import { isMap, parseDocument } from 'yaml';
import { DiagramType } from './detect';

export interface DiagramTemplate {
  /** File name under templates/. */
  file: string;
  type: DiagramType;
  label: string;
  description: string;
  /** Suggested name for the new file, without .archify. */
  defaultName: string;
}

export const TEMPLATES: readonly DiagramTemplate[] = [
  { file: 'architecture.archify', type: 'architecture', label: 'Architecture', description: 'Parts of a system and how they connect', defaultName: 'architecture' },
  { file: 'workflow.archify', type: 'workflow', label: 'Workflow', description: 'Steps of a process, in lanes', defaultName: 'workflow' },
  { file: 'sequence.archify', type: 'sequence', label: 'Sequence', description: 'Who calls whom, in order', defaultName: 'sequence' },
  { file: 'dataflow.archify', type: 'dataflow', label: 'Data Flow', description: 'Where data comes from and where it goes', defaultName: 'dataflow' },
  { file: 'lifecycle.archify', type: 'lifecycle', label: 'Lifecycle', description: 'States something moves through', defaultName: 'lifecycle' },
  { file: 'everyday-plan.archify', type: 'workflow', label: 'Everyday Plan', description: 'A plan or process from daily life', defaultName: 'plan' },
];

/** Strips a typed .archify suffix and surrounding spaces. */
export function diagramName(input: string): string {
  return input.trim().replace(/\.archify$/i, '').trim();
}

/** Why a name cannot be used as a file name, or undefined when it can. */
export function invalidNameReason(input: string): string | undefined {
  const name = diagramName(input);
  if (!name) return 'Enter a name.';
  if (/[\\/:*?"<>|\u0000-\u001f]/.test(name)) return 'A name cannot contain \\ / : * ? " < > | or control characters.';
  if (/^\.+$/.test(name)) return 'Enter a name.';
  return undefined;
}

/** "sales-report_v2" → "Sales report v2". */
export function titleFromName(name: string): string {
  const words = name.replace(/[-_.]+/g, ' ').replace(/\s+/g, ' ').trim();
  return words ? words.charAt(0).toUpperCase() + words.slice(1) : name;
}

/**
 * Template YAML with meta.title and meta.output set for the new file.
 * Works on the YAML document so the template's comments and layout stay.
 */
export function diagramFromTemplate(templateText: string, name: string): string {
  const doc = parseDocument(templateText);
  if (!isMap(doc.get('meta'))) doc.set('meta', doc.createNode({}));
  doc.setIn(['meta', 'title'], titleFromName(name));
  doc.setIn(['meta', 'output'], `${name}.html`);
  return doc.toString({ lineWidth: 0, flowCollectionPadding: false });
}