"use client"

import { useChat } from "@ai-sdk/react"
import { DefaultChatTransport } from "ai"
import {
    MessageSquarePlus,
    PanelRightClose,
    PanelRightOpen,
    Settings,
} from "lucide-react"
import Image from "next/image"
import type React from "react"
import { useCallback, useEffect, useRef, useState } from "react"
import { flushSync } from "react-dom"
import { Toaster, toast } from "sonner"
import { ButtonWithTooltip } from "@/components/button-with-tooltip"
import { ChatInput } from "@/components/chat-input"
import { ModelConfigDialog } from "@/components/model-config-dialog"
import { ResetWarningModal } from "@/components/reset-warning-modal"
import { SettingsDialog } from "@/components/settings-dialog"
import { useDiagram } from "@/contexts/diagram-context"
import { useDiagramToolHandlers } from "@/hooks/use-diagram-tool-handlers"
import { useDictionary } from "@/hooks/use-dictionary"
import { getSelectedAIConfig, useModelConfig } from "@/hooks/use-model-config"
import { getApiEndpoint } from "@/lib/base-path"
import { findCachedResponse } from "@/lib/cached-responses"
import { formatMessage } from "@/lib/i18n/utils"
import { isPdfFile, isTextFile } from "@/lib/pdf-utils"
import { type FileData, useFileProcessor } from "@/lib/use-file-processor"
import { useQuotaManager } from "@/lib/use-quota-manager"
import { formatXML } from "@/lib/utils"
import { ChatMessageDisplay } from "./chat-message-display"
import { DevXmlSimulator } from "./dev-xml-simulator"

// localStorage keys for persistence
const STORAGE_MESSAGES_KEY = "next-ai-draw-io-messages"
const STORAGE_XML_SNAPSHOTS_KEY = "next-ai-draw-io-xml-snapshots"
const STORAGE_SESSION_ID_KEY = "next-ai-draw-io-session-id"
export const STORAGE_DIAGRAM_XML_KEY = "next-ai-draw-io-diagram-xml"

// sessionStorage keys
const SESSION_STORAGE_INPUT_KEY = "next-ai-draw-io-input"

// Type for message parts (tool calls and their states)
interface MessagePart {
    type: string
    state?: string
    toolName?: string
    input?: { xml?: string; [key: string]: unknown }
    [key: string]: unknown
}

interface ChatMessage {
    role: string
    parts?: MessagePart[]
    [key: string]: unknown
}

interface ChatPanelProps {
    isVisible: boolean
    onToggleVisibility: () => void
    drawioUi: "min" | "sketch"
    onToggleDrawioUi: () => void
    darkMode: boolean
    onToggleDarkMode: () => void
    isMobile?: boolean
    onCloseProtectionChange?: (enabled: boolean) => void
}

// Constants for tool states
const TOOL_ERROR_STATE = "output-error" as const
const DEBUG = process.env.NODE_ENV === "development"
const MAX_AUTO_RETRY_COUNT = 1

const MAX_CONTINUATION_RETRY_COUNT = 2 // Limit for truncation continuation retries

/**
 * Check if auto-resubmit should happen based on tool errors.
 * Only checks the LAST tool part (most recent tool call), not all tool parts.
 */
function hasToolErrors(messages: ChatMessage[]): boolean {
    const lastMessage = messages[messages.length - 1]
    if (!lastMessage || lastMessage.role !== "assistant") {
        return false
    }

    const toolParts =
        (lastMessage.parts as MessagePart[] | undefined)?.filter((part) =>
            part.type?.startsWith("tool-"),
        ) || []

    if (toolParts.length === 0) {
        return false
    }

    const lastToolPart = toolParts[toolParts.length - 1]
    return lastToolPart?.state === TOOL_ERROR_STATE
}

export default function ChatPanel({
    isVisible,
    onToggleVisibility,
    drawioUi,
    onToggleDrawioUi,
    darkMode,
    onToggleDarkMode,
    isMobile = false,
    onCloseProtectionChange,
}: ChatPanelProps) {
    const {
        loadDiagram: onDisplayChart,
        handleExport: onExport,
        handleExportWithoutHistory,
        resolverRef,
        chartXML,
        clearDiagram,
    } = useDiagram()

    const dict = useDictionary()

    const onFetchChart = (saveToHistory = true) => {
        return Promise.race([
            new Promise<string>((resolve) => {
                if (resolverRef && "current" in resolverRef) {
                    resolverRef.current = resolve
                }
                if (saveToHistory) {
                    onExport()
                } else {
                    handleExportWithoutHistory()
                }
            }),
            new Promise<string>((_, reject) =>
                setTimeout(
                    () =>
                        reject(
                            new Error(
                                "Chart export timed out after 10 seconds",
                            ),
                        ),
                    10000,
                ),
            ),
        ])
    }

    // File processing using extracted hook
    const { files, pdfData, handleFileChange, setFiles } = useFileProcessor()

    const [showSettingsDialog, setShowSettingsDialog] = useState(false)
    const [showModelConfigDialog, setShowModelConfigDialog] = useState(false)

    // Model configuration hook
    const modelConfig = useModelConfig()
    const [input, setInput] = useState("")
    const [dailyRequestLimit, setDailyRequestLimit] = useState(0)
    const [dailyTokenLimit, setDailyTokenLimit] = useState(0)
    const [tpmLimit, setTpmLimit] = useState(0)
    const [showNewChatDialog, setShowNewChatDialog] = useState(false)
    const [minimalStyle, setMinimalStyle] = useState(false)

    // Restore input from sessionStorage on mount (when ChatPanel remounts due to key change)
    useEffect(() => {
        const savedInput = sessionStorage.getItem(SESSION_STORAGE_INPUT_KEY)
        if (savedInput) {
            setInput(savedInput)
        }
    }, [])

    // Check config on mount
    useEffect(() => {
        fetch(getApiEndpoint("/api/config"))
            .then((res) => res.json())
            .then((data) => {
                setDailyRequestLimit(data.dailyRequestLimit || 0)
                setDailyTokenLimit(data.dailyTokenLimit || 0)
                setTpmLimit(data.tpmLimit || 0)
            })
            .catch(() => {})
    }, [])

    // Quota management using extracted hook
    const quotaManager = useQuotaManager({
        dailyRequestLimit,
        dailyTokenLimit,
        tpmLimit,
        onConfigModel: () => setShowModelConfigDialog(true),
    })

    // Generate a unique session ID for Langfuse tracing (restore from localStorage if available)
    const [sessionId, setSessionId] = useState(() => {
        if (typeof window !== "undefined") {
            const saved = localStorage.getItem(STORAGE_SESSION_ID_KEY)
            if (saved) return saved
        }
        return `session-${Date.now()}-${Math.random().toString(36).slice(2, 9)}`
    })

    // Store XML snapshots for each user message (keyed by message index)
    const xmlSnapshotsRef = useRef<Map<number, string>>(new Map())

    // Flag to track if we've restored from localStorage
    const hasRestoredRef = useRef(false)

    // Ref to track latest chartXML for use in callbacks (avoids stale closure)
    const chartXMLRef = useRef(chartXML)
    useEffect(() => {
        chartXMLRef.current = chartXML
    }, [chartXML])

    // Ref to track consecutive auto-retry count (reset on user action)
    const autoRetryCountRef = useRef(0)
    // Ref to track continuation retry count (for truncation handling)
    const continuationRetryCountRef = useRef(0)

    // Ref to accumulate partial XML when output is truncated due to maxOutputTokens
    // When partialXmlRef.current.length > 0, we're in continuation mode
    const partialXmlRef = useRef<string>("")

    // Persist processed tool call IDs so collapsing the chat doesn't replay old tool outputs
    const processedToolCallsRef = useRef<Set<string>>(new Set())

    // Store original XML for edit_diagram streaming - shared between streaming preview and tool handler
    // Key: toolCallId, Value: original XML before any operations applied
    const editDiagramOriginalXmlRef = useRef<Map<string, string>>(new Map())

    // Debounce timeout for localStorage writes (prevents blocking during streaming)
    const localStorageDebounceRef = useRef<ReturnType<
        typeof setTimeout
    > | null>(null)
    const LOCAL_STORAGE_DEBOUNCE_MS = 1000 // Save at most once per second

    // Diagram tool handlers (display_diagram, edit_diagram, append_diagram)
    const { handleToolCall } = useDiagramToolHandlers({
        partialXmlRef,
        editDiagramOriginalXmlRef,
        chartXMLRef,
        onDisplayChart,
        onFetchChart,
        onExport,
    })

    const { messages, sendMessage, addToolOutput, status, error, setMessages } =
        useChat({
            transport: new DefaultChatTransport({
                api: getApiEndpoint("/api/chat"),
            }),
            onToolCall: async ({ toolCall }) => {
                await handleToolCall({ toolCall }, addToolOutput)
            },
            onError: (error) => {
                // Handle server-side quota limit (429 response)
                // AI SDK puts the full response body in error.message for non-OK responses
                try {
                    const data = JSON.parse(error.message)
                    if (data.type === "request") {
                        quotaManager.showQuotaLimitToast(data.used, data.limit)
                        return
                    }
                    if (data.type === "token") {
                        quotaManager.showTokenLimitToast(data.used, data.limit)
                        return
                    }
                    if (data.type === "tpm") {
                        quotaManager.showTPMLimitToast(data.limit)
                        return
                    }
                } catch {
                    // Not JSON, fall through to string matching for backwards compatibility
                }

                // Fallback to string matching
                if (error.message.includes("Daily request limit")) {
                    quotaManager.showQuotaLimitToast()
                    return
                }
                if (error.message.includes("Daily token limit")) {
                    quotaManager.showTokenLimitToast()
                    return
                }
                if (
                    error.message.includes("Rate limit exceeded") ||
                    error.message.includes("tokens per minute")
                ) {
                    quotaManager.showTPMLimitToast()
                    return
                }

                // Silence access code error in console since it's handled by UI
                if (!error.message.includes("Invalid or missing access code")) {
                    console.error("Chat error:", error)
                    // Debug: Log messages structure when error occurs
                    console.log("[onError] messages count:", messages.length)
                    messages.forEach((msg, idx) => {
                        console.log(`[onError] Message ${idx}:`, {
                            role: msg.role,
                            partsCount: msg.parts?.length,
                        })
                        if (msg.parts) {
                            msg.parts.forEach((part: any, partIdx: number) => {
                                console.log(
                                    `[onError]   Part ${partIdx}:`,
                                    JSON.stringify({
                                        type: part.type,
                                        toolName: part.toolName,
                                        hasInput: !!part.input,
                                        inputType: typeof part.input,
                                        inputKeys:
                                            part.input &&
                                            typeof part.input === "object"
                                                ? Object.keys(part.input)
                                                : null,
                                    }),
                                )
                            })
                        }
                    })
                }

                // Translate technical errors into user-friendly messages
                // The server now handles detailed error messages, so we can display them directly.
                // But we still handle connection/network errors that happen before reaching the server.
                let friendlyMessage = error.message

                // Simple check for network errors if message is generic
                if (friendlyMessage === "Failed to fetch") {
                    friendlyMessage =
                        "Network error. Please check your connection."
                }

                // Truncated tool input error (model output limit too low)
                if (friendlyMessage.includes("toolUse.input is invalid")) {
                    friendlyMessage =
                        "Output was truncated before the diagram could be generated. Try a simpler request or increase the maxOutputLength."
                }

                // Translate image not supported error
                if (
                    friendlyMessage.includes("image content block") ||
                    friendlyMessage.toLowerCase().includes("image_url")
                ) {
                    friendlyMessage = "This model doesn't support image input."
                }

                // Add system message for error so it can be cleared
                setMessages((currentMessages) => {
                    const errorMessage = {
                        id: `error-${Date.now()}`,
                        role: "system" as const,
                        content: friendlyMessage,
                        parts: [
                            { type: "text" as const, text: friendlyMessage },
                        ],
                    }
                    return [...currentMessages, errorMessage]
                })

                if (error.message.includes("Invalid or missing access code")) {
                    // Show settings dialog to help user fix it
                    setShowSettingsDialog(true)
                }
            },
            onFinish: ({ message }) => {
                // Track actual token usage from server metadata
                const metadata = message?.metadata as
                    | Record<string, unknown>
                    | undefined

                // DEBUG: Log finish reason to diagnose truncation
                console.log("[onFinish] finishReason:", metadata?.finishReason)
            },
            sendAutomaticallyWhen: ({ messages }) => {
                const isInContinuationMode = partialXmlRef.current.length > 0

                const shouldRetry = hasToolErrors(
                    messages as unknown as ChatMessage[],
                )

                if (!shouldRetry) {
                    // No error, reset retry count and clear state
                    autoRetryCountRef.current = 0
                    continuationRetryCountRef.current = 0
                    partialXmlRef.current = ""
                    return false
                }

                // Continuation mode: limited retries for truncation handling
                if (isInContinuationMode) {
                    if (
                        continuationRetryCountRef.current >=
                        MAX_CONTINUATION_RETRY_COUNT
                    ) {
                        toast.error(
                            formatMessage(dict.errors.continuationRetryLimit, {
                                max: MAX_CONTINUATION_RETRY_COUNT,
                            }),
                        )
                        continuationRetryCountRef.current = 0
                        partialXmlRef.current = ""
                        return false
                    }
                    continuationRetryCountRef.current++
                } else {
                    // Regular error: check retry count limit
                    if (autoRetryCountRef.current >= MAX_AUTO_RETRY_COUNT) {
                        toast.error(
                            formatMessage(dict.errors.retryLimit, {
                                max: MAX_AUTO_RETRY_COUNT,
                            }),
                        )
                        autoRetryCountRef.current = 0
                        partialXmlRef.current = ""
                        return false
                    }
                    // Increment retry count for actual errors
                    autoRetryCountRef.current++
                }

                return true
            },
        })

    // Ref to track latest messages for unload persistence
    const messagesRef = useRef(messages)
    useEffect(() => {
        messagesRef.current = messages
    }, [messages])

    const messagesEndRef = useRef<HTMLDivElement>(null)

    // Restore messages and XML snapshots from localStorage on mount
    useEffect(() => {
        if (hasRestoredRef.current) return
        hasRestoredRef.current = true

        try {
            // Restore messages
            const savedMessages = localStorage.getItem(STORAGE_MESSAGES_KEY)
            if (savedMessages) {
                const parsed = JSON.parse(savedMessages)
                if (Array.isArray(parsed) && parsed.length > 0) {
                    setMessages(parsed)
                }
            }

            // Restore XML snapshots
            const savedSnapshots = localStorage.getItem(
                STORAGE_XML_SNAPSHOTS_KEY,
            )
            if (savedSnapshots) {
                const parsed = JSON.parse(savedSnapshots)
                xmlSnapshotsRef.current = new Map(parsed)
            }
        } catch (error) {
            console.error("Failed to restore from localStorage:", error)
            // On complete failure, clear storage to allow recovery
            localStorage.removeItem(STORAGE_MESSAGES_KEY)
            localStorage.removeItem(STORAGE_XML_SNAPSHOTS_KEY)
            toast.error(dict.errors.sessionCorrupted)
        }
    }, [setMessages])

    // Save messages to localStorage whenever they change (debounced to prevent blocking during streaming)
    useEffect(() => {
        if (!hasRestoredRef.current) return

        // Clear any pending save
        if (localStorageDebounceRef.current) {
            clearTimeout(localStorageDebounceRef.current)
        }

        // Debounce: save after 1 second of no changes
        localStorageDebounceRef.current = setTimeout(() => {
            try {
                localStorage.setItem(
                    STORAGE_MESSAGES_KEY,
                    JSON.stringify(messages),
                )
            } catch (error) {
                console.error("Failed to save messages to localStorage:", error)
            }
        }, LOCAL_STORAGE_DEBOUNCE_MS)

        // Cleanup on unmount
        return () => {
            if (localStorageDebounceRef.current) {
                clearTimeout(localStorageDebounceRef.current)
            }
        }
    }, [messages])

    // Save XML snapshots to localStorage whenever they change
    const saveXmlSnapshots = useCallback(() => {
        try {
            const snapshotsArray = Array.from(xmlSnapshotsRef.current.entries())
            localStorage.setItem(
                STORAGE_XML_SNAPSHOTS_KEY,
                JSON.stringify(snapshotsArray),
            )
        } catch (error) {
            console.error(
                "Failed to save XML snapshots to localStorage:",
                error,
            )
        }
    }, [])

    // Save session ID to localStorage
    useEffect(() => {
        localStorage.setItem(STORAGE_SESSION_ID_KEY, sessionId)
    }, [sessionId])

    useEffect(() => {
        if (messagesEndRef.current) {
            messagesEndRef.current.scrollIntoView({ behavior: "smooth" })
        }
    }, [messages])

    // Save state right before page unload (refresh/close)
    useEffect(() => {
        const handleBeforeUnload = () => {
            try {
                localStorage.setItem(
                    STORAGE_MESSAGES_KEY,
                    JSON.stringify(messagesRef.current),
                )
                localStorage.setItem(
                    STORAGE_XML_SNAPSHOTS_KEY,
                    JSON.stringify(
                        Array.from(xmlSnapshotsRef.current.entries()),
                    ),
                )
                const xml = chartXMLRef.current
                if (xml && xml.length > 300) {
                    localStorage.setItem(STORAGE_DIAGRAM_XML_KEY, xml)
                }
                localStorage.setItem(STORAGE_SESSION_ID_KEY, sessionId)
            } catch (error) {
                console.error("Failed to persist state before unload:", error)
            }
        }

        window.addEventListener("beforeunload", handleBeforeUnload)
        return () =>
            window.removeEventListener("beforeunload", handleBeforeUnload)
    }, [sessionId])

    const onFormSubmit = async (e: React.FormEvent<HTMLFormElement>) => {
        e.preventDefault()
        const isProcessing = status === "streaming" || status === "submitted"
        if (input.trim() && !isProcessing) {
            // Check if input matches a cached example (only when no messages yet)
            if (messages.length === 0) {
                const cached = findCachedResponse(
                    input.trim(),
                    files.length > 0,
                )
                if (cached) {
                    // Add user message and fake assistant response to messages
                    // The chat-message-display useEffect will handle displaying the diagram
                    const toolCallId = `cached-${Date.now()}`

                    // Build user message text including any file content
                    const userText = await processFilesAndAppendContent(
                        input,
                        files,
                        pdfData,
                    )

                    setMessages([
                        {
                            id: `user-${Date.now()}`,
                            role: "user" as const,
                            parts: [{ type: "text" as const, text: userText }],
                        },
                        {
                            id: `assistant-${Date.now()}`,
                            role: "assistant" as const,
                            parts: [
                                {
                                    type: "tool-display_diagram" as const,
                                    toolCallId,
                                    state: "output-available" as const,
                                    input: { xml: cached.xml },
                                    output: "Successfully displayed the diagram.",
                                },
                            ],
                        },
                    ] as any)
                    setInput("")
                    sessionStorage.removeItem(SESSION_STORAGE_INPUT_KEY)
                    setFiles([])
                    return
                }
            }

            try {
                let chartXml = await onFetchChart()
                chartXml = formatXML(chartXml)

                // Update ref directly to avoid race condition with React's async state update
                // This ensures edit_diagram has the correct XML before AI responds
                chartXMLRef.current = chartXml

                // Build user text by concatenating input with pre-extracted text
                // (Backend only reads first text part, so we must combine them)
                const parts: any[] = []
                const userText = await processFilesAndAppendContent(
                    input,
                    files,
                    pdfData,
                    parts,
                )

                // Add the combined text as the first part
                parts.unshift({ type: "text", text: userText })

                // Get previous XML from the last snapshot (before this message)
                const snapshotKeys = Array.from(
                    xmlSnapshotsRef.current.keys(),
                ).sort((a, b) => b - a)
                const previousXml =
                    snapshotKeys.length > 0
                        ? xmlSnapshotsRef.current.get(snapshotKeys[0]) || ""
                        : ""

                // Save XML snapshot for this message (will be at index = current messages.length)
                const messageIndex = messages.length
                xmlSnapshotsRef.current.set(messageIndex, chartXml)
                saveXmlSnapshots()

                sendChatMessage(parts, chartXml, previousXml, sessionId)

                // Token count is tracked in onFinish with actual server usage
                setInput("")
                sessionStorage.removeItem(SESSION_STORAGE_INPUT_KEY)
                setFiles([])
            } catch (error) {
                console.error("Error fetching chart data:", error)
            }
        }
    }

    const handleNewChat = useCallback(() => {
        setMessages([])
        clearDiagram()
        handleFileChange([]) // Use handleFileChange to also clear pdfData
        const newSessionId = `session-${Date.now()}-${Math.random()
            .toString(36)
            .slice(2, 9)}`
        setSessionId(newSessionId)
        xmlSnapshotsRef.current.clear()
        // Clear localStorage with error handling
        try {
            localStorage.removeItem(STORAGE_MESSAGES_KEY)
            localStorage.removeItem(STORAGE_XML_SNAPSHOTS_KEY)
            localStorage.removeItem(STORAGE_DIAGRAM_XML_KEY)
            localStorage.setItem(STORAGE_SESSION_ID_KEY, newSessionId)
            sessionStorage.removeItem(SESSION_STORAGE_INPUT_KEY)
            toast.success(dict.dialogs.clearSuccess)
        } catch (error) {
            console.error("Failed to clear localStorage:", error)
            toast.warning(dict.errors.storageUpdateFailed)
        }

        setShowNewChatDialog(false)
    }, [clearDiagram, handleFileChange, setMessages, setSessionId])

    const handleInputChange = (
        e: React.ChangeEvent<HTMLInputElement | HTMLTextAreaElement>,
    ) => {
        saveInputToSessionStorage(e.target.value)
        setInput(e.target.value)
    }

    const saveInputToSessionStorage = (input: string) => {
        sessionStorage.setItem(SESSION_STORAGE_INPUT_KEY, input)
    }

    // Helper functions for message actions (regenerate/edit)
    // Extract previous XML snapshot before a given message index
    const getPreviousXml = (beforeIndex: number): string => {
        const snapshotKeys = Array.from(xmlSnapshotsRef.current.keys())
            .filter((k) => k < beforeIndex)
            .sort((a, b) => b - a)
        return snapshotKeys.length > 0
            ? xmlSnapshotsRef.current.get(snapshotKeys[0]) || ""
            : ""
    }

    // Restore diagram from snapshot and update ref
    const restoreDiagramFromSnapshot = (savedXml: string) => {
        onDisplayChart(savedXml, true) // Skip validation for trusted snapshots
        chartXMLRef.current = savedXml
    }

    // Clean up snapshots after a given message index
    const cleanupSnapshotsAfter = (messageIndex: number) => {
        for (const key of xmlSnapshotsRef.current.keys()) {
            if (key > messageIndex) {
                xmlSnapshotsRef.current.delete(key)
            }
        }
        saveXmlSnapshots()
    }

    // Send chat message with headers
    const sendChatMessage = (
        parts: any,
        xml: string,
        previousXml: string,
        sessionId: string,
    ) => {
        // Reset all retry/continuation state on user-initiated message
        autoRetryCountRef.current = 0
        continuationRetryCountRef.current = 0
        partialXmlRef.current = ""

        const config = getSelectedAIConfig()

        sendMessage(
            { parts },
            {
                body: { xml, previousXml, sessionId },
                headers: {
                    "x-access-code": config.accessCode,
                    ...(config.aiProvider && {
                        "x-ai-provider": config.aiProvider,
                        ...(config.aiBaseUrl && {
                            "x-ai-base-url": config.aiBaseUrl,
                        }),
                        ...(config.aiApiKey && {
                            "x-ai-api-key": config.aiApiKey,
                        }),
                        ...(config.aiModel && { "x-ai-model": config.aiModel }),
                        // AWS Bedrock credentials
                        ...(config.awsAccessKeyId && {
                            "x-aws-access-key-id": config.awsAccessKeyId,
                        }),
                        ...(config.awsSecretAccessKey && {
                            "x-aws-secret-access-key":
                                config.awsSecretAccessKey,
                        }),
                        ...(config.awsRegion && {
                            "x-aws-region": config.awsRegion,
                        }),
                        ...(config.awsSessionToken && {
                            "x-aws-session-token": config.awsSessionToken,
                        }),
                    }),
                    ...(minimalStyle && {
                        "x-minimal-style": "true",
                    }),
                },
            },
        )
    }

    // Process files and append content to user text (handles PDF, text, and optionally images)
    const processFilesAndAppendContent = async (
        baseText: string,
        files: File[],
        pdfData: Map<File, FileData>,
        imageParts?: any[],
    ): Promise<string> => {
        let userText = baseText

        for (const file of files) {
            if (isPdfFile(file)) {
                const extracted = pdfData.get(file)
                if (extracted?.text) {
                    userText += `\n\n[PDF: ${file.name}]\n${extracted.text}`
                }
            } else if (isTextFile(file)) {
                const extracted = pdfData.get(file)
                if (extracted?.text) {
                    userText += `\n\n[File: ${file.name}]\n${extracted.text}`
                }
            } else if (imageParts) {
                // Handle as image (only if imageParts array provided)
                const reader = new FileReader()
                const dataUrl = await new Promise<string>((resolve) => {
                    reader.onload = () => resolve(reader.result as string)
                    reader.readAsDataURL(file)
                })

                imageParts.push({
                    type: "file",
                    url: dataUrl,
                    mediaType: file.type,
                })
            }
        }

        return userText
    }

    const handleRegenerate = async (messageIndex: number) => {
        const isProcessing = status === "streaming" || status === "submitted"
        if (isProcessing) return

        // Find the user message before this assistant message
        let userMessageIndex = messageIndex - 1
        while (
            userMessageIndex >= 0 &&
            messages[userMessageIndex].role !== "user"
        ) {
            userMessageIndex--
        }

        if (userMessageIndex < 0) return

        const userMessage = messages[userMessageIndex]
        const userParts = userMessage.parts

        // Get the text from the user message
        const textPart = userParts?.find((p: any) => p.type === "text")
        if (!textPart) return

        // Get the saved XML snapshot for this user message
        const savedXml = xmlSnapshotsRef.current.get(userMessageIndex)
        if (!savedXml) {
            console.error(
                "No saved XML snapshot for message index:",
                userMessageIndex,
            )
            return
        }

        // Get previous XML and restore diagram state
        const previousXml = getPreviousXml(userMessageIndex)
        restoreDiagramFromSnapshot(savedXml)

        // Clean up snapshots for messages after the user message (they will be removed)
        cleanupSnapshotsAfter(userMessageIndex)

        // Remove the user message AND assistant message onwards (sendMessage will re-add the user message)
        // Use flushSync to ensure state update is processed synchronously before sending
        const newMessages = messages.slice(0, userMessageIndex)
        flushSync(() => {
            setMessages(newMessages)
        })

        // Now send the message after state is guaranteed to be updated
        sendChatMessage(userParts, savedXml, previousXml, sessionId)
    }

    const handleEditMessage = async (messageIndex: number, newText: string) => {
        const isProcessing = status === "streaming" || status === "submitted"
        if (isProcessing) return

        const message = messages[messageIndex]
        if (!message || message.role !== "user") return

        // Get the saved XML snapshot for this user message
        const savedXml = xmlSnapshotsRef.current.get(messageIndex)
        if (!savedXml) {
            console.error(
                "No saved XML snapshot for message index:",
                messageIndex,
            )
            return
        }

        // Get previous XML and restore diagram state
        const previousXml = getPreviousXml(messageIndex)
        restoreDiagramFromSnapshot(savedXml)

        // Clean up snapshots for messages after the user message (they will be removed)
        cleanupSnapshotsAfter(messageIndex)

        // Create new parts with updated text
        const newParts = message.parts?.map((part: any) => {
            if (part.type === "text") {
                return { ...part, text: newText }
            }
            return part
        }) || [{ type: "text", text: newText }]

        // Remove the user message AND assistant message onwards (sendMessage will re-add the user message)
        // Use flushSync to ensure state update is processed synchronously before sending
        const newMessages = messages.slice(0, messageIndex)
        flushSync(() => {
            setMessages(newMessages)
        })

        // Now send the edited message after state is guaranteed to be updated
        sendChatMessage(newParts, savedXml, previousXml, sessionId)
    }

    // Collapsed view (desktop only)
    if (!isVisible && !isMobile) {
        return (
            <div className="h-full flex flex-col items-center pt-4 bg-card border border-border/30 rounded-xl">
                <ButtonWithTooltip
                    tooltipContent={dict.nav.showPanel}
                    variant="ghost"
                    size="icon"
                    onClick={onToggleVisibility}
                    className="hover:bg-accent transition-colors"
                >
                    <PanelRightOpen className="h-5 w-5 text-muted-foreground" />
                </ButtonWithTooltip>
                <div
                    className="text-sm font-medium text-muted-foreground mt-8 tracking-wide"
                    style={{
                        writingMode: "vertical-rl",
                    }}
                >
                    {dict.nav.aiChat}
                </div>
            </div>
        )
    }

    // Full view
    return (
        <div className="h-full flex flex-col bg-card shadow-soft animate-slide-in-right rounded-xl border border-border/30 relative">
            <Toaster
                position="bottom-center"
                richColors
                expand
                style={{ position: "absolute" }}
                toastOptions={{
                    style: {
                        maxWidth: "480px",
                    },
                    duration: 2000,
                }}
            />
            {/* Header */}
            <header
                className={`${isMobile ? "px-3 py-2" : "px-5 py-4"} border-b border-border/50`}
            >
                <div className="flex items-center justify-between">
                    <div className="flex items-center gap-2 overflow-x-hidden">
                        <div className="flex items-center gap-2">
                            <Image
                                src={
                                    darkMode
                                        ? "/favicon-white.svg"
                                        : "/favicon.ico"
                                }
                                alt="Next AI Drawio"
                                width={isMobile ? 24 : 28}
                                height={isMobile ? 24 : 28}
                                className="rounded flex-shrink-0"
                            />
                            <h1
                                className={`${isMobile ? "text-sm" : "text-base"} font-semibold tracking-tight whitespace-nowrap`}
                            >
                                Next AI Drawio
                            </h1>
                        </div>
                    </div>
                    <div className="flex items-center gap-1 justify-end overflow-visible">
                        <ButtonWithTooltip
                            tooltipContent={dict.nav.newChat}
                            variant="ghost"
                            size="icon"
                            onClick={() => setShowNewChatDialog(true)}
                            className="hover:bg-accent"
                        >
                            <MessageSquarePlus
                                className={`${isMobile ? "h-4 w-4" : "h-5 w-5"} text-muted-foreground`}
                            />
                        </ButtonWithTooltip>

                        <ButtonWithTooltip
                            tooltipContent={dict.nav.settings}
                            variant="ghost"
                            size="icon"
                            onClick={() => setShowSettingsDialog(true)}
                            className="hover:bg-accent"
                        >
                            <Settings
                                className={`${isMobile ? "h-4 w-4" : "h-5 w-5"} text-muted-foreground`}
                            />
                        </ButtonWithTooltip>
                        <div className="hidden sm:flex items-center gap-2">
                            {!isMobile && (
                                <ButtonWithTooltip
                                    tooltipContent={dict.nav.hidePanel}
                                    variant="ghost"
                                    size="icon"
                                    className="hover:bg-accent"
                                    onClick={onToggleVisibility}
                                >
                                    <PanelRightClose className="h-5 w-5 text-muted-foreground" />
                                </ButtonWithTooltip>
                            )}
                        </div>
                    </div>
                </div>
            </header>

            {/* Messages */}
            <main className="flex-1 w-full overflow-hidden">
                <ChatMessageDisplay
                    messages={messages}
                    setInput={setInput}
                    setFiles={handleFileChange}
                    processedToolCallsRef={processedToolCallsRef}
                    editDiagramOriginalXmlRef={editDiagramOriginalXmlRef}
                    sessionId={sessionId}
                    onRegenerate={handleRegenerate}
                    status={status}
                    onEditMessage={handleEditMessage}
                />
            </main>

            {/* Dev XML Streaming Simulator - only in development */}
            {DEBUG && (
                <DevXmlSimulator
                    setMessages={setMessages}
                    onDisplayChart={onDisplayChart}
                    onShowQuotaToast={() =>
                        quotaManager.showQuotaLimitToast(50, 50)
                    }
                />
            )}

            {/* Input */}
            <footer
                className={`${isMobile ? "p-2" : "p-4"} border-t border-border/50 bg-card/50`}
            >
                <ChatInput
                    input={input}
                    status={status}
                    onSubmit={onFormSubmit}
                    onChange={handleInputChange}
                    onClearChat={handleNewChat}
                    files={files}
                    onFileChange={handleFileChange}
                    pdfData={pdfData}
                    sessionId={sessionId}
                    error={error}
                    models={modelConfig.models}
                    selectedModelId={modelConfig.selectedModelId}
                    onModelSelect={modelConfig.setSelectedModelId}
                    showUnvalidatedModels={modelConfig.showUnvalidatedModels}
                    onConfigureModels={() => setShowModelConfigDialog(true)}
                />
            </footer>

            <SettingsDialog
                open={showSettingsDialog}
                onOpenChange={setShowSettingsDialog}
                onCloseProtectionChange={onCloseProtectionChange}
                drawioUi={drawioUi}
                onToggleDrawioUi={onToggleDrawioUi}
                darkMode={darkMode}
                onToggleDarkMode={onToggleDarkMode}
                minimalStyle={minimalStyle}
                onMinimalStyleChange={setMinimalStyle}
            />

            <ModelConfigDialog
                open={showModelConfigDialog}
                onOpenChange={setShowModelConfigDialog}
                modelConfig={modelConfig}
            />

            <ResetWarningModal
                open={showNewChatDialog}
                onOpenChange={setShowNewChatDialog}
                onClear={handleNewChat}
            />
        </div>
    )
}