// Glue for `type: prosekit` requirement fields (see AlternativeCard in
// src/app.rs) - mounts a headless ProseKit (ProseMirror) rich-text
// editor into a container element, then mirrors its rendered HTML into
// a paired hidden <input> on every change, firing a real `input` event
// on it. That lets the Rust side reuse the exact same RwSignal/on:input
// wiring every other requirement kind already goes through, instead of
// needing its own submit-time collection path.
//
// Loaded straight from a CDN as an ES module (no bundler in this
// project, same pattern as yes.js) - prosekit ships pre-bundled ESM,
// and re-exports the ProseMirror packages it's built on under
// `prosekit/pm/*`, so importing primitives (InputRule, etc.) from there
// instead of a separate prosemirror-* package guarantees they're the
// exact same module instance the editor itself uses.
//
// Least-verified part of this file (worth an actual hwatu pass after
// deploy, not just trusting the docs): the exact shape `createEditor`
// wants for `defaultContent` when seeding from an HTML string, and the
// precise `definePasteHandler` callback signature. Everything else here
// mirrors prosekit's own documented examples closely.

import 'https://esm.sh/prosekit/basic/style.css'
import 'https://esm.sh/prosekit/basic/typography.css'
import { defineBasicExtension } from 'https://esm.sh/prosekit/basic'
import {
  createEditor,
  defineNodeSpec,
  definePasteHandler,
  defineUpdateHandler,
  union,
} from 'https://esm.sh/prosekit/core'

// project.uhhm.no/<owner>/<repo>, no trailing path - a bare repo link,
// not a file/issue/PR link within one (those aren't "the repo", and
// trying to card-ify them too isn't what was asked for).
const GITEA_REPO_URL_RE = /^https:\/\/project\.uhhm\.no\/([\w.-]+)\/([\w.-]+)\/?$/

// Loads each stylesheet once regardless of how many editors this page
// mounts - <link> tags, not a JS import, since plain `import 'x.css'`
// isn't valid outside a bundler and esm.sh's CSS-as-JS support isn't
// worth depending on here.
function ensureStylesheet(href) {
  if (document.querySelector(`link[href="${href}"]`)) return
  const link = document.createElement('link')
  link.rel = 'stylesheet'
  link.href = href
  document.head.appendChild(link)
}

function defineGiteaRepoEmbed() {
  return defineNodeSpec({
    name: 'giteaRepoEmbed',
    group: 'block',
    atom: true,
    selectable: true,
    attrs: {
      owner: { default: '' },
      repo: { default: '' },
      description: { default: '' },
      url: { default: '' },
    },
    parseDOM: [
      {
        tag: 'div[data-gitea-repo]',
        getAttrs: (dom) => ({
          owner: dom.getAttribute('data-owner') || '',
          repo: dom.getAttribute('data-repo') || '',
          description: dom.getAttribute('data-description') || '',
          url: dom.getAttribute('data-url') || '',
        }),
      },
    ],
    // Plain inline styles, not a class - this same markup is what ends
    // up as the newsletter's HTML body, read by an email client with no
    // access to this app's stylesheet.
    toDOM: (node) => {
      const { owner, repo, description, url } = node.attrs
      return [
        'div',
        {
          'data-gitea-repo': 'true',
          'data-owner': owner,
          'data-repo': repo,
          'data-description': description,
          'data-url': url,
          style:
            'display:block;border:1px solid #ddd;border-radius:8px;' +
            'padding:12px 16px;margin:8px 0;font-family:inherit;',
        },
        [
          'a',
          { href: url, style: 'font-weight:600;text-decoration:none;color:inherit;' },
          `${owner}/${repo}`,
        ],
        ['div', { style: 'opacity:0.7;font-size:0.9em;margin-top:4px;' }, description],
      ]
    },
  })
}

// Resolves owner/repo via portal's own /gitea-repo handler
// (content::gitea_repo_handler in src/content.rs), not Gitea's API
// directly - keeps this editor from needing a CORS allowance on
// Gitea's side, and matches every other backing store in this app
// being server-resolved only.
async function resolveGiteaRepo(owner, repo) {
  const res = await fetch(
    `/gitea-repo?owner=${encodeURIComponent(owner)}&repo=${encodeURIComponent(repo)}`,
  )
  if (!res.ok) {
    throw new Error(`resolve_gitea_repo failed with status ${res.status}`)
  }
  return await res.json()
}

function defineGiteaRepoEmbedPasteRule() {
  return definePasteHandler((view, event) => {
    const text = event.clipboardData?.getData('text/plain')?.trim()
    const match = text && text.match(GITEA_REPO_URL_RE)
    if (!match) return false

    event.preventDefault()
    const [, owner, repo] = match
    const pos = view.state.selection.from

    resolveGiteaRepo(owner, repo)
      .then((info) => {
        const nodeType = view.state.schema.nodes.giteaRepoEmbed
        if (!nodeType) return
        const node = nodeType.create(info)
        const tr = view.state.tr.replaceRangeWith(pos, pos, node)
        view.dispatch(tr)
      })
      .catch((err) => {
        console.error('gitea repo embed failed', err)
      })
    return true
  })
}

export function mountEditor(container, hiddenInput, initial) {
  ensureStylesheet('https://esm.sh/prosekit/basic/style.css')
  ensureStylesheet('https://esm.sh/prosekit/basic/typography.css')

  const extension = union(
    defineBasicExtension(),
    defineGiteaRepoEmbed(),
    defineGiteaRepoEmbedPasteRule(),
  )

  const editor = createEditor({
    extension,
    // Seeds from the hidden input's current value (only ever non-empty
    // when re-mounting content that already went through this same
    // editor, since that's the only place this HTML shape comes from).
    defaultContent: initial || undefined,
  })

  const sync = () => {
    const html = editor.view.dom.innerHTML
    if (hiddenInput.value === html) return
    hiddenInput.value = html
    hiddenInput.dispatchEvent(new Event('input', { bubbles: true }))
  }

  editor.use(defineUpdateHandler(sync))
  editor.mount(container)
  sync()
}