import { parseSkill } from './registry';

/**
 * Account-authored skills, as stored.
 *
 * A custom skill is its Markdown source and nothing else — the same artefact a
 * file in `src/skills/` is, read back by the same parser. These helpers exist so
 * the Add Skill dialog and the Skills page write that list identically; two
 * writers with two shapes would be a second skill system by accident.
 */

/** The starting definition offered to an author, in the existing format. */
export const skillTemplate = ({ id = '', name = '', description = '', pages = [] } = {}) => `---
id: ${id || 'my-skill'}
name: ${name || 'My Skill'}
description: ${description || 'What this skill helps Owliver do.'}
pages:
${(pages?.length ? pages : ['positions']).map((p) => `  - ${p}`).join('\n')}
status: active
triggers:
  - ${(name || 'my skill').toLowerCase()}
---

# ${name || 'My Skill'}

## Purpose

Describe what Owliver should help with on these pages.

## Capabilities

- Describe one thing the skill can do.
- Add more as needed.
`;

/** Parses a stored entry, tolerating the bare-string form. */
const sourceOf = (entry) => (typeof entry === 'string' ? entry : entry?.raw ?? '');

/**
 * The stored list with `source` added or replaced.
 *
 * Matching is by skill id, so editing a skill overwrites its own entry rather
 * than adding a near-duplicate beside it.
 */
export function upsertCustomSkill(existing = [], source) {
  const skill = parseSkill(source, { custom: true });
  const rest = existing.filter((entry) => {
    try {
      return parseSkill(sourceOf(entry), { custom: true }).id !== skill.id;
    } catch {
      return true;
    }
  });
  return { skill, next: [...rest, { path: `custom/${skill.id}.md`, raw: source }] };
}

/** The stored list without the skill of this id. */
export function removeCustomSkill(existing = [], id) {
  return existing.filter((entry) => {
    try {
      return parseSkill(sourceOf(entry), { custom: true }).id !== id;
    } catch {
      return true;
    }
  });
}

/** The stored Markdown for one custom skill, or null if the account has none. */
export function customSkillSource(existing = [], id) {
  for (const entry of existing) {
    try {
      if (parseSkill(sourceOf(entry), { custom: true }).id === id) return sourceOf(entry);
    } catch {
      /* An unparseable entry cannot be the one being edited. */
    }
  }
  return null;
}