/**
 * Shared constants and small utilities for pi-c2c.
 *
 * These are pure values or simple env-reading helpers used across multiple
 * modules (index.ts, tools.ts, commands.ts, debug.ts). Keeping them here
 * avoids circular imports.
 */

import { createRequire } from "node:module";
import * as os from "node:os";
import * as path from "node:path";
import type { RelayMessage } from "./c2c-cli.ts";
import type { C2cMessage } from "./c2c-cli.ts";

const requirePackageJson = createRequire(import.meta.url);
export const PI_C2C_VERSION = (requirePackageJson("../package.json") as { version?: string }).version ?? "unknown";

export const SPOOL_DIR = path.join(os.homedir(), ".pi", "c2c");
export const SPOOL_TTL_MS = 7 * 24 * 60 * 60 * 1000; // GC spool files older than a week

// Default to 5s. The pollTick drains 3 sources (per-repo, sessions, relay)
// and dedups + injects. At 5s, worst-case e2e latency is ~5s + ~1s drain =
// ~6s, down from the old 30s default which made relay messages routinely
// take 30-45s. C2C_PI_POLL_INTERVAL_MS overrides (min 1000ms) for power
// users; inotify push delivery is the next step (see task #35).
const DEFAULT_POLL_INTERVAL_MS = 5_000;

export function readPollInterval(): number {
  const raw = Number.parseInt(process.env.C2C_PI_POLL_INTERVAL_MS ?? "", 10);
  return Number.isFinite(raw) && raw >= 1000 ? raw : DEFAULT_POLL_INTERVAL_MS;
}

export function readStatusInterval(): number {
  const raw = Number.parseInt(process.env.C2C_PI_STATUS_INTERVAL_MS ?? "", 10);
  return Number.isFinite(raw) && raw >= 500 ? raw : 2_000;
}

export function readAutoJoinRooms(): string[] {
  return (process.env.C2C_PI_AUTO_JOIN_ROOMS ?? "")
    .split(",")
    .map((s) => s.trim())
    .filter(Boolean);
}

/**
 * Render the raw `collectDebugState` text as a small aligned table for
 * pi's `ctx.ui.notify`. The TUI strips trailing whitespace and may wrap
 * lines, so we deliberately keep it minimal: aligned two-column key/value
 * rows, no box-drawing characters, no right-side padding. Problems are
 * listed under a `--- problems ---` header with a remedy line per problem.
 */
export function formatDebugTable(raw: string): string {
  const KEY_WIDTH = 16;

  const lines: string[] = [];
  const problems: string[] = [];
  let inProblems = false;

  for (const line of raw.split("\n")) {
    if (line.startsWith("=== c2c pi debug ===")) continue;
    if (line.startsWith("=== problems ===")) {
      inProblems = true;
      continue;
    }
    if (inProblems) {
      problems.push(line);
      continue;
    }
    const m = line.match(/^([^:]+):\s*(.*)$/);
    if (!m) {
      if (line.length > 0) lines.push(line);
      continue;
    }
    const [, key, value] = m;
    lines.push(`${key.padEnd(KEY_WIDTH, " ")}  ${value}`);
  }

  let out = lines.join("\n");
  if (problems.length > 0) {
    out += "\n\n--- problems ---\n";
    out += problems.join("\n");
  }
  return out;
}

/** Type alias for the relay-to-c2c converter function. */
export type RelayToC2cFn = (msgs: RelayMessage[]) => C2cMessage[];

/**
 * Map a relay DM envelope (`fromAlias`/`toAlias`) into the broker DM shape
 * (`from_alias`/`to_alias`) so the rest of the drain pipeline is identical
 * to local broker messages — status filtering, dedup, spool, inject.
 */
export function relayToC2c(msgs: RelayMessage[]): C2cMessage[] {
  const out: C2cMessage[] = [];
  for (const m of msgs) {
    out.push({
      from_alias: m.fromAlias,
      to_alias: m.toAlias,
      content: m.content,
      ts: m.ts,
      source: "relay",
      kind: "dm",
    });
  }
  return out;
}