import { reactive } from "vue";
import {
  ApiError,
  fetchHost,
  fetchHostRemoteJob,
  runHostAgentUpdateFallback,
  updateHostAgentViaSsh,
  type HostDetail,
  type HostRemoteActionJobStatus,
} from "../api";
import { emitHostPatch } from "../utils/hostPatchBus";

export type HostRemoteActionKind = "fallback" | "ssh-update";

export type HostRemoteActionLogEntry = {
  id: string;
  hostId: number;
  open: boolean;
  logVisible: boolean;
  loading: boolean;
  ok: boolean | null;
  title: string;
  message: string;
  output: string;
};

export const hostRemoteActionLogs = reactive<HostRemoteActionLogEntry[]>([]);

const POLL_MS = 1500;
const SUCCESS_AUTO_CLOSE_MS = 30_000;

let nextLogSeq = 1;
const autoCloseTimers = new Map<string, ReturnType<typeof setTimeout>>();
const hostRunningPromises = new Map<number, Promise<HostRemoteActionJobStatus | null>>();

function sleep(ms: number): Promise<void> {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

function newLogId(): string {
  return `ra-${Date.now()}-${nextLogSeq++}`;
}

function findLogById(entryId: string): HostRemoteActionLogEntry | undefined {
  return hostRemoteActionLogs.find((e) => e.id === entryId);
}

function findLoadingLogForHost(hostId: number): HostRemoteActionLogEntry | undefined {
  return hostRemoteActionLogs.find((e) => e.hostId === hostId && e.loading);
}

function clearAutoCloseTimer(entryId: string) {
  const timer = autoCloseTimers.get(entryId);
  if (timer != null) {
    clearTimeout(timer);
    autoCloseTimers.delete(entryId);
  }
}

function removeClosedFinishedLog(entryId: string) {
  const idx = hostRemoteActionLogs.findIndex((e) => e.id === entryId);
  if (idx < 0) return;
  const entry = hostRemoteActionLogs[idx];
  if (!entry.loading && !entry.open) {
    hostRemoteActionLogs.splice(idx, 1);
  }
}

function scheduleSuccessAutoClose(entryId: string) {
  clearAutoCloseTimer(entryId);
  autoCloseTimers.set(
    entryId,
    setTimeout(() => {
      const entry = findLogById(entryId);
      if (entry) {
        entry.open = false;
        removeClosedFinishedLog(entryId);
      }
      autoCloseTimers.delete(entryId);
    }, SUCCESS_AUTO_CLOSE_MS),
  );
}

function applyJobToEntry(entry: HostRemoteActionLogEntry, job: HostRemoteActionJobStatus) {
  if (job.title) {
    entry.title = job.title;
  }
  if (job.message) {
    entry.message = job.message;
  }
  const nextOutput = (job.output || job.stdout || "").trim();
  if (nextOutput) {
    entry.output = job.output || job.stdout || "";
  }
}

function finishEntry(entry: HostRemoteActionLogEntry, job: HostRemoteActionJobStatus) {
  if (!entry.loading && entry.ok != null) {
    return;
  }
  entry.loading = false;
  entry.ok = job.ok ?? job.status === "success";
  applyJobToEntry(entry, job);
  entry.open = true;
  if (entry.ok) {
    scheduleSuccessAutoClose(entry.id);
  }
}

export function syncHostRemoteActionJobFinished(
  entryId: string,
  job: HostRemoteActionJobStatus,
): void {
  const entry = findLogById(entryId);
  if (!entry) return;
  finishEntry(entry, job);
  void patchHostFromJob(entry.hostId, job);
}

async function pollRemoteJob(hostId: number, entry: HostRemoteActionLogEntry): Promise<HostRemoteActionJobStatus> {
  for (;;) {
    const job = await fetchHostRemoteJob(hostId);
    applyJobToEntry(entry, job);
    if (!job.active && job.status !== "running") {
      return job;
    }
    await sleep(POLL_MS);
  }
}

async function patchHostFromJob(hostId: number, job: HostRemoteActionJobStatus) {
  try {
    const detail: HostDetail = await fetchHost(hostId);
    if (job.product_version) {
      detail.product_version = job.product_version;
    }
    if (job.agent_update_state) {
      detail.agent_update_state = job.agent_update_state;
    }
    if (job.ok === false && job.message) {
      detail.agent_update_last_error = job.message;
    }
    emitHostPatch(detail);
  } catch {
    /* list refresh on next open is enough */
  }
}

async function startRemoteAction(hostId: number, kind: HostRemoteActionKind) {
  if (kind === "fallback") {
    await runHostAgentUpdateFallback(hostId);
    return;
  }
  await updateHostAgentViaSsh(hostId);
}

async function executeRemoteAction(
  hostId: number,
  title: string,
  kind: HostRemoteActionKind,
  entry: HostRemoteActionLogEntry,
): Promise<HostRemoteActionJobStatus | null> {
  try {
    try {
      await startRemoteAction(hostId, kind);
    } catch (e) {
      if (e instanceof ApiError && e.status === 409) {
        /* already running — poll existing job */
      } else {
        throw e;
      }
    }
    entry.message = "Выполняется на удалённом хосте… Можно запустить обновление других хостов.";
    const job = await pollRemoteJob(hostId, entry);
    finishEntry(entry, job);
    await patchHostFromJob(hostId, job);
    return job;
  } catch (e) {
    entry.loading = false;
    entry.ok = false;
    entry.message = e instanceof Error ? e.message : "Ошибка выполнения";
    entry.open = true;
    return null;
  }
}

export async function pollHostRemoteAction(
  hostId: number,
  title: string,
): Promise<HostRemoteActionJobStatus | null> {
  const existingPromise = hostRunningPromises.get(hostId);
  if (existingPromise) {
    const existing = findLoadingLogForHost(hostId);
    if (existing) {
      existing.open = true;
    }
    return existingPromise;
  }

  const entry: HostRemoteActionLogEntry = {
    id: newLogId(),
    hostId,
    open: true,
    logVisible: false,
    loading: true,
    ok: null,
    title,
    message: "Выполняется на удалённом хосте…",
    output: "",
  };
  hostRemoteActionLogs.push(entry);

  const promise = (async () => {
    try {
      const job = await pollRemoteJob(hostId, entry);
      finishEntry(entry, job);
      await patchHostFromJob(hostId, job);
      return job;
    } catch (e) {
      entry.loading = false;
      entry.ok = false;
      entry.message = e instanceof Error ? e.message : "Ошибка выполнения";
      entry.open = true;
      return null;
    }
  })();

  hostRunningPromises.set(hostId, promise);
  try {
    return await promise;
  } finally {
    hostRunningPromises.delete(hostId);
  }
}

export async function runHostRemoteAction(
  hostId: number,
  title: string,
  kind: HostRemoteActionKind,
): Promise<HostRemoteActionJobStatus | null> {
  const existingPromise = hostRunningPromises.get(hostId);
  if (existingPromise) {
    const existing = findLoadingLogForHost(hostId);
    if (existing) {
      existing.open = true;
    }
    return existingPromise;
  }

  const entry: HostRemoteActionLogEntry = {
    id: newLogId(),
    hostId,
    open: true,
    logVisible: false,
    loading: true,
    ok: null,
    title,
    message: "Запуск на сервере SAC…",
    output: "",
  };
  hostRemoteActionLogs.push(entry);

  const promise = executeRemoteAction(hostId, title, kind, entry);
  hostRunningPromises.set(hostId, promise);
  try {
    return await promise;
  } finally {
    hostRunningPromises.delete(hostId);
  }
}

export function toggleHostRemoteActionLog(entryId: string) {
  const entry = findLogById(entryId);
  if (!entry) return;
  entry.logVisible = !entry.logVisible;
  entry.open = true;
}

export function closeHostRemoteActionLog(entryId: string) {
  clearAutoCloseTimer(entryId);
  const entry = findLogById(entryId);
  if (!entry) return;
  entry.open = false;
  if (!entry.loading) {
    removeClosedFinishedLog(entryId);
  }
}

export function showHostRemoteActionLog(hostId?: number) {
  if (hostId != null) {
    for (const entry of hostRemoteActionLogs) {
      if (entry.hostId === hostId && (entry.loading || entry.ok != null)) {
        entry.open = true;
      }
    }
    return;
  }
  for (const entry of hostRemoteActionLogs) {
    if (entry.loading || entry.ok === false) {
      entry.open = true;
    }
  }
}

export function isHostRemoteActionActive(hostId: number): boolean {
  return hostRemoteActionLogs.some((e) => e.hostId === hostId && e.loading);
}

export function hasActiveHostRemoteAction(): boolean {
  return hostRemoteActionLogs.some((e) => e.loading);
}

export function hasOpenRemoteActionLogForHost(hostId: number): boolean {
  return hostRemoteActionLogs.some((e) => e.hostId === hostId && e.open);
}

export function anyRemoteActionLogOpen(): boolean {
  return hostRemoteActionLogs.some((e) => e.open);
}