<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>

    <template v-else>
      <article
        v-for="e in state.entries" :key="e.provenance_id" class="fc-prov__card"
      >
        <div class="fc-prov__head">
          <span class="fc-prov__platform">{{ e.source.platform }}</span>
          <span v-if="postDate(e)" class="fc-prov__date">{{ postDate(e) }}</span>
        </div>
        <div class="fc-prov__post">
          {{ e.post.title || `Post ${e.post.external_post_id}` }}
        </div>
        <div class="fc-prov__meta">
          <RouterLink :to="`/artist/${e.artist.slug}`">
            by {{ e.artist.name }}
          </RouterLink>
          <span v-if="e.post.attachment_count != null">
            · {{ e.post.attachment_count }} files
          </span>
        </div>
        <div class="fc-prov__actions">
          <a
            v-if="e.post.url" :href="e.post.url"
            target="_blank" rel="noopener noreferrer"
          >↗ View original post</a>
          <a href="#" @click.prevent="openPost(e.post.id)">
            View images from this post
          </a>
        </div>
        <div
          v-if="e.post.description_html"
          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>
    </template>

    <div v-if="attachments.length" class="fc-prov__attach">
      <h4 class="fc-prov__attach-title">Attachments</h4>
      <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>
  </section>
</template>

<script setup>
import { computed, 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'

const modal = useModalStore()
const prov = useProvenanceStore()
const router = useRouter()

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

const state = computed(() =>
  modal.currentImageId == null ? null : prov.imageProv(modal.currentImageId)
)

const fallbackArtist = computed(() => modal.current?.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) }

function openPost(postId) {
  router.push({ path: '/gallery', query: { post_id: postId } })
  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__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 {
  font-weight: 600; margin: 4px 0;
  color: rgb(var(--v-theme-on-surface));
}
.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-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>
