<script setup lang='ts'>
import { computed, onMounted, onUnmounted, ref } from 'vue'
import { useRoute } from 'vue-router'
import { NButton, NInput, useDialog, useMessage } from 'naive-ui'
import html2canvas from 'html2canvas'
import { Message } from './components'
import { useScroll } from './hooks/useScroll'
import { useChat } from './hooks/useChat'
import { useCopyCode } from './hooks/useCopyCode'
import HeaderComponent from './components/Header/index.vue'
import { HoverButton, SvgIcon } from '@/components/common'
import { useBasicLayout } from '@/hooks/useBasicLayout'
import { useChatStore } from '@/store'
import { fetchChatAPIProcess } from '@/api'
import { t } from '@/locales'

let controller = new AbortController()

const openLongReply = import.meta.env.VITE_GLOB_OPEN_LONG_REPLY === 'true'

const route = useRoute()
const dialog = useDialog()
const ms = useMessage()

const chatStore = useChatStore()

useCopyCode()
const { isMobile } = useBasicLayout()
const { addChat, updateChat, updateChatSome, getChatByUuidAndIndex } = useChat()
const { scrollRef, scrollToBottom } = useScroll()

const { uuid } = route.params as { uuid: string }

const dataSources = computed(() => chatStore.getChatByUuid(+uuid))
const conversationList = computed(() => dataSources.value.filter(item => (!item.inversion && !item.error)))

const prompt = ref<string>('')
const loading = ref<boolean>(false)
const usingContext = ref<boolean>(true)

function handleSubmit() {
  onConversation()
}

async function onConversation() {
  let message = prompt.value

  if (loading.value)
    return

  if (!message || message.trim() === '')
    return

  controller = new AbortController()

  addChat(
    +uuid,
    {
      dateTime: new Date().toLocaleString(),
      text: message,
      inversion: true,
      error: false,
      conversationOptions: null,
      requestOptions: { prompt: message, options: null },
    },
  )
  scrollToBottom()

  loading.value = true
  prompt.value = ''

  let options: Chat.ConversationRequest = {}
  const lastContext = conversationList.value[conversationList.value.length - 1]?.conversationOptions

  if (lastContext && usingContext.value)
    options = { ...lastContext }

  addChat(
    +uuid,
    {
      dateTime: new Date().toLocaleString(),
      text: '',
      loading: true,
      inversion: false,
      error: false,
      conversationOptions: null,
      requestOptions: { prompt: message, options: { ...options } },
    },
  )
  scrollToBottom()

  try {
    let lastText = ''
    const fetchChatAPIOnce = async () => {
      await fetchChatAPIProcess<Chat.ConversationResponse>({
        prompt: message,
        options,
        signal: controller.signal,
        onDownloadProgress: ({ event }) => {
          const xhr = event.target
          const { responseText } = xhr
          // Always process the final line
          const lastIndex = responseText.lastIndexOf('\n')
          let chunk = responseText
          if (lastIndex !== -1)
            chunk = responseText.substring(lastIndex)
          try {
            const data = JSON.parse(chunk)
            updateChat(
              +uuid,
              dataSources.value.length - 1,
              {
                dateTime: new Date().toLocaleString(),
                text: lastText + data.text ?? '',
                inversion: false,
                error: false,
                loading: false,
                conversationOptions: { conversationId: data.conversationId, parentMessageId: data.id },
                requestOptions: { prompt: message, options: { ...options } },
              },
            )

            if (openLongReply && data.detail.choices[0].finish_reason === 'length') {
              options.parentMessageId = data.id
              lastText = data.text
              message = ''
              return fetchChatAPIOnce()
            }

            scrollToBottom()
          }
          catch (error) {
          //
          }
        },
      })
    }

    await fetchChatAPIOnce()
  }
  catch (error: any) {
    const errorMessage = error?.message ?? t('common.wrong')

    if (error.message === 'canceled') {
      updateChatSome(
        +uuid,
        dataSources.value.length - 1,
        {
          loading: false,
        },
      )
      scrollToBottom()
      return
    }

    const currentChat = getChatByUuidAndIndex(+uuid, dataSources.value.length - 1)

    if (currentChat?.text && currentChat.text !== '') {
      updateChatSome(
        +uuid,
        dataSources.value.length - 1,
        {
          text: `${currentChat.text}\n[${errorMessage}]`,
          error: false,
          loading: false,
        },
      )
      return
    }

    updateChat(
      +uuid,
      dataSources.value.length - 1,
      {
        dateTime: new Date().toLocaleString(),
        text: errorMessage,
        inversion: false,
        error: true,
        loading: false,
        conversationOptions: null,
        requestOptions: { prompt: message, options: { ...options } },
      },
    )
    scrollToBottom()
  }
  finally {
    loading.value = false
  }
}

async function onRegenerate(index: number) {
  if (loading.value)
    return

  controller = new AbortController()

  const { requestOptions } = dataSources.value[index]

  let message = requestOptions?.prompt ?? ''

  let options: Chat.ConversationRequest = {}

  if (requestOptions.options)
    options = { ...requestOptions.options }

  loading.value = true

  updateChat(
    +uuid,
    index,
    {
      dateTime: new Date().toLocaleString(),
      text: '',
      inversion: false,
      error: false,
      loading: true,
      conversationOptions: null,
      requestOptions: { prompt: message, ...options },
    },
  )

  try {
    let lastText = ''
    const fetchChatAPIOnce = async () => {
      await fetchChatAPIProcess<Chat.ConversationResponse>({
        prompt: message,
        options,
        signal: controller.signal,
        onDownloadProgress: ({ event }) => {
          const xhr = event.target
          const { responseText } = xhr
          // Always process the final line
          const lastIndex = responseText.lastIndexOf('\n')
          let chunk = responseText
          if (lastIndex !== -1)
            chunk = responseText.substring(lastIndex)
          try {
            const data = JSON.parse(chunk)
            updateChat(
              +uuid,
              index,
              {
                dateTime: new Date().toLocaleString(),
                text: lastText + data.text ?? '',
                inversion: false,
                error: false,
                loading: false,
                conversationOptions: { conversationId: data.conversationId, parentMessageId: data.id },
                requestOptions: { prompt: message, ...options },
              },
            )

            if (openLongReply && data.detail.choices[0].finish_reason === 'length') {
              options.parentMessageId = data.id
              lastText = data.text
              message = ''
              return fetchChatAPIOnce()
            }
          }
          catch (error) {
            //
          }
        },
      })
    }
    await fetchChatAPIOnce()
  }
  catch (error: any) {
    if (error.message === 'canceled') {
      updateChatSome(
        +uuid,
        index,
        {
          loading: false,
        },
      )
      return
    }

    const errorMessage = error?.message ?? t('common.wrong')

    updateChat(
      +uuid,
      index,
      {
        dateTime: new Date().toLocaleString(),
        text: errorMessage,
        inversion: false,
        error: true,
        loading: false,
        conversationOptions: null,
        requestOptions: { prompt: message, ...options },
      },
    )
  }
  finally {
    loading.value = false
  }
}

function handleExport() {
  if (loading.value)
    return

  const d = dialog.warning({
    title: t('chat.exportImage'),
    content: t('chat.exportImageConfirm'),
    positiveText: t('common.yes'),
    negativeText: t('common.no'),
    onPositiveClick: async () => {
      try {
        d.loading = true
        const ele = document.getElementById('image-wrapper')
        const canvas = await html2canvas(ele as HTMLDivElement, {
          useCORS: true,
        })
        const imgUrl = canvas.toDataURL('image/png')
        const tempLink = document.createElement('a')
        tempLink.style.display = 'none'
        tempLink.href = imgUrl
        tempLink.setAttribute('download', 'chat-shot.png')
        if (typeof tempLink.download === 'undefined')
          tempLink.setAttribute('target', '_blank')

        document.body.appendChild(tempLink)
        tempLink.click()
        document.body.removeChild(tempLink)
        window.URL.revokeObjectURL(imgUrl)
        d.loading = false
        ms.success(t('chat.exportSuccess'))
        Promise.resolve()
      }
      catch (error: any) {
        ms.error(t('chat.exportFailed'))
      }
      finally {
        d.loading = false
      }
    },
  })
}

function handleDelete(index: number) {
  if (loading.value)
    return

  dialog.warning({
    title: t('chat.deleteMessage'),
    content: t('chat.deleteMessageConfirm'),
    positiveText: t('common.yes'),
    negativeText: t('common.no'),
    onPositiveClick: () => {
      chatStore.deleteChatByUuid(+uuid, index)
    },
  })
}

function handleClear() {
  if (loading.value)
    return

  dialog.warning({
    title: t('chat.clearChat'),
    content: t('chat.clearChatConfirm'),
    positiveText: t('common.yes'),
    negativeText: t('common.no'),
    onPositiveClick: () => {
      chatStore.clearChatByUuid(+uuid)
    },
  })
}

function handleEnter(event: KeyboardEvent) {
  if (!isMobile.value) {
    if (event.key === 'Enter' && !event.shiftKey) {
      event.preventDefault()
      handleSubmit()
    }
  }
  else {
    if (event.key === 'Enter' && event.ctrlKey) {
      event.preventDefault()
      handleSubmit()
    }
  }
}

function handleStop() {
  if (loading.value) {
    controller.abort()
    loading.value = false
  }
}

function toggleUsingContext() {
  usingContext.value = !usingContext.value
  if (usingContext.value)
    ms.success(t('chat.turnOnContext'))
  else
    ms.warning(t('chat.turnOffContext'))
}

const placeholder = computed(() => {
  if (isMobile.value)
    return t('chat.placeholderMobile')
  return t('chat.placeholder')
})

const buttonDisabled = computed(() => {
  return loading.value || !prompt.value || prompt.value.trim() === ''
})

const footerClass = computed(() => {
  let classes = ['p-4']
  if (isMobile.value)
    classes = ['sticky', 'left-0', 'bottom-0', 'right-0', 'p-2', 'pr-3', 'overflow-hidden']
  return classes
})

onMounted(() => {
  scrollToBottom()
})

onUnmounted(() => {
  if (loading.value)
    controller.abort()
})
</script>

<template>
  <div class="flex flex-col w-full h-full">
    <HeaderComponent
      v-if="isMobile"
      :using-context="usingContext"
      @export="handleExport"
      @toggle-using-context="toggleUsingContext"
    />
    <main class="flex-1 overflow-hidden">
      <div
        id="scrollRef"
        ref="scrollRef"
        class="h-full overflow-hidden overflow-y-auto"
      >
        <div
          id="image-wrapper"
          class="w-full max-w-screen-xl m-auto dark:bg-[#101014]"
          :class="[isMobile ? 'p-2' : 'p-4']"
        >
          <template v-if="!dataSources.length">
            <div class="flex items-center justify-center mt-4 text-center text-neutral-300">
              <SvgIcon icon="ri:bubble-chart-fill" class="mr-2 text-3xl" />
              <span>Aha~</span>
            </div>
          </template>
          <template v-else>
            <div>
              <Message
                v-for="(item, index) of dataSources"
                :key="index"
                :date-time="item.dateTime"
                :text="item.text"
                :inversion="item.inversion"
                :error="item.error"
                :loading="item.loading"
                @regenerate="onRegenerate(index)"
                @delete="handleDelete(index)"
              />
              <div class="sticky bottom-0 left-0 flex justify-center">
                <NButton v-if="loading" type="warning" @click="handleStop">
                  <template #icon>
                    <SvgIcon icon="ri:stop-circle-line" />
                  </template>
                  Stop Responding
                </NButton>
              </div>
            </div>
          </template>
        </div>
      </div>
    </main>
    <footer :class="footerClass">
      <div class="w-full max-w-screen-xl m-auto">
        <div class="flex items-center justify-between space-x-2">
          <HoverButton @click="handleClear">
            <span class="text-xl text-[#4f555e] dark:text-white">
              <SvgIcon icon="ri:delete-bin-line" />
            </span>
          </HoverButton>
          <HoverButton v-if="!isMobile" @click="handleExport">
            <span class="text-xl text-[#4f555e] dark:text-white">
              <SvgIcon icon="ri:download-2-line" />
            </span>
          </HoverButton>
          <HoverButton v-if="!isMobile" @click="toggleUsingContext">
            <span class="text-xl" :class="{ 'text-[#4b9e5f]': usingContext, 'text-[#a8071a]': !usingContext }">
              <SvgIcon icon="ri:chat-history-line" />
            </span>
          </HoverButton>
          <NInput
            v-model:value="prompt"
            type="textarea"
            :autosize="{ minRows: 1, maxRows: 2 }"
            :placeholder="placeholder"
            @keypress="handleEnter"
          />
          <NButton type="primary" :disabled="buttonDisabled" @click="handleSubmit">
            <template #icon>
              <span class="dark:text-black">
                <SvgIcon icon="ri:send-plane-fill" />
              </span>
            </template>
          </NButton>
        </div>
      </div>
    </footer>
  </div>
</template>
