
}

function publicTime(value: unknown): number | undefined {
	return typeof value === "number" && Number.isSafeInteger(value) && value >= 0 ? value : undefined;
}

function publicCount(value: unknown): number | undefined {
	return typeof value === "number" && Number.isSafeInteger(value) && value >= 0 ? value : undefined;
}

function normalizeState(value: string): AsyncStatusSnapshotState {
	if (value === "completed") return "complete";
	if (value === "pending") return "queued";
	if (isAsyncStatusSnapshotState(value)) return value;
	return "partial";
}

function terminalState(state: AsyncStatusSnapshotState): boolean {
	return state === "complete" || state === "failed" || state === "partial" || state === "paused" || state === "stopped" || state === "rejected";
}

function kindForMode(mode: SubagentRunMode | undefined): AsyncStatusSnapshotKind {
	return mode === "workflow" ? "workflow" : "subagent";
}

function labelForAgents(agents: readonly string[] | undefined, fallback: string, maxLength: number): string {
	if (!agents?.length) return publicText(fallback, fallback, maxLength);
	const visible = agents.slice(0, 3).map((agent) => publicText(agent, "agent", maxLength)).join(", ");
	const suffix = agents.length > 3 ? `, +${agents.length - 3} more` : "";
	return truncateDisplayText(`${visible}${suffix}`, maxLength);
}

function activityFor(source: {
	activityState?: unknown;
	currentTool?: unknown;
	lastActivityAt?: unknown;
	currentToolStartedAt?: unknown;
	turnCount?: unknown;
	toolCount?: unknown;
}, ctx: ProjectionContext): AsyncStatusSnapshotActivity | undefined {
	const currentTool = publicOptionalText(source.currentTool, ctx.caps.maxStringLength);
	const lastActivityAt = publicTime(source.lastActivityAt);
	const currentToolStartedAt = publicTime(source.currentToolStartedAt);
	const turnCount = publicCount(source.turnCount);
	const toolCount = publicCount(source.toolCount);
	const activity: AsyncStatusSnapshotActivity = {
		...(typeof source.activityState === "string" ? { state: publicText(source.activityState, "unknown", ctx.caps.maxStringLength) } : {}),
		...(currentTool ? { currentTool } : {}),
		...(lastActivityAt !== undefined ? { lastActivityAt } : {}),
		...(currentToolStartedAt !== undefined ? { currentToolStartedAt } : {}),
		...(turnCount !== undefined ? { turnCount } : {}),
		...(toolCount !== undefined ? { toolCount } : {}),
	};
	return Object.keys(activity).length ? activity : undefined;
}

function appendBoundedChildren(children: AsyncStatusSnapshotNode[], source: readonly AsyncStatusSnapshotNode[], ctx: ProjectionContext): void {
	const remaining = Math.max(0, ctx.caps.maxChildrenPerNode - children.length);
	children.push(...source.slice(0, remaining));
	ctx.omitted.children += Math.max(0, source.length - remaining);
}

function stepIdentity(step: AsyncJobStep | NestedStepSummary, index: number, ctx: ProjectionContext) {
	return {
		id: publicText("workflowKey" in step && step.workflowKey ? step.workflowKey : "runId" in step && step.runId ? step.runId : `step:${index}`, `step:${index}`, ctx.caps.maxStringLength),
		label: publicText("label" in step && step.label ? step.label : step.agent, "step", ctx.caps.maxStringLength),
	};
}

function projectStep(step: AsyncJobStep | NestedStepSummary, index: number, depth: number, ctx: ProjectionContext): AsyncStatusSnapshotNode {
	const state = normalizeState(step.status);
	const startedAt = publicTime(step.startedAt);
	const durationMs = "durationMs" in step ? publicTime(step.durationMs) : undefined;
	const endedAt = publicTime(step.endedAt) ?? (terminalState(state) && startedAt !== undefined && durationMs !== undefined ? publicTime(startedAt + durationMs) : undefined);
	const updatedAt = endedAt ?? publicTime(step.lastActivityAt) ?? startedAt;
	const activity = activityFor(step, ctx);
	const { id, label } = stepIdentity(step, index, ctx);
	const node: AsyncStatusSnapshotNode = {
		id,
		kind: "step",
		label,
		state,
		...(startedAt !== undefined ? { startedAt } : {}),
		...(updatedAt !== undefined ? { updatedAt } : {}),
		...(terminalState(state) && endedAt !== undefined ? { endedAt } : {}),
		...(activity ? { activity } : {}),
	};
	if (depth < ctx.caps.maxDepth && step.children?.length) {
		const nested = step.children.map((child, childIndex) => projectNestedRun(child, childIndex, depth + 1, ctx));
		const bounded: AsyncStatusSnapshotNode[] = [];
		appendBoundedChildren(bounded, nested, ctx);
		if (bounded.length) node.children = bounded;
	} else if (step.children?.length) {
		ctx.omitted.children += step.children.length;
	}
	return node;
}

function projectNestedRun(child: NestedRunSummary, index: number, depth: number, ctx: ProjectionContext): AsyncStatusSnapshotNode {
	const state = normalizeState(child.state);
	const startedAt = publicTime(child.startedAt);
	const endedAt = publicTime(child.endedAt);
	const updatedAt = publicTime(child.lastUpdate) ?? endedAt ?? publicTime(child.lastActivityAt) ?? startedAt;
	const activity = activityFor(child, ctx);
	const node: AsyncStatusSnapshotNode = {
		id: publicText(child.id, `nested:${index}`, ctx.caps.maxStringLength),
		kind: kindForMode(child.mode),
		label: child.agent ? publicText(child.agent, "subagent", ctx.caps.maxStringLength) : labelForAgents(child.agents, child.mode ?? "subagent", ctx.caps.maxStringLength),
		state,
		...(startedAt !== undefined ? { startedAt } : {}),
		...(updatedAt !== undefined ? { updatedAt } : {}),
		...(terminalState(state) && endedAt !== undefined ? { endedAt } : {}),
		...(activity ? { activity } : {}),
	};
	if (depth < ctx.caps.maxDepth) {
		const nestedSteps = child.steps?.map((step, stepIndex) => projectStep(step, stepIndex, depth + 1, ctx)) ?? [];
		const nestedChildren = child.children?.map((nested, childIndex) => projectNestedRun(nested, childIndex, depth + 1, ctx)) ?? [];
		const bounded: AsyncStatusSnapshotNode[] = [];
		appendBoundedChildren(bounded, [...nestedSteps, ...nestedChildren], ctx);
		if (bounded.length) node.children = bounded;
	} else {
		ctx.omitted.children += (child.steps?.length ?? 0) + (child.children?.length ?? 0);
	}
	return node;
}

function hostStepSnapshotState(state: HostStepState, verdict: HostStepVerdict | undefined): AsyncStatusSnapshotState {
	if (state === "pending") return "queued";
	if (state === "running") return "running";
	if (state === "cancelled") return "stopped";
	if (state === "error" || verdict === "fail") return "failed";
	return verdict === undefined || verdict === "inconclusive" ? "partial" : "complete";
}

function projectHostStep(hostStep: HostStepNode, ctx: ProjectionContext): AsyncStatusSnapshotNode {
	const state = hostStepSnapshotState(hostStep.state, hostStep.verdict);
	const detail = publicOptionalText(hostStep.detail, ctx.caps.maxStringLength);
	const report = publicOptionalText(hostStepReportName(hostStep.reportPath), ctx.caps.maxStringLength);
	const hostMetadata: AsyncStatusSnapshotHostStep = {
		kind: hostStep.monitorKind,
		state: hostStep.state,
		...(hostStep.provider ? { provider: publicText(hostStep.provider, "provider", ctx.caps.maxStringLength) } : {}),
		...(hostStep.role ? { role: publicText(hostStep.role, "role", ctx.caps.maxStringLength) } : {}),
		...(hostStep.verdict ? { verdict: hostStep.verdict } : {}),
		...(hostStep.reasonCode ? { reasonCode: publicText(hostStep.reasonCode, "reason", ctx.caps.maxStringLength) } : {}),
		...(detail ? { detail } : {}),
		...(hostStep.target ? { target: publicText(hostStep.target, "target", ctx.caps.maxStringLength) } : {}),
		...(hostStep.freshness?.stale !== undefined ? { stale: hostStep.freshness.stale } : {}),
		...(report ? { report } : {}),
	};
	return {
		id: publicText(hostStep.id, "host-step", ctx.caps.maxStringLength),
		kind: "host-step",
		label: publicText(hostStep.label, "host step", ctx.caps.maxStringLength),
		state,
		updatedAt: hostStep.updatedAt,
		...(terminalState(state) ? { endedAt: hostStep.updatedAt } : {}),
		hostStep: hostMetadata,
	};
}

type MaterializedChildren = Map<string, AsyncJobState[]>;

function asyncJobOrder(left: AsyncJobState, right: AsyncJobState): number {
	const leftRank = left.status === "running" ? 0 : left.status === "queued" ? 1 : 2;
	const rightRank = right.status === "running" ? 0 : right.status === "queued" ? 1 : 2;
	const leftTime = left.updatedAt ?? left.startedAt ?? 0;
	const rightTime = right.updatedAt ?? right.startedAt ?? 0;
	return leftRank - rightRank || rightTime - leftTime || left.asyncId.localeCompare(right.asyncId);
}

function hasCyclicWorkflowParent(job: AsyncJobState, parents: ReadonlyMap<string, AsyncJobState>): boolean {
	const seen = new Set([job.asyncId]);
	let parentId = job.parentWorkflowRunId;
	while (parentId) {
		if (seen.has(parentId)) return true;
		seen.add(parentId);
		parentId = parents.get(parentId)?.parentWorkflowRunId;
	}
	return false;
}

function groupMaterializedChildren(jobs: readonly AsyncJobState[]) {
	const parents = new Map(jobs.filter((job) => job.mode === "workflow").map((job) => [job.asyncId, job]));
	const childrenByParent: MaterializedChildren = new Map();
	const liveRoots = new Set<AsyncJobState>();
	const roots: AsyncJobState[] = [];
	for (const job of jobs) {
		const parent = job.parentWorkflowRunId ? parents.get(job.parentWorkflowRunId) : undefined;
		const keepLiveRoot = (job.status === "running" || job.status === "queued") && parent?.status !== "running";
		if (parent && !hasCyclicWorkflowParent(job, parents)) {
			const siblings = childrenByParent.get(parent.asyncId) ?? [];
			siblings.push(job);
			childrenByParent.set(parent.asyncId, siblings);
			if (keepLiveRoot) {
				liveRoots.add(job);
				roots.push(job);
			}
		} else {
			roots.push(job);
		}
	}
	for (const children of childrenByParent.values()) children.sort(asyncJobOrder);
	return { roots, childrenByParent, liveRoots };
}

function assignMaterializedChildren(steps: readonly AsyncJobStep[], children: readonly AsyncJobState[]): Map<AsyncJobStep, AsyncJobState> {
	const assigned = new Map<AsyncJobStep, AsyncJobState>();
	const claimed = new Set<AsyncJobState>();
	for (const step of steps) {
		if (!step.runId) continue;
		const child = children.find((candidate) => !claimed.has(candidate) && candidate.asyncId === step.runId);
		if (child) {
			assigned.set(step, child);
			claimed.add(child);
		}
	}
	for (const step of steps) {
		if (assigned.has(step) || !step.workflowKey) continue;
		const child = children.find((candidate) => !claimed.has(candidate) && candidate.workflowKey === step.workflowKey);
		if (child) {
			assigned.set(step, child);
			claimed.add(child);
		}
	}
	return assigned;
}

function projectMaterializedStep(step: AsyncJobStep, index: number, child: AsyncJobState, depth: number, ctx: ProjectionContext, childrenByParent: MaterializedChildren, liveRoots: ReadonlySet<AsyncJobState>): AsyncStatusSnapshotNode {
	const { id, label } = stepIdentity(step, index, ctx);
	const selfStep = child.mode === undefined || child.mode === "single" ? child.steps?.[0] : undefined;
	const live = projectRun(child, ctx, depth, childrenByParent, liveRoots, selfStep !== undefined);
	const laneActivity = activityFor(step, ctx);
	const selfActivity = selfStep ? activityFor(selfStep, ctx) : undefined;
	const activity = laneActivity || selfActivity || live.activity ? { ...laneActivity, ...selfActivity, ...live.activity } : undefined;
	const node: AsyncStatusSnapshotNode = { ...live, id, kind: "step", label };
	if (activity) node.activity = activity;
	return node;
}

function projectRun(job: AsyncJobState, ctx: ProjectionContext, depth: number, childrenByParent: MaterializedChildren, liveRoots: ReadonlySet<AsyncJobState>, omitSteps = false): AsyncStatusSnapshotNode {
	const state = normalizeState(job.status);
	const startedAt = publicTime(job.startedAt);
	const updatedAt = publicTime(job.updatedAt) ?? startedAt;
	const activity = activityFor(job, ctx);
	const node: AsyncStatusSnapshotNode = {
		id: publicText(job.asyncId, "async", ctx.caps.maxStringLength),
		kind: kindForMode(job.mode),
		label: labelForAgents(job.agents, job.mode ?? "subagent", ctx.caps.maxStringLength),
		state,
		...(startedAt !== undefined ? { startedAt } : {}),
		...(updatedAt !== undefined ? { updatedAt } : {}),
		...(terminalState(state) && updatedAt !== undefined ? { endedAt: updatedAt } : {}),
		...(activity ? { activity } : {}),
	};
	const steps = omitSteps ? [] : job.steps ?? [];
	const materialized = childrenByParent.get(job.asyncId) ?? [];
	const nestedSummaries = (job.nestedChildren ?? []).filter((child) => !materialized.some((live) => live.asyncId === child.id));
	const loadedKeys = new Set(steps.flatMap((step) => step.workflowKey ? [step.workflowKey] : []));
	const graphStages = job.mode === "workflow" ? workflowGraphStageNodes(job.workflowGraph).filter((graphNode) => !loadedKeys.has(graphNode.id)) : [];
	const graphSteps = graphStages.map((node, index) => ({
		step: { agent: node.agent ?? node.label, status: workflowGraphStepStatus(node.status), workflowKey: node.id, label: node.label },
		index: node.flatIndex ?? index,
	}));
	const lanes = [...steps, ...graphSteps.map(({ step }) => step)];
	const assigned = assignMaterializedChildren(lanes, materialized);
	const claimed = new Set(assigned.values());
	if (depth < ctx.caps.maxDepth) {
		const childDepth = depth + 1;
		const projectLane = (step: AsyncJobStep, index: number): AsyncStatusSnapshotNode | undefined => {
			const child = assigned.get(step);
			if (!child) return projectStep(step, index, childDepth, ctx);
			if (liveRoots.has(child)) return undefined;
			return projectMaterializedStep(step, index, child, childDepth, ctx, childrenByParent, liveRoots);
		};
		const stepChildren = steps.map((step, index) => projectLane(step, step.index ?? index)).filter((child): child is AsyncStatusSnapshotNode => child !== undefined);
		const graphChildren = graphSteps.map(({ step, index }) => projectLane(step, index)).filter((child): child is AsyncStatusSnapshotNode => child !== undefined);
		const nestedChildren = nestedSummaries.map((child, index) => projectNestedRun(child, index, childDepth, ctx));
		const unclaimedChildren = materialized.filter((child) => !claimed.has(child) && !liveRoots.has(child)).map((child) => projectRun(child, ctx, childDepth, childrenByParent, liveRoots));
		const hostStepChildren = validHostStepList(job.hostSteps).map((hostStep) => projectHostStep(hostStep, ctx));
		const ordinaryChildren = [...stepChildren, ...graphChildren, ...nestedChildren, ...unclaimedChildren];
		const retainedHostSteps = hostStepChildren.slice(0, ctx.caps.maxChildrenPerNode);
		const retainedOrdinaryChildren = ordinaryChildren.slice(0, ctx.caps.maxChildrenPerNode - retainedHostSteps.length);
		const bounded: AsyncStatusSnapshotNode[] = [];
		bounded.push(...retainedOrdinaryChildren, ...retainedHostSteps);
		ctx.omitted.children += ordinaryChildren.length - retainedOrdinaryChildren.length + hostStepChildren.length - retainedHostSteps.length;
		if (bounded.length) node.children = bounded;
	} else {
		const rootAssignments = [...assigned.values()].filter((child) => liveRoots.has(child)).length;
		const unclaimedChildren = materialized.filter((child) => !claimed.has(child) && !liveRoots.has(child)).length;
		ctx.omitted.children += lanes.length - rootAssignments + nestedSummaries.length + unclaimedChildren + validHostStepList(job.hostSteps).length;
	}
	return node;
}

function snapshotBytes(snapshot: AsyncStatusSnapshot): number {
	return Buffer.byteLength(JSON.stringify(snapshot), "utf8");
}

function enforceByteLimit(snapshot: AsyncStatusSnapshot): void {
	if (snapshotBytes(snapshot) <= snapshot.caps.maxSerializedBytes) return;
	snapshot.omitted.byteLimitExceeded = true;
	const runs = snapshot.runs;
	const initialOmittedRuns = snapshot.omitted.runs;
	let lower = 0;
	let upper = Math.max(0, runs.length - 1);
	while (lower < upper) {
		const retained = Math.ceil((lower + upper) / 2);
		snapshot.runs = runs.slice(0, retained);
		snapshot.omitted.runs = initialOmittedRuns + runs.length - retained;
		if (snapshotBytes(snapshot) <= snapshot.caps.maxSerializedBytes) lower = retained;
		else upper = retained - 1;
	}
	snapshot.runs = runs.slice(0, lower);
	snapshot.omitted.runs = initialOmittedRuns + runs.length - lower;
}

function workflowStepActivity(step: AsyncJobStep): string | undefined {
	if (step.currentTool) return `tool ${step.currentTool}`;
	if (step.currentPath) return step.currentPath.split(/[\\/]/).at(-1);
	if (step.activityState === "needs_attention") return "needs attention";
	if (step.activityState === "active_long_running") return "long-running";
	if (step.turnCount !== undefined) return `${step.turnCount} turns`;
	if (step.toolCount !== undefined) return `${step.toolCount} tools`;
	return undefined;
}

function workflowStepName(step: AsyncJobStep, index: number): string {
	const key = step.workflowKey ?? `step ${index + 1}`;
	const label = step.label && step.label !== key ? ` · ${step.label}` : "";
	const phase = step.phase ? `${step.phase}: ` : "";
	return `${phase}${key}${label} (${step.agent})`;
}

function hostStepRow(hostStep: HostStepNode): AsyncStatusWorkflowRow {
	const freshness = hostStep.freshness
		? {
			expectedRef: publicText(hostStep.freshness.expectedRef, "ref", HOST_STEP_MAX_REF_CHARS),
			...(hostStep.freshness.observedRef ? { observedRef: publicText(hostStep.freshness.observedRef, "ref", HOST_STEP_MAX_REF_CHARS) } : {}),
			...(hostStep.freshness.stale !== undefined ? { stale: hostStep.freshness.stale } : {}),
		}
		: undefined;
	return {
		name: publicText(hostStep.label, "host step", HOST_STEP_MAX_LABEL_CHARS),
		kind: hostStep.monitorKind,
		state: hostStep.state,
		...(hostStep.role ? { role: publicText(hostStep.role, "role", HOST_STEP_MAX_ROLE_CHARS) } : {}),
		...(hostStep.provider ? { provider: publicText(hostStep.provider, "provider", HOST_STEP_MAX_PROVIDER_CHARS) } : {}),
		...(hostStep.verdict ? { verdict: hostStep.verdict } : {}),
		...(hostStep.reasonCode ? { reasonCode: publicText(hostStep.reasonCode, "reason", HOST_STEP_MAX_REASON_CHARS) } : {}),
		...(hostStep.detail ? { detail: publicText(hostStep.detail, "detail", HOST_STEP_MAX_DETAIL_CHARS) } : {}),
		...(hostStep.target ? { target: publicText(hostStep.target, "target", HOST_STEP_MAX_TARGET_CHARS) } : {}),
		...(freshness ? { freshness } : {}),
		...(hostStep.reportPath ? { reportPath: hostStepReportName(hostStep.reportPath) } : {}),
	};
}


function isWorkflowPreflight(value: readonly HostStepNode[] | WorkflowGraphSnapshot | WorkflowPreflight | undefined): value is WorkflowPreflight {
	return value !== undefined && !Array.isArray(value) && "lanes" in value;
}

function isWorkflowGraph(value: readonly HostStepNode[] | WorkflowGraphSnapshot | WorkflowPreflight | undefined): value is WorkflowGraphSnapshot {
	return value !== undefined && !Array.isArray(value) && "nodes" in value;
}

function workflowGraphRowState(status: WorkflowGraphSnapshot["nodes"][number]["status"]): AsyncStatusWorkflowRow["state"] {
	switch (status) {
		case "pending":
			return "planned";
		case "completed":
			return "complete";
		case "detached":
			return "paused";
		default:
			return status;
	}
}

function workflowGraphStepStatus(status: WorkflowGraphSnapshot["nodes"][number]["status"]): AsyncJobStep["status"] {
	switch (status) {
		case "completed":
			return "complete";
		case "detached":
			return "paused";
		default:
			return status;
	}
}

function workflowGraphRowName(node: WorkflowGraphSnapshot["nodes"][number]): string {
	const key = publicText(node.id, "stage", HOST_STEP_MAX_LABEL_CHARS);
	const label = publicOptionalText(node.label, HOST_STEP_MAX_LABEL_CHARS);
	const phase = publicOptionalText(node.phase, HOST_STEP_MAX_LABEL_CHARS);
	const agent = publicOptionalText(node.agent, HOST_STEP_MAX_LABEL_CHARS);
	return `${phase ? `${phase}: ` : ""}${key}${label && label !== node.id ? ` · ${label}` : ""}${agent ? ` (${agent})` : ""}`;
}

function projectWorkflowGraphRow(node: WorkflowGraphSnapshot["nodes"][number], preflight?: WorkflowPreflightLane): AsyncStatusWorkflowRow {
	return {
		name: workflowGraphRowName(node),
		state: workflowGraphRowState(node.status),
		...(preflight ? { preflight } : {}),
	};
}

/** Project authoritative workflow facts into compact rows, annotated by preflight hints. */
export function projectAsyncWorkflowRows(
	steps: readonly AsyncJobStep[] | undefined,
	hostStepsOrPreflight?: readonly HostStepNode[] | WorkflowGraphSnapshot | WorkflowPreflight,
	preflightOverride?: WorkflowPreflight,
): AsyncStatusWorkflowRow[] {
	const preflight = preflightOverride ?? (isWorkflowPreflight(hostStepsOrPreflight) ? hostStepsOrPreflight : undefined);
	const graph = isWorkflowGraph(hostStepsOrPreflight) ? hostStepsOrPreflight : undefined;
	const hostSteps = isWorkflowPreflight(hostStepsOrPreflight) || graph ? undefined : hostStepsOrPreflight;
	const loaded = steps ?? [];
	const preflightForKey = (key: string, groupKeys: readonly (string | undefined)[] = []): WorkflowPreflightLane | undefined =>
		workflowPreflightLaneForRuntimeKey(preflight, key, groupKeys);
	if (graph) {
		const loadedIndexesByKey = new Map<string, number[]>();
		for (const [index, step] of loaded.entries()) {
			if (!step.workflowKey) continue;
			const indexes = loadedIndexesByKey.get(step.workflowKey) ?? [];
			indexes.push(index);
			loadedIndexesByKey.set(step.workflowKey, indexes);
		}
		const consumed = new Set<number>();
		const childRows: AsyncStatusWorkflowRow[] = [];
		const graphStages = workflowGraphStageNodes(graph);
		const graphKeys = new Set(graphStages.map((node) => node.id));
		const graphPhaseByNodeId = new Map<string, string>();
		for (const phase of graph.phases) {
			for (const nodeId of phase.nodeIds) {
				if (graphKeys.has(nodeId) && !graphPhaseByNodeId.has(nodeId)) graphPhaseByNodeId.set(nodeId, phase.title);
			}
		}
		for (const node of graphStages) {
			const lane = preflightForKey(node.id, [node.phase, graphPhaseByNodeId.get(node.id)]);
			const indexes = (loadedIndexesByKey.get(node.id) ?? []).filter((index) => !consumed.has(index));
			if (indexes.length > 0) {
				for (const index of indexes) {
					consumed.add(index);
					childRows.push(projectLoadedWorkflowRow(loaded[index]!, index, lane));
				}
			} else {
				childRows.push(projectWorkflowGraphRow(node, lane));
			}
		}
		for (const [index, step] of loaded.entries()) {
			if (!consumed.has(index)) childRows.push(projectLoadedWorkflowRow(step, index, step.workflowKey ? preflightForKey(step.workflowKey, [step.phase]) : undefined));
		}
		return [...childRows, ...validHostStepList(graph).map(hostStepRow)];
	}
	return [
		...loaded.map((step, index) => projectLoadedWorkflowRow(step, index, step.workflowKey ? preflightForKey(step.workflowKey, [step.phase]) : undefined)),
		...validHostStepList(hostSteps).map(hostStepRow),
	];
}

function projectLoadedWorkflowRow(step: AsyncJobStep, index: number, preflight?: WorkflowPreflightLane): AsyncStatusWorkflowRow {
	const modelThinking = formatModelThinking(step.model, step.thinking) || undefined;
	const thinking = childThinkingLevel(step);
	const activity = workflowStepActivity(step);
	return {
		name: workflowStepName(step, index),
		state: step.status,
		...(step.context ? { context: step.context } : {}),
		...(modelThinking ? { modelThinking } : {}),
		...(thinking ? { thinking } : {}),
		...(activity ? { activity } : {}),
		...(step.startedAt !== undefined ? { startedAt: step.startedAt } : {}),
		...(step.endedAt !== undefined ? { endedAt: step.endedAt } : {}),
		...(step.durationMs !== undefined ? { durationMs: step.durationMs } : {}),
		...(step.tokens?.total !== undefined ? { tokens: step.tokens.total } : {}),
		...(step.tokens?.window !== undefined ? { window: step.tokens.window } : {}),
		...(preflight ? { preflight } : {}),
	};
}

/** Project already-loaded async status facts into the bounded public snapshot shape. */
export function projectAsyncStatusSnapshot(jobs: Iterable<AsyncJobState>, options: AsyncStatusSnapshotOptions = {}): AsyncStatusSnapshot {
	const caps = resolveCaps(options);
	const ctx: ProjectionContext = { caps, omitted: { runs: 0, children: 0, byteLimitExceeded: false } };
	const { roots, childrenByParent, liveRoots } = groupMaterializedChildren([...jobs]);
	const sorted = roots.sort(asyncJobOrder);
	ctx.omitted.runs += Math.max(0, sorted.length - caps.maxRuns);
	const snapshot: AsyncStatusSnapshot = {
		kind: ASYNC_STATUS_SNAPSHOT_KIND,
		version: ASYNC_STATUS_SNAPSHOT_VERSION,
		generatedAt: options.generatedAt ?? Date.now(),
		caps,
		omitted: ctx.omitted,
		runs: sorted.slice(0, caps.maxRuns).map((job) => projectRun(job, ctx, 0, childrenByParent, liveRoots)),
	};
	enforceByteLimit(snapshot);
	return snapshot;
}