import { createHash } from 'crypto'
import type { PublishEnhanceSpec, PublishRewriteSpec, PublishTemplateId } from './types'
import { extractPublishImageUrls, isAllowedImageSrc, processNoteHtmlForPublish } from './process-note-html'

function esc(text: string): string {
  return text
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
}

function heroFigure(src: string): string {
  if (!isAllowedImageSrc(src)) return ''
  return `<figure class="pub-hero"><img src="${esc(src)}" alt="" class="pub-hero-img" loading="eager" decoding="async" /></figure>`
}

function galleryFigures(urls: string[]): string {
  const items = urls.map((src) => {
    if (!isAllowedImageSrc(src)) return ''
    return `<figure class="pub-gallery-item"><img src="${esc(src)}" alt="" class="pub-gallery-img" loading="lazy" decoding="async" /></figure>`
  }).filter(Boolean).join('')
  if (!items) return ''
  return `<div class="pub-gallery" aria-label="Images">${items}</div>`
}

function removeFirstImageFromHtml(html: string): string {
  return html.replace(/<figure[^>]*>[\s\S]*?<img[^>]*>[\s\S]*?<\/figure>|<img[^>]*>/i, '')
}

/* ─── Mode éditorial (texte original + habillage) ──────────────────────── */
export function renderPublishedTemplate(
  spec: PublishEnhanceSpec,
  template: PublishTemplateId,
  sourceHtml: string,
): string {
  const images = extractPublishImageUrls(sourceHtml)
  const bodySource = images[0] ? removeFirstImageFromHtml(sourceHtml) : sourceHtml
  const processedBody = processNoteHtmlForPublish(bodySource)
  const hero = images[0] ? heroFigure(images[0]) : ''
  const gallery = images.length > 1 ? galleryFigures(images.slice(1)) : ''

  const summary = esc(spec.summary)
  const pullQuote = spec.pullQuote
    ? `<blockquote class="pub-pull-quote"><p>${esc(spec.pullQuote)}</p></blockquote>`
    : ''
  const epigraph = spec.epigraph
    ? `<p class="pub-epigraph">${esc(spec.epigraph)}</p>`
    : ''
  const keyPoints = spec.keyPoints?.length
    ? `<div class="pub-key-points">
        <p class="pub-key-points-label">Points clés</p>
        <ul>${spec.keyPoints.map((k) => `<li>${esc(k)}</li>`).join('')}</ul>
      </div>`
    : ''

  const bodyBlock = `<div class="pub-body-source">${processedBody}</div>`

  if (template === 'brief') {
    return `<div class="pub-tpl pub-tpl-brief">
      ${hero}
      ${summary ? `<div class="pub-brief-lead"><p>${summary}</p></div>` : ''}
      ${keyPoints}
      ${bodyBlock}
      ${gallery}
    </div>`
  }

  if (template === 'essay') {
    return `<div class="pub-tpl pub-tpl-essay">
      ${hero}
      ${epigraph}
      ${summary ? `<p class="pub-essay-summary">${summary}</p>` : ''}
      ${bodyBlock}
      ${gallery}
    </div>`
  }

  return `<div class="pub-tpl pub-tpl-magazine">
    ${hero}
    ${summary ? `<p class="pub-magazine-dek">${summary}</p>` : ''}
    ${pullQuote}
    ${bodyBlock}
    ${gallery}
  </div>`
}

/* ─── Mode réécriture (HTML sémantique IA) ─────────────────────────────── */
export function renderRewrittenTemplate(
  spec: PublishRewriteSpec,
  template: PublishTemplateId,
  sourceHtml: string,
): string {
  const images = extractPublishImageUrls(sourceHtml)
  const hero = images[0] ? heroFigure(images[0]) : ''
  const gallery = images.length > 1 ? galleryFigures(images.slice(1)) : ''

  const summary = spec.summary
    ? `<p class="pub-rewrite-summary">${esc(spec.summary)}</p>`
    : ''

  const processedBody = processNoteHtmlForPublish(spec.body)

  return `<div class="pub-tpl pub-tpl-${template} pub-tpl-rewrite" data-content-type="${spec.contentType}">
    ${hero}
    ${summary}
    <div class="pub-rewrite-body">
      ${processedBody}
    </div>
    ${gallery}
  </div>`
}

export function computePublishedSourceHash(content: string): string {
  return createHash('sha256').update(content || '').digest('hex').slice(0, 16)
}