/*
 * Veskslop daemon — persistent action log.
 *
 * Writes one JSON line per event: triggers, commands, replies, and errors.
 * The file rotates at a size limit. Secret-looking strings are redacted.
 */

import { appendFileSync, existsSync, mkdirSync, readFileSync, renameSync, statSync } from "node:fs";
import { dirname } from "node:path";

import { redactValue } from "./communication.js";

export const ACTION_LOG_MAX_BYTES = 5 * 1024 * 1024;

export class ActionLog {
    constructor(
        private readonly file = process.env.VESKSLOP_ACTION_LOG ?? ".veskslop-actions.jsonl",
        private readonly maxBytes = Number(process.env.VESKSLOP_ACTION_LOG_MAX_BYTES ?? ACTION_LOG_MAX_BYTES)
    ) {
        try {
            mkdirSync(dirname(this.file), { recursive: true });
        } catch {
            // the current directory works
        }
    }

    append(entry: Record<string, unknown> & { type: string }) {
        const line = JSON.stringify(redactValue({ timestamp: new Date().toISOString(), ...entry }));

        try {
            if (existsSync(this.file) && statSync(this.file).size + line.length + 1 > this.maxBytes) {
                renameSync(this.file, `${this.file}.1`);
            }
            appendFileSync(this.file, line + "\n");
        } catch (error) {
            console.error("[action-log] write failed:", error);
        }
    }

    read(limit = 100): unknown[] {
        try {
            if (!existsSync(this.file)) return [];
            const lines = readFileSync(this.file, "utf8").split("\n").filter(Boolean);
            return lines.slice(-limit).map(line => {
                try {
                    return JSON.parse(line);
                } catch {
                    return { type: "unparsed", line };
                }
            });
        } catch (error) {
            console.error("[action-log] read failed:", error);
            return [];
        }
    }
}