// Every connector action, timestamped: kept in memory for the panel and
// appended to <dataDir>/actions.log as JSON lines, rotated at 1 MB (one old
// file kept as actions.log.1).

const fs = require("node:fs");
const path = require("node:path");

const KEEP = 500;
const ROTATE_BYTES = 1024 * 1024;

class ActionLog {
  constructor(dir, { onEntry } = {}) {
    this.file = path.join(dir, "actions.log");
    this.onEntry = typeof onEntry === "function" ? onEntry : null;
    this.entries = [];
    this.seq = 0;
    try {
      const lines = fs.readFileSync(this.file, "utf8").trim().split("\n").slice(-KEEP);
      for (const l of lines) { try { this.entries.push(JSON.parse(l)); } catch {} }
      this.seq = this.entries.reduce((m, e) => Math.max(m, Number(e.seq) || 0), 0);
    } catch {}
  }

  add(fields) {
    const entry = { seq: ++this.seq, ts: new Date().toISOString(), ...fields };
    this.entries.push(entry);
    if (this.entries.length > KEEP) this.entries.splice(0, this.entries.length - KEEP);
    try {
      try { if (fs.statSync(this.file).size > ROTATE_BYTES) fs.renameSync(this.file, this.file + ".1"); } catch {}
      fs.appendFileSync(this.file, JSON.stringify(entry) + "\n");
    } catch {}
    if (this.onEntry) { try { this.onEntry(entry); } catch {} }
    return entry;
  }

  recent(n = 200) { return this.entries.slice(-Math.max(1, Math.min(KEEP, n))); }

  clear() {
    this.entries = [];
    try { fs.rmSync(this.file, { force: true }); fs.rmSync(this.file + ".1", { force: true }); } catch {}
  }
}

// A short, safe description of a tool's arguments for the log. Typed and
// pasted content is logged by length and its first characters only.
function summarizeArgs(args) {
  const a = args && typeof args === "object" ? args : {};
  const out = [];
  const clip = (s, n) => { s = String(s); return s.length > n ? s.slice(0, n) + "…" : s; };
  for (const [k, v] of Object.entries(a)) {
    if (v == null || k === "tab_id") continue;
    if (k === "text" || k === "html" || k === "expression") {
      const s = String(v);
      out.push(`${k}: ${s.length} chars "${clip(s.replace(/\s+/g, " "), 60)}"`);
    } else if (typeof v === "object") out.push(`${k}: ${clip(JSON.stringify(v), 80)}`);
    else out.push(`${k}: ${clip(v, 120)}`);
  }
  return out.join(", ");
}

module.exports = { ActionLog, summarizeArgs };