/**
 * Edit log — append-only log of file mutations. Mirrors `edit_log.rs`.
 */

/** A single recorded file edit event. */
export interface EditLogEntry {
  /** Unix timestamp (ms) when the edit occurred. */
  ts: number;
  /** Name of the tool that performed the edit. */
  tool: string;
  /** Absolute file path that was modified. */
  path: string;
  /** Human-readable explanation of why the edit was made. */
  reason: string;
  /** SHA-256 hex digest of the content after the edit. */
  content_sha256: string;
  /** Signed byte count change (+added, -removed). */
  bytes_delta: number;
  /** Origin identifier (which agent / session context). */
  origin: string;
  /** Session in which this edit was performed. */
  session_id: string;
}

/** Maximum number of edit entries held in memory at once. */
export const MAX_MEMORY_ENTRIES = 10_000;

/** In-memory view of a session's edit log. */
export class EditLog {
  entries: EditLogEntry[];

  constructor() {
    this.entries = [];
  }

  /** Number of in-memory entries. */
  get length(): number {
    return this.entries.length;
  }

  /** Whether the log contains no entries. */
  get isEmpty(): boolean {
    return this.entries.length === 0;
  }

  /** Append an entry, evicting oldest beyond MAX_MEMORY_ENTRIES. */
  push(entry: EditLogEntry): void {
    this.entries.push(entry);
    if (this.entries.length > MAX_MEMORY_ENTRIES) {
      this.entries.shift();
    }
  }
}