"use client";

import { useChat } from "@ai-sdk/react";
import Link from "next/link";
import { useEffect, useRef } from "react";
import { useForm } from "react-hook-form";

import { MemoizedMarkdown } from "@/components/lighthouse/memoized-markdown";
import { CustomButton, CustomTextarea } from "@/components/ui/custom";
import { Form } from "@/components/ui/form";

interface SuggestedAction {
  title: string;
  label: string;
  action: string;
}

interface ChatProps {
  hasConfig: boolean;
  isActive: boolean;
}

interface ChatFormData {
  message: string;
}

export const Chat = ({ hasConfig, isActive }: ChatProps) => {
  const { messages, handleSubmit, handleInputChange, append, status } = useChat(
    {
      api: "/api/lighthouse/analyst",
      credentials: "same-origin",
      experimental_throttle: 100,
      sendExtraMessageFields: true,
      onFinish: () => {
        // Handle chat completion
      },
      onError: (error) => {
        console.error("Chat error:", error);
      },
    },
  );

  const form = useForm<ChatFormData>({
    defaultValues: {
      message: "",
    },
  });

  const messageValue = form.watch("message");
  const messagesContainerRef = useRef<HTMLDivElement | null>(null);
  const latestUserMsgRef = useRef<HTMLDivElement | null>(null);

  // Sync form value with chat input
  useEffect(() => {
    const syntheticEvent = {
      target: { value: messageValue },
    } as React.ChangeEvent<HTMLInputElement>;
    handleInputChange(syntheticEvent);
  }, [messageValue, handleInputChange]);

  // Reset form when message is sent
  useEffect(() => {
    if (status === "submitted") {
      form.reset({ message: "" });
    }
  }, [status, form]);

  const onFormSubmit = form.handleSubmit((data) => {
    if (data.message.trim()) {
      handleSubmit();
    }
  });

  // Global keyboard shortcut handler
  useEffect(() => {
    const handleKeyDown = (e: KeyboardEvent) => {
      if ((e.metaKey || e.ctrlKey) && e.key === "Enter") {
        e.preventDefault();
        if (messageValue?.trim()) {
          onFormSubmit();
        }
      }
    };

    document.addEventListener("keydown", handleKeyDown);
    return () => document.removeEventListener("keydown", handleKeyDown);
  }, [messageValue, onFormSubmit]);

  useEffect(() => {
    if (messagesContainerRef.current && latestUserMsgRef.current) {
      const container = messagesContainerRef.current;
      const userMsg = latestUserMsgRef.current;
      const containerPadding = 16; // p-4 in Tailwind = 16px
      container.scrollTop =
        userMsg.offsetTop - container.offsetTop - containerPadding;
    }
  }, [messages]);

  const suggestedActions: SuggestedAction[] = [
    {
      title: "Are there any exposed S3",
      label: "buckets in my AWS accounts?",
      action: "List exposed S3 buckets in my AWS accounts",
    },
    {
      title: "What is the risk of having",
      label: "RDS databases unencrypted?",
      action: "What is the risk of having RDS databases unencrypted?",
    },
    {
      title: "What is the CIS 1.10 compliance status",
      label: "of my Kubernetes cluster?",
      action:
        "What is the CIS 1.10 compliance status of my Kubernetes cluster?",
    },
    {
      title: "List my highest privileged",
      label: "AWS IAM users with full admin access?",
      action: "List my highest privileged AWS IAM users with full admin access",
    },
  ];

  // Determine if chat should be disabled
  const shouldDisableChat = !hasConfig || !isActive;

  return (
    <div className="relative flex h-[calc(100vh-theme(spacing.16))] min-w-0 flex-col bg-background">
      {shouldDisableChat && (
        <div className="absolute inset-0 z-50 flex items-center justify-center bg-background/80 backdrop-blur-sm">
          <div className="bg-card max-w-md rounded-lg p-6 text-center shadow-lg">
            <h3 className="mb-2 text-lg font-semibold">
              {!hasConfig
                ? "OpenAI API Key Required"
                : "OpenAI API Key Invalid"}
            </h3>
            <p className="text-muted-foreground mb-4">
              {!hasConfig
                ? "Please configure your OpenAI API key to use the Lighthouse Cloud Security Analyst."
                : "OpenAI API key is invalid. Please update your key to use Lighthouse Cloud Security Analyst."}
            </p>
            <Link
              href="/lighthouse/config"
              className="inline-flex items-center justify-center rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:bg-primary/90"
            >
              Configure API Key
            </Link>
          </div>
        </div>
      )}

      {messages.length === 0 ? (
        <div className="flex flex-1 items-center justify-center p-4">
          <div className="w-full max-w-2xl">
            <h2 className="mb-4 text-center font-sans text-xl">Suggestions</h2>
            <div className="grid gap-2 sm:grid-cols-2">
              {suggestedActions.map((action, index) => (
                <CustomButton
                  key={`suggested-action-${index}`}
                  ariaLabel={`Send message: ${action.action}`}
                  onPress={() => {
                    append({
                      role: "user",
                      content: action.action,
                    });
                  }}
                  className="hover:bg-muted flex h-auto w-full flex-col items-start justify-start rounded-xl border bg-gray-50 px-4 py-3.5 text-left font-sans text-sm dark:bg-gray-900"
                >
                  <span>{action.title}</span>
                  <span className="text-muted-foreground">{action.label}</span>
                </CustomButton>
              ))}
            </div>
          </div>
        </div>
      ) : (
        <div
          className="flex-1 space-y-4 overflow-y-auto p-4"
          ref={messagesContainerRef}
        >
          {messages.map((message, idx) => {
            const lastUserIdx = messages
              .map((m, i) => (m.role === "user" ? i : -1))
              .filter((i) => i !== -1)
              .pop();
            const isLatestUserMsg =
              message.role === "user" && lastUserIdx === idx;
            return (
              <div
                key={message.id}
                ref={isLatestUserMsg ? latestUserMsgRef : undefined}
                className={`flex ${
                  message.role === "user" ? "justify-end" : "justify-start"
                }`}
              >
                <div
                  className={`max-w-[80%] rounded-lg px-4 py-2 ${
                    message.role === "user"
                      ? "bg-primary text-primary-foreground dark:!text-black"
                      : "bg-muted"
                  }`}
                >
                  <div
                    className={`prose dark:prose-invert ${message.role === "user" ? "dark:!text-black" : ""}`}
                  >
                    <MemoizedMarkdown
                      id={message.id}
                      content={message.content}
                    />
                  </div>
                </div>
              </div>
            );
          })}
          {status === "submitted" && (
            <div className="flex justify-start">
              <div className="bg-muted max-w-[80%] rounded-lg px-4 py-2">
                <div className="animate-pulse">Thinking...</div>
              </div>
            </div>
          )}
        </div>
      )}

      <Form {...form}>
        <form
          onSubmit={onFormSubmit}
          className="mx-auto flex w-full gap-2 px-4 pb-4 md:max-w-3xl md:pb-6"
        >
          <div className="flex w-full items-end gap-2">
            <div className="w-full flex-1">
              <CustomTextarea
                control={form.control}
                name="message"
                label=""
                placeholder="Type your message..."
                variant="bordered"
                minRows={1}
                maxRows={6}
                fullWidth={true}
                disableAutosize={false}
              />
            </div>
            <CustomButton
              type="submit"
              ariaLabel={
                status === "submitted" ? "Stop generation" : "Send message"
              }
              isDisabled={status === "submitted" || !messageValue?.trim()}
              className="flex h-10 w-10 flex-shrink-0 items-center justify-center rounded-lg bg-primary p-2 text-primary-foreground hover:bg-primary/90 disabled:opacity-50 dark:bg-primary/90"
            >
              {status === "submitted" ? <span>■</span> : <span>➤</span>}
            </CustomButton>
          </div>
        </form>
      </Form>
    </div>
  );
};

export default Chat;