import type { WizardPrompter } from '../prompter/interface.js';
import type { WizardState } from '../types.js';
import { loadSkillsCatalog } from '../skills/catalog.js';
import { SKILL_CATEGORIES, categorizeSkill } from '../skills/categories.js';

function truncate(str: string, max: number): string {
  if (str.length <= max) return str;
  return str.slice(0, max - 1) + '\u2026';
}

export async function skillsSelectStage(
  p: WizardPrompter,
  state: WizardState,
): Promise<void> {
  p.separator();

  const spin = p.spinner();
  spin.update('Loading skills catalog...');

  const catalog = loadSkillsCatalog(state.mosaicHome);
  spin.stop(`Found ${catalog.length} available skills`);

  if (catalog.length === 0) {
    p.warn(
      "No skills found. Run 'mosaic sync' after installation to fetch skills.",
    );
    state.selectedSkills = [];
    return;
  }

  if (state.mode === 'quick') {
    const defaults = catalog
      .filter((s) => s.recommended)
      .map((s) => s.name);
    state.selectedSkills = defaults;
    p.note(
      `Selected ${defaults.length} recommended skills.\n` +
        `Run 'mosaic sync' later to browse the full catalog.`,
      'Skills',
    );
    return;
  }

  // Advanced mode: categorized browsing
  p.note(
    'Skills give agents domain expertise for specific tasks.\n' +
      'Browse by category and select the ones you want.\n' +
      "You can always change this later with 'mosaic sync'.",
    'Skills Selection',
  );

  // Build grouped options
  const grouped: Record<
    string,
    { value: string; label: string; hint?: string; selected?: boolean }[]
  > = {};

  // Initialize all categories
  for (const categoryName of Object.keys(SKILL_CATEGORIES)) {
    grouped[categoryName] = [];
  }

  for (const skill of catalog) {
    const category = categorizeSkill(skill.name, skill.description);
    if (!grouped[category]) grouped[category] = [];
    grouped[category].push({
      value: skill.name,
      label: skill.name,
      hint: truncate(skill.description, 60),
      selected: skill.recommended,
    });
  }

  // Remove empty categories
  for (const key of Object.keys(grouped)) {
    if (grouped[key].length === 0) delete grouped[key];
  }

  state.selectedSkills = await p.groupMultiselect({
    message: 'Select skills (space to toggle)',
    options: grouped,
    required: false,
  });
}