export type Note = {
  id: string;
  text: string;
  x: number;
  y: number;
  author: string;
  color: string;
};

/** Shape accepted when writing a note; positional and color fields fall back to defaults. */
export type NoteInput = {
  id: string;
  text: string;
  author: string;
  x?: number;
  y?: number;
  color?: string;
  sourceMeta?: Record<string, unknown>;
};

export type Cluster = {
  label: string;
  noteIds: string[];
};

export type ClusterResponse = {
  clusters: Cluster[];
  score: number;
};

export type ValidationResult = {
  valid: boolean;
  reasons: string[];
};

/** noteId to embedding vector. */
export type EmbeddingMap = Map<string, number[]>;

const isStringArray = (value: unknown): value is string[] =>
  Array.isArray(value) && value.every((entry) => typeof entry === 'string');

/**
 * Runtime guard for LLM output, which arrives as parsed JSON of unknown shape.
 * Structural correctness beyond this (complete coverage, no duplicates) is the
 * job of validateStructure.
 */
export const isClusterArray = (value: unknown): value is Cluster[] => {
  if (!Array.isArray(value)) return false;

  return value.every((entry) => {
    if (typeof entry !== 'object' || entry === null) return false;
    const candidate = entry as Record<string, unknown>;
    return typeof candidate.label === 'string' && isStringArray(candidate.noteIds);
  });
};