import { Button, Flex, Group, Stack, Text, Title } from "@mantine/core";
import type {
  BlobResourceContents,
  ContentBlock,
  Resource,
  TextResourceContents,
} from "@modelcontextprotocol/sdk/types.js";
import { AnnotationBadge } from "../../elements/AnnotationBadge/AnnotationBadge";
import { ContentViewer } from "../../elements/ContentViewer/ContentViewer";
import { CopyButton } from "../../elements/CopyButton/CopyButton";
import { SubscribeButton } from "../../elements/SubscribeButton/SubscribeButton";

export interface ResourcePreviewPanelProps {
  resource: Resource;
  contents: (TextResourceContents | BlobResourceContents)[];
  lastUpdated?: Date;
  isSubscribed: boolean;
  onRefresh: () => void;
  onSubscribe: () => void;
  onUnsubscribe: () => void;
}

function toContentBlock(
  item: TextResourceContents | BlobResourceContents,
): ContentBlock {
  if ("text" in item) {
    return { type: "text", text: item.text };
  }
  const mimeType = item.mimeType ?? "application/octet-stream";
  if (mimeType.startsWith("image/")) {
    return { type: "image", data: item.blob, mimeType };
  }
  if (mimeType.startsWith("audio/")) {
    return { type: "audio", data: item.blob, mimeType };
  }
  return {
    type: "text",
    text: `[Binary content (${mimeType}) — preview not supported]`,
  };
}

function formatLastUpdated(date: Date): string {
  return `Last updated: ${date.toLocaleString()}`;
}

const HeaderRow = Group.withProps({
  justify: "space-between",
  wrap: "nowrap",
});

const UriGroup = Group.withProps({
  gap: "xs",
  wrap: "nowrap",
});

const UriText = Text.withProps({
  size: "sm",
  c: "blue",
  truncate: "end",
});

const MetaRow = Group.withProps({
  justify: "space-between",
  wrap: "nowrap",
});

const TimestampText = Text.withProps({
  size: "xs",
  c: "dimmed",
});

const MimeText = Text.withProps({
  size: "sm",
  c: "dimmed",
});

const FooterRow = Group.withProps({
  justify: "space-between",
});

const AnnotationGroup = Group.withProps({
  gap: "xs",
});

const ActionGroup = Group.withProps({
  gap: "xs",
});

const Spacer = Flex.withProps({});

export function ResourcePreviewPanel({
  resource,
  contents,
  lastUpdated,
  isSubscribed,
  onRefresh,
  onSubscribe,
  onUnsubscribe,
}: ResourcePreviewPanelProps) {
  const { uri, annotations } = resource;
  const mimeType =
    contents[0]?.mimeType ?? resource.mimeType ?? "application/octet-stream";

  return (
    <Stack gap="md">
      <HeaderRow>
        <Title order={4}>Resource</Title>
        <UriGroup>
          <UriText>{uri}</UriText>
          <CopyButton value={uri} />
        </UriGroup>
      </HeaderRow>
      {contents.map((item, index) => (
        <ContentViewer key={index} block={toContentBlock(item)} copyable />
      ))}
      <MetaRow>
        {lastUpdated ? (
          <TimestampText>{formatLastUpdated(lastUpdated)}</TimestampText>
        ) : (
          <Spacer />
        )}
        {contents.length <= 1 && <MimeText>{mimeType}</MimeText>}
      </MetaRow>
      <FooterRow>
        <AnnotationGroup>
          {annotations?.audience && (
            <AnnotationBadge facet="audience" value={annotations.audience} />
          )}
          {annotations?.priority !== undefined && (
            <AnnotationBadge facet="priority" value={annotations.priority} />
          )}
        </AnnotationGroup>
        <ActionGroup>
          <Button variant="subtle" size="sm" onClick={onRefresh}>
            Refresh
          </Button>
          <SubscribeButton
            subscribed={isSubscribed}
            onToggle={isSubscribed ? onUnsubscribe : onSubscribe}
          />
        </ActionGroup>
      </FooterRow>
    </Stack>
  );
}