import { useState, useEffect, useRef } from "react";
import { Link, useNavigate } from "react-router-dom";
import type { User, Project, DroneRegistration, ChatSession, SubProcessStat } from "../lib/api";
import { projectApi, droneApi, chatSessionApi } from "../lib/api";
import { socketClient } from "../lib/socket";
import Clock from "../components/Clock";
import GadgetGrid from "../components/GadgetGrid";
import LogRenderer from "../components/LogRenderer";
import type { LogRendererEntry } from "../components/LogRenderer";

function SystemReady() {
  return (
    <div className="flex flex-col items-center">
      <div className="mt-8 border-2 border-border-default p-6 rounded bg-bg-secondary">
        <div className="font-mono text-text-secondary text-sm">
          <div className="mb-1 text-text-muted">// SYSTEM READY</div>
          <div className="mb-3">Please sign in to continue.</div>
          <div className="text-text-muted mb-4">
            Accounts are administered. Contact your administrator for access.
          </div>
          <a
            href="/sign-in"
            className="inline-block px-4 py-2 border border-border-highlight text-text-primary hover:bg-bg-tertiary hover:text-text-primary rounded transition-colors"
          >
            Sign In
          </a>
        </div>
      </div>
    </div>
  );
}

interface DashboardSidebarProps {
  onNavigate: (view: string, data?: unknown) => void;
  selectedDrone: DroneRegistration | null;
  onSelectDrone: (drone: DroneRegistration | null) => void;
}

function DroneInspector({
  drone,
  onClose,
}: {
  drone: DroneRegistration;
  onClose: () => void;
}) {
  const navigate = useNavigate();
  const [processStats, setProcessStats] = useState<SubProcessStat[]>([]);
  const [logEntries, setLogEntries] = useState<LogRendererEntry[]>([]);
  const mountedRef = useRef(true);
  const pollRef = useRef<ReturnType<typeof setInterval> | null>(null);

  useEffect(() => {
    mountedRef.current = true;
    const regId = drone._id;

    if (drone.status === 'offline') return;

    socketClient.subscribeDrone(regId);

    const handleLog = (data: { timestamp: string; level: string; component: string; message: string }) => {
      if (!mountedRef.current) return;
      setLogEntries((prev) => {
        const next = [...prev, {
          id: `insp-log-${prev.length}`,
          timestamp: new Date(data.timestamp),
          level: data.level,
          component: data.component,
          message: data.message,
        }];
        return next.length > 100 ? next.slice(next.length - 100) : next;
      });
    };

    socketClient.on('drone:log', handleLog);

    const poll = async () => {
      if (!mountedRef.current) return;
      const result = await socketClient.requestProcessStats(regId);
      if (result.success && result.processes && mountedRef.current) {
        setProcessStats(result.processes as SubProcessStat[]);
      }
    };

    poll();
    pollRef.current = setInterval(poll, 1000);

    return () => {
      mountedRef.current = false;
      if (pollRef.current) clearInterval(pollRef.current);
      socketClient.off('drone:log', handleLog);
      socketClient.unsubscribeDrone(regId);
    };
  }, [drone._id, drone.status]);

  const runningCount = processStats.filter((p) => p.status === 'running').length;

  return (
    <div className="flex-1 flex items-start justify-center p-8 overflow-y-auto">
      <div className="max-w-lg w-full">
        <div className="flex items-center justify-between mb-6">
          <h2 className="text-xl font-semibold">Drone Inspector</h2>
          <button
            onClick={onClose}
            className="text-text-secondary hover:text-text-primary text-sm"
          >
            ← Back to Dashboard
          </button>
        </div>
        <div className="bg-bg-secondary border border-border-default rounded p-4 space-y-4">
          <div>
            <div className="text-sm text-text-muted">Hostname</div>
            <div className="font-mono text-text-primary">{drone.hostname}</div>
          </div>
          <div>
            <div className="text-sm text-text-muted">Workspace</div>
            <div className="font-mono text-text-primary text-sm truncate">
              {drone.workspaceDir}
            </div>
          </div>
          <div>
            <div className="text-sm text-text-muted">Status</div>
            <div className="flex items-center gap-2">
              <span
                className={`w-2 h-2 rounded-full ${
                  drone.status === "available"
                    ? "bg-green-500"
                    : drone.status === "busy"
                      ? "bg-yellow-500"
                      : "bg-gray-600"
                }`}
              />
              <span className="text-text-primary capitalize">
                {drone.status}
              </span>
            </div>
          </div>
          <div>
            <div className="text-sm text-text-muted">SubProcesses</div>
            <div className="text-text-primary text-sm">
              {runningCount > 0
                ? `${runningCount} running`
                : processStats.length > 0
                  ? 'All stopped'
                  : 'No managed processes'}
            </div>
          </div>
          <div>
            <div className="text-sm text-text-muted">Registered</div>
            <div className="text-text-primary text-sm">
              {new Date(drone.createdAt).toLocaleString()}
            </div>
          </div>
        </div>

        {drone.status !== 'offline' && (
          <div className="mt-4">
            <button
              onClick={() => navigate('/drones', { state: { droneId: drone._id } })}
              className="w-full px-4 py-2 border border-border-default text-text-secondary hover:bg-bg-tertiary hover:text-text-primary rounded transition-colors text-sm"
            >
              Open in Drone Manager →
            </button>
          </div>
        )}

        {drone.status !== 'offline' && logEntries.length > 0 && (
          <div className="mt-4 border border-border-default rounded overflow-hidden max-h-48">
            <div className="p-2 bg-bg-tertiary border-b border-border-subtle">
              <h3 className="text-xs font-semibold text-text-secondary uppercase tracking-wider">
                Live Log
              </h3>
            </div>
            <div className="h-40 overflow-y-auto">
              <LogRenderer logs={logEntries.slice(-50)} />
            </div>
          </div>
        )}
      </div>
    </div>
  );
}

function DashboardSidebar({
  onNavigate: _onNavigate,
  selectedDrone,
  onSelectDrone,
}: DashboardSidebarProps) {
  const navigate = useNavigate();
  const [projects, setProjects] = useState<Project[]>([]);
  const [drones, setDrones] = useState<DroneRegistration[]>([]);
  const [recentChats, setRecentChats] = useState<ChatSession[]>([]);
  const [loading, setLoading] = useState(true);
  const [noDroneMessage, setNoDroneMessage] = useState<string | null>(null);

  useEffect(() => {
    loadData();
  }, []);

  const loadData = async () => {
    try {
      const [projectsData, dronesData, recentChatsData] = await Promise.all([
        projectApi.getAll(),
        droneApi.getAll(),
        chatSessionApi.getAll(undefined, 10),
      ]);
      setProjects(projectsData);
      setDrones(dronesData);
      setRecentChats(recentChatsData);
    } catch (err) {
      console.error("Failed to load dashboard data", err);
    } finally {
      setLoading(false);
    }
  };

  const getProjectName = (session: ChatSession): string => {
    const projectRef = session.project;
    if (typeof projectRef === 'object' && projectRef !== null && 'name' in projectRef) {
      return projectRef.name;
    }
    return 'Unknown Project';
  };

  const getProjectId = (session: ChatSession): string => {
    const projectRef = session.project;
    if (typeof projectRef === 'object' && projectRef !== null && '_id' in projectRef) {
      return projectRef._id;
    }
    return typeof projectRef === 'string' ? projectRef : '';
  };

  const handleOpenChat = (session: ChatSession) => {
    if (!selectedDrone) {
      setNoDroneMessage('Select a drone first to resume a chat');
      setTimeout(() => setNoDroneMessage(null), 3000);
      return;
    }
    const projectId = getProjectId(session);
    navigate(`/projects/${projectId}/chat-session/${session._id}`, {
      state: {
        drone: selectedDrone,
        project: typeof session.project === 'object' ? session.project : undefined,
      },
    });
  };

  const modeBadgeColors: Record<string, string> = {
    plan: 'bg-blue-500/20 text-blue-400',
    build: 'bg-brand/20 text-brand',
    test: 'bg-green-500/20 text-green-400',
    ship: 'bg-purple-500/20 text-purple-400',
    dev: 'bg-orange-500/20 text-orange-400',
  };

  const formatRelativeTime = (dateStr: string): string => {
    const now = Date.now();
    const then = new Date(dateStr).getTime();
    const diffMs = now - then;
    const diffSec = Math.floor(diffMs / 1000);
    const diffMin = Math.floor(diffSec / 60);
    const diffHr = Math.floor(diffMin / 60);
    const diffDay = Math.floor(diffHr / 24);

    if (diffSec < 60) return 'just now';
    if (diffMin < 60) return `${diffMin}m ago`;
    if (diffHr < 24) return `${diffHr}h ago`;
    if (diffDay < 7) return `${diffDay}d ago`;
    return new Date(dateStr).toLocaleDateString();
  };

  return (
    <aside className="w-64 border-l border-border-subtle bg-bg-secondary flex flex-col overflow-hidden min-h-0">
      <Clock />

      {/* Projects */}
      <div className="flex-1 min-h-0 flex flex-col border-t border-border-subtle">
        <div className="shrink-0 px-3 pt-3 pb-2 flex items-center justify-between text-xs font-semibold text-text-muted uppercase tracking-wider">
          <span>Projects</span>
          <Link
            to="/projects"
            className="text-brand hover:text-red-400 transition-colors"
          >
            [+]
          </Link>
        </div>
        <div className="flex-1 min-h-0 overflow-y-auto px-3 pb-3">
          {loading ? (
            <p className="text-sm text-text-muted px-2">Loading...</p>
          ) : projects.length === 0 ? (
            <p className="text-sm text-text-muted px-2">No projects yet.</p>
          ) : (
            <div className="space-y-1">
              {projects.map((project) => (
                <button
                  key={project._id}
                  onClick={() => navigate(`/projects/${project.slug}`)}
                  className="w-full text-left px-2 py-1.5 text-sm text-text-secondary hover:bg-bg-tertiary hover:text-text-primary rounded truncate transition-colors"
                >
                  {project.name}
                </button>
              ))}
            </div>
          )}
        </div>
      </div>

      {/* Drones */}
      <div className="flex-1 min-h-0 flex flex-col border-t border-border-subtle">
        <div className="shrink-0 px-3 pt-3 pb-2 flex items-center justify-between text-xs font-semibold text-text-muted uppercase tracking-wider">
          <span>Drones</span>
          <Link
            to="/drones"
            className="text-text-secondary hover:text-text-primary transition-colors"
            title="Drone Manager"
          >
            <svg
              className="w-4 h-4"
              fill="none"
              stroke="currentColor"
              viewBox="0 0 24 24"
            >
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.065 2.572c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.572 1.065c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.065-2.572c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z"
              />
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M15 12a3 3 0 11-6 0 3 3 0 016 0z"
              />
            </svg>
          </Link>
        </div>
        <div className="flex-1 min-h-0 overflow-y-auto px-3 pb-3">
          {loading ? (
            <p className="text-sm text-text-muted px-2">Loading...</p>
          ) : drones.length === 0 ? (
            <p className="text-sm text-text-muted px-2">No drones available.</p>
          ) : (
            <div className="space-y-1">
              {drones.map((drone) => (
                <button
                  key={drone._id}
                  onClick={() => onSelectDrone(drone)}
                  className={`w-full text-left px-2 py-1 rounded transition-colors ${
                    selectedDrone?._id === drone._id
                      ? "bg-brand text-white"
                      : "text-text-secondary hover:bg-bg-tertiary hover:text-text-primary"
                  }`}
                >
                  <div className="flex items-center gap-2">
                    <span
                      className={`w-2 h-2 rounded-full shrink-0 ${
                        drone.status === "available"
                          ? "bg-green-500"
                          : "bg-yellow-500"
                      }`}
                    />
                    <div className="overflow-hidden">
                      <div className="text-sm truncate">{drone.hostname}</div>
                      {drone.workspaceDir && (
                        <div
                          className={`text-xs truncate ${
                            selectedDrone?._id === drone._id
                              ? "text-white/70"
                              : "text-text-muted"
                          }`}
                        >
                          {drone.workspaceDir.length > 24
                            ? "..." + drone.workspaceDir.slice(-21)
                            : drone.workspaceDir}
                        </div>
                      )}
                    </div>
                  </div>
                </button>
              ))}
            </div>
          )}
        </div>
      </div>

      {/* Recent Chats */}
      <div className="flex-1 min-h-0 flex flex-col border-t border-border-subtle">
        <div className="shrink-0 px-3 pt-3 pb-2 text-xs font-semibold text-text-muted uppercase tracking-wider">
          Recent Chats
        </div>
        <div className="flex-1 min-h-0 overflow-y-auto px-3 pb-3">
          {loading ? (
            <p className="text-sm text-text-muted px-2">Loading...</p>
          ) : recentChats.length === 0 ? (
            <p className="text-sm text-text-muted px-2">No recent chats.</p>
          ) : (
            <div className="space-y-1">
              {recentChats.map((session) => (
                <button
                  key={session._id}
                  onClick={() => handleOpenChat(session)}
                  className="w-full text-left px-2 py-1.5 text-sm text-text-secondary hover:bg-bg-tertiary hover:text-text-primary rounded transition-colors"
                >
                  <div className="flex items-center justify-between gap-1">
                    <span className="truncate font-medium text-xs">{session.name || 'Untitled'}</span>
                    <span className={`text-[10px] px-1.5 py-0.5 rounded-full font-medium shrink-0 ${modeBadgeColors[session.mode] || 'bg-gray-500/20 text-gray-400'}`}>
                      {session.mode}
                    </span>
                  </div>
                  <div className="flex items-center justify-between gap-1 mt-0.5">
                    <span className="text-[11px] text-text-muted truncate">{getProjectName(session)}</span>
                    <span className="text-[10px] text-text-muted shrink-0">
                      {formatRelativeTime(session.lastMessageAt || session.createdAt)}
                    </span>
                  </div>
                </button>
              ))}
            </div>
          )}
        </div>
        <div className="shrink-0 px-3 pb-3">
          {noDroneMessage && (
            <p className="text-xs text-yellow-400 mt-2 px-2">{noDroneMessage}</p>
          )}
          {selectedDrone && (
            <p className="text-[10px] text-text-muted mt-2 px-2 italic">
              Select a chat to resume with {selectedDrone.hostname}
            </p>
          )}
        </div>
      </div>

    </aside>
  );
}

interface HomeProps {
  user: User | null;
}

export default function Home({ user }: HomeProps) {
  const navigate = useNavigate();
  const [selectedDrone, setSelectedDrone] = useState<DroneRegistration | null>(
    null,
  );

  if (!user) {
    return (
      <div className="relative flex-1 flex bg-bg-primary overflow-hidden">
        <div className="absolute inset-0">
          <GadgetGrid />
        </div>
        <div className="relative z-10 flex items-center justify-center p-8">
          <SystemReady />
        </div>
      </div>
    );
  }

  const mainContent = selectedDrone ? (
    <div className="relative z-10 flex-1 flex min-h-0">
      <DroneInspector
        drone={selectedDrone}
        onClose={() => setSelectedDrone(null)}
      />
      <DashboardSidebar
        onNavigate={(view) => {
          if (view === "project" && typeof navigate === "function") {
            navigate("/projects");
          }
        }}
        selectedDrone={selectedDrone}
        onSelectDrone={setSelectedDrone}
      />
    </div>
  ) : (
    <div className="relative z-10 flex-1 flex flex-col min-h-0">
      <div className="flex-1 flex min-h-0">
        <div className="flex-1 flex items-center justify-center p-8">
          <div className="text-center">
            <h1 className="text-2xl font-semibold mb-4">
              Welcome, {user.displayName}!
            </h1>
            <p className="text-text-secondary mb-4">
              Your dashboard is under construction.
            </p>
            <p className="text-text-muted text-sm mb-6">
              Select a project or chat session from the sidebar to get started.
            </p>
            <div className="flex gap-3 justify-center">
              <Link
                to="/projects"
                className="px-4 py-2 border border-border-default text-text-secondary hover:bg-bg-tertiary hover:text-text-primary rounded transition-colors"
              >
                Open Project Manager
              </Link>
            </div>
          </div>
        </div>
        <DashboardSidebar
          onNavigate={(view) => {
            if (view === "project" && typeof navigate === "function") {
              navigate("/projects");
            }
          }}
          selectedDrone={selectedDrone}
          onSelectDrone={setSelectedDrone}
        />
      </div>
    </div>
  );

  return (
    <div className="relative flex-1 flex bg-bg-primary overflow-hidden">
      <div className="absolute inset-0">
        <GadgetGrid />
      </div>
      {mainContent}
    </div>
  );
}