import React from "react"
import { cleanUrl } from "~libs/clean-url"
import {
  getOllamaURL,
  promptForRag,
  systemPromptForNonRag
} from "~services/ollama"
import { useStoreMessage, type ChatHistory, type Message } from "~store"
import { ChatOllama } from "@langchain/community/chat_models/ollama"
import {
  HumanMessage,
  AIMessage,
  type MessageContent,
  SystemMessage
} from "@langchain/core/messages"
import { getHtmlOfCurrentTab } from "~libs/get-html"
import { PageAssistHtmlLoader } from "~loader/html"
import { RecursiveCharacterTextSplitter } from "langchain/text_splitter"
import { OllamaEmbeddings } from "@langchain/community/embeddings/ollama"
import { createChatWithWebsiteChain } from "~chain/chat-with-website"
import { MemoryVectorStore } from "langchain/vectorstores/memory"

export type BotResponse = {
  bot: {
    text: string
    sourceDocuments: any[]
  }
  history: ChatHistory
  history_id: string
}

const generateHistory = (
  messages: {
    role: "user" | "assistant" | "system"
    content: string
    image?: string
  }[]
) => {
  let history = []
  for (const message of messages) {
    if (message.role === "user") {
      let content: MessageContent = [
        {
          type: "text",
          text: message.content
        }
      ]

      if (message.image) {
        content = [
          {
            type: "image_url",
            image_url: message.image
          },
          {
            type: "text",
            text: message.content
          }
        ]
      }
      history.push(
        new HumanMessage({
          content: content
        })
      )
    } else if (message.role === "assistant") {
      history.push(
        new AIMessage({
          content: [
            {
              type: "text",
              text: message.content
            }
          ]
        })
      )
    }
  }
  return history
}

export const useMessage = () => {
  const {
    history,
    messages,
    setHistory,
    setMessages,
    setStreaming,
    streaming,
    setIsFirstMessage,
    historyId,
    setHistoryId,
    isLoading,
    setIsLoading,
    isProcessing,
    setIsProcessing,
    selectedModel,
    setSelectedModel,
    chatMode,
    setChatMode,
    setIsEmbedding,
    isEmbedding
  } = useStoreMessage()

  const abortControllerRef = React.useRef<AbortController | null>(null)

  const [keepTrackOfEmbedding, setKeepTrackOfEmbedding] = React.useState<{
    [key: string]: MemoryVectorStore
  }>({})

  const clearChat = () => {
    stopStreamingRequest()
    setMessages([])
    setHistory([])
    setHistoryId(null)
    setIsFirstMessage(true)
    setIsLoading(false)
    setIsProcessing(false)
    setStreaming(false)
  }

  const memoryEmbedding = async (
    url: string,
    html: string,
    ollamaEmbedding: OllamaEmbeddings
  ) => {
    const loader = new PageAssistHtmlLoader({
      html,
      url
    })
    const docs = await loader.load()
    const textSplitter = new RecursiveCharacterTextSplitter({
      chunkSize: 1000,
      chunkOverlap: 200
    })

    const chunks = await textSplitter.splitDocuments(docs)

    const store = new MemoryVectorStore(ollamaEmbedding)

    setIsEmbedding(true)

    await store.addDocuments(chunks)
    setKeepTrackOfEmbedding({
      ...keepTrackOfEmbedding,
      [url]: store
    })
    setIsEmbedding(false)

    return store
  }

  const chatWithWebsiteMode = async (message: string) => {
    const ollamaUrl = await getOllamaURL()
    const { html, url } = await getHtmlOfCurrentTab()
    const isAlreadyExistEmbedding = keepTrackOfEmbedding[url]
    let newMessage: Message[] = [
      ...messages,
      {
        isBot: false,
        name: "You",
        message,
        sources: []
      },
      {
        isBot: true,
        name: selectedModel,
        message: "▋",
        sources: []
      }
    ]

    const appendingIndex = newMessage.length - 1
    setMessages(newMessage)
    const ollamaEmbedding = new OllamaEmbeddings({
      model: selectedModel,
      baseUrl: cleanUrl(ollamaUrl)
    })

    const ollamaChat = new ChatOllama({
      model: selectedModel,
      baseUrl: cleanUrl(ollamaUrl)
    })

    let vectorstore: MemoryVectorStore

    if (isAlreadyExistEmbedding) {
      vectorstore = isAlreadyExistEmbedding
    } else {
      vectorstore = await memoryEmbedding(url, html, ollamaEmbedding)
    }

    const { ragPrompt: systemPrompt, ragQuestionPrompt: questionPrompt } =
      await promptForRag()

    const sanitizedQuestion = message.trim().replaceAll("\n", " ")

    const chain = createChatWithWebsiteChain({
      llm: ollamaChat,
      question_llm: ollamaChat,
      question_template: questionPrompt,
      response_template: systemPrompt,
      retriever: vectorstore.asRetriever()
    })

    try {
      const chunks = await chain.stream({
        question: sanitizedQuestion
      })
      let count = 0
      for await (const chunk of chunks) {
        if (count === 0) {
          setIsProcessing(true)
          newMessage[appendingIndex].message = chunk + "▋"
          setMessages(newMessage)
        } else {
          newMessage[appendingIndex].message =
            newMessage[appendingIndex].message.slice(0, -1) + chunk + "▋"
          setMessages(newMessage)
        }

        count++
      }

      newMessage[appendingIndex].message = newMessage[
        appendingIndex
      ].message.slice(0, -1)

      setHistory([
        ...history,
        {
          role: "user",
          content: message
        },
        {
          role: "assistant",
          content: newMessage[appendingIndex].message
        }
      ])

      setIsProcessing(false)
    } catch (e) {
      console.log(e)
      setIsProcessing(false)
      setStreaming(false)

      setMessages([
        ...messages,
        {
          isBot: true,
          name: selectedModel,
          message: `Something went wrong. Check out the following logs:
~~~
${e?.message}
 ~~~
        `,
          sources: []
        }
      ])
    }
  }

  const normalChatMode = async (message: string, image: string) => {
    const url = await getOllamaURL()

    if (image.length > 0) {
      image = `data:image/jpeg;base64,${image.split(",")[1]}`
    }
    abortControllerRef.current = new AbortController()

    const ollama = new ChatOllama({
      model: selectedModel,
      baseUrl: cleanUrl(url)
    })

    let newMessage: Message[] = [
      ...messages,
      {
        isBot: false,
        name: "You",
        message,
        sources: [],
        images: [image]
      },
      {
        isBot: true,
        name: selectedModel,
        message: "▋",
        sources: []
      }
    ]

    const appendingIndex = newMessage.length - 1
    setMessages(newMessage)

    try {
      const prompt = await systemPromptForNonRag()

      message = message.trim().replaceAll("\n", " ")

      let humanMessage = new HumanMessage({
        content: [
          {
            text: message,
            type: "text"
          }
        ]
      })
      if (image.length > 0) {
        humanMessage = new HumanMessage({
          content: [
            {
              text: message,
              type: "text"
            },
            {
              image_url: image,
              type: "image_url"
            }
          ]
        })
      }

      const applicationChatHistory = generateHistory(history)

      if (prompt) {
        applicationChatHistory.unshift(
          new SystemMessage({
            content: [
              {
                text: prompt,
                type: "text"
              }
            ]
          })
        )
      }

      const chunks = await ollama.stream(
        [...applicationChatHistory, humanMessage],
        {
          signal: abortControllerRef.current.signal
        }
      )
      let count = 0
      for await (const chunk of chunks) {
        if (count === 0) {
          setIsProcessing(true)
          newMessage[appendingIndex].message = chunk.content + "▋"
          setMessages(newMessage)
        } else {
          newMessage[appendingIndex].message =
            newMessage[appendingIndex].message.slice(0, -1) +
            chunk.content +
            "▋"
          setMessages(newMessage)
        }

        count++
      }

      newMessage[appendingIndex].message = newMessage[
        appendingIndex
      ].message.slice(0, -1)

      setHistory([
        ...history,
        {
          role: "user",
          content: message,
          image
        },
        {
          role: "assistant",
          content: newMessage[appendingIndex].message
        }
      ])

      setIsProcessing(false)
    } catch (e) {
      console.log(e)
      setIsProcessing(false)
      setStreaming(false)

      setMessages([
        ...messages,
        {
          isBot: true,
          name: selectedModel,
          message: `Something went wrong. Check out the following logs:
        \`\`\`
        ${e?.message}
        \`\`\`
        `,
          sources: []
        }
      ])
    }
  }

  const onSubmit = async ({
    message,
    image
  }: {
    message: string
    image: string
  }) => {
    if (chatMode === "normal") {
      await normalChatMode(message, image)
    } else {
      await chatWithWebsiteMode(message)
    }
  }

  const stopStreamingRequest = () => {
    if (abortControllerRef.current) {
      abortControllerRef.current.abort()
      abortControllerRef.current = null
    }
  }

  return {
    messages,
    setMessages,
    onSubmit,
    setStreaming,
    streaming,
    setHistory,
    historyId,
    setHistoryId,
    setIsFirstMessage,
    isLoading,
    setIsLoading,
    isProcessing,
    stopStreamingRequest,
    clearChat,
    selectedModel,
    setSelectedModel,
    chatMode,
    setChatMode,
    isEmbedding
  }
}