"use client";

import { useSearchParams } from "next/navigation";
import { useCallback, useEffect, useMemo, useRef, useState } from "react";

import { type PromptInputMessage } from "@/components/ai-elements/prompt-input";
import { ArtifactTrigger } from "@/components/workspace/artifacts";
import {
  ChatBox,
  useSpecificChatMode,
  useThreadChat,
} from "@/components/workspace/chats";
import { ExportTrigger } from "@/components/workspace/export-trigger";
import { InputBox } from "@/components/workspace/input-box";
import {
  MessageList,
  MESSAGE_LIST_DEFAULT_PADDING_BOTTOM,
  MESSAGE_LIST_FOLLOWUPS_EXTRA_PADDING_BOTTOM,
} from "@/components/workspace/messages";
import { ThreadContext } from "@/components/workspace/messages/context";
import { ThreadTitle } from "@/components/workspace/thread-title";
import { TodoList } from "@/components/workspace/todo-list";
import { TokenUsageIndicator } from "@/components/workspace/token-usage-indicator";
import { Welcome } from "@/components/workspace/welcome";
import { useI18n } from "@/core/i18n/hooks";
import { useNotification } from "@/core/notification/hooks";
import { useThreadSettings } from "@/core/settings";
import { bootstrapRemoteSkill } from "@/core/skills";
import { useThreadStream } from "@/core/threads/hooks";
import { textOfMessage } from "@/core/threads/utils";
import { uuid } from "@/core/utils/uuid";
import { env } from "@/env";
import { cn } from "@/lib/utils";

const UUID_REGEX =
  /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

export default function ChatPage() {
  const { t } = useI18n();
  const [showFollowups, setShowFollowups] = useState(false);
  const searchParams = useSearchParams();  const generatedThreadIdRef = useRef<string>("");
  if (!generatedThreadIdRef.current) {
    const queryThreadId = searchParams.get("thread_id")?.trim();
    generatedThreadIdRef.current =
      queryThreadId && UUID_REGEX.test(queryThreadId) ? queryThreadId : uuid();
  }

  const { threadId, isNewThread, setIsNewThread, isMock } = useThreadChat({
    newThreadId: generatedThreadIdRef.current,
  });
  const [settings, setSettings] = useThreadSettings(threadId);
  const [mounted, setMounted] = useState(false);
  useSpecificChatMode();

  useEffect(() => {
    setMounted(true);
  }, []);

  const { showNotification } = useNotification();
  const skillBootstrappedKeysRef = useRef<Set<string>>(new Set());
  const skillBootstrappingKeysRef = useRef<Set<string>>(new Set());

  const skillBootstrap = useMemo(() => {
    const skillIdRaw = searchParams.get("skill_id")?.trim();
    if (!skillIdRaw) return undefined;

    const contentIds = skillIdRaw
      .split(",")
      .map((value) => value.trim())
      .filter((value) => value.length > 0)
      .map((value) => Number(value))
      .filter((value) => Number.isFinite(value));

    // Deduplicate while preserving incoming order.
    const uniqueContentIds = Array.from(new Set(contentIds));
    if (uniqueContentIds.length === 0) return undefined;

    const languageTypeRaw =
      searchParams.get("languageType")?.trim() ??
      searchParams.get("language_type")?.trim();
    const languageType = languageTypeRaw ? Number(languageTypeRaw) : 0;

    return {
      contentIds: uniqueContentIds,
      languageType: Number.isFinite(languageType) ? languageType : 0,
    };
  }, [searchParams]);

  const [thread, sendMessage, isUploading] = useThreadStream({
    threadId: isNewThread ? undefined : threadId,
    context: settings.context,
    isMock,
    onStart: () => {
      setIsNewThread(false);
      // ! Important: Never use next.js router for navigation in this case, otherwise it will cause the thread to re-mount and lose all states. Use native history API instead.
      history.replaceState(null, "", `/workspace/chats/${threadId}`);
    },
    onFinish: (state) => {
      if (document.hidden || !document.hasFocus()) {
        let body = "Conversation finished";
        const lastMessage = state.messages.at(-1);
        if (lastMessage) {
          const textContent = textOfMessage(lastMessage);
          if (textContent) {
            body =
              textContent.length > 200
                ? textContent.substring(0, 200) + "..."
                : textContent;
          }
        }
        showNotification(state.title, { body });
      }
    },
  });

  useEffect(() => {
    if (!threadId || !skillBootstrap?.contentIds?.length) {
      return;
    }

    const languageType = skillBootstrap.languageType ?? 0;
    const initKey = `${threadId}:${skillBootstrap.contentIds.join(",")}:${languageType}`;
    if (
      skillBootstrappedKeysRef.current.has(initKey) ||
      skillBootstrappingKeysRef.current.has(initKey)
    ) {
      return;
    }

    skillBootstrappingKeysRef.current.add(initKey);

    const runBootstrap = async () => {
      try {
        await bootstrapRemoteSkill({
          thread_id: threadId,
          content_ids: skillBootstrap.contentIds,
          language_type: languageType,
          target_dir: "/mnt/user-data/uploads/skill",
          clear_target: true,
        });

        skillBootstrappedKeysRef.current.add(initKey);
      } catch (error) {
        const message =
          error instanceof Error ? error.message : "Skill initialization failed";
        showNotification("Skill initialization failed", { body: message });
      } finally {
        skillBootstrappingKeysRef.current.delete(initKey);
      }
    };

    void runBootstrap();
  }, [threadId, skillBootstrap, showNotification]);

  const handleSubmit = useCallback(
    (message: PromptInputMessage) => {
      void sendMessage(threadId, message);
    },
    [sendMessage, threadId],
  );
  const handleStop = useCallback(async () => {
    await thread.stop();
  }, [thread]);

  const messageListPaddingBottom = showFollowups
    ? MESSAGE_LIST_DEFAULT_PADDING_BOTTOM +
      MESSAGE_LIST_FOLLOWUPS_EXTRA_PADDING_BOTTOM
    : undefined;

  return (
    <ThreadContext.Provider value={{ thread, isMock }}>
      <ChatBox threadId={threadId}>
        <div className="relative flex size-full min-h-0 justify-between">
          <header
            className={cn(
              "absolute top-0 right-0 left-0 z-30 flex h-12 shrink-0 items-center px-4",
              isNewThread
                ? "bg-background/0 backdrop-blur-none"
                : "bg-background/80 shadow-xs backdrop-blur",
            )}
          >
            <div className="flex w-full items-center text-sm font-medium">
              <ThreadTitle threadId={threadId} thread={thread} />
            </div>
            <div className="flex items-center gap-2">
              <TokenUsageIndicator messages={thread.messages} />
              <ExportTrigger threadId={threadId} />
              <ArtifactTrigger />
            </div>
          </header>
          <main className="flex min-h-0 max-w-full grow flex-col">
            <div className="flex size-full justify-center">
              <MessageList
                className={cn("size-full", !isNewThread && "pt-10")}
                threadId={threadId}
                thread={thread}
                paddingBottom={messageListPaddingBottom}
              />
            </div>
            <div className="absolute right-0 bottom-0 left-0 z-30 flex justify-center px-4">
              <div
                className={cn(
                  "relative w-full",
                  isNewThread && "-translate-y-[calc(50vh-96px)]",
                  isNewThread
                    ? "max-w-(--container-width-sm)"
                    : "max-w-(--container-width-md)",
                )}
              >
                <div className="absolute -top-4 right-0 left-0 z-0">
                  <div className="absolute right-0 bottom-0 left-0">
                    <TodoList
                      className="bg-background/5"
                      todos={thread.values.todos ?? []}
                      hidden={
                        !thread.values.todos || thread.values.todos.length === 0
                      }
                    />
                  </div>
                </div>
                {mounted ? (
                  <InputBox
                    className={cn("bg-background/5 w-full -translate-y-4")}
                    isNewThread={isNewThread}
                    threadId={threadId}
                    autoFocus={isNewThread}
                    status={
                      thread.error
                        ? "error"
                        : thread.isLoading
                          ? "streaming"
                          : "ready"
                    }
                    context={settings.context}
                    extraHeader={
                      isNewThread && <Welcome mode={settings.context.mode} />
                    }
                    disabled={
                      env.NEXT_PUBLIC_STATIC_WEBSITE_ONLY === "true" ||
                      isUploading
                    }
                    onContextChange={(context) =>
                      setSettings("context", context)
                    }
                    onFollowupsVisibilityChange={setShowFollowups}
                    onSubmit={handleSubmit}
                    onStop={handleStop}
                  />
                ) : (
                  <div
                    aria-hidden="true"
                    className={cn(
                      "bg-background/5 h-32 w-full -translate-y-4 rounded-2xl border",
                    )}
                  />
                )}
                {env.NEXT_PUBLIC_STATIC_WEBSITE_ONLY === "true" && (
                  <div className="text-muted-foreground/67 w-full translate-y-12 text-center text-xs">
                    {t.common.notAvailableInDemoMode}
                  </div>
                )}
              </div>
            </div>
          </main>
        </div>
      </ChatBox>
    </ThreadContext.Provider>
  );
}