import { ArrowDownIcon, ArrowUpIcon, CheckIcon, CopyIcon, RefreshCwIcon, Square } from 'lucide-react';

import { ActionBarPrimitive, ComposerPrimitive, ErrorPrimitive, MessagePrimitive, ThreadPrimitive } from '@assistant-ui/react';

import type { FC } from 'react';

import { Button } from '@/components/ui/button';
import { MarkdownText } from '@/components/assistant-ui/markdown-text';
import { ToolFallback } from '@/components/assistant-ui/tool-fallback';
import { TooltipIconButton } from '@/components/assistant-ui/tooltip-icon-button';
import { ComposerAddAttachment, ComposerAttachments, UserMessageAttachments } from '@/components/assistant-ui/attachment';

export const Thread: FC = () => {
  return (
    <ThreadPrimitive.Root
      className="aui-root aui-thread-root @container flex h-full flex-col bg-background"
      style={{
        ['--thread-max-width' as string]: '44rem',
      }}
    >
      <ThreadPrimitive.Viewport
        turnAnchor="top"
        className="aui-thread-viewport relative flex flex-1 flex-col overflow-x-auto overflow-y-scroll scroll-smooth px-4 pt-4"
      >
        <ThreadPrimitive.If empty>
          <ThreadWelcome />
        </ThreadPrimitive.If>

        <ThreadPrimitive.Messages
          components={{
            UserMessage,
            EditComposer,
            AssistantMessage,
          }}
        />

        <ThreadPrimitive.ViewportFooter className="aui-thread-viewport-footer sticky bottom-0 mx-auto mt-4 flex w-full max-w-(--thread-max-width) flex-col gap-4 overflow-visible rounded-t-3xl bg-background pb-4 md:pb-6">
          <ThreadScrollToBottom />
          <Composer />
        </ThreadPrimitive.ViewportFooter>
      </ThreadPrimitive.Viewport>
    </ThreadPrimitive.Root>
  );
};

const ThreadScrollToBottom: FC = () => {
  return (
    <ThreadPrimitive.ScrollToBottom asChild>
      <TooltipIconButton
        tooltip="Scroll to bottom"
        variant="outline"
        className="aui-thread-scroll-to-bottom -top-12 absolute z-10 self-center rounded-full p-4 disabled:invisible dark:bg-background dark:hover:bg-accent"
      >
        <ArrowDownIcon />
      </TooltipIconButton>
    </ThreadPrimitive.ScrollToBottom>
  );
};

const ThreadWelcome: FC = () => {
  return (
    <div className="aui-thread-welcome-root mx-auto my-auto flex w-full max-w-(--thread-max-width) grow flex-col">
      <div className="aui-thread-welcome-center flex w-full grow flex-col items-center justify-center">
        <div className="aui-thread-welcome-message flex size-full flex-col justify-center px-8">
          <div className="aui-thread-welcome-message-inner fade-in slide-in-from-bottom-2 animate-in font-semibold text-2xl duration-300 ease-out">
            Hello there!
          </div>
          <div className="aui-thread-welcome-message-inner fade-in slide-in-from-bottom-2 animate-in text-2xl text-muted-foreground/65 delay-100 duration-300 ease-out">
            How can I help you today?
          </div>
        </div>
      </div>
      <ThreadSuggestions />
    </div>
  );
};

const ThreadSuggestions: FC = () => {
  return (
    <div className="aui-thread-welcome-suggestions grid w-full @md:grid-cols-2 gap-2 pb-4">
      {[
        {
          title: "What's the weather",
          label: 'in San Francisco?',
          action: "What's the weather in San Francisco?",
        },
        {
          title: 'Explain React hooks',
          label: 'like useState and useEffect',
          action: 'Explain React hooks like useState and useEffect',
        },
        {
          title: 'Write a SQL query',
          label: 'to find top customers',
          action: 'Write a SQL query to find top customers',
        },
        {
          title: 'Create a meal plan',
          label: 'for healthy weight loss',
          action: 'Create a meal plan for healthy weight loss',
        },
      ].map((suggestedAction, index) => (
        <div
          key={`suggested-action-${suggestedAction.title}-${index}`}
          className="aui-thread-welcome-suggestion-display fade-in slide-in-from-bottom-4 @md:nth-[n+3]:block nth-[n+3]:hidden animate-in fill-mode-both duration-300 ease-out"
          style={{ animationDelay: `${index * 50}ms` }}
        >
          <ThreadPrimitive.Suggestion prompt={suggestedAction.action} send asChild>
            <Button
              variant="ghost"
              className="aui-thread-welcome-suggestion h-auto w-full flex-1 @md:flex-col flex-wrap items-start justify-start gap-1 rounded-3xl border px-5 py-4 text-left text-sm dark:hover:bg-accent/60"
              aria-label={suggestedAction.action}
            >
              <span className="aui-thread-welcome-suggestion-text-1 font-medium">{suggestedAction.title}</span>
              <span className="aui-thread-welcome-suggestion-text-2 text-muted-foreground">{suggestedAction.label}</span>
            </Button>
          </ThreadPrimitive.Suggestion>
        </div>
      ))}
    </div>
  );
};

const Composer: FC = () => {
  return (
    <ComposerPrimitive.Root className="aui-composer-root relative flex w-full flex-col">
      <ComposerPrimitive.AttachmentDropzone className="aui-composer-attachment-dropzone flex w-full flex-col rounded-3xl border border-input bg-background px-1 pt-2 shadow-xs outline-none transition-[color,box-shadow] has-[textarea:focus-visible]:border-ring has-[textarea:focus-visible]:ring-[3px] has-[textarea:focus-visible]:ring-ring/50 data-[dragging=true]:border-ring data-[dragging=true]:border-dashed data-[dragging=true]:bg-accent/50 dark:bg-background">
        <ComposerAttachments />
        <ComposerPrimitive.Input
          placeholder="Send a message..."
          className="aui-composer-input mb-1 max-h-32 min-h-16 w-full resize-none bg-transparent px-3.5 pt-1.5 pb-3 text-base outline-none placeholder:text-muted-foreground focus-visible:ring-0"
          rows={1}
          autoFocus
          aria-label="Message input"
        />
        <ComposerAction />
      </ComposerPrimitive.AttachmentDropzone>
    </ComposerPrimitive.Root>
  );
};

const ComposerAction: FC = () => {
  return (
    <div className="aui-composer-action-wrapper relative mx-1 mt-2 mb-2 flex items-center justify-between">
      <ComposerAddAttachment />

      <ThreadPrimitive.If running={false}>
        <ComposerPrimitive.Send asChild>
          <TooltipIconButton
            tooltip="Send message"
            side="bottom"
            type="submit"
            variant="default"
            size="icon"
            className="aui-composer-send size-[34px] rounded-full p-1"
            aria-label="Send message"
          >
            <ArrowUpIcon className="aui-composer-send-icon size-5" />
          </TooltipIconButton>
        </ComposerPrimitive.Send>
      </ThreadPrimitive.If>

      <ThreadPrimitive.If running>
        <ComposerPrimitive.Cancel asChild>
          <Button
            type="button"
            variant="default"
            size="icon"
            className="aui-composer-cancel size-[34px] rounded-full border border-muted-foreground/60 hover:bg-primary/75 dark:border-muted-foreground/90"
            aria-label="Stop generating"
          >
            <Square className="aui-composer-cancel-icon size-3.5 fill-white dark:fill-black" />
          </Button>
        </ComposerPrimitive.Cancel>
      </ThreadPrimitive.If>
    </div>
  );
};

const MessageError: FC = () => {
  return (
    <MessagePrimitive.Error>
      <ErrorPrimitive.Root className="aui-message-error-root mt-2 rounded-md border border-destructive bg-destructive/10 p-3 text-destructive text-sm dark:bg-destructive/5 dark:text-red-200">
        <ErrorPrimitive.Message className="aui-message-error-message line-clamp-2" />
      </ErrorPrimitive.Root>
    </MessagePrimitive.Error>
  );
};

const ReasoningContent: FC<{ text: string }> = ({ text }) => {
  return (
    <div className="aui-reasoning-content my-2 rounded-lg border border-muted bg-muted/30 p-3 text-muted-foreground text-sm italic">
      <div className="mb-1 font-semibold text-xs uppercase tracking-wide">Thinking...</div>
      <div>{text}</div>
    </div>
  );
};

const AssistantMessage: FC = () => {
  return (
    <MessagePrimitive.Root
      className="aui-assistant-message-root fade-in slide-in-from-bottom-1 relative mx-auto w-full max-w-(--thread-max-width) animate-in py-4 duration-150 ease-out"
      data-role="assistant"
    >
      <div className="aui-assistant-message-content wrap-break-word mx-2 text-foreground leading-7">
        <MessagePrimitive.Parts
          components={{
            Text: MarkdownText,
            Reasoning: ReasoningContent,
            tools: { Fallback: ToolFallback },
          }}
        />
        <MessageError />
      </div>

      <div className="aui-assistant-message-footer mt-2 ml-2 flex">
        <AssistantActionBar />
      </div>
    </MessagePrimitive.Root>
  );
};

const AssistantActionBar: FC = () => {
  return (
    <ActionBarPrimitive.Root
      hideWhenRunning
      autohide="not-last"
      autohideFloat="single-branch"
      className="aui-assistant-action-bar-root -ml-1 col-start-3 row-start-2 flex gap-1 text-muted-foreground data-floating:absolute data-floating:rounded-md data-floating:border data-floating:bg-background data-floating:p-1 data-floating:shadow-sm"
    >
      <ActionBarPrimitive.Copy asChild>
        <TooltipIconButton tooltip="Copy">
          <MessagePrimitive.If copied>
            <CheckIcon />
          </MessagePrimitive.If>
          <MessagePrimitive.If copied={false}>
            <CopyIcon />
          </MessagePrimitive.If>
        </TooltipIconButton>
      </ActionBarPrimitive.Copy>
      <ActionBarPrimitive.Reload asChild>
        <TooltipIconButton tooltip="Refresh">
          <RefreshCwIcon />
        </TooltipIconButton>
      </ActionBarPrimitive.Reload>
    </ActionBarPrimitive.Root>
  );
};

const UserMessage: FC = () => {
  return (
    <MessagePrimitive.Root
      className="aui-user-message-root fade-in slide-in-from-bottom-1 mx-auto grid w-full max-w-(--thread-max-width) animate-in auto-rows-auto grid-cols-[minmax(72px,1fr)_auto] content-start gap-y-2 px-2 py-4 duration-150 ease-out [&:where(>*)]:col-start-2"
      data-role="user"
    >
      <UserMessageAttachments />

      <div className="aui-user-message-content-wrapper relative col-start-2 min-w-0">
        <div className="aui-user-message-content wrap-break-word rounded-3xl bg-muted px-5 py-2.5 text-foreground">
          <MessagePrimitive.Parts />
        </div>
        <div className="aui-user-action-bar-wrapper -translate-x-full -translate-y-1/2 absolute top-1/2 left-0 pr-2">
          <UserActionBar />
        </div>
      </div>
    </MessagePrimitive.Root>
  );
};

const UserActionBar: FC = () => {
  return (
    <ActionBarPrimitive.Root hideWhenRunning autohide="not-last" className="aui-user-action-bar-root flex flex-col items-end">
      {/* Edit button disabled */}
    </ActionBarPrimitive.Root>
  );
};

const EditComposer: FC = () => {
  return (
    <MessagePrimitive.Root className="aui-edit-composer-wrapper mx-auto flex w-full max-w-(--thread-max-width) flex-col gap-4 px-2">
      <ComposerPrimitive.Root className="aui-edit-composer-root ml-auto flex w-full max-w-7/8 flex-col rounded-xl bg-muted">
        <ComposerPrimitive.Input
          className="aui-edit-composer-input flex min-h-[60px] w-full resize-none bg-transparent p-4 text-foreground outline-none"
          autoFocus
        />

        <div className="aui-edit-composer-footer mx-3 mb-3 flex items-center justify-center gap-2 self-end">
          <ComposerPrimitive.Cancel asChild>
            <Button variant="ghost" size="sm" aria-label="Cancel edit">
              Cancel
            </Button>
          </ComposerPrimitive.Cancel>
          <ComposerPrimitive.Send asChild>
            <Button size="sm" aria-label="Update message">
              Update
            </Button>
          </ComposerPrimitive.Send>
        </div>
      </ComposerPrimitive.Root>
    </MessagePrimitive.Root>
  );
};