<template>
  <section v-if="show" class="fc-prov" aria-label="Provenance">
    <h3 class="fc-prov__title">Provenance</h3>

    <v-progress-circular
      v-if="state && state.loading" indeterminate color="accent" size="22"
    />
    <v-alert
      v-else-if="state && state.error" type="error" variant="tonal"
      density="compact"
    >{{ state.error }}</v-alert>

    <!-- Cards scroll independently of the section title + attachments
         below them. Cap at ~2.5 cards visible (operator-asked 2026-06-01:
         keeps the Tags section anchored below at a consistent position;
         the half-visible third card hints there's more). -->
    <div v-else class="fc-prov__cards">
      <article
        v-for="e in state.entries" :key="e.provenance_id" class="fc-prov__card"
      >
        <div class="fc-prov__head">
          <!-- Posts with no live subscription have source=null (alembic
               0030); render an explicit "filesystem import" affordance
               instead of a platform chip. -->
          <span class="fc-prov__platform">
            {{ e.source?.platform ?? 'filesystem import' }}
          </span>
          <span v-if="postDate(e)" class="fc-prov__date">{{ postDate(e) }}</span>
        </div>
        <button
          type="button" class="fc-prov__post"
          :title="`Open ${postTitle(e)} in the posts feed for ${e.artist.name}`"
          @click="openPost(e.post.id, e.artist.id)"
        >
          {{ postTitle(e) }}
        </button>
        <div class="fc-prov__meta">
          <RouterLink :to="`/artist/${e.artist.slug}`">
            by {{ e.artist.name }}
          </RouterLink>
          <span v-if="e.post.attachment_count != null">
            · {{ e.post.attachment_count }} files
          </span>
        </div>
        <div v-if="hasTranslation(e)" class="fc-prov__actions">
          <a
            href="#" @click.prevent="toggleOrig(e.provenance_id)"
          >{{ showOrig[e.provenance_id] ? 'Show translation' : `Show original${langLabel(e)}` }}</a>
        </div>
        <div v-if="e.post.description_html" class="fc-prov__actions">
          <a
            href="#" @click.prevent="toggleDesc(e.provenance_id)"
          >{{ expanded[e.provenance_id] ? 'Hide description ▴' : 'Show description ▾' }}</a>
        </div>
        <!-- Translated body = plain text; original = sanitized HTML (#143). -->
        <p
          v-if="showTranslated(e) && expanded[e.provenance_id] && e.post.description_translated"
          class="fc-prov__desc"
        >{{ e.post.description_translated }}</p>
        <div
          v-else-if="e.post.description_html && expanded[e.provenance_id]"
          class="fc-prov__desc" v-html="e.post.description_html"
        />
      </article>

      <!-- Fallback: image has artist_id set (folder-derived from
           filesystem import or set by tag_apply) but no ImageProvenance
           row exists. Show a minimal "by <artist>" line so the modal
           isn't blank for IR-imported images that aren't in any post. -->
      <article
        v-if="showArtistFallback"
        class="fc-prov__card"
      >
        <div class="fc-prov__meta">
          <RouterLink :to="`/artist/${fallbackArtist.slug}`">
            by {{ fallbackArtist.name }}
          </RouterLink>
        </div>
      </article>
    </div>

    <div v-if="attachments.length" class="fc-prov__attach">
      <h4 class="fc-prov__attach-title">
        {{ attachments.length === 1 ? 'Attachment' : `Attachments (${attachments.length})` }}
      </h4>
      <!-- Scroll-capped: a single post can carry dozens of archives (HR
           bundle posts), which previously ballooned the panel past the
           viewport. Mirror the cards' independent-scroll treatment. -->
      <div class="fc-prov__attach-list">
        <a
          v-for="at in attachments" :key="at.id"
          class="fc-prov__attach-row"
          :href="at.download_url" :download="at.original_filename"
        >⬇ {{ at.original_filename }}
          <span class="fc-prov__attach-size">({{ at.size_bytes }} B)</span>
        </a>
      </div>
    </div>
  </section>
</template>

<script setup>
import { computed, reactive, watch } from 'vue'
import { useRouter } from 'vue-router'
import { useModalStore } from '../../stores/modal.js'
import { useProvenanceStore } from '../../stores/provenance.js'
import { formatPostDate } from '../../utils/date.js'
import { toPlainText } from '../../utils/htmlSanitize.js'

// `imageId`/`image` let a non-modal surface (the Explore workspace) render
// provenance for its anchor. Default to the modal store's current image so the
// image modal is unchanged. Provenance is its own system (loaded by id via the
// provenance store), so it only needs the right id + the artist fallback.
const props = defineProps({
  imageId: { type: Number, default: null },
  image: { type: Object, default: null },
})
const modal = useModalStore()
const prov = useProvenanceStore()
const router = useRouter()
const effectiveId = computed(() => props.imageId ?? modal.currentImageId)
const effectiveImage = computed(() => props.image ?? modal.current)

// Per-post description collapse state (keyed by provenance_id). Default
// collapsed so multiple posts don't each eat ~180px of the panel — the
// operator flagged the descriptions consuming a lot of real estate
// 2026-05-28. Reset when the viewed image changes.
const expanded = reactive({})
function toggleDesc(id) { expanded[id] = !expanded[id] }
// Per-entry "show the original (untranslated) text" toggle (#143).
const showOrig = reactive({})
function toggleOrig(id) { showOrig[id] = !showOrig[id] }
watch(() => effectiveId.value, () => {
  for (const k of Object.keys(expanded)) delete expanded[k]
  for (const k of Object.keys(showOrig)) delete showOrig[k]
})

watch(
  () => effectiveId.value,
  (id) => { if (id != null) prov.loadForImage(id) },
  { immediate: true }
)

const state = computed(() =>
  effectiveId.value == null ? null : prov.imageProv(effectiveId.value)
)

const fallbackArtist = computed(() => effectiveImage.value?.artist || null)

const showArtistFallback = computed(() => {
  const st = state.value
  // Only show the fallback when provenance is genuinely empty (no
  // entries, not loading, no error) AND the image has a direct
  // artist_id we can surface.
  if (!st || st.loading || st.error) return false
  if (Array.isArray(st.entries) && st.entries.length > 0) return false
  return fallbackArtist.value != null
})

// Show the panel while loading or on error, when there is >=1 entry,
// or when the artist fallback applies (image_record.artist_id set but
// no ImageProvenance row, e.g. filesystem-imported IR images).
const show = computed(() => {
  const st = state.value
  if (!st) return false
  if (st.loading || st.error) return true
  if (Array.isArray(st.entries) && st.entries.length > 0) return true
  return showArtistFallback.value
})

const attachments = computed(() => state.value?.attachments || [])

function postDate(e) { return formatPostDate(e.post.date) }
// Translation-forward (#143): show the English by default when present.
function hasTranslation(e) {
  return !!(e.post.title_translated || e.post.description_translated)
}
function showTranslated(e) {
  return hasTranslation(e) && !showOrig[e.provenance_id]
}
function langLabel(e) {
  return e.post.translated_source_lang ? ` (${e.post.translated_source_lang})` : ''
}
function postTitle(e) {
  // Titles can arrive as stored HTML (e.g. "<strong>…</strong>"); render
  // as plain text (the CSS makes it bold).
  const t = showTranslated(e) && e.post.title_translated
    ? e.post.title_translated
    : e.post.title
  return toPlainText(t) || `Post ${e.post.external_post_id}`
}

function openPost(postId, artistId) {
  // Land on the post in the posts feed (in context), not the gallery
  // image grid. Scope the feed to this artist so the user lands in
  // that creator's stream, not the global one — operator-flagged
  // 2026-06-01. PostsView reads `artist_id` from the query string
  // (PostsView.vue line ~92) and filters via post_feed_service.
  router.push({
    path: '/posts',
    query: { post_id: postId, artist_id: artistId },
  })
  modal.close()
}
</script>

<style scoped>
.fc-prov { padding: 16px 16px 0; }
.fc-prov__title {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 18px; font-weight: 500;
  color: rgb(var(--v-theme-on-surface));
  margin-bottom: 12px;
}
.fc-prov__cards {
  /* 2.5 cards-worth at the typical collapsed card height (~108px each
     incl. 10px gap). Slightly under to ensure the third card's bottom
     edge is clipped — the visual cue that there's more below. */
  max-height: 270px;
  overflow-y: auto;
  /* Hairline scrollbar that doesn't compete with content. */
  scrollbar-width: thin;
  scrollbar-color: rgb(var(--v-theme-surface-light)) transparent;
  /* Pad-right so the scrollbar gutter doesn't squeeze card borders. */
  padding-right: 4px;
}
.fc-prov__card {
  border: 1px solid rgb(var(--v-theme-surface-light));
  border-radius: 6px; padding: 10px 12px; margin-bottom: 10px;
}
.fc-prov__head {
  display: flex; justify-content: space-between; align-items: baseline;
  font-size: 12px; color: rgb(var(--v-theme-on-surface-variant));
  text-transform: lowercase;
}
.fc-prov__post {
  /* Clickable title — opens the post in the artist-scoped feed
     (operator-flagged 2026-06-01: title IS the primary action, the
     prior "View post" link was redundant). Styled as a button-link:
     accent color, underline on hover, focus ring for keyboard nav. */
  display: block; width: 100%; text-align: left;
  background: none; border: none; padding: 0;
  font: inherit; font-weight: 700;
  margin: 4px 0;
  color: rgb(var(--v-theme-accent));
  cursor: pointer;
}
.fc-prov__post:hover { text-decoration: underline; }
.fc-prov__post:focus-visible {
  outline: 2px solid rgb(var(--v-theme-accent));
  outline-offset: 2px; border-radius: 3px;
}
.fc-prov__meta {
  font-size: 13px; color: rgb(var(--v-theme-on-surface-variant));
  display: flex; gap: 6px; flex-wrap: wrap;
}
.fc-prov__meta a { color: rgb(var(--v-theme-accent)); text-decoration: none; }
.fc-prov__actions {
  display: flex; gap: 12px; flex-wrap: wrap;
  margin-top: 6px; font-size: 13px;
}
.fc-prov__actions a {
  color: rgb(var(--v-theme-accent)); text-decoration: none;
}
.fc-prov__desc {
  margin-top: 8px; font-size: 13px; line-height: 1.5;
  max-height: 180px; overflow: auto;
  color: rgb(var(--v-theme-on-surface-variant));
}
.fc-prov__desc :deep(a) { color: rgb(var(--v-theme-accent)); }
.fc-prov__attach { padding: 0 0 12px; }
.fc-prov__attach-title {
  font-size: 13px; color: rgb(var(--v-theme-on-surface-variant));
  margin: 8px 0 4px;
}
.fc-prov__attach-list {
  /* ~7 rows visible before scrolling; the clipped row hints at more.
     Hairline scrollbar matching .fc-prov__cards. */
  max-height: 180px;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgb(var(--v-theme-surface-light)) transparent;
  padding-right: 4px;
}
.fc-prov__attach-row {
  display: block; font-size: 13px; text-decoration: none;
  color: rgb(var(--v-theme-accent)); padding: 2px 0;
}
.fc-prov__attach-size { color: rgb(var(--v-theme-on-surface-variant)); }
</style>
