import { useCallback, useEffect, useMemo, useRef, useState } from "react";
import { useQueryClient } from "@tanstack/react-query";
import { toast } from "sonner";
import { stacksApi } from "@/api/stacks";
import { apiErrorMessage } from "@/api/client";

export type StackActionPhase = "running" | "success" | "error";

export type StackActionStatus = {
  id: string;
  label: string;
  phase: StackActionPhase;
  message?: string;
  at: number;
};

/** Success rows self-clear so they don't pile up; errors stay until dismissed
 *  or until the same stack is acted on again. */
const SUCCESS_CLEAR_MS = 5000;

/**
 * Runs stack lifecycle actions and tracks their progress.
 *
 * Actions on different stacks run concurrently (the stacks list lets you hit
 * Update on several rows), so both busy state and status are keyed by stack id
 * rather than held as a single value — otherwise the first action to finish
 * would clear the other rows' spinners and status.
 */
export function useStackActions() {
  const qc = useQueryClient();
  const [busy, setBusy] = useState<Record<string, true>>({});
  const [statusMap, setStatusMap] = useState<Record<string, StackActionStatus>>({});
  const timers = useRef<Record<string, number>>({});

  useEffect(
    () => () => {
      Object.values(timers.current).forEach(window.clearTimeout);
    },
    []
  );

  const run = async (
    id: string,
    label: string,
    fn: (id: string) => Promise<unknown>
  ) => {
    window.clearTimeout(timers.current[id]);
    delete timers.current[id];
    setBusy((b) => ({ ...b, [id]: true }));
    setStatusMap((s) => ({ ...s, [id]: { id, label, phase: "running", at: Date.now() } }));
    const t = toast.loading(`${label} ${id}…`);
    try {
      await fn(id);
      toast.success(`${label} ${id} ✓`, { id: t });
      setStatusMap((s) => ({ ...s, [id]: { id, label, phase: "success", at: Date.now() } }));
      timers.current[id] = window.setTimeout(() => {
        delete timers.current[id];
        setStatusMap((s) => (s[id]?.phase === "success" ? omit(s, id) : s));
      }, SUCCESS_CLEAR_MS);
      qc.invalidateQueries({ queryKey: ["stacks"] });
      qc.invalidateQueries({ queryKey: ["stack", id] });
      qc.invalidateQueries({ queryKey: ["stack-updates"] });
    } catch (err) {
      const message = apiErrorMessage(err);
      toast.error(message, { id: t });
      setStatusMap((s) => ({ ...s, [id]: { id, label, phase: "error", message, at: Date.now() } }));
    } finally {
      setBusy((b) => omit(b, id));
    }
  };

  // Oldest first, so a row doesn't jump around as other actions finish.
  const statuses = useMemo(
    () => Object.values(statusMap).sort((a, b) => a.at - b.at),
    [statusMap]
  );

  const isBusy = useCallback((id: string) => busy[id] === true, [busy]);

  const dismissStatus = useCallback((id: string) => {
    window.clearTimeout(timers.current[id]);
    delete timers.current[id];
    setStatusMap((s) => omit(s, id));
  }, []);

  return {
    isBusy,
    statuses,
    dismissStatus,
    start: (id: string) => run(id, "Starting", stacksApi.start),
    stop: (id: string) => run(id, "Stopping", stacksApi.stop),
    restart: (id: string) => run(id, "Restarting", stacksApi.restart),
    pull: (id: string) => run(id, "Pulling", stacksApi.pull),
    updateImages: (id: string) => run(id, "Updating", stacksApi.update_images),
    down: (id: string) => run(id, "Tearing down", stacksApi.down),
  };
}

function omit<T>(obj: Record<string, T>, key: string): Record<string, T> {
  const { [key]: _dropped, ...rest } = obj;
  return rest;
}