import {
  useState,
  useEffect,
  useCallback,
  useMemo,
  useRef,
  type ReactNode,
} from "react";
import {
  useTranslation,
  useToast,
  usePluginApi,
  usePermission,
} from "@termix/plugin-sdk/frontend";
import {
  Input,
  Tooltip,
  TooltipContent,
  TooltipProvider,
  TooltipTrigger,
  copyToClipboard,
} from "@termix/plugin-sdk/ui";
import {
  ArrowLeft,
  Check,
  Copy,
  Download,
  Eye,
  FileText,
  Loader2,
  ScrollText,
  Search,
  X,
} from "lucide-react";
import { SessionRecordingPlayer } from "./SessionRecordingPlayer";
import { asciicastToPlainText, parseAsciicast } from "./asciicast";
import {
  createSessionRecordingApi,
  type SessionLogRecord,
} from "./session-recording-api";

function useAdaptivePolling(
  fn: () => Promise<boolean | void>,
  options: { minIntervalMs: number; maxIntervalMs: number },
  enabled: boolean,
) {
  const fnRef = useRef(fn);
  fnRef.current = fn;

  useEffect(() => {
    if (!enabled) return;
    let interval = options.minIntervalMs;
    let stable = 0;
    let cancelled = false;
    let timer: ReturnType<typeof setTimeout>;

    const tick = async () => {
      if (cancelled) return;
      try {
        const changed = await fnRef.current();
        if (changed) {
          interval = options.minIntervalMs;
          stable = 0;
        } else {
          stable++;
          if (stable >= 3) {
            interval = Math.min(interval * 1.5, options.maxIntervalMs);
          }
        }
      } catch {
        // keep polling
      }
      if (!cancelled) timer = setTimeout(tick, interval);
    };

    timer = setTimeout(tick, interval);
    return () => {
      cancelled = true;
      clearTimeout(timer);
    };
  }, [enabled, options.minIntervalMs, options.maxIntervalMs]);
}

function formatDuration(seconds: number | null): string {
  if (seconds == null) return "--";
  if (seconds < 60) return `${seconds}s`;
  const m = Math.floor(seconds / 60);
  const s = seconds % 60;
  return s > 0 ? `${m}m ${s}s` : `${m}m`;
}

function formatBytes(bytes: number | null): string {
  if (bytes == null || bytes === 0) return "--";
  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
}

function formatDate(iso: string): string {
  const d = new Date(iso);
  return d.toLocaleString(undefined, {
    month: "short",
    day: "numeric",
    hour: "2-digit",
    minute: "2-digit",
  });
}

function buildFilename(log: SessionLogRecord): string {
  const host = (log.hostName ?? log.hostIp ?? "session")
    .replace(/[^a-zA-Z0-9._-]/g, "_")
    .slice(0, 40);
  const d = new Date(log.startedAt);
  const y = d.getFullYear();
  const m = String(d.getMonth() + 1).padStart(2, "0");
  const day = String(d.getDate()).padStart(2, "0");
  const h = String(d.getHours()).padStart(2, "0");
  const min = String(d.getMinutes()).padStart(2, "0");
  const s = String(d.getSeconds()).padStart(2, "0");
  const extension =
    log.format === "guacamole"
      ? "guac"
      : log.format === "asciicast"
        ? "cast"
        : "log";
  return `${host}_${y}-${m}-${day}_${h}-${min}-${s}.${extension}`;
}

function buildTextFilename(log: SessionLogRecord): string {
  return buildFilename(log).replace(/\.(cast|guac|log)$/, ".txt");
}

async function extractPlainText(
  log: SessionLogRecord,
  blob: Blob,
): Promise<string | null> {
  if (log.format === "guacamole") return null;
  const source = await blob.text();
  if (log.format === "text") return source;
  return asciicastToPlainText(parseAsciicast(source));
}

function SectionHeader({ label, count }: { label: string; count: number }) {
  return (
    <div className="flex items-center gap-2 px-3 py-2 border-b border-border/60 bg-muted/20">
      <span className="text-[10px] font-bold uppercase tracking-widest text-muted-foreground/60 flex-1">
        {label}
      </span>
      <span className="text-[10px] font-semibold text-muted-foreground/40 bg-muted/60 px-1.5 py-0.5">
        {count}
      </span>
    </div>
  );
}

function LogMeta({
  items,
  className,
}: {
  items: (string | null | undefined)[];
  className?: string;
}) {
  return (
    <span
      className={`flex min-w-0 items-center gap-x-2.5 overflow-hidden whitespace-nowrap text-[10px] ${className ?? ""}`}
    >
      {items.filter(Boolean).map((item, i) => (
        <span key={i} className="truncate last:shrink-0">
          {item}
        </span>
      ))}
    </span>
  );
}

const ACTION_BUTTON =
  "size-6 flex items-center justify-center text-muted-foreground/50 hover:text-foreground hover:bg-muted/60 transition-colors";

function ActionButton({
  label,
  onClick,
  destructive,
  children,
}: {
  label: string;
  onClick: () => void;
  destructive?: boolean;
  children: ReactNode;
}) {
  return (
    <Tooltip>
      <TooltipTrigger asChild>
        <button
          type="button"
          onClick={onClick}
          aria-label={label}
          className={
            destructive
              ? "size-6 flex items-center justify-center text-muted-foreground/50 hover:text-destructive hover:bg-destructive/10 transition-colors"
              : ACTION_BUTTON
          }
        >
          {children}
        </button>
      </TooltipTrigger>
      <TooltipContent side="top" sideOffset={6}>
        {label}
      </TooltipContent>
    </Tooltip>
  );
}

function LogRow({
  log,
  onView,
  onDownload,
  onDownloadText,
  onDelete,
}: {
  log: SessionLogRecord;
  onView: () => void;
  onDownload: () => void;
  onDownloadText: () => void;
  onDelete: () => void;
}) {
  const { t } = useTranslation();
  const hostLabel =
    log.hostName ??
    log.hostIp ??
    t("sessionLogs.hostFallback", { id: log.hostId });

  return (
    <div className="group flex items-center gap-2.5 px-3 py-2.5 border-b border-border/40 last:border-b-0 hover:bg-muted/40 transition-colors">
      <div className="shrink-0 flex items-center justify-center size-7 bg-muted/60 text-muted-foreground">
        <ScrollText className="size-3.5" />
      </div>

      <div className="flex flex-col flex-1 min-w-0 gap-0.5">
        <span className="text-xs font-semibold truncate text-foreground">
          {hostLabel}
        </span>
        <LogMeta
          className="text-muted-foreground/60"
          items={[
            formatDate(log.startedAt),
            (log.protocol ?? "ssh").toUpperCase(),
            log.username,
            formatDuration(log.duration),
            formatBytes(log.sizeBytes),
          ]}
        />
      </div>

      <TooltipProvider disableHoverableContent>
        <div className="shrink-0 flex items-center gap-0.5 opacity-0 group-hover:opacity-100 transition-opacity">
          <ActionButton label={t("sessionLogs.viewLog")} onClick={onView}>
            <Eye className="size-3" />
          </ActionButton>
          {log.format === "asciicast" && (
            <ActionButton
              label={t("sessionLogs.downloadAsText")}
              onClick={onDownloadText}
            >
              <FileText className="size-3" />
            </ActionButton>
          )}
          <ActionButton
            label={t("sessionLogs.downloadLog")}
            onClick={onDownload}
          >
            <Download className="size-3" />
          </ActionButton>
          <ActionButton
            label={t("sessionLogs.deleteLog")}
            onClick={onDelete}
            destructive
          >
            <X className="size-3" />
          </ActionButton>
        </div>
      </TooltipProvider>
    </div>
  );
}

export function SessionLogsPanel() {
  const { t } = useTranslation();
  const toast = useToast();
  const pluginApi = usePluginApi();
  const api = useMemo(() => createSessionRecordingApi(pluginApi), [pluginApi]);
  const canView = usePermission("view");
  const [logs, setLogs] = useState<SessionLogRecord[]>([]);
  const [loading, setLoading] = useState(true);
  const [filter, setFilter] = useState("");
  const [viewLog, setViewLog] = useState<SessionLogRecord | null>(null);
  const [viewContent, setViewContent] = useState<string>("");
  const [viewBlob, setViewBlob] = useState<Blob | null>(null);
  const [viewText, setViewText] = useState<string | null>(null);
  const [viewLoading, setViewLoading] = useState(false);
  const [deleteTarget, setDeleteTarget] = useState<SessionLogRecord | null>(
    null,
  );
  const [deleting, setDeleting] = useState(false);
  const [copied, setCopied] = useState(false);
  const logsRef = useRef(logs);
  logsRef.current = logs;

  const load = useCallback(
    async (initial = false) => {
      if (initial) setLoading(true);
      try {
        const fresh = await api.list();
        const changed =
          logsRef.current.length !== fresh.length ||
          logsRef.current.some((log, i) => log.id !== fresh[i]?.id);
        if (changed) {
          logsRef.current = fresh;
          setLogs(fresh);
        }
        return changed;
      } catch (error) {
        if (initial) {
          toast.error(t("sessionLogs.loadError"));
          return false;
        }
        throw error;
      } finally {
        if (initial) setLoading(false);
      }
    },
    [api, t, toast],
  );

  useEffect(() => {
    if (!canView) return;
    void load(true);
  }, [canView, load]);

  useAdaptivePolling(
    () => load(false),
    {
      minIntervalMs: 5_000,
      maxIntervalMs: 30_000,
    },
    canView,
  );

  const q = filter.trim().toLowerCase();
  const filtered = q
    ? logs.filter((l) =>
        `${l.hostName ?? ""} ${l.hostIp ?? ""} ${l.username ?? ""} ${l.protocol}`
          .toLowerCase()
          .includes(q),
      )
    : logs;

  const handleView = async (log: SessionLogRecord) => {
    setViewLog(log);
    setViewContent("");
    setViewBlob(null);
    setViewText(null);
    setViewLoading(true);
    try {
      if (log.format === "text") {
        const text = await api.getContent(log.id);
        setViewContent(text);
        setViewText(text);
      } else {
        const blob = await api.getBlob(log.id);
        setViewBlob(blob);
        setViewText(await extractPlainText(log, blob));
      }
    } catch {
      toast.error(t("sessionLogs.loadError"));
    } finally {
      setViewLoading(false);
    }
  };

  const downloadBlob = (blob: Blob, filename: string) => {
    const url = URL.createObjectURL(blob);
    const a = document.createElement("a");
    a.href = url;
    a.download = filename;
    a.click();
    URL.revokeObjectURL(url);
  };

  const handleDownload = async (log: SessionLogRecord) => {
    try {
      downloadBlob(await api.getBlob(log.id), buildFilename(log));
    } catch {
      toast.error(t("sessionLogs.loadError"));
    }
  };

  const handleDownloadText = async (log: SessionLogRecord) => {
    try {
      const text =
        log.id === viewLog?.id && viewText != null
          ? viewText
          : await extractPlainText(log, await api.getBlob(log.id));
      if (text == null) {
        toast.error(t("sessionLogs.loadError"));
        return;
      }
      downloadBlob(
        new Blob([text], { type: "text/plain" }),
        buildTextFilename(log),
      );
    } catch {
      toast.error(t("sessionLogs.loadError"));
    }
  };

  const handleDelete = async () => {
    if (!deleteTarget) return;
    setDeleting(true);
    try {
      await api.delete(deleteTarget.id);
      setLogs((prev) => prev.filter((l) => l.id !== deleteTarget.id));
      setDeleteTarget(null);
    } catch {
      toast.error(t("sessionLogs.deleteError"));
    } finally {
      setDeleting(false);
    }
  };

  const handleCopy = async () => {
    if (!viewText) return;
    const ok = await copyToClipboard(viewText);
    if (ok) {
      setCopied(true);
      setTimeout(() => setCopied(false), 1500);
    } else {
      toast.error(t("common.copyFailed"));
    }
  };

  if (loading) {
    return (
      <div className="flex items-center justify-center flex-1 p-8">
        <Loader2 className="size-5 text-muted-foreground animate-spin" />
      </div>
    );
  }

  // Inline log viewer
  if (viewLog) {
    const hostLabel =
      viewLog.hostName ??
      viewLog.hostIp ??
      t("sessionLogs.hostFallback", { id: viewLog.hostId });
    return (
      <div className="flex flex-col flex-1 min-h-0 overflow-hidden">
        {/* Viewer header */}
        <div className="flex items-center gap-2 px-2 py-2 border-b border-border/60 bg-muted/20 shrink-0">
          <button
            type="button"
            onClick={() => setViewLog(null)}
            aria-label={t("sessionLogs.back")}
            className={ACTION_BUTTON}
          >
            <ArrowLeft className="size-3.5" />
          </button>
          <div className="flex flex-col flex-1 min-w-0">
            <span className="text-xs font-semibold truncate text-foreground">
              {hostLabel}
            </span>
            <LogMeta
              className="text-muted-foreground/50"
              items={[
                formatDate(viewLog.startedAt),
                viewLog.protocol.toUpperCase(),
                viewLog.duration != null
                  ? formatDuration(viewLog.duration)
                  : null,
                formatBytes(viewLog.sizeBytes),
              ]}
            />
          </div>
          <TooltipProvider disableHoverableContent>
            <div className="flex items-center gap-0.5 shrink-0">
              {viewText != null && (
                <ActionButton
                  label={
                    copied
                      ? t("sessionLogs.copied")
                      : t("sessionLogs.copyContent")
                  }
                  onClick={handleCopy}
                >
                  {copied ? (
                    <Check className="size-3 text-green-500" />
                  ) : (
                    <Copy className="size-3" />
                  )}
                </ActionButton>
              )}
              {viewLog.format === "asciicast" && (
                <ActionButton
                  label={t("sessionLogs.downloadAsText")}
                  onClick={() => handleDownloadText(viewLog)}
                >
                  <FileText className="size-3" />
                </ActionButton>
              )}
              <ActionButton
                label={t("sessionLogs.downloadLog")}
                onClick={() => handleDownload(viewLog)}
              >
                <Download className="size-3" />
              </ActionButton>
            </div>
          </TooltipProvider>
        </div>

        {/* Log content */}
        <div
          className={`flex-1 min-h-0 min-w-0 ${viewBlob ? "overflow-hidden" : "overflow-y-auto overflow-x-hidden"}`}
        >
          {viewLoading ? (
            <div className="flex items-center justify-center py-16">
              <Loader2 className="size-4 animate-spin text-muted-foreground" />
            </div>
          ) : viewBlob ? (
            <SessionRecordingPlayer log={viewLog} blob={viewBlob} />
          ) : (
            <pre className="p-3 text-[11px] font-mono whitespace-pre-wrap break-all text-foreground/80 leading-relaxed">
              {viewContent || t("sessionLogs.empty")}
            </pre>
          )}
        </div>
      </div>
    );
  }

  return (
    <div className="flex flex-col flex-1 min-h-0">
      <div className="flex-1 overflow-y-auto">
        {logs.length === 0 ? (
          <div className="flex flex-col items-center justify-center flex-1 gap-3 p-6 text-center py-16">
            <div className="size-10 bg-muted/40 flex items-center justify-center">
              <ScrollText className="size-5 text-muted-foreground/30" />
            </div>
            <div className="flex flex-col gap-1">
              <span className="text-sm font-semibold text-muted-foreground/60">
                {t("sessionLogs.noLogs")}
              </span>
              <span className="text-xs text-muted-foreground/40">
                {t("sessionLogs.noLogsDesc")}
              </span>
            </div>
          </div>
        ) : (
          <>
            <div className="relative px-3 py-2 border-b border-border/60">
              <Search className="absolute left-5.5 top-1/2 -translate-y-1/2 size-3.5 text-muted-foreground/50 pointer-events-none" />
              <Input
                placeholder={t("sessionLogs.filterByHost")}
                value={filter}
                onChange={(e) => setFilter(e.target.value)}
                className="pl-8 h-7 text-xs"
              />
            </div>

            {filtered.length === 0 ? (
              <div className="flex flex-col items-center justify-center gap-2 py-10 text-center">
                <span className="text-xs text-muted-foreground/50">
                  {t("sessionLogs.noResults", { query: filter })}
                </span>
              </div>
            ) : (
              <div className="flex flex-col">
                <SectionHeader
                  label={t("sessionLogs.title")}
                  count={filtered.length}
                />
                {filtered.map((log) => (
                  <LogRow
                    key={log.id}
                    log={log}
                    onView={() => handleView(log)}
                    onDownload={() => handleDownload(log)}
                    onDownloadText={() => handleDownloadText(log)}
                    onDelete={() => setDeleteTarget(log)}
                  />
                ))}
              </div>
            )}
          </>
        )}
      </div>

      {/* Inline delete confirmation - positioned against the relative parent in AppShell */}
      {deleteTarget && (
        <div className="absolute inset-0 z-50 flex items-center justify-center bg-background/80 backdrop-blur-sm p-4">
          <div className="bg-popover border border-border shadow-xl w-full max-w-xs flex flex-col gap-4 p-4">
            <p className="text-sm text-foreground">
              {t("sessionLogs.confirmDelete")}
            </p>
            <div className="flex flex-col text-xs text-muted-foreground">
              <span className="font-medium text-foreground/80">
                {deleteTarget.hostName ??
                  deleteTarget.hostIp ??
                  t("sessionLogs.sessionFallback", { id: deleteTarget.id })}
              </span>
              <span>{formatDate(deleteTarget.startedAt)}</span>
            </div>
            <div className="flex justify-end gap-2">
              <button
                onClick={() => setDeleteTarget(null)}
                className="px-3 py-1.5 text-xs border border-border text-muted-foreground hover:text-foreground hover:bg-muted transition-colors"
              >
                {t("common.cancel")}
              </button>
              <button
                onClick={handleDelete}
                disabled={deleting}
                className="px-3 py-1.5 text-xs bg-destructive text-destructive-foreground hover:bg-destructive/90 transition-colors flex items-center gap-1.5"
              >
                {deleting && <Loader2 className="size-3 animate-spin" />}
                {t("sessionLogs.deleteLog")}
              </button>
            </div>
          </div>
        </div>
      )}
    </div>
  );
}