// 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.

// CSS is loaded via ensureStylesheet() (a <link> tag) inside
// mountEditor below, not a JS import - esm.sh serves these paths as a
// redirect to a real text/css response, which a plain `import 'x.css'`
// (no `with { type: 'css' }` assertion, which browsers don't uniformly
// support yet) fails to load as a module and aborts this entire file's
// evaluation. Confirmed the hard way: this is exactly what silently
// broke the first deploy of this file - mountEditor never got defined,
// so the visible editor container just stayed empty.
import { defineBasicExtension } from 'https://esm.sh/prosekit/basic'
import {
  createEditor,
  defineNodeSpec,
  definePasteHandler,
  defineUpdateHandler,
  toggleMark,
  toggleNode,
  union,
} from 'https://esm.sh/prosekit/core'

// Bold/italic/link are marks (toggleMark); headings are nodes
// (toggleNode) - both confirmed exports of prosekit/core, matching the
// same shape as the `defineMyBold` example in prosekit's own "Custom
// extensions" guide (`toggleBold: () => toggleMark({ type: 'bold' })`).
// A command is `(state, dispatch, view) => boolean`; toolbar buttons
// just call one directly rather than going through editor.commands,
// since the exact convenience-command names prosekit/basic exposes
// under `commands` aren't documented anywhere as precisely as this.
const TOOLBAR_BUTTONS = [
  { text: 'B', title: 'Bold', markType: 'bold', run: () => toggleMark({ type: 'bold' }) },
  { text: 'I', title: 'Italic', markType: 'italic', run: () => toggleMark({ type: 'italic' }) },
  {
    text: 'H1',
    title: 'Heading',
    nodeType: 'heading',
    nodeAttrs: { level: 1 },
    run: () => toggleNode({ type: 'heading', attrs: { level: 1 }, toggleType: 'paragraph' }),
  },
  {
    text: 'H2',
    title: 'Subheading',
    nodeType: 'heading',
    nodeAttrs: { level: 2 },
    run: () => toggleNode({ type: 'heading', attrs: { level: 2 }, toggleType: 'paragraph' }),
  },
  {
    text: 'Link',
    title: 'Link',
    markType: 'link',
    run: () => {
      const href = window.prompt('Link URL:')
      if (!href) return () => false
      return toggleMark({ type: 'link', attrs: { href } })
    },
  },
]

// 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:0.06em solid #ddd;border-radius:0.5em;' +
            'padding:0.75em 1em;margin:0.5em 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:0.9rem;margin-top:0.25em;' }, 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()
}

// Shared by the paste rule and the toolbar button below - resolves
// owner/repo, then inserts the embed at `pos` (captured before the
// async fetch, since the selection may have moved by the time it
// resolves).
function insertGiteaRepoEmbed(view, owner, repo, pos) {
  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)
    })
}

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
    insertGiteaRepoEmbed(view, owner, repo, view.state.selection.from)
    return true
  })
}

// Standard ProseMirror active-state check (same idiom
// prosemirror-example-setup's own menu uses): with a collapsed
// selection, look at stored/marks-at-cursor; otherwise check the
// whole range actually carries the mark.
function markActive(state, typeName) {
  const type = state.schema.marks[typeName]
  if (!type) return false
  const { from, to, empty } = state.selection
  if (empty) {
    return !!type.isInSet(state.storedMarks || state.selection.$from.marks())
  }
  return state.doc.rangeHasMark(from, to, type)
}

function nodeActive(state, typeName, attrs) {
  const type = state.schema.nodes[typeName]
  if (!type) return false
  const { $from } = state.selection
  for (let d = $from.depth; d >= 0; d--) {
    const node = $from.node(d)
    if (node.type === type) {
      return !attrs || Object.entries(attrs).every(([k, v]) => node.attrs[k] === v)
    }
  }
  return false
}

function buildToolbar(editor) {
  const bar = document.createElement('div')
  bar.className = 'prosekit-toolbar'

  const buttons = TOOLBAR_BUTTONS.map((spec) => {
    const button = document.createElement('button')
    button.type = 'button'
    button.textContent = spec.text
    button.title = spec.title
    // preventDefault on mousedown, not just handling click - a plain
    // click already lost the editor's selection to a focus change by
    // the time it fires, so a mark/node toggle would apply at the
    // wrong (collapsed) position.
    button.addEventListener('mousedown', (event) => {
      event.preventDefault()
      const { view } = editor
      try {
        spec.run()(view.state, view.dispatch, view)
      } catch (err) {
        console.error('toolbar command failed', spec.title, err)
      }
      view.focus()
    })
    bar.appendChild(button)
    return { button, spec }
  })

  const updateActiveStates = () => {
    const { state } = editor.view
    for (const { button, spec } of buttons) {
      const active = spec.markType
        ? markActive(state, spec.markType)
        : nodeActive(state, spec.nodeType, spec.nodeAttrs)
      button.classList.toggle('is-active', active)
    }
  }

  // Same embed the paste rule creates, but explicit - accepts either a
  // full project.uhhm.no URL or a bare "owner/repo" shorthand, so you
  // don't need an actual link on the clipboard to use it.
  const giteaButton = document.createElement('button')
  giteaButton.type = 'button'
  giteaButton.textContent = 'Repo'
  giteaButton.title = 'Link a Gitea project'
  giteaButton.addEventListener('mousedown', (event) => {
    event.preventDefault()
    const input = window.prompt('Gitea repo (owner/repo or a project.uhhm.no link):')
    if (!input) return
    const trimmed = input.trim()
    const urlMatch = trimmed.match(GITEA_REPO_URL_RE)
    const shorthandMatch = trimmed.match(/^([\w.-]+)\/([\w.-]+)$/)
    const match = urlMatch || shorthandMatch
    if (!match) {
      window.alert('Not a recognized owner/repo or project.uhhm.no URL.')
      return
    }
    const [, owner, repo] = match
    const { view } = editor
    insertGiteaRepoEmbed(view, owner, repo, view.state.selection.from)
    view.focus()
  })
  bar.appendChild(giteaButton)

  return { bar, updateActiveStates }
}

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 { bar, updateActiveStates } = buildToolbar(editor)
  const editorMount = document.createElement('div')
  editorMount.className = 'prosekit-editor'
  container.appendChild(bar)
  container.appendChild(editorMount)

  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()
      updateActiveStates()
    }),
  )
  editor.mount(editorMount)
  sync()
  updateActiveStates()
}