import { ListChecks, Send, Sparkles, Terminal, Trash2, X } from "lucide-react";
import { type FormEvent, type KeyboardEvent as ReactKeyboardEvent, type ReactNode, useCallback, useEffect, useMemo, useRef, useState } from "react";

import { platformApiClient } from "../api/client";
import type { GameClientBridgeCommandResponse, LogEntryBody, LogStreamResponse } from "../api/types";
import { scumManagementRCONCommandRequest } from "../schemas/scumManagementRcon";
import { cx } from "../utils/classes";
import { mergeLogStreams, parseLogStreamEvent, parseServerLogEvent, streamFromServerLogEvent } from "../utils/logEvents";
import { EmptyState, ErrorState, LoadingState, ResultBadge } from "./StateViews";

type LoadState<T> = { status: "loading" } | { status: "error"; reason: string } | { status: "ready"; data: T };
type TerminalLine = { id: string; tone: "input" | "info" | "success" | "warn" | "error"; text: string; at: string; sortKey: number; streamKey?: string; level?: string; seq?: number };
type TerminalQuickCommand = { label: string; command: string; hint: string };

const terminalBridgeResultPollMs = 1000;
const terminalBridgeResultPollAttempts = 30;
const terminalInitialHistoryWindow = 500;
const maxTerminalLines = 10000;
const terminalQuickCommandCatalog: Record<string, TerminalQuickCommand[]> = {
  "game.scum": [
    { label: "查询玩家", command: "#ListPlayers", hint: "在线玩家列表" },
    { label: "查询队伍", command: "#ListSquads 1", hint: "服务器队伍列表" },
    { label: "查询车辆", command: "#ListSpawnedVehicles true", hint: "已生成车辆列表" },
    { label: "设为中午", command: "#SetTime 12", hint: "设置游戏时间" }
  ]
};

interface LiveOperationDrawerProps {
  open: boolean;
  title: string;
  description?: string;
  onClose: () => void;
  children: ReactNode;
  backdropClassName?: string;
  panelClassName?: string;
  bodyClassName?: string;
  hideHeader?: boolean;
}

function LiveOperationDrawer({ open, title, description, onClose, children, backdropClassName, panelClassName, bodyClassName, hideHeader }: LiveOperationDrawerProps) {
  useEffect(() => {
    if (!open) return undefined;
    const previous = document.body.style.overflow;
    const handleKeyDown = (event: KeyboardEvent) => {
      if (event.key === "Escape") onClose();
    };
    document.body.style.overflow = "hidden";
    document.addEventListener("keydown", handleKeyDown);
    return () => {
      document.body.style.overflow = previous;
      document.removeEventListener("keydown", handleKeyDown);
    };
  }, [onClose, open]);

  if (!open) return null;
  return (
    <div className={cx("drawer-backdrop", backdropClassName)} role="presentation" onClick={onClose}>
      <aside className={cx("drawer-panel live-operation-drawer", panelClassName)} role="dialog" aria-modal="true" aria-label={title} onClick={(event) => event.stopPropagation()}>
        {!hideHeader && (
          <div className="panel-header">
            <div>
              <h2>{title}</h2>
              {description && <p className="page-status">{description}</p>}
            </div>
            <button type="button" className="theme-upload drawer-close" aria-label={`关闭${title}`} onClick={onClose}><X size={14} /><span>关闭</span></button>
          </div>
        )}
        <div className={cx("live-operation-content", bodyClassName)}>{children}</div>
      </aside>
    </div>
  );
}

interface ServerManagementTerminalDrawerProps {
  open: boolean;
  serverId: string;
  serverName: string;
  pluginId: string;
  canManage: boolean;
  onClose: () => void;
}

export function ServerManagementTerminalDrawer({ open, serverId, serverName, pluginId, canManage, onClose }: ServerManagementTerminalDrawerProps) {
  const [command, setCommand] = useState("");
  const [pending, setPending] = useState(false);
  const [lines, setLines] = useState<TerminalLine[]>([]);
  const [streams, setStreams] = useState<LoadState<LogStreamResponse[]>>({ status: "loading" });
  const [commandHistory, setCommandHistory] = useState<string[]>([]);
  const [historyIndex, setHistoryIndex] = useState<number | null>(null);
  const [result, setResult] = useState<{ status: "pending" | "succeeded" | "failed"; label: string } | null>(null);
  const [followLatest, setFollowLatest] = useState(true);
  const outputRef = useRef<HTMLDivElement>(null);
  const followLatestRef = useRef(true);
  const initialHistoryPendingRef = useRef(false);
  const quickCommands = useMemo(() => terminalQuickCommandsForPlugin(pluginId), [pluginId]);
  const supportsCommands = quickCommands.length > 0;

  const appendLines = useCallback((incoming: TerminalLine[]) => {
    if (incoming.length === 0) return;
    setLines((current) => mergeTerminalLines(current, incoming));
  }, []);

  const lockTerminalFollow = useCallback(() => {
    followLatestRef.current = true;
    setFollowLatest(true);
    window.requestAnimationFrame(() => {
      const output = outputRef.current;
      if (output) output.scrollTop = output.scrollHeight;
      window.requestAnimationFrame(() => {
        const output = outputRef.current;
        if (output) output.scrollTop = output.scrollHeight;
        initialHistoryPendingRef.current = false;
      });
    });
  }, []);

  useEffect(() => {
    if (!open) return;
    setStreams({ status: "loading" });
    setCommand("");
    setPending(false);
    setResult(null);
    setHistoryIndex(null);
    initialHistoryPendingRef.current = true;
    followLatestRef.current = true;
    setFollowLatest(true);
    setLines([terminalSystemLine("info", supportsCommands ? "连接平台日志推送，先补最近历史再实时追加。" : "该插件暂未声明可用的管理终端命令通道。", "SYSTEM")]);
  }, [open, supportsCommands]);

  useEffect(() => {
    if (!open || initialHistoryPendingRef.current || !followLatestRef.current) return undefined;
    const frame = window.requestAnimationFrame(() => {
      const output = outputRef.current;
      if (output) output.scrollTop = output.scrollHeight;
    });
    return () => window.cancelAnimationFrame(frame);
  }, [lines, open]);

  useEffect(() => {
    if (!open) return undefined;
    let ready = false;
    const events = platformApiClient.openServerLogEvents(serverId, { historyLimit: terminalInitialHistoryWindow });
    events.addEventListener("stream", (event) => {
      const stream = parseLogStreamEvent(event);
      if (!stream) return;
      ready = true;
      setStreams((current) => ({ status: "ready", data: mergeLogStreams(current.status === "ready" ? current.data : [], stream) }));
    });
    events.addEventListener("ready", () => {
      ready = true;
      setStreams((current) => current.status === "ready" ? current : { status: "ready", data: [] });
      lockTerminalFollow();
    });
    events.addEventListener("log", (event) => {
      const payload = parseServerLogEvent(event);
      if (!payload) return;
      ready = true;
      const stream = streamFromServerLogEvent(payload);
      setStreams((current) => ({ status: "ready", data: mergeLogStreams(current.status === "ready" ? current.data : [], stream) }));
      appendLines([terminalLineFromLog(stream, payload.entry)]);
    });
    events.onerror = () => {
      if (!ready) setStreams({ status: "error", reason: "实时日志推送连接失败" });
    };
    return () => events.close();
  }, [appendLines, lockTerminalFollow, open, serverId]);

  function selectQuickCommand(item: TerminalQuickCommand) {
    setCommand(item.command);
    setHistoryIndex(null);
  }

  function handleCommandKeyDown(event: ReactKeyboardEvent<HTMLInputElement>) {
    if (event.key !== "ArrowUp" && event.key !== "ArrowDown") return;
    if (commandHistory.length === 0) return;
    event.preventDefault();
    const lastIndex = commandHistory.length - 1;
    if (event.key === "ArrowUp") {
      const nextIndex = historyIndex === null ? lastIndex : Math.max(0, historyIndex - 1);
      setHistoryIndex(nextIndex);
      setCommand(commandHistory[nextIndex] ?? "");
      return;
    }
    if (historyIndex === null) return;
    const nextIndex = historyIndex + 1;
    if (nextIndex > lastIndex) {
      setHistoryIndex(null);
      setCommand("");
      return;
    }
    setHistoryIndex(nextIndex);
    setCommand(commandHistory[nextIndex] ?? "");
  }

  function clearTerminalBuffer() {
    setLines([]);
  }

  function handleTerminalScroll() {
    const output = outputRef.current;
    if (!output || initialHistoryPendingRef.current) return;
    const nextFollowLatest = output.scrollHeight - output.clientHeight - output.scrollTop <= 24;
    followLatestRef.current = nextFollowLatest;
    setFollowLatest(nextFollowLatest);
  }

  async function submitCommand(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    if (!supportsCommands || !canManage || pending || !command.trim()) return;
    const submitted = command.trim();
    setCommand("");
    setHistoryIndex(null);
    setCommandHistory((current) => [...current.filter((item) => item !== submitted), submitted].slice(-50));
    setPending(true);
    setResult({ status: "pending", label: "正在提交命令" });
    appendLines([terminalSystemLine("input", `> ${submitted}`, "COMMAND")]);
    try {
      const response = await platformApiClient.queueGameClientBridgeCommand(serverId, scumManagementRCONCommandRequest(serverId, submitted));
      const label = bridgeCommandDispatchLabel(response.state, response.id);
      setResult({ status: "pending", label: `${label} · 等待 Run 返回结果` });
      appendLines([terminalSystemLine("success", `${label} · protected RCON`, "PLATFORM", `ok-${response.id}`)]);
      const finalCommand = await waitForBridgeCommandTerminal(response.id);
      if (finalCommand) {
        const outcome = terminalLineFromBridgeCommand(finalCommand);
        setResult({ status: outcome.tone === "success" ? "succeeded" : "failed", label: outcome.text });
        appendLines([outcome]);
      } else {
        const timeoutLine = terminalSystemLine("warn", `桥接命令 ${response.id} 已排队，但尚未返回终态；继续观察实时日志。`, "PLATFORM", `pending-${response.id}`);
        setResult({ status: "pending", label: "等待 Run 返回结果" });
        appendLines([timeoutLine]);
      }
    } catch (error) {
      const label = error instanceof Error ? error.message : "命令提交失败";
      setResult({ status: "failed", label });
      appendLines([terminalSystemLine("error", label, "ERROR")]);
    } finally {
      setPending(false);
    }
  }

  async function waitForBridgeCommandTerminal(commandId: string): Promise<GameClientBridgeCommandResponse | null> {
    for (let attempt = 0; attempt < terminalBridgeResultPollAttempts; attempt += 1) {
      const current = await platformApiClient.getGameClientBridgeCommand(serverId, commandId);
      if (isTerminalBridgeCommandState(current.state)) return current;
      await delay(terminalBridgeResultPollMs);
    }
    return null;
  }

  return (
    <LiveOperationDrawer open={open} title="管理终端" onClose={onClose} backdropClassName="terminal-drawer-backdrop" panelClassName="management-terminal-drawer" bodyClassName="management-terminal-body" hideHeader>
      <section className="terminal-output-panel" aria-label="terminal output">
        <div className="terminal-output-topbar">
          <div>
            <strong>{serverName}</strong>
	          <span>当前服务器 Run 日志 · 已接受历史 + SSE 实时推送 · {streams.status === "ready" ? "等待当前输出" : streams.status === "loading" ? "连接日志流" : "日志流异常"} · {followLatest ? "自动置底" : "已解锁滚动"}</span>
          </div>
          <div>
            <button type="button" className="terminal-output-action" onClick={clearTerminalBuffer}><Trash2 size={14} /><span>清屏</span></button>
            <button type="button" className="terminal-output-action" aria-label="关闭管理终端" onClick={onClose}><X size={14} /><span>关闭</span></button>
          </div>
        </div>
        <div ref={outputRef} className="terminal-output" role="log" aria-live="polite" onScroll={handleTerminalScroll}>
          {streams.status === "error" && <div className="terminal-line terminal-line-error"><time>{new Date().toLocaleTimeString()}</time><span className="terminal-stream">LOGS</span><span className="terminal-text">{streams.reason}</span></div>}
	        {streams.status === "ready" && streams.data.length === 0 && <div className="terminal-line terminal-line-warn"><time>{new Date().toLocaleTimeString()}</time><span className="terminal-stream">LOGS</span><span className="terminal-text">暂无已接受日志。Run 恢复连接并完成日志水位校准后，新输出会继续追加。</span></div>}
          {lines.map((line) => <div key={line.id} className={`terminal-line terminal-line-${line.tone}`}><time>{line.at}</time><span className="terminal-stream">{line.streamKey || line.level || "LOG"}</span><span className="terminal-text">{line.text}</span></div>)}
        </div>
      </section>
      <section className="terminal-command-dock" aria-label="terminal command controls">
        <div className="terminal-command-dock-header">
          <span><ListChecks size={14} />{quickCommands.length > 0 ? "插件快捷指令" : "命令输入"}</span>
          {result && <ResultBadge status={result.status} label={result.label} />}
        </div>
        {quickCommands.length > 0 && <div className="terminal-quick-command-list">
          {quickCommands.map((item) => <button key={item.command} type="button" className="terminal-quick-command" disabled={!canManage || pending} onClick={() => selectQuickCommand(item)}><strong>{item.label}</strong><span>{item.command}</span><small>{item.hint}</small></button>)}
        </div>}
        {!supportsCommands && <EmptyState icon={<Terminal size={24} />} title="终端不可用" description="当前插件没有声明平台可调度的即时命令能力，因此不会开放浏览器直连 shell。" />}
        {supportsCommands && (
          <form className="terminal-command-form" onSubmit={(event) => void submitCommand(event)}>
            <label>
              <span>SCUM 管理命令</span>
              <small>Enter 发送，↑/↓ 调出历史；命令结果以 Run 日志追加为准。</small>
              <input value={command} disabled={!canManage || pending} placeholder={canManage ? "输入单行命令" : "当前账号没有运行操作权限"} onKeyDown={handleCommandKeyDown} onChange={(event) => { setCommand(event.target.value); setHistoryIndex(null); }} />
            </label>
            <button type="submit" className="primary-command" disabled={!canManage || pending || !command.trim()}>{pending ? <Sparkles size={15} /> : <Send size={15} />}<span>{pending ? "提交中…" : "发送"}</span></button>
          </form>
        )}
      </section>
    </LiveOperationDrawer>
  );
}

function terminalQuickCommandsForPlugin(pluginId: string): TerminalQuickCommand[] {
  return terminalQuickCommandCatalog[pluginId] ?? [];
}

function bridgeCommandDispatchLabel(state: string, commandId: string): string {
  return `已${state === "pending" ? "排队" : "提交"} · 桥接命令 ${commandId}`;
}

function terminalLineFromLog(stream: LogStreamResponse, entry: LogEntryBody): TerminalLine {
  return {
    id: `log-${stream.id}-${entry.seq}`,
    tone: terminalTone(entry),
    text: entry.line,
    at: new Date(entry.timestamp).toLocaleTimeString(),
    sortKey: Date.parse(entry.timestamp) || Date.now(),
    streamKey: stream.streamKey || stream.source,
    level: entry.level,
    seq: entry.seq
  };
}

function terminalSystemLine(tone: TerminalLine["tone"], text: string, streamKey: string, id = `${streamKey.toLowerCase()}-${Date.now()}-${Math.random().toString(36).slice(2, 7)}`): TerminalLine {
  const now = Date.now();
  return { id, tone, text, at: new Date(now).toLocaleTimeString(), sortKey: now, streamKey };
}

function isTerminalBridgeCommandState(state: GameClientBridgeCommandResponse["state"]): boolean {
  return state === "succeeded" || state === "failed" || state === "cancelled" || state === "expired" || state === "unknown";
}

function terminalLineFromBridgeCommand(command: GameClientBridgeCommandResponse): TerminalLine {
  const summary = command.result?.summary || command.resultSummary || command.cancellation?.reason || bridgeCommandStateLabel(command.state);
  const completed = command.completedAt || command.result?.completedAt || command.cancellation?.cancelledAt || command.updatedAt;
  const sortKey = Date.parse(completed) || Date.now();
  const tone: TerminalLine["tone"] = command.state === "succeeded" ? "success" : command.state === "failed" ? "error" : "warn";
  return { id: `bridge-${command.id}-${command.state}`, tone, text: `桥接命令 ${command.id} · ${bridgeCommandStateLabel(command.state)} · ${summary}`, at: new Date(sortKey).toLocaleTimeString(), sortKey, streamKey: "BRIDGE" };
}

function bridgeCommandStateLabel(state: GameClientBridgeCommandResponse["state"]): string {
  switch (state) {
    case "succeeded": return "已成功";
    case "failed": return "已失败";
    case "cancelled": return "已取消";
    case "expired": return "已过期";
    case "unknown": return "状态未知";
    case "claimed": return "Run 已领取";
    case "pending": return "已排队";
  }
}

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

function terminalTone(entry: LogEntryBody): TerminalLine["tone"] {
  const value = `${entry.level ?? ""} ${entry.line}`.toLowerCase();
  if (/\b(error|fatal|panic|exception|failed|failure)\b/.test(value)) return "error";
  if (/\b(warn|warning|timeout|retry)\b/.test(value)) return "warn";
  if (/\b(success|succeeded|ready|started|online|listening|accepted)\b/.test(value)) return "success";
  return "info";
}

function mergeTerminalLines(current: TerminalLine[], incoming: TerminalLine[]): TerminalLine[] {
  const seen = new Set(current.map((line) => line.id));
  const merged = [...current];
  for (const line of incoming) {
    if (seen.has(line.id)) continue;
    seen.add(line.id);
    merged.push(line);
  }
  return merged.sort(compareTerminalLines).slice(-maxTerminalLines);
}

function compareTerminalLines(a: TerminalLine, b: TerminalLine): number {
  return a.sortKey - b.sortKey || (a.seq ?? 0) - (b.seq ?? 0) || a.id.localeCompare(b.id);
}