/**
 * Builds a rich, readable "card" for a single Grok session: a plain-text body
 * (no MarkdownV2 so Windows paths and titles never need escaping) plus an
 * inline keyboard with Connect / History / Watch actions.
 *
 * Callback data is unchanged (`sess:` / `hist:` / `watch:` + UUID) so the
 * existing handlers in sessions.ts keep working.
 */
import { InlineKeyboard } from "grammy";
import { basename } from "node:path";
import { progressBar } from "../../render/progress.js";
import type { SessionMeta } from "../../sessions/types.js";
// Note: callers may pass `comment` from runtime or history (last-turn outcome).

export interface SessionCardExtras {
  /** Context-usage %, when the session is loaded in the current ACP process. */
  contextPct?: number;
  /**
   * PID of the bot's own `grok acp` process. A session locked by this PID
   * powers the bot itself, so its card omits the Kill button (killing it would
   * take the bot down). Other live sessions get a 🛑 Kill button.
   */
  selfPid?: number;
  /** Latest task-completion % (0–100) for this session, if this chat runs it. */
  progress?: number;
  /**
   * Last user prompt (and, when busy, last AI thinking on a second line).
   * Overrides `m.comment` when provided by the controlling chat runtime.
   */
  comment?: string;
}

export interface SessionCard {
  text: string;
  keyboard: InlineKeyboard;
}

const COMMENT_LINE_MAX = 250;

/** Build the card body + buttons for one session. */
export function buildSessionCard(m: SessionMeta, extra: SessionCardExtras = {}): SessionCard {
  const dot = m.active ? "\u{1F7E2}" : "\u26AA";
  const state = m.active ? `running${m.lockPid ? ` \u00B7 pid ${m.lockPid}` : ""}` : "idle";
  const proj = m.cwd ? basename(m.cwd) : "(no project)";
  const comment = (extra.comment || m.comment || "").trim();

  const lines = [`${dot} ${m.title}`, `\u{1F4C1} ${proj}`];
  if (m.cwd) lines.push(`   ${m.cwd}`);
  // Last user prompt always; second line = thinking while running.
  if (comment) {
    const busy = m.active || typeof extra.progress === "number";
    const parts = comment.split("\n").map((l) => l.trim()).filter(Boolean);
    parts.forEach((part, i) => {
      const clipped = part.length > COMMENT_LINE_MAX ? part.slice(0, COMMENT_LINE_MAX - 1) + "\u2026" : part;
      // First line: user prompt; later lines (thinking): hourglass when busy.
      const icon = i === 0 ? (busy ? "\u23F3" : "\u{1F4AC}") : "\u{1F9E0}";
      lines.push(`${icon} ${clipped}`);
    });
  }
  lines.push(`\u{1F552} updated ${relTime(m.updatedAt)} \u00B7 created ${relTime(m.createdAt)}`);
  const ctx = typeof extra.contextPct === "number" ? ` \u00B7 \u{1F9E0} ctx ${Math.round(extra.contextPct)}%` : "";
  lines.push(`\u{1F4CA} ${state} \u00B7 \u{1F4DC} history ${humanSize(m.historyBytes)}${ctx}`);
  if (typeof extra.progress === "number") lines.push(`\u{1F4C8} ${progressBar(extra.progress)}`);
  lines.push(`\u{1F194} ${m.sessionId.slice(0, 8)}`);

  const connect = m.active ? "\u{1F374} Continue (fork)" : "\u{1F517} Resume";
  const keyboard = new InlineKeyboard()
    .text(connect, `sess:${m.sessionId}`)
    .text("\u{1F4DC} History", `hist:${m.sessionId}`)
    .text("\u{1F4E1} Watch", `watch:${m.sessionId}`);

  // A live session running in another process can be terminated by PID. The
  // bot's own agent (selfPid) is never offered — killing it would stop the bot.
  if (m.active && typeof m.lockPid === "number" && m.lockPid !== extra.selfPid) {
    keyboard.row().text(`\u{1F6D1} Kill \u00B7 pid ${m.lockPid}`, `killsess:${m.sessionId}`);
  }

  return { text: lines.join("\n"), keyboard };
}

/** Compact relative time, e.g. "42s ago", "5m ago", "3h ago", "2d ago". */
export function relTime(iso: string): string {
  const t = Date.parse(iso);
  if (!Number.isFinite(t)) return "unknown";
  const s = Math.max(0, Math.round((Date.now() - t) / 1000));
  if (s < 60) return `${s}s ago`;
  const m = Math.floor(s / 60);
  if (m < 60) return `${m}m ago`;
  const h = Math.floor(m / 60);
  if (h < 24) return `${h}h ago`;
  const d = Math.floor(h / 24);
  return `${d}d ago`;
}

/** Human-readable byte size, e.g. "812 B", "42.3 KB", "1.2 MB". */
export function humanSize(bytes: number): string {
  if (!Number.isFinite(bytes) || bytes <= 0) return "0 B";
  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
  return `${(bytes / 1024 / 1024).toFixed(1)} MB`;
}