import * as React from "react";
import {
  Badge,
  Button,
  MessageBar,
  MessageBarBody,
  Spinner,
  Text,
  makeStyles,
  tokens,
} from "@fluentui/react-components";
import {
  ArrowDownload24Regular,
  DocumentPdf24Regular,
  History24Regular,
} from "@fluentui/react-icons";
import { VersionRecord } from "../../models/versionRecord";

interface VersionHistoryPanelProps {
  versions: VersionRecord[];
  loading: boolean;
  error: string | null;
  /** versionId ของ version ที่กำลังดาวน์โหลดอยู่ (แสดง spinner ที่ปุ่ม) */
  downloadingVersionId: string | null;
  downloadingPdfVersionId: string | null;
  onDownloadPdf: (version: VersionRecord) => void;
  onDownload: (version: VersionRecord) => void;
  onRetry: () => void;
}

const useStyles = makeStyles({
  root: {
    display: "flex",
    flexDirection: "column",
    gap: tokens.spacingVerticalS,
  },
  header: {
    display: "flex",
    alignItems: "center",
    gap: tokens.spacingHorizontalXS,
    marginTop: tokens.spacingVerticalL,
    marginBottom: tokens.spacingVerticalXXS,
  },
  item: {
    display: "flex",
    alignItems: "center",
    justifyContent: "space-between",
    gap: tokens.spacingHorizontalS,
    padding: `${tokens.spacingVerticalXS} ${tokens.spacingHorizontalS}`,
    borderRadius: tokens.borderRadiusMedium,
    ":hover": {
      backgroundColor: tokens.colorNeutralBackground1Hover,
    },
  },
  actions: { display: "flex", flexDirection: "column", flexShrink: 0 },
  itemInfo: {
    display: "flex",
    flexDirection: "column",
    minWidth: 0,
  },
  metaRow: {
    color: tokens.colorNeutralForeground3,
    fontSize: tokens.fontSizeBase200,
  },
  messageRow: {
    color: tokens.colorNeutralForeground2,
    fontSize: tokens.fontSizeBase200,
    whiteSpace: "pre-wrap",
    overflowWrap: "anywhere",
  },
});

function formatTimestamp(iso: string): string {
  const date = new Date(iso);
  return Number.isNaN(date.getTime())
    ? iso
    : date.toLocaleString(undefined, { dateStyle: "medium", timeStyle: "short" });
}

/** FR-4 — แสดง version history (เลข version / เวลา / ผู้สร้าง) + ปุ่มดาวน์โหลด version นั้น */
export const VersionHistoryPanel: React.FC<VersionHistoryPanelProps> = ({
  versions,
  loading,
  error,
  downloadingVersionId,
  downloadingPdfVersionId,
  onDownloadPdf,
  onDownload,
  onRetry,
}) => {
  const styles = useStyles();

  return (
    <div className={styles.root}>
      <div className={styles.header}>
        <History24Regular />
        <Text weight="semibold">Version history</Text>
      </div>

      {loading ? <Spinner size="small" label="กำลังโหลด…" /> : null}

      {error ? (
        <MessageBar intent="error">
          <MessageBarBody>
            {error}{" "}
            <Button size="small" appearance="subtle" onClick={onRetry}>
              ลองใหม่
            </Button>
          </MessageBarBody>
        </MessageBar>
      ) : null}

      {!loading && !error && versions.length === 0 ? (
        <Text size={200} style={{ color: tokens.colorNeutralForeground3 }}>
          ยังไม่มี version ในระบบ
        </Text>
      ) : null}

      {versions.map((version) => (
        <div className={styles.item} key={version.versionId}>
          <div className={styles.itemInfo}>
            <Badge appearance="filled" color="brand">
              v{version.versionNumber}
            </Badge>
            <span className={styles.metaRow}>{formatTimestamp(version.createdAt)}</span>
            <span className={styles.metaRow}>โดย {version.createdByUserId}</span>
            {version.message ? <span className={styles.messageRow}>{version.message}</span> : null}
          </div>
          <div className={styles.actions}>
            <Button
              icon={<ArrowDownload24Regular />}
              size="small"
              appearance="subtle"
              disabled={downloadingVersionId !== null || downloadingPdfVersionId !== null}
              onClick={() => onDownload(version)}
            >
              {downloadingVersionId === version.versionId ? "กำลังดาวน์โหลด…" : "ดาวน์โหลด"}
            </Button>
            {version.hasPdf ? (
              <Button
                icon={<DocumentPdf24Regular />}
                size="small"
                appearance="subtle"
                disabled={downloadingVersionId !== null || downloadingPdfVersionId !== null}
                onClick={() => onDownloadPdf(version)}
              >
                {downloadingPdfVersionId === version.versionId ? "กำลังเปิด…" : "PDF"}
              </Button>
            ) : null}
          </div>
        </div>
      ))}
    </div>
  );
};

export default VersionHistoryPanel;