import { VSCodeButton, VSCodeLink } from "@vscode/webview-ui-toolkit/react"
import debounce from "debounce"
import { useCallback, useEffect, useMemo, useRef, useState } from "react"
import { useDeepCompareEffect, useEvent, useMount } from "react-use"
import { Virtuoso, type VirtuosoHandle } from "react-virtuoso"
import styled from "styled-components"
import {
	ClineAsk,
	ClineMessage,
	ClineSayBrowserAction,
	ClineSayTool,
	ExtensionMessage,
} from "../../../../src/shared/ExtensionMessage"
import { McpServer, McpTool } from "../../../../src/shared/mcp"
import { findLast } from "../../../../src/shared/array"
import { combineApiRequests } from "../../../../src/shared/combineApiRequests"
import { combineCommandSequences } from "../../../../src/shared/combineCommandSequences"
import { getApiMetrics } from "../../../../src/shared/getApiMetrics"
import { useExtensionState } from "../../context/ExtensionStateContext"
import { vscode } from "../../utils/vscode"
import HistoryPreview from "../history/HistoryPreview"
import { normalizeApiConfiguration } from "../settings/ApiOptions"
import Announcement from "./Announcement"
import BrowserSessionRow from "./BrowserSessionRow"
import ChatRow from "./ChatRow"
import ChatTextArea from "./ChatTextArea"
import TaskHeader from "./TaskHeader"
import { AudioType } from "../../../../src/shared/WebviewMessage"

interface ChatViewProps {
	isHidden: boolean
	showAnnouncement: boolean
	hideAnnouncement: () => void
	showHistoryView: () => void
}

export const MAX_IMAGES_PER_MESSAGE = 20 // Anthropic limits to 20 images

const ChatView = ({ isHidden, showAnnouncement, hideAnnouncement, showHistoryView }: ChatViewProps) => {
	const { version, clineMessages: messages, taskHistory, apiConfiguration, mcpServers, alwaysAllowBrowser, alwaysAllowReadOnly, alwaysAllowWrite, alwaysAllowExecute, alwaysAllowMcp, allowedCommands } = useExtensionState()

	//const task = messages.length > 0 ? (messages[0].say === "task" ? messages[0] : undefined) : undefined) : undefined
	const task = useMemo(() => messages.at(0), [messages]) // leaving this less safe version here since if the first message is not a task, then the extension is in a bad state and needs to be debugged (see Cline.abort)
	const modifiedMessages = useMemo(() => combineApiRequests(combineCommandSequences(messages.slice(1))), [messages])
	// has to be after api_req_finished are all reduced into api_req_started messages
	const apiMetrics = useMemo(() => getApiMetrics(modifiedMessages), [modifiedMessages])

	const [inputValue, setInputValue] = useState("")
	const textAreaRef = useRef<HTMLTextAreaElement>(null)
	const [textAreaDisabled, setTextAreaDisabled] = useState(false)
	const [selectedImages, setSelectedImages] = useState<string[]>([])

	// we need to hold on to the ask because useEffect > lastMessage will always let us know when an ask comes in and handle it, but by the time handleMessage is called, the last message might not be the ask anymore (it could be a say that followed)
	const [clineAsk, setClineAsk] = useState<ClineAsk | undefined>(undefined)
	const [enableButtons, setEnableButtons] = useState<boolean>(false)
	const [primaryButtonText, setPrimaryButtonText] = useState<string | undefined>(undefined)
	const [secondaryButtonText, setSecondaryButtonText] = useState<string | undefined>(undefined)
	const [didClickCancel, setDidClickCancel] = useState(false)
	const virtuosoRef = useRef<VirtuosoHandle>(null)
	const [expandedRows, setExpandedRows] = useState<Record<number, boolean>>({})
	const scrollContainerRef = useRef<HTMLDivElement>(null)
	const disableAutoScrollRef = useRef(false)
	const [showScrollToBottom, setShowScrollToBottom] = useState(false)
	const [isAtBottom, setIsAtBottom] = useState(false)

	const [wasStreaming, setWasStreaming] = useState<boolean>(false)

	// UI layout depends on the last 2 messages
	// (since it relies on the content of these messages, we are deep comparing. i.e. the button state after hitting button sets enableButtons to false, and this effect otherwise would have to true again even if messages didn't change
	const lastMessage = useMemo(() => messages.at(-1), [messages])
	const secondLastMessage = useMemo(() => messages.at(-2), [messages])

	function playSound(audioType: AudioType) {
		vscode.postMessage({ type: "playSound", audioType })
	}

	useDeepCompareEffect(() => {
		// if last message is an ask, show user ask UI
		// if user finished a task, then start a new task with a new conversation history since in this moment that the extension is waiting for user response, the user could close the extension and the conversation history would be lost.
		// basically as long as a task is active, the conversation history will be persisted
		if (lastMessage) {
			switch (lastMessage.type) {
				case "ask":
					const isPartial = lastMessage.partial === true
					switch (lastMessage.ask) {
						case "api_req_failed":
							playSound("progress_loop")
							setTextAreaDisabled(true)
							setClineAsk("api_req_failed")
							setEnableButtons(true)
							setPrimaryButtonText("Retry")
							setSecondaryButtonText("Start New Task")
							break
						case "mistake_limit_reached":
							playSound("progress_loop")
							setTextAreaDisabled(false)
							setClineAsk("mistake_limit_reached")
							setEnableButtons(true)
							setPrimaryButtonText("Proceed Anyways")
							setSecondaryButtonText("Start New Task")
							break
						case "followup":
							setTextAreaDisabled(isPartial)
							setClineAsk("followup")
							setEnableButtons(isPartial)
							// setPrimaryButtonText(undefined)
							// setSecondaryButtonText(undefined)
							break
						case "tool":
							if (!isAutoApproved(lastMessage)) {
								playSound("notification")
							}
							setTextAreaDisabled(isPartial)
							setClineAsk("tool")
							setEnableButtons(!isPartial)
							const tool = JSON.parse(lastMessage.text || "{}") as ClineSayTool
							switch (tool.tool) {
								case "editedExistingFile":
								case "appliedDiff":
								case "newFileCreated":
									setPrimaryButtonText("Save")
									setSecondaryButtonText("Reject")
									break
								default:
									setPrimaryButtonText("Approve")
									setSecondaryButtonText("Reject")
									break
							}
							break
						case "browser_action_launch":
							if (!isAutoApproved(lastMessage)) {
								playSound("notification")
							}
							setTextAreaDisabled(isPartial)
							setClineAsk("browser_action_launch")
							setEnableButtons(!isPartial)
							setPrimaryButtonText("Approve")
							setSecondaryButtonText("Reject")
							break
						case "command":
							if (!isAutoApproved(lastMessage)) {
								playSound("notification")
							}
							setTextAreaDisabled(isPartial)
							setClineAsk("command")
							setEnableButtons(!isPartial)
							setPrimaryButtonText("Run Command")
							setSecondaryButtonText("Reject")
							break
						case "command_output":
							setTextAreaDisabled(false)
							setClineAsk("command_output")
							setEnableButtons(true)
							setPrimaryButtonText("Proceed While Running")
							setSecondaryButtonText(undefined)
							break
						case "use_mcp_server":
							setTextAreaDisabled(isPartial)
							setClineAsk("use_mcp_server")
							setEnableButtons(!isPartial)
							setPrimaryButtonText("Approve")
							setSecondaryButtonText("Reject")
							break
						case "completion_result":
							// extension waiting for feedback. but we can just present a new task button
							playSound("celebration")
							setTextAreaDisabled(isPartial)
							setClineAsk("completion_result")
							setEnableButtons(!isPartial)
							setPrimaryButtonText("Start New Task")
							setSecondaryButtonText(undefined)
							break
						case "resume_task":
							setTextAreaDisabled(false)
							setClineAsk("resume_task")
							setEnableButtons(true)
							setPrimaryButtonText("Resume Task")
							setSecondaryButtonText("Terminate")
							setDidClickCancel(false) // special case where we reset the cancel button state							
							break
						case "resume_completed_task":
							playSound("celebration")
							setTextAreaDisabled(false)
							setClineAsk("resume_completed_task")
							setEnableButtons(true)
							setPrimaryButtonText("Start New Task")
							setSecondaryButtonText(undefined)
							setDidClickCancel(false)
							break
					}
					break
				case "say":
					// don't want to reset since there could be a "say" after an "ask" while ask is waiting for response
					switch (lastMessage.say) {
						case "api_req_started":
							if (secondLastMessage?.ask === "command_output") {
								// if the last ask is a command_output, and we receive an api_req_started, then that means the command has finished and we don't need input from the user anymore (in every other case, the user has to interact with input field or buttons to continue, which does the following automatically)
								setInputValue("")
								setTextAreaDisabled(true)
								setSelectedImages([])
								setClineAsk(undefined)
								setEnableButtons(false)
							}
							break
						case "task":
						case "error":
						case "api_req_finished":
						case "text":
						case "browser_action":
						case "browser_action_result":
						case "command_output":
						case "mcp_server_request_started":
						case "mcp_server_response":
						case "completion_result":
						case "tool":
							break
					}
					break
			}
		} else {
			// this would get called after sending the first message, so we have to watch messages.length instead
			// No messages, so user has to submit a task
			// setTextAreaDisabled(false)
			// setClineAsk(undefined)
			// setPrimaryButtonText(undefined)
			// setSecondaryButtonText(undefined)
		}
	}, [lastMessage, secondLastMessage])

	useEffect(() => {
		if (messages.length === 0) {
			setTextAreaDisabled(false)
			setClineAsk(undefined)
			setEnableButtons(false)
			setPrimaryButtonText(undefined)
			setSecondaryButtonText(undefined)
		}
	}, [messages.length])

	useEffect(() => {
		setExpandedRows({})
	}, [task?.ts])

	const isStreaming = useMemo(() => {
		const isLastAsk = !!modifiedMessages.at(-1)?.ask // checking clineAsk isn't enough since messages effect may be called again for a tool for example, set clineAsk to its value, and if the next message is not an ask then it doesn't reset. This is likely due to how much more often we're updating messages as compared to before, and should be resolved with optimizations as it's likely a rendering bug. but as a final guard for now, the cancel button will show if the last message is not an ask
		const isToolCurrentlyAsking =
			isLastAsk && clineAsk !== undefined && enableButtons && primaryButtonText !== undefined
		if (isToolCurrentlyAsking) {
			return false
		}

		const isLastMessagePartial = modifiedMessages.at(-1)?.partial === true
		if (isLastMessagePartial) {
			return true
		} else {
			const lastApiReqStarted = findLast(modifiedMessages, (message) => message.say === "api_req_started")
			if (lastApiReqStarted && lastApiReqStarted.text != null && lastApiReqStarted.say === "api_req_started") {
				const cost = JSON.parse(lastApiReqStarted.text).cost
				if (cost === undefined) {
					// api request has not finished yet
					return true
				}
			}
		}

		return false
	}, [modifiedMessages, clineAsk, enableButtons, primaryButtonText])

	const handleSendMessage = useCallback(
		(text: string, images: string[]) => {
			text = text.trim()
			if (text || images.length > 0) {
				if (messages.length === 0) {
					vscode.postMessage({ type: "newTask", text, images })
				} else if (clineAsk) {
					switch (clineAsk) {
						case "followup":
						case "tool":
						case "browser_action_launch":
						case "command": // user can provide feedback to a tool or command use
						case "command_output": // user can send input to command stdin
						case "use_mcp_server":
						case "completion_result": // if this happens then the user has feedback for the completion result
						case "resume_task":
						case "resume_completed_task":
						case "mistake_limit_reached":
							vscode.postMessage({
								type: "askResponse",
								askResponse: "messageResponse",
								text,
								images,
							})
							break
						// there is no other case that a textfield should be enabled
					}
				}
				setInputValue("")
				setTextAreaDisabled(true)
				setSelectedImages([])
				setClineAsk(undefined)
				setEnableButtons(false)
				// setPrimaryButtonText(undefined)
				// setSecondaryButtonText(undefined)
				disableAutoScrollRef.current = false
			}
		},
		[messages.length, clineAsk],
	)

	const startNewTask = useCallback(() => {
		vscode.postMessage({ type: "clearTask" })
	}, [])

	/*
	This logic depends on the useEffect[messages] above to set clineAsk, after which buttons are shown and we then send an askResponse to the extension.
	*/
	const handlePrimaryButtonClick = useCallback(() => {
		switch (clineAsk) {
			case "api_req_failed":
			case "command":
			case "command_output":
			case "tool":
			case "browser_action_launch":
			case "use_mcp_server":
			case "resume_task":
			case "mistake_limit_reached":
				vscode.postMessage({ type: "askResponse", askResponse: "yesButtonClicked" })
				break
			case "completion_result":
			case "resume_completed_task":
				// extension waiting for feedback. but we can just present a new task button
				startNewTask()
				break
		}
		setTextAreaDisabled(true)
		setClineAsk(undefined)
		setEnableButtons(false)
		// setPrimaryButtonText(undefined)
		// setSecondaryButtonText(undefined)
		disableAutoScrollRef.current = false
	}, [clineAsk, startNewTask])

	const handleSecondaryButtonClick = useCallback(() => {
		if (isStreaming) {
			vscode.postMessage({ type: "cancelTask" })
			setDidClickCancel(true)
			return
		}

		switch (clineAsk) {
			case "api_req_failed":
			case "mistake_limit_reached":
			case "resume_task":
				startNewTask()
				break
			case "command":
			case "tool":
			case "browser_action_launch":
			case "use_mcp_server":
				// responds to the API with a "This operation failed" and lets it try again
				vscode.postMessage({ type: "askResponse", askResponse: "noButtonClicked" })
				break
		}
		setTextAreaDisabled(true)
		setClineAsk(undefined)
		setEnableButtons(false)
		// setPrimaryButtonText(undefined)
		// setSecondaryButtonText(undefined)
		disableAutoScrollRef.current = false
	}, [clineAsk, startNewTask, isStreaming])

	const handleTaskCloseButtonClick = useCallback(() => {
		startNewTask()
	}, [startNewTask])

	const { selectedModelInfo } = useMemo(() => {
		return normalizeApiConfiguration(apiConfiguration)
	}, [apiConfiguration])

	const selectImages = useCallback(() => {
		vscode.postMessage({ type: "selectImages" })
	}, [])

	const shouldDisableImages =
		!selectedModelInfo.supportsImages || textAreaDisabled || selectedImages.length >= MAX_IMAGES_PER_MESSAGE

	const handleMessage = useCallback(
		(e: MessageEvent) => {
			const message: ExtensionMessage = e.data
			switch (message.type) {
				case "action":
					switch (message.action!) {
						case "didBecomeVisible":
							if (!isHidden && !textAreaDisabled && !enableButtons) {
								textAreaRef.current?.focus()
							}
							break
					}
					break
				case "selectedImages":
					const newImages = message.images ?? []
					if (newImages.length > 0) {
						setSelectedImages((prevImages) =>
							[...prevImages, ...newImages].slice(0, MAX_IMAGES_PER_MESSAGE),
						)
					}
					break
				case "invoke":
					switch (message.invoke!) {
						case "sendMessage":
							handleSendMessage(message.text ?? "", message.images ?? [])
							break
						case "primaryButtonClick":
							handlePrimaryButtonClick()
							break
						case "secondaryButtonClick":
							handleSecondaryButtonClick()
							break
					}
			}
			// textAreaRef.current is not explicitly required here since react gaurantees that ref will be stable across re-renders, and we're not using its value but its reference.
		},
		[
			isHidden,
			textAreaDisabled,
			enableButtons,
			handleSendMessage,
			handlePrimaryButtonClick,
			handleSecondaryButtonClick,
		],
	)

	useEvent("message", handleMessage)

	useMount(() => {
		// NOTE: the vscode window needs to be focused for this to work
		textAreaRef.current?.focus()
	})

	useEffect(() => {
		const timer = setTimeout(() => {
			if (!isHidden && !textAreaDisabled && !enableButtons) {
				textAreaRef.current?.focus()
			}
		}, 50)
		return () => {
			clearTimeout(timer)
		}
	}, [isHidden, textAreaDisabled, enableButtons])

	const visibleMessages = useMemo(() => {
		return modifiedMessages.filter((message) => {
			switch (message.ask) {
				case "completion_result":
					// don't show a chat row for a completion_result ask without text. This specific type of message only occurs if cline wants to execute a command as part of its completion result, in which case we interject the completion_result tool with the execute_command tool.
					if (message.text === "") {
						return false
					}
					break
				case "api_req_failed": // this message is used to update the latest api_req_started that the request failed
				case "resume_task":
				case "resume_completed_task":
					return false
			}
			switch (message.say) {
				case "api_req_finished": // combineApiRequests removes this from modifiedMessages anyways
				case "api_req_retried": // this message is used to update the latest api_req_started that the request was retried
					return false
				case "text":
					// Sometimes cline returns an empty text message, we don't want to render these. (We also use a say text for user messages, so in case they just sent images we still render that)
					if ((message.text ?? "") === "" && (message.images?.length ?? 0) === 0) {
						return false
					}
					break
				case "mcp_server_request_started":
					return false
			}
			return true
		})
	}, [modifiedMessages])

	const isReadOnlyToolAction = useCallback((message: ClineMessage | undefined) => {
		if (message?.type === "ask") {
			if (!message.text) {
				return true
			}
			const tool = JSON.parse(message.text)
			return ["readFile", "listFiles", "listFilesTopLevel", "listFilesRecursive", "listCodeDefinitionNames", "searchFiles"].includes(tool.tool)
		}
		return false
	}, [])

	const isWriteToolAction = useCallback((message: ClineMessage | undefined) => {
		if (message?.type === "ask") {
			if (!message.text) {
				return true
			}
			const tool = JSON.parse(message.text)
			return ["editedExistingFile", "appliedDiff", "newFileCreated"].includes(tool.tool)
		}
		return false
	}, [])

	const isMcpToolAlwaysAllowed = useCallback((message: ClineMessage | undefined) => {
		if (message?.type === "ask" && message.ask === "use_mcp_server") {
			if (!message.text) {
				return true
			}
			const mcpServerUse = JSON.parse(message.text) as { type: string; serverName: string; toolName: string }
			if (mcpServerUse.type === "use_mcp_tool") {
				const server = mcpServers?.find((s: McpServer) => s.name === mcpServerUse.serverName)
				const tool = server?.tools?.find((t: McpTool) => t.name === mcpServerUse.toolName)
				return tool?.alwaysAllow || false
			}
		}
		return false
	}, [mcpServers])

	const isAllowedCommand = useCallback((message: ClineMessage | undefined) => {
		if (message?.type === "ask") {
			const command = message.text
			if (!command) {
				return true
			}

			// Split command by chaining operators
			const commands = command.split(/&&|\|\||;|\||\$\(|`/).map(cmd => cmd.trim())

			// Check if all individual commands are allowed
			return commands.every((cmd) => {
				const trimmedCommand = cmd.toLowerCase()
				return allowedCommands?.some((prefix) => trimmedCommand.startsWith(prefix.toLowerCase()))
			})
		}
		return false
	}, [allowedCommands])

	const isAutoApproved = useCallback(
		(message: ClineMessage | undefined) => {
			if (!message || message.type !== "ask") return false

			return (
				(alwaysAllowBrowser && message.ask === "browser_action_launch") ||
				(alwaysAllowReadOnly && message.ask === "tool" && isReadOnlyToolAction(message)) ||
				(alwaysAllowWrite && message.ask === "tool" && isWriteToolAction(message)) ||
				(alwaysAllowExecute && message.ask === "command" && isAllowedCommand(message)) ||
				(alwaysAllowMcp && message.ask === "use_mcp_server" && isMcpToolAlwaysAllowed(message))
			)
		},
		[
			alwaysAllowBrowser,
			alwaysAllowReadOnly,
			alwaysAllowWrite,
			alwaysAllowExecute,
			alwaysAllowMcp,
			isReadOnlyToolAction,
			isWriteToolAction,
			isAllowedCommand,
			isMcpToolAlwaysAllowed
		]
	)

	useEffect(() => {
		// Only execute when isStreaming changes from true to false
		if (wasStreaming && !isStreaming && lastMessage) {
			// Play appropriate sound based on lastMessage content
			if (lastMessage.type === "ask") {
				// Don't play sounds for auto-approved actions
				if (!isAutoApproved(lastMessage)) {
					switch (lastMessage.ask) {
						case "api_req_failed":
						case "mistake_limit_reached":
							playSound("progress_loop")
							break
						case "followup":
							if (!lastMessage.partial) {
								playSound("notification")
							}
							break
						case "tool":
						case "browser_action_launch":
						case "resume_task":
						case "use_mcp_server":
							playSound("notification")
							break
						case "completion_result":
						case "resume_completed_task":
							playSound("celebration")
							break
					}
				}
			}
		}
		// Update previous value
		setWasStreaming(isStreaming)
	}, [isStreaming, lastMessage, wasStreaming, isAutoApproved])

	const isBrowserSessionMessage = (message: ClineMessage): boolean => {
		// which of visible messages are browser session messages, see above
		if (message.type === "ask") {
			return ["browser_action_launch"].includes(message.ask!)
		}
		if (message.type === "say") {
			return ["api_req_started", "text", "browser_action", "browser_action_result"].includes(message.say!)
		}
		return false
	}

	const groupedMessages = useMemo(() => {
		const result: (ClineMessage | ClineMessage[])[] = []
		let currentGroup: ClineMessage[] = []
		let isInBrowserSession = false

		const endBrowserSession = () => {
			if (currentGroup.length > 0) {
				result.push([...currentGroup])
				currentGroup = []
				isInBrowserSession = false
			}
		}

		visibleMessages.forEach((message) => {
			if (message.ask === "browser_action_launch") {
				// complete existing browser session if any
				endBrowserSession()
				// start new
				isInBrowserSession = true
				currentGroup.push(message)
			} else if (isInBrowserSession) {
				// end session if api_req_started is cancelled

				if (message.say === "api_req_started") {
					// get last api_req_started in currentGroup to check if it's cancelled. If it is then this api req is not part of the current browser session
					const lastApiReqStarted = [...currentGroup].reverse().find((m) => m.say === "api_req_started")
					if (lastApiReqStarted?.text != null) {
						const info = JSON.parse(lastApiReqStarted.text)
						const isCancelled = info.cancelReason != null
						if (isCancelled) {
							endBrowserSession()
							result.push(message)
							return
						}
					}
				}

				if (isBrowserSessionMessage(message)) {
					currentGroup.push(message)

					// Check if this is a close action
					if (message.say === "browser_action") {
						const browserAction = JSON.parse(message.text || "{}") as ClineSayBrowserAction
						if (browserAction.action === "close") {
							endBrowserSession()
						}
					}
				} else {
					// complete existing browser session if any
					endBrowserSession()
					result.push(message)
				}
			} else {
				result.push(message)
			}
		})

		// Handle case where browser session is the last group
		if (currentGroup.length > 0) {
			result.push([...currentGroup])
		}

		return result
	}, [visibleMessages])

	// scrolling

	const scrollToBottomSmooth = useMemo(
		() =>
			debounce(
				() => {
					virtuosoRef.current?.scrollTo({
						top: Number.MAX_SAFE_INTEGER,
						behavior: "smooth",
					})
				},
				10,
				{ immediate: true },
			),
		[],
	)

	const scrollToBottomAuto = useCallback(() => {
		virtuosoRef.current?.scrollTo({
			top: Number.MAX_SAFE_INTEGER,
			behavior: "auto", // instant causes crash
		})
	}, [])

	// scroll when user toggles certain rows
	const toggleRowExpansion = useCallback(
		(ts: number) => {
			const isCollapsing = expandedRows[ts] ?? false
			const lastGroup = groupedMessages.at(-1)
			const isLast = Array.isArray(lastGroup) ? lastGroup[0].ts === ts : lastGroup?.ts === ts
			const secondToLastGroup = groupedMessages.at(-2)
			const isSecondToLast = Array.isArray(secondToLastGroup)
				? secondToLastGroup[0].ts === ts
				: secondToLastGroup?.ts === ts

			const isLastCollapsedApiReq =
				isLast &&
				!Array.isArray(lastGroup) && // Make sure it's not a browser session group
				lastGroup?.say === "api_req_started" &&
				!expandedRows[lastGroup.ts]

			setExpandedRows((prev) => ({
				...prev,
				[ts]: !prev[ts],
			}))

			// disable auto scroll when user expands row
			if (!isCollapsing) {
				disableAutoScrollRef.current = true
			}

			if (isCollapsing && isAtBottom) {
				const timer = setTimeout(() => {
					scrollToBottomAuto()
				}, 0)
				return () => clearTimeout(timer)
			} else if (isLast || isSecondToLast) {
				if (isCollapsing) {
					if (isSecondToLast && !isLastCollapsedApiReq) {
						return
					}
					const timer = setTimeout(() => {
						scrollToBottomAuto()
					}, 0)
					return () => clearTimeout(timer)
				} else {
					const timer = setTimeout(() => {
						virtuosoRef.current?.scrollToIndex({
							index: groupedMessages.length - (isLast ? 1 : 2),
							align: "start",
						})
					}, 0)
					return () => clearTimeout(timer)
				}
			}
		},
		[groupedMessages, expandedRows, scrollToBottomAuto, isAtBottom],
	)

	const handleRowHeightChange = useCallback(
		(isTaller: boolean) => {
			if (!disableAutoScrollRef.current) {
				if (isTaller) {
					scrollToBottomSmooth()
				} else {
					setTimeout(() => {
						scrollToBottomAuto()
					}, 0)
				}
			}
		},
		[scrollToBottomSmooth, scrollToBottomAuto],
	)

	useEffect(() => {
		if (!disableAutoScrollRef.current) {
			setTimeout(() => {
				scrollToBottomSmooth()
			}, 50)
			// return () => clearTimeout(timer) // dont cleanup since if visibleMessages.length changes it cancels.
		}
	}, [groupedMessages.length, scrollToBottomSmooth])

	const handleWheel = useCallback((event: Event) => {
		const wheelEvent = event as WheelEvent
		if (wheelEvent.deltaY && wheelEvent.deltaY < 0) {
			if (scrollContainerRef.current?.contains(wheelEvent.target as Node)) {
				// user scrolled up
				disableAutoScrollRef.current = true
			}
		}
	}, [])
	useEvent("wheel", handleWheel, window, { passive: true }) // passive improves scrolling performance

	const placeholderText = useMemo(() => {
		const text = task ? "Type a message...\n(@ to add context, hold shift to drag in images)" : "Type your task here...\n(@ to add context, hold shift to drag in images)"
		return text
	}, [task])

	const itemContent = useCallback(
		(index: number, messageOrGroup: ClineMessage | ClineMessage[]) => {
			// browser session group
			if (Array.isArray(messageOrGroup)) {
				return (
					<BrowserSessionRow
						messages={messageOrGroup}
						isLast={index === groupedMessages.length - 1}
						lastModifiedMessage={modifiedMessages.at(-1)}
						onHeightChange={handleRowHeightChange}
						// Pass handlers for each message in the group
						isExpanded={(messageTs: number) => expandedRows[messageTs] ?? false}
						onToggleExpand={(messageTs: number) => {
							setExpandedRows((prev) => ({
								...prev,
								[messageTs]: !prev[messageTs],
							}))
						}}
					/>
				)
			}

			// regular message
			return (
				<ChatRow
					key={messageOrGroup.ts}
					message={messageOrGroup}
					isExpanded={expandedRows[messageOrGroup.ts] || false}
					onToggleExpand={() => toggleRowExpansion(messageOrGroup.ts)}
					lastModifiedMessage={modifiedMessages.at(-1)}
					isLast={index === groupedMessages.length - 1}
					onHeightChange={handleRowHeightChange}
				/>
			)
		},
		[expandedRows, modifiedMessages, groupedMessages.length, toggleRowExpansion, handleRowHeightChange],
	)

	useEffect(() => {
		// Only proceed if we have an ask and buttons are enabled
		if (!clineAsk || !enableButtons) return

		if (isAutoApproved(lastMessage)) {
			handlePrimaryButtonClick()
		}
	}, [clineAsk, enableButtons, handlePrimaryButtonClick, alwaysAllowBrowser, alwaysAllowReadOnly, alwaysAllowWrite, alwaysAllowExecute, alwaysAllowMcp, messages, allowedCommands, mcpServers, isAutoApproved, lastMessage])

	return (
		<div
			style={{
				position: "fixed",
				top: 0,
				left: 0,
				right: 0,
				bottom: 0,
				display: isHidden ? "none" : "flex",
				flexDirection: "column",
				overflow: "hidden",
			}}>
			{task ? (
				<TaskHeader
					task={task}
					tokensIn={apiMetrics.totalTokensIn}
					tokensOut={apiMetrics.totalTokensOut}
					doesModelSupportPromptCache={selectedModelInfo.supportsPromptCache}
					cacheWrites={apiMetrics.totalCacheWrites}
					cacheReads={apiMetrics.totalCacheReads}
					totalCost={apiMetrics.totalCost}
					onClose={handleTaskCloseButtonClick}
				/>
			) : (
				<div
					style={{
						flexGrow: 1,
						overflowY: "auto",
						display: "flex",
						flexDirection: "column",
					}}>
					{showAnnouncement && <Announcement version={version} hideAnnouncement={hideAnnouncement} />}
					<div style={{ padding: "0 20px", flexShrink: 0 }}>
						<h2>What can I do for you?</h2>
						<p>
							Thanks to{" "}
							<VSCodeLink
								href="https://www-cdn.anthropic.com/fed9cc193a14b84131812372d8d5857f8f304c52/Model_Card_Claude_3_Addendum.pdf"
								style={{ display: "inline" }}>
								Claude 3.5 Sonnet's agentic coding capabilities,
							</VSCodeLink>{" "}
							I can handle complex software development tasks step-by-step. With tools that let me create
							& edit files, explore complex projects, use the browser, and execute terminal commands
							(after you grant permission), I can assist you in ways that go beyond code completion or
							tech support. I can even use MCP to create new tools and extend my own capabilities.
						</p>
					</div>
					{taskHistory.length > 0 && <HistoryPreview showHistoryView={showHistoryView} />}
				</div>
			)}
			{task && (
				<>
					<div style={{ flexGrow: 1, display: "flex" }} ref={scrollContainerRef}>
						<Virtuoso
							ref={virtuosoRef}
							key={task.ts} // trick to make sure virtuoso re-renders when task changes, and we use initialTopMostItemIndex to start at the bottom
							className="scrollable"
							style={{
								flexGrow: 1,
								overflowY: "scroll", // always show scrollbar
							}}
							components={{
								Footer: () => <div style={{ height: 5 }} />, // Add empty padding at the bottom
							}}
							// increasing top by 3_000 to prevent jumping around when user collapses a row
							increaseViewportBy={{ top: 3_000, bottom: Number.MAX_SAFE_INTEGER }} // hack to make sure the last message is always rendered to get truly perfect scroll to bottom animation when new messages are added (Number.MAX_SAFE_INTEGER is safe for arithmetic operations, which is all virtuoso uses this value for in src/sizeRangeSystem.ts)
							data={groupedMessages} // messages is the raw format returned by extension, modifiedMessages is the manipulated structure that combines certain messages of related type, and visibleMessages is the filtered structure that removes messages that should not be rendered
							itemContent={itemContent}
							atBottomStateChange={(isAtBottom) => {
								setIsAtBottom(isAtBottom)
								if (isAtBottom) {
									disableAutoScrollRef.current = false
								}
								setShowScrollToBottom(disableAutoScrollRef.current && !isAtBottom)
							}}
							atBottomThreshold={10} // anything lower causes issues with followOutput
							initialTopMostItemIndex={groupedMessages.length - 1}
						/>
					</div>
					{showScrollToBottom ? (
						<div
							style={{
								display: "flex",
								padding: "10px 15px 0px 15px",
							}}>
							<ScrollToBottomButton
								onClick={() => {
									scrollToBottomSmooth()
									disableAutoScrollRef.current = false
								}}>
								<span className="codicon codicon-chevron-down" style={{ fontSize: "18px" }}></span>
							</ScrollToBottomButton>
						</div>
					) : (
						<div
							style={{
								opacity:
									primaryButtonText || secondaryButtonText || isStreaming
										? enableButtons || (isStreaming && !didClickCancel)
											? 1
											: 0.5
										: 0,
								display: "flex",
								padding: "10px 15px 0px 15px",
							}}>
							{primaryButtonText && !isStreaming && (
								<VSCodeButton
									appearance="primary"
									disabled={!enableButtons}
									style={{
										flex: secondaryButtonText ? 1 : 2,
										marginRight: secondaryButtonText ? "6px" : "0",
									}}
									onClick={handlePrimaryButtonClick}>
									{primaryButtonText}
								</VSCodeButton>
							)}
							{(secondaryButtonText || isStreaming) && (
								<VSCodeButton
									appearance="secondary"
									disabled={!enableButtons && !(isStreaming && !didClickCancel)}
									style={{
										flex: isStreaming ? 2 : 1,
										marginLeft: isStreaming ? 0 : "6px",
									}}
									onClick={handleSecondaryButtonClick}>
									{isStreaming ? "Cancel" : secondaryButtonText}
								</VSCodeButton>
							)}
						</div>
					)}
				</>
			)}
			<ChatTextArea
				ref={textAreaRef}
				inputValue={inputValue}
				setInputValue={setInputValue}
				textAreaDisabled={textAreaDisabled}
				placeholderText={placeholderText}
				selectedImages={selectedImages}
				setSelectedImages={setSelectedImages}
				onSend={() => handleSendMessage(inputValue, selectedImages)}
				onSelectImages={selectImages}
				shouldDisableImages={shouldDisableImages}
				onHeightChange={() => {
					if (isAtBottom) {
						scrollToBottomAuto()
					}
				}}
			/>
		</div>
	)
}

const ScrollToBottomButton = styled.div`
	background-color: color-mix(in srgb, var(--vscode-toolbar-hoverBackground) 55%, transparent);
	border-radius: 3px;
	overflow: hidden;
	cursor: pointer;
	display: flex;
	justify-content: center;
	align-items: center;
	flex: 1;
	height: 25px;

	&:hover {
		background-color: color-mix(in srgb, var(--vscode-toolbar-hoverBackground) 90%, transparent);
	}

	&:active {
		background-color: color-mix(in srgb, var(--vscode-toolbar-hoverBackground) 70%, transparent);
	}
`

export default ChatView