import type { FileEntity } from '../../file-uploader/types'
import type { HumanInputFormSubmitData } from '../chat/answer/human-input-content/type'
import type {
  ChatConfig,
  ChatItem,
  ChatItemInTree,
  OnSend,
} from '../types'
import { Avatar } from '@langgenius/dify-ui/avatar'
import { cn } from '@langgenius/dify-ui/cn'
import { RiArrowDownSLine, RiArrowUpSLine } from '@remixicon/react'
import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
import { useTranslation } from 'react-i18next'
import AnswerIcon from '@/app/components/base/answer-icon'
import AppIcon from '@/app/components/base/app-icon'
import SuggestedQuestions from '@/app/components/base/chat/chat/answer/suggested-questions'
import InputsForm from '@/app/components/base/chat/embedded-chatbot/inputs-form'
import LogoAvatar from '@/app/components/base/logo/logo-embedded-chat-avatar'
import { Markdown } from '@/app/components/base/markdown'
import { InputVarType } from '@/app/components/workflow/types'
import {
  AppSourceType,
  fetchSuggestedQuestions,
  getUrl,
  stopChatMessageResponding,
  submitHumanInputForm,
} from '@/service/share'
import { submitHumanInputForm as submitHumanInputFormService } from '@/service/workflow'
import { TransferMethod } from '@/types/app'
import Chat from '../chat'
import { useChat } from '../chat/hooks'
import { getLastAnswer, isValidGeneratedAnswer } from '../utils'
import { useEmbeddedChatbotContext } from './context'
import { isDify } from './utils'

const ChatWrapper = () => {
  const { t } = useTranslation()
  const {
    appData,
    appParams,
    appPrevChatList,
    currentConversationId,
    currentConversationItem,
    currentConversationInputs,
    inputsForms,
    newConversationInputs,
    newConversationInputsRef,
    handleNewConversationCompleted,
    isMobile,
    isInstalledApp,
    appId,
    appMeta,
    disableFeedback,
    handleFeedback,
    currentChatInstanceRef,
    themeBuilder,
    clearChatList,
    setClearChatList,
    setIsResponding,
    allInputsHidden,
    initUserVariables,
    appSourceType,
  } = useEmbeddedChatbotContext()

  // Read sendOnEnter from URL params (e.g., ?sendOnEnter=false)
  const sendOnEnter = useMemo(() => {
    if (typeof window === 'undefined')
      return true
    const urlParams = new URLSearchParams(window.location.search)
    const param = urlParams.get('sendOnEnter')
    return param !== 'false'
  }, [])

  const appConfig = useMemo(() => {
    const config = appParams || {}

    return {
      ...config,
      file_upload: {
        ...(config as any).file_upload,
        fileUploadConfig: (config as any).system_parameters,
      },
      supportFeedback: true,
      opening_statement: currentConversationItem?.introduction || (config as any).opening_statement,
    } as ChatConfig
  }, [appParams, currentConversationItem?.introduction])
  const {
    chatList,
    handleSend,
    handleStop,
    handleSwitchSibling,
    isResponding: respondingState,
    suggestedQuestions,
  } = useChat(
    appConfig,
    {
      inputs: (currentConversationId ? currentConversationInputs : newConversationInputs) as any,
      inputsForm: inputsForms,
    },
    appPrevChatList,
    taskId => stopChatMessageResponding('', taskId, appSourceType, appId),
    clearChatList,
    setClearChatList,
  )
  const inputsFormValue = currentConversationId ? currentConversationInputs : newConversationInputsRef?.current
  const inputDisabled = useMemo(() => {
    if (allInputsHidden)
      return false

    let hasEmptyInput = ''
    let fileIsUploading = false
    const requiredVars = inputsForms.filter(({ required, type }) => required && type !== InputVarType.checkbox) // boolean can be not checked
    if (requiredVars.length) {
      requiredVars.forEach(({ variable, label, type }) => {
        if (hasEmptyInput)
          return

        if (fileIsUploading)
          return

        if (!inputsFormValue?.[variable])
          hasEmptyInput = label as string

        if ((type === InputVarType.singleFile || type === InputVarType.multiFiles) && inputsFormValue?.[variable]) {
          const files = inputsFormValue[variable]
          if (Array.isArray(files))
            fileIsUploading = files.find(item => item.transferMethod === TransferMethod.local_file && !item.uploadedId)
          else
            fileIsUploading = files.transferMethod === TransferMethod.local_file && !files.uploadedId
        }
      })
    }
    if (hasEmptyInput)
      return true

    if (fileIsUploading)
      return true
    return false
  }, [inputsFormValue, inputsForms, allInputsHidden])

  useEffect(() => {
    if (currentChatInstanceRef.current)
      currentChatInstanceRef.current.handleStop = handleStop
  }, [currentChatInstanceRef, handleStop])
  useEffect(() => {
    setIsResponding(respondingState)
  }, [respondingState, setIsResponding])

  // Resume paused workflows when chat history is loaded
  useEffect(() => {
    if (!appPrevChatList || appPrevChatList.length === 0)
      return

    // Find the last answer item with workflow_run_id that needs resumption (DFS - find deepest first)
    let lastPausedNode: ChatItemInTree | undefined
    const findLastPausedWorkflow = (nodes: ChatItemInTree[]) => {
      nodes.forEach((node) => {
        // DFS: recurse to children first
        if (node.children && node.children.length > 0)
          findLastPausedWorkflow(node.children)

        // Track the last node with humanInputFormDataList
        if (node.isAnswer && node.workflow_run_id && node.humanInputFormDataList && node.humanInputFormDataList.length > 0)
          lastPausedNode = node
      })
    }

    findLastPausedWorkflow(appPrevChatList)

    // Only resume the last paused workflow
    if (lastPausedNode) {
      handleSwitchSibling(
        lastPausedNode.id,
        {
          onGetSuggestedQuestions: responseItemId => fetchSuggestedQuestions(responseItemId, appSourceType, appId),
          onConversationComplete: currentConversationId ? undefined : handleNewConversationCompleted,
          isPublicAPI: appSourceType === AppSourceType.webApp,
        },
      )
    }
  }, [])

  const [hasSent, setHasSent] = useState(false)
  const [prevConversationId, setPrevConversationId] = useState(currentConversationId)
  if (prevConversationId !== currentConversationId) {
    setPrevConversationId(currentConversationId)
    if (!currentConversationId)
      setHasSent(false)
  }

  const doSend: OnSend = useCallback((message, files, isRegenerate = false, parentAnswer: ChatItem | null = null) => {
    if (!currentConversationId)
      setHasSent(true)
    const data: any = {
      query: message,
      files,
      inputs: currentConversationId ? currentConversationInputs : newConversationInputs,
      conversation_id: currentConversationId,
      parent_message_id: (isRegenerate ? parentAnswer?.id : getLastAnswer(chatList)?.id) || null,
    }
    handleSend(
      getUrl('chat-messages', appSourceType, appId || ''),
      data,
      {
        onGetSuggestedQuestions: responseItemId => fetchSuggestedQuestions(responseItemId, appSourceType, appId),
        onConversationComplete: currentConversationId ? undefined : handleNewConversationCompleted,
        isPublicAPI: appSourceType === AppSourceType.webApp,
      },
    )
  }, [currentConversationId, currentConversationInputs, newConversationInputs, chatList, handleSend, appSourceType, appId, handleNewConversationCompleted])

  const doRegenerate = useCallback((chatItem: ChatItem, editedQuestion?: { message: string, files?: FileEntity[] }) => {
    const question = editedQuestion ? chatItem : chatList.find(item => item.id === chatItem.parentMessageId)!
    const parentAnswer = chatList.find(item => item.id === question.parentMessageId)
    doSend(editedQuestion ? editedQuestion.message : question.content, editedQuestion ? editedQuestion.files : question.message_files, true, isValidGeneratedAnswer(parentAnswer) ? parentAnswer : null)
  }, [chatList, doSend])

  const doSwitchSibling = useCallback((siblingMessageId: string) => {
    handleSwitchSibling(siblingMessageId, {
      onGetSuggestedQuestions: responseItemId => fetchSuggestedQuestions(responseItemId, appSourceType, appId),
      onConversationComplete: currentConversationId ? undefined : handleNewConversationCompleted,
      isPublicAPI: appSourceType === AppSourceType.webApp,
    })
  }, [handleSwitchSibling, appSourceType, appId, currentConversationId, handleNewConversationCompleted])

  const messageList = useMemo(() => {
    if (currentConversationId || chatList.length > 1)
      return chatList
    // Without messages we are in the welcome screen, so hide the opening statement from chatlist
    return chatList.filter(item => !item.isOpeningStatement)
  }, [chatList, currentConversationId])

  const isTryApp = appSourceType === AppSourceType.tryApp
  const [collapsed, setCollapsed] = useState(!!currentConversationId && !isTryApp) // try app always use the new chat
  const [descExpanded, setDescExpanded] = useState(false)

  const description = appData?.site.description
  const [showDescToggle, setShowDescToggle] = useState(false)
  const descRef = useRef<HTMLDivElement>(null)
  useEffect(() => {
    const el = descRef.current
    if (!el)
      return
    if (el.offsetWidth > 0) {
      setShowDescToggle(el.scrollHeight > el.clientHeight)
      return
    }
    const observer = new ResizeObserver((entries) => {
      if (!entries[0] || entries[0].contentRect.width === 0)
        return
      setShowDescToggle(el.scrollHeight > el.clientHeight)
      observer.disconnect()
    })
    observer.observe(el)
    return () => observer.disconnect()
  }, [description])

  const descriptionNode = useMemo(() => {
    if (!description || currentConversationId || hasSent)
      return null
    return (
      <div className={cn('flex flex-col items-center px-4 pt-6', isMobile && 'pt-4')}>
        <div className="w-full max-w-[672px] rounded-2xl border-[0.5px] border-components-panel-border bg-components-panel-bg shadow-md">
          <div className={cn('p-6', isMobile && 'p-4')}>
            <div
              ref={descRef}
              className={cn(
                'relative system-xs-regular break-words whitespace-pre-wrap text-text-tertiary',
                !descExpanded && 'line-clamp-3',
                descExpanded && 'max-h-32 overflow-y-auto',
              )}
            >
              {description}
              {!descExpanded && showDescToggle && (
                <div className="pointer-events-none absolute inset-x-0 bottom-0 h-6 bg-linear-to-b from-components-panel-bg-transparent to-components-panel-bg" />
              )}
            </div>
            {showDescToggle && (
              <button
                type="button"
                className="mt-0.5 flex items-center gap-0.5 system-xs-regular text-text-accent hover:opacity-80"
                onClick={() => setDescExpanded(v => !v)}
              >
                {descExpanded
                  ? (
                      <>
                        <RiArrowUpSLine className="size-3" />
                        {t('chat.collapse', { ns: 'share' })}
                      </>
                    )
                  : (
                      <>
                        <RiArrowDownSLine className="size-3" />
                        {t('chat.expand', { ns: 'share' })}
                      </>
                    )}
              </button>
            )}
          </div>
        </div>
      </div>
    )
  }, [description, isMobile, currentConversationId, hasSent, descExpanded, showDescToggle, t])

  const chatNode = useMemo(() => {
    if (allInputsHidden || !inputsForms.length)
      return null
    if (isMobile) {
      if (!currentConversationId)
        return <InputsForm collapsed={collapsed} setCollapsed={setCollapsed} />
      return <div className="mb-4"></div>
    }
    else {
      return <InputsForm collapsed={collapsed} setCollapsed={setCollapsed} />
    }
  }, [inputsForms.length, isMobile, currentConversationId, collapsed, allInputsHidden])

  const handleSubmitHumanInputForm = useCallback(async (formToken: string, formData: HumanInputFormSubmitData) => {
    if (isInstalledApp)
      await submitHumanInputFormService(formToken, formData)
    else
      await submitHumanInputForm(formToken, formData)
  }, [isInstalledApp])

  const welcome = useMemo(() => {
    const welcomeMessage = chatList.find(item => item.isOpeningStatement)
    if (respondingState)
      return null
    if (currentConversationId)
      return null
    if (!welcomeMessage)
      return null
    if (!collapsed && inputsForms.length > 0 && !allInputsHidden)
      return null
    if (!appData?.site)
      return null
    if (welcomeMessage.suggestedQuestions && welcomeMessage.suggestedQuestions?.length > 0) {
      return (
        <div className={cn('flex items-center justify-center px-4 py-12', isMobile ? 'min-h-[30vh] py-0' : 'h-[50vh]')}>
          <div className="flex max-w-[720px] grow gap-4">
            <AppIcon
              size="xl"
              iconType={appData?.site.icon_type}
              icon={appData?.site.icon}
              background={appData?.site.icon_background}
              imageUrl={appData?.site.icon_url}
            />
            <div className="grow rounded-2xl bg-chat-bubble-bg px-4 py-3 body-lg-regular text-text-primary">
              <Markdown content={welcomeMessage.content} />
              <SuggestedQuestions item={welcomeMessage} />
            </div>
          </div>
        </div>
      )
    }
    return (
      <div className={cn('flex min-h-[50vh] flex-col items-center justify-center gap-3 py-12', isMobile ? 'min-h-[30vh] py-0' : 'h-[50vh]')}>
        <AppIcon
          size="xl"
          iconType={appData?.site.icon_type}
          icon={appData?.site.icon}
          background={appData?.site.icon_background}
          imageUrl={appData?.site.icon_url}
        />
        <div className="max-w-[768px] px-4">
          <Markdown className="body-2xl-regular! text-text-tertiary!" content={welcomeMessage.content} />
        </div>
      </div>
    )
  }, [chatList, respondingState, currentConversationId, collapsed, inputsForms.length, allInputsHidden, appData?.site, isMobile])

  const answerIcon = isDify()
    ? <LogoAvatar className="relative shrink-0" />
    : (appData?.site && appData.site.use_icon_as_answer_icon)
        ? (
            <AnswerIcon
              iconType={appData.site.icon_type}
              icon={appData.site.icon}
              background={appData.site.icon_background}
              imageUrl={appData.site.icon_url}
            />
          )
        : null

  return (
    <Chat
      isTryApp={isTryApp}
      appData={appData || undefined}
      config={appConfig}
      chatList={messageList}
      isResponding={respondingState}
      chatContainerInnerClassName={cn('mx-auto w-full max-w-full px-4', messageList.length && 'pt-4')}
      chatFooterClassName={cn('pb-4', !isMobile && 'rounded-b-2xl')}
      chatFooterInnerClassName={cn('mx-auto w-full max-w-full px-4', isMobile && 'px-2')}
      onSend={doSend}
      inputs={currentConversationId ? currentConversationInputs as any : newConversationInputs}
      inputsForm={inputsForms}
      onRegenerate={doRegenerate}
      onStopResponding={handleStop}
      onHumanInputFormSubmit={handleSubmitHumanInputForm}
      chatNode={(
        <>
          {descriptionNode}
          {chatNode}
          {welcome}
        </>
      )}
      allToolIcons={appMeta?.tool_icons || {}}
      disableFeedback={disableFeedback}
      onFeedback={handleFeedback}
      suggestedQuestions={suggestedQuestions}
      answerIcon={answerIcon}
      hideProcessDetail
      themeBuilder={themeBuilder}
      switchSibling={doSwitchSibling}
      inputDisabled={inputDisabled}
      sendOnEnter={sendOnEnter}
      questionIcon={
        initUserVariables?.avatar_url
          ? (
              <Avatar
                avatar={initUserVariables.avatar_url}
                name={initUserVariables.name || 'user'}
                size="xl"
              />
            )
          : undefined
      }
    />
  )
}

export default ChatWrapper
