import { useState, useEffect, useCallback } from "react";
import { useNavigate } from "react-router";
import { Masthead } from "../components/Masthead";
import { useAuth } from "../contexts/AuthContext";
import {
  listDaemons,
  restartDaemon,
  type Daemon,
} from "../lib/api";

// =============================================================================
// Types
// =============================================================================

interface GitHubAsset {
  name: string;
  browser_download_url: string;
  size: number;
}

interface GitHubRelease {
  tag_name: string;
  name: string;
  published_at: string;
  html_url: string;
  assets: GitHubAsset[];
}

interface PlatformDownload {
  label: string;
  arch: string;
  pattern: string;
  asset: GitHubAsset | null;
  recommended: boolean;
}

// =============================================================================
// Helpers
// =============================================================================

function detectPlatform(): string {
  const ua = navigator.userAgent.toLowerCase();
  const platform = navigator.platform?.toLowerCase() || "";

  if (platform.includes("mac") || ua.includes("macintosh")) {
    // Check for Apple Silicon
    // navigator.platform is "MacIntel" even on ARM for some browsers,
    // but we can check userAgent for hints or default to arm64 for modern Macs
    if (
      ua.includes("arm") ||
      ua.includes("aarch64") ||
      // Chrome 93+ on ARM Macs reports this
      (typeof navigator !== "undefined" &&
        "userAgentData" in navigator &&
        // @ts-expect-error -- userAgentData may not be typed
        navigator.userAgentData?.platform === "macOS")
    ) {
      return "macos-arm64";
    }
    return "macos-arm64"; // Default to ARM64 for modern Macs
  }

  if (platform.includes("linux") || ua.includes("linux")) {
    return "linux-x86_64";
  }

  return "linux-x86_64"; // fallback
}

function formatBytes(bytes: number): string {
  if (bytes === 0) return "0 B";
  const k = 1024;
  const sizes = ["B", "KB", "MB", "GB"];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  return `${parseFloat((bytes / Math.pow(k, i)).toFixed(1))} ${sizes[i]}`;
}

function formatDate(dateStr: string): string {
  return new Date(dateStr).toLocaleDateString("en-US", {
    year: "numeric",
    month: "short",
    day: "numeric",
  });
}

// =============================================================================
// Sub-components
// =============================================================================

function SectionHeader({ children }: { children: React.ReactNode }) {
  return (
    <h2 className="text-[11px] font-mono uppercase tracking-wide text-[#8899aa] mb-3 pb-2 border-b border-[rgba(117,170,252,0.15)]">
      {children}
    </h2>
  );
}

function ErrorAlert({ children }: { children: React.ReactNode }) {
  return (
    <div className="border border-red-700/50 bg-red-900/20 text-red-400 px-3 py-2 mb-4 font-mono text-xs">
      {children}
    </div>
  );
}

function CodeBlock({ children }: { children: React.ReactNode }) {
  return (
    <code className="block bg-black/50 px-3 py-2 text-[11px] font-mono text-green-400 mb-2 overflow-x-auto">
      {children}
    </code>
  );
}

function StepNumber({ n }: { n: number }) {
  return (
    <span className="inline-flex items-center justify-center w-5 h-5 border border-[rgba(117,170,252,0.35)] text-[10px] font-mono text-[#75aafc] mr-2 shrink-0">
      {n}
    </span>
  );
}

// =============================================================================
// Download Section
// =============================================================================

function DownloadSection() {
  const [release, setRelease] = useState<GitHubRelease | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [userPlatform] = useState(detectPlatform);

  useEffect(() => {
    const fetchRelease = async () => {
      try {
        setLoading(true);
        setError(null);
        const res = await fetch(
          "https://api.github.com/repos/soryu-co/makima/releases/latest"
        );
        if (!res.ok) {
          throw new Error(`GitHub API returned ${res.status}`);
        }
        const data: GitHubRelease = await res.json();
        setRelease(data);
      } catch (err) {
        setError(
          err instanceof Error ? err.message : "Failed to fetch release info"
        );
      } finally {
        setLoading(false);
      }
    };
    fetchRelease();
  }, []);

  const platforms: PlatformDownload[] = [
    {
      label: "Linux x86_64",
      arch: "linux-x86_64",
      pattern: "linux-x86_64.tar.gz",
      asset: null,
      recommended: userPlatform === "linux-x86_64",
    },
    {
      label: "macOS Intel (x86_64)",
      arch: "macos-x86_64",
      pattern: "macos-x86_64.tar.gz",
      asset: null,
      recommended: userPlatform === "macos-x86_64",
    },
    {
      label: "macOS Apple Silicon (ARM64)",
      arch: "macos-arm64",
      pattern: "macos-arm64.tar.gz",
      asset: null,
      recommended: userPlatform === "macos-arm64",
    },
  ];

  // Match assets to platforms
  if (release) {
    for (const p of platforms) {
      p.asset =
        release.assets.find((a) => a.name.includes(p.pattern)) || null;
    }
  }

  // Sort recommended first
  const sortedPlatforms = [...platforms].sort(
    (a, b) => (b.recommended ? 1 : 0) - (a.recommended ? 1 : 0)
  );

  return (
    <section className="border border-[rgba(117,170,252,0.25)] bg-[#0d1b2d] p-4">
      <SectionHeader>Download Daemon</SectionHeader>

      {loading && (
        <p className="text-[#7788aa] font-mono text-xs">
          Fetching latest release...
        </p>
      )}

      {error && <ErrorAlert>Failed to load release: {error}</ErrorAlert>}

      {release && (
        <>
          <div className="flex items-center justify-between mb-4">
            <div className="flex items-center gap-3">
              <span className="text-[#9bc3ff] font-mono text-sm">
                {release.tag_name}
              </span>
              <span className="text-[#556677] font-mono text-[10px]">
                {formatDate(release.published_at)}
              </span>
            </div>
            <a
              href="https://github.com/soryu-co/makima/releases"
              target="_blank"
              rel="noopener noreferrer"
              className="text-[10px] font-mono text-[#75aafc] hover:text-[#9bc3ff] transition-colors"
            >
              All Releases &rarr;
            </a>
          </div>

          <div className="space-y-2">
            {sortedPlatforms.map((p) => (
              <div
                key={p.arch}
                className={`border p-3 flex items-center justify-between ${
                  p.recommended
                    ? "border-[rgba(117,170,252,0.5)] bg-[#0a1628]"
                    : "border-[rgba(117,170,252,0.15)] bg-[#0a1525]"
                }`}
              >
                <div className="flex items-center gap-3">
                  <span className="font-mono text-xs text-[#9bc3ff]">
                    {p.label}
                  </span>
                  {p.recommended && (
                    <span className="text-[9px] font-mono uppercase px-1.5 py-0.5 border border-[rgba(117,170,252,0.4)] text-[#75aafc] bg-[rgba(117,170,252,0.08)]">
                      Detected
                    </span>
                  )}
                  {p.asset && (
                    <span className="text-[10px] font-mono text-[#556677]">
                      {formatBytes(p.asset.size)}
                    </span>
                  )}
                </div>
                {p.asset ? (
                  <a
                    href={p.asset.browser_download_url}
                    className={`text-[10px] font-mono uppercase px-3 py-1.5 border transition-colors ${
                      p.recommended
                        ? "text-[#9bc3ff] border-[rgba(117,170,252,0.5)] bg-[rgba(117,170,252,0.1)] hover:bg-[rgba(117,170,252,0.2)]"
                        : "text-[#75aafc] border-[rgba(117,170,252,0.25)] hover:bg-[rgba(117,170,252,0.1)]"
                    }`}
                    download
                  >
                    Download
                  </a>
                ) : (
                  <span className="text-[10px] font-mono text-[#556677]">
                    Not available
                  </span>
                )}
              </div>
            ))}
          </div>
        </>
      )}
    </section>
  );
}

// =============================================================================
// Setup Instructions Section
// =============================================================================

function SetupSection() {
  const [showConfig, setShowConfig] = useState(false);

  return (
    <section className="border border-[rgba(117,170,252,0.25)] bg-[#0d1b2d] p-4">
      <SectionHeader>Setup Instructions</SectionHeader>
      <div className="space-y-3">
        <div className="flex items-start">
          <StepNumber n={1} />
          <div className="flex-1">
            <p className="text-[#7788aa] font-mono text-[10px] mb-1">
              Download the binary for your platform above
            </p>
          </div>
        </div>

        <div className="flex items-start">
          <StepNumber n={2} />
          <div className="flex-1">
            <p className="text-[#7788aa] font-mono text-[10px] mb-1">
              Extract the archive
            </p>
            <CodeBlock>tar xzf makima-*.tar.gz</CodeBlock>
          </div>
        </div>

        <div className="flex items-start">
          <StepNumber n={3} />
          <div className="flex-1">
            <p className="text-[#7788aa] font-mono text-[10px] mb-1">
              Move to PATH
            </p>
            <CodeBlock>sudo mv makima /usr/local/bin/</CodeBlock>
          </div>
        </div>

        <div className="flex items-start">
          <StepNumber n={4} />
          <div className="flex-1">
            <p className="text-[#7788aa] font-mono text-[10px] mb-1">
              Set your API key (
              <a
                href="/settings"
                className="text-[#75aafc] hover:text-[#9bc3ff] transition-colors"
              >
                generate one in Settings
              </a>
              )
            </p>
            <CodeBlock>export MAKIMA_API_KEY="your-key"</CodeBlock>
          </div>
        </div>

        <div className="flex items-start">
          <StepNumber n={5} />
          <div className="flex-1">
            <p className="text-[#7788aa] font-mono text-[10px] mb-1">
              Set server URL
            </p>
            <CodeBlock>
              export MAKIMA_DAEMON_SERVER_URL="ws://your-server:8080"
            </CodeBlock>
          </div>
        </div>

        <div className="flex items-start">
          <StepNumber n={6} />
          <div className="flex-1">
            <p className="text-[#7788aa] font-mono text-[10px] mb-1">
              Run the daemon
            </p>
            <CodeBlock>makima daemon</CodeBlock>
          </div>
        </div>
      </div>

      {/* Config file alternative */}
      <div className="mt-4 pt-3 border-t border-[rgba(117,170,252,0.1)]">
        <button
          onClick={() => setShowConfig(!showConfig)}
          className="text-[10px] font-mono text-[#75aafc] hover:text-[#9bc3ff] transition-colors bg-transparent border-none cursor-pointer p-0"
        >
          {showConfig ? "- Hide" : "+"} Config file alternative
        </button>
        {showConfig && (
          <div className="mt-3">
            <p className="text-[#7788aa] font-mono text-[10px] mb-2">
              Create <code className="text-green-400">makima-daemon.toml</code>{" "}
              in the working directory:
            </p>
            <code className="block bg-black/50 px-3 py-2 text-[11px] font-mono text-green-400 whitespace-pre overflow-x-auto">
              {`[daemon]
api_key = "your-key"
server_url = "ws://your-server:8080"
max_concurrent_tasks = 4`}
            </code>
          </div>
        )}
      </div>
    </section>
  );
}

// =============================================================================
// Cloudflare Edge Deployment Section
// =============================================================================

function CloudflareAgentSection() {
  const [showSetup, setShowSetup] = useState(false);

  const benefits = [
    {
      label: "Global edge presence",
      desc: "Lower latency from 300+ Cloudflare locations worldwide",
    },
    {
      label: "Auto-scaling & hibernation",
      desc: "Cost-efficient — only runs when needed",
    },
    {
      label: "WebSocket relay",
      desc: "Coordinate remote daemon instances through persistent connections",
    },
    {
      label: "Durable Objects",
      desc: "Built on Cloudflare's stateful edge compute primitives",
    },
  ];

  return (
    <section className="border border-[rgba(117,170,252,0.25)] bg-[#0d1b2d] p-4">
      <SectionHeader>Edge Deployment</SectionHeader>

      <p className="text-[#7788aa] font-mono text-[10px] mb-4 leading-relaxed">
        Deploy a lightweight Makima relay agent on Cloudflare's edge network for
        global, low-latency daemon coordination. Ideal for distributed teams or
        production deployments requiring high availability.
      </p>

      {/* Benefits */}
      <div className="space-y-2 mb-4">
        {benefits.map((b) => (
          <div
            key={b.label}
            className="flex items-start gap-2 text-[10px] font-mono"
          >
            <span className="text-[#75aafc] mt-px shrink-0">&#x25B8;</span>
            <div>
              <span className="text-[#9bc3ff]">{b.label}</span>
              <span className="text-[#556677] ml-1">— {b.desc}</span>
            </div>
          </div>
        ))}
      </div>

      {/* Quick Setup */}
      <div className="border-t border-[rgba(117,170,252,0.1)] pt-3">
        <button
          onClick={() => setShowSetup(!showSetup)}
          className="text-[10px] font-mono text-[#75aafc] hover:text-[#9bc3ff] transition-colors bg-transparent border-none cursor-pointer p-0"
        >
          {showSetup ? "- Hide" : "+"} Quick setup
        </button>
        {showSetup && (
          <div className="mt-3 space-y-3">
            <div className="flex items-start">
              <StepNumber n={1} />
              <div className="flex-1">
                <p className="text-[#7788aa] font-mono text-[10px] mb-1">
                  Navigate to the Cloudflare agent directory
                </p>
                <CodeBlock>cd makima/cloudflare-agent</CodeBlock>
              </div>
            </div>
            <div className="flex items-start">
              <StepNumber n={2} />
              <div className="flex-1">
                <p className="text-[#7788aa] font-mono text-[10px] mb-1">
                  Run the setup script
                </p>
                <CodeBlock>./setup.sh</CodeBlock>
              </div>
            </div>
            <div className="flex items-start">
              <StepNumber n={3} />
              <div className="flex-1">
                <p className="text-[#7788aa] font-mono text-[10px] mb-1">
                  Deploy to Cloudflare
                </p>
                <CodeBlock>npx wrangler deploy</CodeBlock>
              </div>
            </div>
          </div>
        )}
      </div>

      {/* Link to repo */}
      <div className="mt-4 pt-3 border-t border-[rgba(117,170,252,0.1)] flex items-center justify-between">
        <span className="text-[10px] font-mono text-[#556677]">
          Full documentation & source
        </span>
        <a
          href="https://github.com/soryu-co/soryu/tree/master/makima/cloudflare-agent"
          target="_blank"
          rel="noopener noreferrer"
          className="text-[10px] font-mono text-[#75aafc] hover:text-[#9bc3ff] transition-colors px-3 py-1.5 border border-[rgba(117,170,252,0.25)] hover:bg-[rgba(117,170,252,0.1)]"
        >
          View on GitHub &rarr;
        </a>
      </div>
    </section>
  );
}

// =============================================================================
// Connected Daemons Section
// =============================================================================

function ConnectedDaemonsSection() {
  const [daemons, setDaemons] = useState<Daemon[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [restartingDaemonId, setRestartingDaemonId] = useState<string | null>(
    null
  );
  const [restartConfirmDaemonId, setRestartConfirmDaemonId] = useState<
    string | null
  >(null);

  const loadDaemons = useCallback(async () => {
    try {
      setError(null);
      const response = await listDaemons();
      setDaemons(response.daemons);
    } catch (err) {
      setError(
        err instanceof Error ? err.message : "Failed to load daemons"
      );
    } finally {
      setLoading(false);
    }
  }, []);

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

  // Auto-refresh every 30 seconds
  useEffect(() => {
    const interval = setInterval(() => {
      loadDaemons();
    }, 30000);
    return () => clearInterval(interval);
  }, [loadDaemons]);

  const handleRestartDaemon = async (id: string) => {
    try {
      setRestartingDaemonId(id);
      setError(null);
      await restartDaemon(id);
      setRestartConfirmDaemonId(null);
      // Daemon will restart, so refresh the list after a short delay
      setTimeout(() => {
        loadDaemons();
      }, 2000);
    } catch (err) {
      setError(
        err instanceof Error ? err.message : "Failed to restart daemon"
      );
    } finally {
      setRestartingDaemonId(null);
    }
  };

  return (
    <section className="border border-[rgba(117,170,252,0.25)] bg-[#0d1b2d] p-4">
      <div className="flex items-center justify-between mb-3 pb-2 border-b border-[rgba(117,170,252,0.15)]">
        <div className="flex items-center gap-2">
          <h2 className="text-[11px] font-mono uppercase tracking-wide text-[#8899aa]">
            Connected Daemons
          </h2>
          {daemons.length > 0 && (
            <span className="text-[10px] font-mono text-[#556677]">
              ({daemons.filter((d) => d.status === "connected").length}{" "}
              connected / {daemons.length} total)
            </span>
          )}
        </div>
        <button
          onClick={loadDaemons}
          disabled={loading}
          className="text-[10px] font-mono text-[#75aafc] hover:text-[#9bc3ff] disabled:opacity-50 bg-transparent border-none cursor-pointer p-0"
          title="Refresh"
        >
          {loading ? "..." : "\u21BB"}
        </button>
      </div>

      {error && <ErrorAlert>{error}</ErrorAlert>}

      {loading && daemons.length === 0 ? (
        <p className="text-[#7788aa] font-mono text-xs">Loading...</p>
      ) : daemons.length === 0 ? (
        <div className="text-center py-6">
          <p className="text-[#7788aa] font-mono text-xs mb-2">
            No daemons connected
          </p>
          <p className="text-[#556677] font-mono text-[10px]">
            Follow the setup instructions above to connect a daemon
          </p>
        </div>
      ) : (
        <div className="space-y-2">
          {daemons.map((daemon) => (
            <div
              key={daemon.id}
              className="border border-[rgba(117,170,252,0.15)] bg-[#0a1525] p-3"
            >
              <div className="flex items-center justify-between mb-2">
                <span className="font-mono text-xs text-[#9bc3ff]">
                  {daemon.hostname || "Unknown Host"}
                </span>
                <div className="flex items-center gap-2">
                  <span
                    className={`text-[10px] font-mono uppercase px-2 py-0.5 border ${
                      daemon.status === "connected"
                        ? "text-green-400 border-green-700/50 bg-green-900/20"
                        : daemon.status === "unhealthy"
                          ? "text-yellow-400 border-yellow-700/50 bg-yellow-900/20"
                          : "text-[#8899aa] border-[rgba(117,170,252,0.25)]"
                    }`}
                  >
                    {daemon.status}
                  </span>
                </div>
              </div>
              <div className="font-mono text-[10px] text-[#7788aa] space-y-1">
                <div className="flex justify-between">
                  <span>Tasks</span>
                  <span className="text-[#9bc3ff]">
                    {daemon.currentTaskCount} / {daemon.maxConcurrentTasks}
                  </span>
                </div>
                <div className="flex justify-between">
                  <span>Connected</span>
                  <span className="text-[#75aafc]">
                    {new Date(daemon.connectedAt).toLocaleString()}
                  </span>
                </div>
                {daemon.machineId && (
                  <div className="flex justify-between">
                    <span>Machine</span>
                    <span
                      className="text-[#556677] truncate ml-2"
                      title={daemon.machineId}
                    >
                      {daemon.machineId.substring(0, 16)}...
                    </span>
                  </div>
                )}
              </div>
              {/* Restart Section */}
              {daemon.status === "connected" && (
                <div className="mt-3 pt-2 border-t border-[rgba(117,170,252,0.1)]">
                  {restartConfirmDaemonId === daemon.id ? (
                    <div className="flex items-center justify-between gap-2">
                      <span className="text-[10px] font-mono text-yellow-400">
                        Restart daemon? Running tasks will be interrupted.
                      </span>
                      <div className="flex gap-2">
                        <button
                          onClick={() => setRestartConfirmDaemonId(null)}
                          className="text-[10px] font-mono text-[#7788aa] hover:text-[#9bc3ff] px-2 py-1 bg-transparent border-none cursor-pointer"
                          disabled={restartingDaemonId === daemon.id}
                        >
                          Cancel
                        </button>
                        <button
                          onClick={() => handleRestartDaemon(daemon.id)}
                          disabled={restartingDaemonId === daemon.id}
                          className="text-[10px] font-mono text-red-400 hover:text-red-300 px-2 py-1 border border-red-700/50 bg-red-900/20 disabled:opacity-50 cursor-pointer"
                        >
                          {restartingDaemonId === daemon.id
                            ? "Restarting..."
                            : "Confirm"}
                        </button>
                      </div>
                    </div>
                  ) : (
                    <button
                      onClick={() => setRestartConfirmDaemonId(daemon.id)}
                      className="text-[10px] font-mono text-[#75aafc] hover:text-[#9bc3ff] bg-transparent border-none cursor-pointer p-0"
                    >
                      &#x27F3; Restart Daemon
                    </button>
                  )}
                </div>
              )}
            </div>
          ))}
        </div>
      )}
    </section>
  );
}

// =============================================================================
// Main Page
// =============================================================================

export default function DaemonPage() {
  const {
    isAuthenticated,
    isAuthConfigured,
    isLoading: authLoading,
  } = useAuth();
  const navigate = useNavigate();

  useEffect(() => {
    if (!authLoading && isAuthConfigured && !isAuthenticated) {
      navigate("/login");
    }
  }, [authLoading, isAuthConfigured, isAuthenticated, navigate]);

  if (authLoading) {
    return (
      <div className="relative z-10 min-h-screen flex flex-col bg-[#0a1628]">
        <Masthead showNav />
        <main className="flex-1 flex items-center justify-center">
          <p className="text-[#7788aa] font-mono text-sm">Loading...</p>
        </main>
      </div>
    );
  }

  return (
    <div className="relative z-10 min-h-screen flex flex-col bg-[#0a1628]">
      <Masthead showNav />
      <main className="flex-1 px-4 py-6 max-w-4xl mx-auto w-full">
        {/* Page header */}
        <div className="mb-6">
          <h1 className="text-sm font-mono uppercase tracking-wide text-[#9bc3ff] mb-1">
            Daemon Management
          </h1>
          <p className="text-[#556677] font-mono text-[10px]">
            Download, configure, and monitor Makima daemons
          </p>
        </div>

        <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
          {/* Left Column: Downloads & Setup */}
          <div className="space-y-6">
            <DownloadSection />
            <SetupSection />
          </div>

          {/* Right Column: Edge Deployment & Connected Daemons */}
          <div className="space-y-6">
            <ConnectedDaemonsSection />
            <CloudflareAgentSection />
          </div>
        </div>
      </main>
    </div>
  );
}