<script setup lang="ts">
import { computed, nextTick, onMounted, ref } from 'vue'
import { ElMessage } from 'element-plus'
import { Close, Picture } from '@element-plus/icons-vue'
import {
  fetchAdminChat,
  fetchAdminChatMessages,
  fetchAdminChats,
  fetchQuickReplies,
  markAdminChatRead,
  sendAdminChatMessage,
  updateChatRemark,
  type ChatConversation,
  type ChatMessage,
  type QuickReply,
} from '@/features/chats'
import { uploadAdminFile } from '@/shared/api/files'
import ChatAttachmentImage from '@/components/ChatAttachmentImage.vue'
import { useChatSSE, type ChatEvent } from '@/features/chats/composables/useChatSSE'
import { formatDateMinute } from '@/utils/time'
import TransferDialog from './components/TransferDialog.vue'
import QuickReplyDialog from './components/QuickReplyDialog.vue'

const currentAdminId = Number(localStorage.getItem('admin_id') || 0)

const conversations = ref<ChatConversation[]>([])
const active = ref<ChatConversation | null>(null)
const messages = ref<ChatMessage[]>([])
const loading = ref(false)
const messageLoading = ref(false)
const sending = ref(false)
const uploading = ref(false)
const content = ref('')
const attachments = ref<string[]>([])
const listRef = ref<HTMLElement | null>(null)
const fileInputRef = ref<HTMLInputElement | null>(null)
const filter = ref<'all' | 'mine' | 'unassigned'>('mine')
const transferVisible = ref(false)
const quickReplyVisible = ref(false)
const quickReplies = ref<QuickReply[]>([])
const remarkEditing = ref(false)
const remarkValue = ref('')

const activeMembers = computed(() => {
  const participants = active.value?.participants || []
  return participants.map(item => {
    const remark = getParticipantRemark(item)
    const name = remark ? `${remark}(${item.display_name})` : item.display_name
    return `${roleLabel(item.role)}：${name}`
  }).join(' / ')
})
const canSend = computed(() => content.value.trim() !== '' || attachments.value.length > 0)

function getParticipantRemark(participant: any) {
  if (!active.value) return ''
  const myParticipant = active.value.participants?.find(
    p => p.participant_type === 'admin' && p.participant_id === currentAdminId
  )
  return myParticipant?.remark || ''
}

function handleSSEEvent(event: ChatEvent) {
  if (event.type === 'conversation_updated') {
    loadConversations(false)
  }
  if (event.type === 'new_message' && active.value && event.conversation_id === active.value.id) {
    const msg = event.message
    if (msg && !messages.value.some(m => m.id === msg.id)) {
      messages.value = [...messages.value, {
        id: msg.id,
        conversation_id: msg.conversation_id,
        sender_type: msg.sender_type as ChatMessage['sender_type'],
        sender_id: msg.sender_id,
        sender_role: msg.sender_role as ChatMessage['sender_role'],
        sender_name: msg.sender_name,
        sender_avatar: '',
        is_self: msg.sender_type === 'admin' && msg.sender_id === currentAdminId,
        content_type: msg.content_type as ChatMessage['content_type'],
        content: msg.content,
        attachment_urls: msg.attachment_urls || [],
        created_at: msg.created_at,
      }]
      nextTick(() => scrollBottom())
    }
  }
}

const { onEvent } = useChatSSE('admin', '/api/admin/chats/events')
onEvent(handleSSEEvent)

onMounted(async () => {
  await Promise.all([loadConversations(), loadQuickReplies()])
})

async function loadConversations(showLoading = true) {
  if (showLoading) loading.value = true
  try {
    const res = await fetchAdminChats(1, 100, filter.value)
    conversations.value = res.items
    const first = conversations.value[0]
    if (!active.value && first) {
      await openConversation(first)
    }
  } catch {
    ElMessage.error('会话加载失败')
  } finally {
    loading.value = false
  }
}

async function loadQuickReplies() {
  try {
    quickReplies.value = await fetchQuickReplies()
  } catch { /* ignore */ }
}

async function openConversation(item: ChatConversation) {
  messageLoading.value = true
  try {
    active.value = await fetchAdminChat(item.id)
    await loadMessages(item.id)
    await markAdminChatRead(item.id)
    await loadConversations(false)
    remarkEditing.value = false
    remarkValue.value = ''
    attachments.value = []
  } catch {
    ElMessage.error('会话详情加载失败')
  } finally {
    messageLoading.value = false
  }
}

async function loadMessages(id: number, scroll = true) {
  const res = await fetchAdminChatMessages(id, 1, 100)
  messages.value = res.items
  if (scroll) {
    await nextTick()
    scrollBottom()
  }
}

async function handleSend() {
  const text = content.value.trim()
  const imageUrls = [...attachments.value]
  if (!active.value || (!text && imageUrls.length === 0) || sending.value || uploading.value) return
  sending.value = true
  try {
    const sent = await sendAdminChatMessage(active.value.id, text, imageUrls)
    appendMessage(sent)
    content.value = ''
    attachments.value = []
    await loadConversations(false)
  } catch {
    ElMessage.error('发送失败')
  } finally {
    sending.value = false
  }
}

function appendMessage(message: ChatMessage) {
  if (messages.value.some(item => item.id === message.id)) return
  messages.value = [...messages.value, message]
  nextTick(() => scrollBottom())
}

function pickImages() {
  if (uploading.value || attachments.value.length >= 9) return
  fileInputRef.value?.click()
}

async function handleImageChange(event: Event) {
  const input = event.target as HTMLInputElement
  const files = Array.from(input.files || [])
  input.value = ''
  if (files.length === 0) return
  const slots = 9 - attachments.value.length
  if (slots <= 0) {
    ElMessage.warning('每条消息最多发送 9 张图片')
    return
  }
  uploading.value = true
  try {
    for (const file of files.slice(0, slots)) {
      if (!['image/jpeg', 'image/png', 'image/webp'].includes(file.type) || file.size > 25 * 1024 * 1024) {
        ElMessage.warning(`${file.name} 不符合图片规则`)
        continue
      }
      const uploaded = await uploadAdminFile(file, 'chat')
      attachments.value.push(uploaded.url)
    }
    if (files.length > slots) {
      ElMessage.warning('每条消息最多发送 9 张图片')
    }
  } catch {
    ElMessage.error('图片上传失败')
  } finally {
    uploading.value = false
  }
}

function removeAttachment(index: number) {
  attachments.value.splice(index, 1)
}

function handleQuickReplySelect(reply: QuickReply) {
  content.value = reply.content
  quickReplyVisible.value = false
}

function handleFilterChange(val: string) {
  filter.value = val as typeof filter.value
  active.value = null
  messages.value = []
  loadConversations()
}

function handleTransferSuccess() {
  loadConversations(false)
  if (active.value) {
    loadMessages(active.value.id, false)
  }
}

async function startEditRemark() {
  if (!active.value) return
  const myParticipant = active.value.participants?.find(
    p => p.participant_type === 'admin' && p.participant_id === currentAdminId
  )
  remarkValue.value = myParticipant?.remark || active.value.title
  remarkEditing.value = true
}

async function saveRemark() {
  if (!active.value) return
  try {
    await updateChatRemark(active.value.id, remarkValue.value)
    ElMessage.success('备注已更新')
    remarkEditing.value = false
    await fetchAdminChat(active.value.id).then(chat => {
      active.value = chat
    })
    await loadConversations(false)
  } catch {
    ElMessage.error('更新备注失败')
  }
}

function scrollBottom() {
  const el = listRef.value
  if (!el) return
  el.scrollTop = el.scrollHeight
}

function roleLabel(role: string) {
  const map: Record<string, string> = {
    renter: '租客',
    owner: '号主',
    support: '客服',
    customer: '咨询',
    system: '系统',
  }
  return map[role] || '成员'
}

function senderLabel(item: ChatMessage) {
  if (item.sender_type === 'system') return '系统'
  return `${roleLabel(item.sender_role)} · ${item.sender_name}`
}

function getConversationTitle(item: ChatConversation) {
  const myParticipant = item.participants?.find(
    p => p.participant_type === 'admin' && p.participant_id === currentAdminId
  )
  return myParticipant?.remark || item.title
}

function getSupportName(item: ChatConversation) {
  const support = item.participants?.find(p => p.role === 'support')
  return support?.display_name || '未分配'
}
</script>

<template>
  <section class="admin-page">
    <div class="page-head">
      <div>
        <h1>客服会话</h1>
        <p>处理订单三方沟通和平台咨询</p>
      </div>
      <div class="head-right">
        <el-button @click="quickReplyVisible = true">快捷回复管理</el-button>
        <el-button :loading="loading" @click="loadConversations()">刷新</el-button>
      </div>
    </div>

    <div class="chat-workbench">
      <aside class="conversation-pane" v-loading="loading">
        <div class="filter-tabs">
          <el-radio-group v-model="filter" size="small" @change="handleFilterChange">
            <el-radio-button value="mine">我的会话</el-radio-button>
            <el-radio-button value="all">全部</el-radio-button>
            <el-radio-button value="unassigned">未分配</el-radio-button>
          </el-radio-group>
        </div>
        <button
          v-for="item in conversations"
          :key="item.id"
          type="button"
          class="conversation-row"
          :class="{ active: active?.id === item.id }"
          @click="openConversation(item)"
        >
          <div class="row-title">
            <strong>{{ getConversationTitle(item) }}</strong>
            <span>{{ formatDateMinute(item.last_message_at || item.created_at) }}</span>
          </div>
          <p>{{ item.last_message_preview || (item.type === 'general_support' ? '客服会话已创建' : '订单群聊已创建') }}</p>
          <div class="row-meta">
            <span class="support-name">{{ getSupportName(item) }}</span>
            <em v-if="item.unread_count > 0">{{ item.unread_count }}</em>
          </div>
        </button>
        <el-empty v-if="!loading && conversations.length === 0" description="暂无客服会话" />
      </aside>

      <main class="message-pane">
        <template v-if="active">
          <header class="message-head">
            <div class="head-title">
              <template v-if="remarkEditing">
                <el-input
                  v-model="remarkValue"
                  size="small"
                  style="width: 200px"
                  placeholder="输入备注"
                  @keyup.enter="saveRemark"
                />
                <el-button size="small" type="primary" @click="saveRemark">保存</el-button>
                <el-button size="small" @click="remarkEditing = false">取消</el-button>
              </template>
              <template v-else>
                <h2>{{ getConversationTitle(active) }} <el-button link size="small" @click="startEditRemark">编辑备注</el-button></h2>
                <p>{{ activeMembers }}</p>
              </template>
            </div>
            <div class="head-actions">
              <el-button size="small" @click="transferVisible = true">转接</el-button>
              <RouterLink v-if="active.order_id" :to="`/admin/orders/${active.order_id}`">
                <el-button size="small">查看订单</el-button>
              </RouterLink>
            </div>
          </header>

          <div ref="listRef" class="message-list" v-loading="messageLoading">
            <div
              v-for="item in messages"
              :key="item.id"
              class="message-row"
              :class="{ self: item.is_self, system: item.sender_type === 'system' }"
            >
              <template v-if="item.sender_type === 'system'">
                <span>{{ item.content }}</span>
              </template>
              <template v-else>
                <small>{{ senderLabel(item) }} · {{ formatDateMinute(item.created_at) }}</small>
                <p v-if="item.content">{{ item.content }}</p>
                <div v-if="item.attachment_urls.length > 0" class="message-attachments">
                  <ChatAttachmentImage
                    v-for="url in item.attachment_urls"
                    :key="url"
                    :source="url"
                    admin
                  />
                </div>
              </template>
            </div>
          </div>

          <footer class="composer">
            <div class="composer-tools">
              <input
                ref="fileInputRef"
                class="hidden-file"
                type="file"
                accept="image/jpeg,image/png,image/webp"
                multiple
                @change="handleImageChange"
              >
              <el-dropdown trigger="click" @command="handleQuickReplySelect">
                <el-button size="small" text>快捷回复</el-button>
                <template #dropdown>
                  <el-dropdown-menu>
                    <el-dropdown-item
                      v-for="reply in quickReplies"
                      :key="reply.id"
                      :command="reply"
                    >
                      <span class="reply-title">{{ reply.title }}</span>
                      <span class="reply-preview">{{ reply.content.slice(0, 30) }}{{ reply.content.length > 30 ? '...' : '' }}</span>
                    </el-dropdown-item>
                    <el-dropdown-item v-if="quickReplies.length === 0" disabled>
                      暂无快捷回复
                    </el-dropdown-item>
                  </el-dropdown-menu>
                </template>
              </el-dropdown>
              <el-button size="small" text :icon="Picture" :loading="uploading" :disabled="attachments.length >= 9" @click="pickImages">
                图片
              </el-button>
            </div>
            <div v-if="attachments.length > 0" class="pending-attachments">
              <div v-for="(url, index) in attachments" :key="url" class="pending-item">
                <ChatAttachmentImage :source="url" admin />
                <button type="button" class="remove-attachment" @click="removeAttachment(index)">
                  <el-icon :size="14"><Close /></el-icon>
                </button>
              </div>
            </div>
            <div class="composer-input">
              <el-input
                v-model="content"
                type="textarea"
                :rows="3"
                maxlength="1000"
                show-word-limit
                placeholder="输入客服回复"
                @keydown.enter.exact.prevent="handleSend"
              />
              <el-button type="primary" :loading="sending" :disabled="!canSend || uploading" @click="handleSend">发送</el-button>
            </div>
          </footer>
        </template>
        <el-empty v-else description="请选择会话" />
      </main>
    </div>

    <TransferDialog
      v-if="active"
      v-model="transferVisible"
      :conversation-id="active.id"
      @success="handleTransferSuccess"
    />

    <QuickReplyDialog
      v-model="quickReplyVisible"
      @success="loadQuickReplies"
    />
  </section>
</template>

<style scoped>
.admin-page {
  display: grid;
  height: 100%;
  min-height: 0;
  grid-template-rows: auto minmax(0, 1fr);
}

.page-head {
  display: flex;
  flex: none;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.page-head h1 {
  margin: 0;
  font-size: 22px;
}

.page-head p {
  margin: 6px 0 0;
  color: #6b7280;
}

.head-right {
  display: flex;
  gap: 8px;
}

.chat-workbench {
  display: grid;
  min-height: 0;
  grid-template-columns: 330px minmax(0, 1fr);
  overflow: hidden;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  background: #fff;
}

.conversation-pane {
  min-height: 0;
  overflow-y: auto;
  border-right: 1px solid #e5e7eb;
  background: #f8fafc;
}

.filter-tabs {
  padding: 12px;
  border-bottom: 1px solid #e5e7eb;
}

.conversation-row {
  position: relative;
  display: block;
  width: 100%;
  padding: 14px;
  border: 0;
  border-bottom: 1px solid #e5e7eb;
  background: transparent;
  text-align: left;
}

.conversation-row.active {
  background: #eef6ff;
}

.row-title {
  display: flex;
  gap: 10px;
  align-items: center;
}

.row-title strong {
  min-width: 0;
  flex: 1;
  overflow: hidden;
  color: #111827;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.row-title span {
  flex: none;
  color: #9ca3af;
  font-size: 12px;
}

.conversation-row p {
  margin: 8px 24px 0 0;
  overflow: hidden;
  color: #6b7280;
  font-size: 13px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.row-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 8px;
}

.support-name {
  color: #8a94a6;
  font-size: 12px;
}

.row-meta em {
  min-width: 18px;
  height: 18px;
  padding: 0 5px;
  border-radius: 9px;
  background: #ef4444;
  color: #fff;
  font-size: 11px;
  font-style: normal;
  font-weight: 700;
  line-height: 18px;
  text-align: center;
}

.message-pane {
  display: grid;
  min-width: 0;
  min-height: 0;
  grid-template-rows: auto minmax(0, 1fr) auto;
}

.message-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid #e5e7eb;
}

.head-title {
  flex: 1;
  min-width: 0;
}

.head-title h2 {
  margin: 0;
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.head-title p {
  margin: 6px 0 0;
  color: #6b7280;
  font-size: 13px;
}

.head-actions {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
}

.head-actions a {
  text-decoration: none;
}

.message-list {
  min-height: 0;
  overflow-y: auto;
  padding: 18px;
  background: #f3f6fa;
}

.message-row {
  max-width: 70%;
  margin-bottom: 14px;
}

.message-row.self {
  margin-left: auto;
  text-align: right;
}

.message-row.system {
  max-width: none;
  text-align: center;
}

.message-row small {
  display: block;
  margin-bottom: 5px;
  color: #8a94a6;
}

.message-row p {
  display: inline-block;
  margin: 0;
  padding: 10px 12px;
  border-radius: 8px;
  background: #fff;
  color: #111827;
  line-height: 1.5;
  text-align: left;
}

.message-row.self p {
  background: #dff5eb;
}

.message-attachments {
  display: grid;
  justify-items: start;
  gap: 6px;
}

.message-row.self .message-attachments {
  justify-items: end;
}

.message-row.system span {
  display: inline-block;
  padding: 5px 10px;
  border-radius: 8px;
  background: #e5e7eb;
  color: #6b7280;
  font-size: 12px;
}

.composer {
  border-top: 1px solid #e5e7eb;
}

.composer-tools {
  display: flex;
  gap: 8px;
  align-items: center;
  padding: 8px 14px;
  border-bottom: 1px solid #f0f0f0;
}

.hidden-file {
  display: none;
}

.pending-attachments {
  display: flex;
  gap: 8px;
  padding: 10px 14px 0;
  overflow-x: auto;
}

.pending-item {
  position: relative;
  flex: none;
}

.pending-item :deep(.chat-image-button) {
  width: 84px;
  height: 84px;
}

.pending-item :deep(.chat-image-button img) {
  height: 84px;
}

.remove-attachment {
  position: absolute;
  top: 4px;
  right: 4px;
  display: grid;
  width: 22px;
  height: 22px;
  place-items: center;
  border: 0;
  border-radius: 50%;
  background: rgba(17, 24, 39, 0.72);
  color: #fff;
  cursor: pointer;
}

.composer-input {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 88px;
  gap: 12px;
  align-items: end;
  padding: 14px;
}

.reply-title {
  font-weight: 500;
  margin-right: 8px;
}

.reply-preview {
  color: #9ca3af;
  font-size: 12px;
}
</style>
