/**
 * Shared workflow run model + formatting helpers, used by the tool renderers
 * (index.ts) and the /workflows dashboard (dashboard.ts).
 */

import * as os from "node:os";
import {
  truncateHead,
  type ExtensionContext,
} from "@earendil-works/pi-coding-agent";
import { formatContextUtilization } from "../shared/context-utilization.ts";
import { safeStringify } from "./serialization.ts";

export type Theme = ExtensionContext["ui"]["theme"];

export const RESULT_JSON_MAX_BYTES = 24 * 1024;
export const RESULT_JSON_MAX_LINES = 600;

export interface AgentUsage {
  input: number;
  output: number;
  cacheRead: number;
  cacheWrite: number;
  cost: number;
  /** Latest compaction-aware conversation occupancy, not cumulative billing. */
  contextTokens?: number;
  turns: number;
}

export function emptyUsage(): AgentUsage {
  return {
    input: 0,
    output: 0,
    cacheRead: 0,
    cacheWrite: 0,
    cost: 0,
    turns: 0,
  };
}

export type AgentState = "running" | "done" | "error";
export type WorkflowStatus = "running" | "completed" | "failed" | "aborted";

export type TranscriptRole =
  "user" | "assistant" | "thinking" | "tool" | "toolResult";

export interface TranscriptEntry {
  role: TranscriptRole;
  text: string;
  /** Tool name for tool calls/results. */
  name?: string;
  /** Stable tool-call identifier used to pair calls, results, and timings. */
  toolCallId?: string;
  isError?: boolean;
  /** Original message timestamp, when provided by the model/session. */
  timestamp?: number;
  /** Tool execution lifecycle timestamps, measured by the child session. */
  startedAt?: number;
  finishedAt?: number;
  durationMs?: number;
}

export interface AgentRecord {
  index: number;
  label: string;
  phase?: string;
  state: AgentState;
  model?: string;
  /** Context capacity of the active model used for this agent. */
  contextWindow?: number;
  startedAt: number;
  finishedAt?: number;
  error?: string;
  preview: string;
  usage: AgentUsage;
  /** Normalized, serializable subagent conversation shown by /workflows. */
  transcript: TranscriptEntry[];
}

export interface WorkflowDetails {
  runId: string;
  /** Pi session that launched this run. */
  sessionId?: string;
  name?: string;
  description?: string;
  background: boolean;
  status: WorkflowStatus;
  startedAt: number;
  finishedAt?: number;
  phases: { title: string; detail?: string }[];
  currentPhase?: string;
  agents: AgentRecord[];
  result?: unknown;
  resultArtifact?: string;
  transcriptArtifact?: string;
  error?: string;
}

/** Colored square state indicator (no emojis/glyphs). */
export const SQUARE = "■";

export function stateSquare(state: AgentState, theme: Theme): string {
  if (state === "done") return theme.fg("success", SQUARE);
  if (state === "error") return theme.fg("error", SQUARE);
  return theme.fg("warning", SQUARE);
}

export function statusSquare(status: WorkflowStatus, theme: Theme): string {
  if (status === "completed") return theme.fg("success", SQUARE);
  if (status === "running") return theme.fg("warning", SQUARE);
  return theme.fg("error", SQUARE);
}

export function statusWord(status: WorkflowStatus): string {
  return status === "completed" ? "done" : status;
}

export function statusColor(
  status: WorkflowStatus,
): "success" | "warning" | "error" {
  if (status === "completed") return "success";
  if (status === "running") return "warning";
  return "error";
}

export function shortenHome(p: string): string {
  const home = os.homedir();
  return p.startsWith(home) ? `~${p.slice(home.length)}` : p;
}

export function formatTokens(count: number): string {
  if (count < 1000) return count.toString();
  if (count < 10000) return `${(count / 1000).toFixed(1)}k`;
  if (count < 1000000) return `${Math.round(count / 1000)}k`;
  return `${(count / 1000000).toFixed(1)}M`;
}

export function formatUsage(usage: AgentUsage, model?: string): string {
  const parts: string[] = [];
  if (usage.turns)
    parts.push(`${usage.turns} turn${usage.turns > 1 ? "s" : ""}`);
  if (usage.input) parts.push(`${formatTokens(usage.input)} in`);
  if (usage.output) parts.push(`${formatTokens(usage.output)} out`);
  if (usage.cost) parts.push(`$${usage.cost.toFixed(4)}`);
  if (model) parts.push(model);
  return parts.join(" · ");
}

/** Current per-agent context-window utilization, e.g. "7%/372k". */
export function agentContext(agent: AgentRecord): string {
  return formatContextUtilization({
    tokens: agent.usage.contextTokens,
    contextWindow: agent.contextWindow,
  });
}

export function formatElapsed(startedAt: number, finishedAt?: number): string {
  const totalSeconds = Math.max(
    0,
    Math.round(((finishedAt ?? Date.now()) - startedAt) / 1000),
  );
  const minutes = Math.floor(totalSeconds / 60);
  const seconds = totalSeconds % 60;
  return minutes > 0
    ? `${minutes}m${seconds.toString().padStart(2, "0")}s`
    : `${seconds}s`;
}

export function aggregateUsage(agents: AgentRecord[]): AgentUsage {
  const total = emptyUsage();
  for (const agent of agents) {
    total.input += agent.usage.input;
    total.output += agent.usage.output;
    total.cacheRead += agent.usage.cacheRead;
    total.cacheWrite += agent.usage.cacheWrite;
    total.cost += agent.usage.cost;
    total.turns += agent.usage.turns;
  }
  return total;
}

export function countStates(details: WorkflowDetails) {
  let done = 0;
  let failed = 0;
  let running = 0;
  for (const agent of details.agents) {
    if (agent.state === "done") done++;
    else if (agent.state === "error") failed++;
    else running++;
  }
  return { done, failed, running };
}

export interface PhaseGroup {
  title: string;
  agents: AgentRecord[];
}

/**
 * Group agents by phase in declared phase order. With `includeEmpty`, phases
 * that have no agents yet are still listed (used by the dashboard sidebar).
 */
export function phaseGroups(
  details: WorkflowDetails,
  includeEmpty = false,
): PhaseGroup[] {
  const byPhase = new Map<string, AgentRecord[]>();
  for (const agent of details.agents) {
    const key = agent.phase ?? "(unphased)";
    const list = byPhase.get(key) ?? [];
    list.push(agent);
    byPhase.set(key, list);
  }
  const groups: PhaseGroup[] = [];
  for (const phase of details.phases) {
    const agents = byPhase.get(phase.title);
    if (agents || includeEmpty)
      groups.push({ title: phase.title, agents: agents ?? [] });
    byPhase.delete(phase.title);
  }
  for (const [title, agents] of byPhase) groups.push({ title, agents });
  return groups;
}

export function resultJson(value: unknown): string {
  const text =
    typeof value === "string"
      ? value
      : safeStringify(value, {
          maxBytes: RESULT_JSON_MAX_BYTES * 2,
          maxDepth: 16,
          maxNodes: 10_000,
        });
  const truncation = truncateHead(text ?? "", {
    maxLines: RESULT_JSON_MAX_LINES,
    maxBytes: RESULT_JSON_MAX_BYTES,
  });
  return truncation.truncated
    ? `${truncation.content}\n…[result truncated; bounded result artifact in result.json]`
    : truncation.content;
}