'use client';

import React, { useState, useEffect, useRef, useCallback } from 'react';
import {
  OperationsInfrastructureData,
  ServiceStatusValue,
  ComponentHealthStatus,
  OperationsRole,
} from './types';
import { normalizeInfrastructureResponse } from '../../lib/ops-data';
import { OperationsActions } from './operations-actions';

interface OperationsInfrastructureProps {
  role: OperationsRole;
}

export function OperationsInfrastructure({ role }: OperationsInfrastructureProps) {
  const [data, setData] = useState<OperationsInfrastructureData | null>(null);
  const [isRefreshing, setIsRefreshing] = useState(false);
  const [lastFetchedAt, setLastFetchedAt] = useState<string | null>(null);
  const [fetchError, setFetchError] = useState<string | null>(null);
  const [copiedSha, setCopiedSha] = useState(false);

  const isFetchingRef = useRef(false);
  const pollTimerRef = useRef<NodeJS.Timeout | null>(null);

  const fetchData = useCallback(async () => {
    if (isFetchingRef.current) return;
    isFetchingRef.current = true;
    setIsRefreshing(true);

    try {
      const resp = await fetch('/api/ops/infrastructure', {
        method: 'GET',
        headers: { accept: 'application/json' },
        cache: 'no-store',
      });

      if (resp.ok) {
        const raw = await resp.json();
        const normalized = normalizeInfrastructureResponse(raw);
        setData(normalized);
        setLastFetchedAt(new Date().toLocaleTimeString());
        setFetchError(null);
      } else if (resp.status === 401 || resp.status === 403) {
        setFetchError('Authorization failed. Access restricted.');
      } else {
        const raw = await resp.json().catch(() => null);
        setData(normalizeInfrastructureResponse(raw));
        setFetchError('Metrics collector degraded or partially unavailable.');
      }
    } catch {
      setFetchError('Network error reaching infrastructure endpoint.');
    } finally {
      isFetchingRef.current = false;
      setIsRefreshing(false);
    }
  }, []);

  // Initial fetch and 30-second visibility-gated polling loop
  useEffect(() => {
    void fetchData();

    const handleVisibilityChange = () => {
      if (document.visibilityState === 'visible') {
        void fetchData();
      }
    };

    document.addEventListener('visibilitychange', handleVisibilityChange);

    pollTimerRef.current = setInterval(() => {
      if (document.visibilityState === 'visible') {
        void fetchData();
      }
    }, 30000);

    return () => {
      document.removeEventListener('visibilitychange', handleVisibilityChange);
      if (pollTimerRef.current) {
        clearInterval(pollTimerRef.current);
      }
    };
  }, [fetchData]);

  const handleCopySha = (sha: string) => {
    if (!sha) return;
    navigator.clipboard.writeText(sha).then(() => {
      setCopiedSha(true);
      setTimeout(() => setCopiedSha(false), 2000);
    });
  };

  const formatBytes = (bytes: number | null): string => {
    if (bytes === null || bytes === undefined) return 'N/A';
    if (bytes >= 1e12) return `${(bytes / 1e12).toFixed(2)} TB`;
    if (bytes >= 1e9) return `${(bytes / 1e9).toFixed(2)} GB`;
    if (bytes >= 1e6) return `${(bytes / 1e6).toFixed(1)} MB`;
    return `${(bytes / 1e3).toFixed(1)} KB`;
  };

  const getServiceStatusBadge = (status: ServiceStatusValue) => {
    switch (status) {
      case 'active':
        return {
          label: 'Active (Running)',
          icon: 'check_circle',
          classes: 'bg-emerald-950/60 text-emerald-400 border-emerald-800/60',
        };
      case 'inactive':
        return {
          label: 'Inactive (Stopped)',
          icon: 'pause_circle',
          classes: 'bg-amber-950/60 text-amber-400 border-amber-800/60',
        };
      case 'failed':
        return {
          label: 'Failed',
          icon: 'cancel',
          classes: 'bg-rose-950/60 text-rose-400 border-rose-800/60',
        };
      case 'unknown':
      default:
        return {
          label: 'Unknown / Unreachable',
          icon: 'help',
          classes: 'bg-slate-900/60 text-slate-400 border-slate-700/60',
        };
    }
  };

  const getComponentHealthBadge = (status: ComponentHealthStatus) => {
    switch (status) {
      case 'available':
        return {
          label: 'Available',
          icon: 'check_circle',
          classes: 'bg-emerald-950/60 text-emerald-400 border-emerald-800/60',
        };
      case 'degraded':
        return {
          label: 'Degraded',
          icon: 'warning',
          classes: 'bg-amber-950/60 text-amber-400 border-amber-800/60',
        };
      case 'unavailable':
        return {
          label: 'Unavailable',
          icon: 'cancel',
          classes: 'bg-rose-950/60 text-rose-400 border-rose-800/60',
        };
      case 'unknown':
      default:
        return {
          label: 'Unknown',
          icon: 'help',
          classes: 'bg-slate-900/60 text-slate-400 border-slate-700/60',
        };
    }
  };

  const resources = data?.resources;
  const services = data?.services ?? [];
  const network = data?.network;
  const deployment = data?.deployment;

  return (
    <div className="space-y-8">
      {/* Header & Controls */}
      <div className="flex flex-col sm:flex-row sm:items-center justify-between gap-4 pb-6 border-b border-outline-variant/20">
        <div>
          <div className="flex items-center gap-2 mb-1">
            <span className="material-symbols-outlined text-primary-container text-2xl">
              dns
            </span>
            <h1 className="text-xl font-bold tracking-tight text-on-surface">
              Infrastructure & Runtime
            </h1>
            <span className="px-2 py-0.5 rounded text-[11px] font-mono bg-surface-container-high border border-outline-variant/30 text-primary-fixed-dim">
              Phase 2 Operations
            </span>
          </div>
          <p className="text-xs text-on-surface-variant">
            Host system resources, systemd core services, network totals, and deployment runtime health.
          </p>
        </div>

        <div className="flex items-center gap-3">
          {/* Polling indicator */}
          <div className="flex items-center gap-1.5 text-[11px] text-on-surface-variant font-mono bg-surface-container-low px-2.5 py-1.5 rounded-lg border border-outline-variant/20">
            <span className="w-2 h-2 rounded-full bg-emerald-400 animate-pulse" />
            <span>Auto 30s</span>
          </div>

          {/* Last refreshed */}
          {lastFetchedAt && (
            <span className="text-[11px] text-outline font-mono hidden md:inline">
              Updated: {lastFetchedAt}
            </span>
          )}

          {/* Manual Refresh Button */}
          <button
            type="button"
            onClick={() => void fetchData()}
            disabled={isRefreshing}
            className="flex items-center gap-2 px-3 py-1.5 rounded-lg text-xs font-semibold bg-surface-container-high hover:bg-surface-container-highest border border-outline-variant/40 text-on-surface disabled:opacity-50 transition-all focus-visible:ring-2 focus-visible:ring-primary-container"
          >
            <span
              className={`material-symbols-outlined text-[16px] ${
                isRefreshing ? 'animate-spin' : ''
              }`}
            >
              refresh
            </span>
            <span>{isRefreshing ? 'Refreshing...' : 'Refresh'}</span>
          </button>
        </div>
      </div>

      {/* Optional Warning Banner */}
      {fetchError && (
        <div className="p-3.5 rounded-lg bg-amber-950/40 border border-amber-800/50 flex items-center gap-2.5 text-xs text-amber-300">
          <span className="material-symbols-outlined text-amber-400 text-base">
            warning
          </span>
          <span>{fetchError}</span>
        </div>
      )}

      {/* SECTION 1: System Resources */}
      <div>
        <div className="flex items-center justify-between mb-3">
          <h2 className="text-xs font-bold uppercase tracking-wider text-outline">
            Server Resources
          </h2>
          <span className="text-[10px] text-outline font-mono">
            Target Host: Ubuntu VPS
          </span>
        </div>

        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-5 gap-4">
          {/* CPU Usage */}
          <div className="p-4 rounded-xl bg-surface-container-low border border-outline-variant/20 space-y-3">
            <div className="flex items-center justify-between">
              <span className="text-xs font-medium text-on-surface-variant">CPU Usage</span>
              <span className="material-symbols-outlined text-base text-primary-fixed-dim">
                memory
              </span>
            </div>
            <div>
              <div className="text-2xl font-bold font-mono tracking-tight text-on-surface">
                {resources?.cpu_percent !== null && resources?.cpu_percent !== undefined
                  ? `${resources.cpu_percent}%`
                  : 'Unavailable'}
              </div>
              <p className="text-[11px] text-outline font-mono mt-0.5">
                Load: {resources?.load_avg ? resources.load_avg.join(', ') : 'N/A'}
              </p>
            </div>
            {/* Progress Bar */}
            <div className="w-full bg-surface-container-highest h-1.5 rounded-full overflow-hidden">
              <div
                className="bg-primary-container h-full rounded-full transition-all duration-300"
                style={{ width: `${Math.min(100, Math.max(0, resources?.cpu_percent ?? 0))}%` }}
              />
            </div>
          </div>

          {/* Memory (RAM) */}
          <div className="p-4 rounded-xl bg-surface-container-low border border-outline-variant/20 space-y-3">
            <div className="flex items-center justify-between">
              <span className="text-xs font-medium text-on-surface-variant">Memory (RAM)</span>
              <span className="material-symbols-outlined text-base text-primary-fixed-dim">
                developer_board
              </span>
            </div>
            <div>
              <div className="text-xl font-bold font-mono tracking-tight text-on-surface">
                {resources?.memory
                  ? `${formatBytes(resources.memory.used)} / ${formatBytes(resources.memory.total)}`
                  : 'Unavailable'}
              </div>
              <p className="text-[11px] text-outline font-mono mt-0.5">
                {resources?.memory
                  ? `${resources.memory.percent}% used (${formatBytes(resources.memory.available)} free)`
                  : 'N/A'}
              </p>
            </div>
            {/* Progress Bar */}
            <div className="w-full bg-surface-container-highest h-1.5 rounded-full overflow-hidden">
              <div
                className={`h-full rounded-full transition-all duration-300 ${
                  (resources?.memory?.percent ?? 0) >= 90
                    ? 'bg-rose-500'
                    : (resources?.memory?.percent ?? 0) >= 80
                    ? 'bg-amber-500'
                    : 'bg-primary-container'
                }`}
                style={{ width: `${Math.min(100, Math.max(0, resources?.memory?.percent ?? 0))}%` }}
              />
            </div>
          </div>

          {/* Swap Memory */}
          <div className="p-4 rounded-xl bg-surface-container-low border border-outline-variant/20 space-y-3">
            <div className="flex items-center justify-between">
              <span className="text-xs font-medium text-on-surface-variant">Swap Space</span>
              <span className="material-symbols-outlined text-base text-primary-fixed-dim">
                swap_horiz
              </span>
            </div>
            <div>
              <div className="text-xl font-bold font-mono tracking-tight text-on-surface">
                {resources?.swap
                  ? `${formatBytes(resources.swap.used)} / ${formatBytes(resources.swap.total)}`
                  : 'Unavailable'}
              </div>
              <p className="text-[11px] text-outline font-mono mt-0.5">
                {resources?.swap ? `${resources.swap.percent}% utilized` : 'N/A'}
              </p>
            </div>
            {/* Progress Bar */}
            <div className="w-full bg-surface-container-highest h-1.5 rounded-full overflow-hidden">
              <div
                className="bg-primary-container/70 h-full rounded-full transition-all duration-300"
                style={{ width: `${Math.min(100, Math.max(0, resources?.swap?.percent ?? 0))}%` }}
              />
            </div>
          </div>

          {/* Disk Storage (/) */}
          <div className="p-4 rounded-xl bg-surface-container-low border border-outline-variant/20 space-y-3">
            <div className="flex items-center justify-between">
              <div className="flex items-center gap-1.5">
                <span className="text-xs font-medium text-on-surface-variant">Root Disk (/)</span>
                {resources?.disk?.critical ? (
                  <span className="px-1.5 py-0.2 rounded text-[9px] font-mono font-bold bg-rose-950 text-rose-300 border border-rose-800">
                    CRITICAL
                  </span>
                ) : resources?.disk?.warning ? (
                  <span className="px-1.5 py-0.2 rounded text-[9px] font-mono font-bold bg-amber-950 text-amber-300 border border-amber-800">
                    WARNING
                  </span>
                ) : null}
              </div>
              <span className="material-symbols-outlined text-base text-primary-fixed-dim">
                hard_drive
              </span>
            </div>
            <div>
              <div className="text-xl font-bold font-mono tracking-tight text-on-surface">
                {resources?.disk
                  ? `${formatBytes(resources.disk.used)} / ${formatBytes(resources.disk.total)}`
                  : 'Unavailable'}
              </div>
              <p className="text-[11px] text-outline font-mono mt-0.5">
                {resources?.disk
                  ? `${resources.disk.percent}% used (${formatBytes(resources.disk.available)} free)`
                  : 'N/A'}
              </p>
            </div>
            {/* Progress Bar */}
            <div className="w-full bg-surface-container-highest h-1.5 rounded-full overflow-hidden">
              <div
                className={`h-full rounded-full transition-all duration-300 ${
                  resources?.disk?.critical
                    ? 'bg-rose-500'
                    : resources?.disk?.warning
                    ? 'bg-amber-500'
                    : 'bg-primary-container'
                }`}
                style={{ width: `${Math.min(100, Math.max(0, resources?.disk?.percent ?? 0))}%` }}
              />
            </div>
          </div>

          {/* Server Uptime */}
          <div className="p-4 rounded-xl bg-surface-container-low border border-outline-variant/20 space-y-3">
            <div className="flex items-center justify-between">
              <span className="text-xs font-medium text-on-surface-variant">Server Uptime</span>
              <span className="material-symbols-outlined text-base text-primary-fixed-dim">
                schedule
              </span>
            </div>
            <div>
              <div className="text-lg font-bold font-mono tracking-tight text-on-surface truncate">
                {resources?.uptime_formatted || 'Unavailable'}
              </div>
              <p className="text-[11px] text-outline font-mono mt-0.5">
                {resources?.uptime_seconds
                  ? `${resources.uptime_seconds.toLocaleString()}s total uptime`
                  : 'N/A'}
              </p>
            </div>
            <div className="text-[10px] text-primary-fixed-dim font-mono">
              System running continuously
            </div>
          </div>
        </div>
      </div>

      {/* SECTION 2: Core Systemd Services */}
      <div>
        <div className="flex items-center justify-between mb-3">
          <h2 className="text-xs font-bold uppercase tracking-wider text-outline">
            Core Services (systemd)
          </h2>
          <span className="text-[10px] text-outline font-mono">
            Strict Allowlist: 4 Services
          </span>
        </div>

        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
          {services.map((svc) => {
            const badge = getServiceStatusBadge(svc.status);
            return (
              <div
                key={svc.name}
                className="p-4 rounded-xl bg-surface-container-low border border-outline-variant/20 flex flex-col justify-between space-y-3"
              >
                <div>
                  <div className="flex items-start justify-between gap-2">
                    <div>
                      <h3 className="text-sm font-semibold text-on-surface">
                        {svc.display_name}
                      </h3>
                      <p className="text-[11px] font-mono text-outline mt-0.5">
                        {svc.name}.service
                      </p>
                    </div>
                  </div>
                  <p className="text-xs text-on-surface-variant mt-2 leading-relaxed">
                    {svc.description}
                  </p>
                </div>

                <div className="pt-3 border-t border-outline-variant/10 flex items-center justify-between">
                  <span className="text-[11px] text-outline">Service Status</span>
                  <div
                    className={`inline-flex items-center gap-1.5 px-2.5 py-1 rounded-full text-[11px] font-mono font-medium border ${badge.classes}`}
                  >
                    <span className="material-symbols-outlined text-[14px]">
                      {badge.icon}
                    </span>
                    <span>{badge.label}</span>
                  </div>
                </div>
              </div>
            );
          })}
        </div>
      </div>

      {/* SECTION 3 & 4: Network Cumulative Totals & Deployment Health */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
        {/* Network Cumulative Totals */}
        <div className="p-5 rounded-xl bg-surface-container-low border border-outline-variant/20 space-y-4">
          <div className="flex items-center justify-between">
            <div className="flex items-center gap-2">
              <span className="material-symbols-outlined text-primary-container text-xl">
                network_check
              </span>
              <div>
                <h3 className="text-sm font-bold text-on-surface">
                  Network Cumulative Totals
                </h3>
                <p className="text-[11px] text-outline">
                  Aggregated across non-loopback interfaces since host boot
                </p>
              </div>
            </div>
            <span className="px-2 py-0.5 rounded text-[10px] font-mono bg-surface-container-high text-primary-fixed-dim border border-outline-variant/30">
              Not a rate
            </span>
          </div>

          <div className="grid grid-cols-2 gap-4 pt-2">
            <div className="p-3.5 rounded-lg bg-surface-container-lowest border border-outline-variant/15 space-y-1">
              <div className="flex items-center gap-1.5 text-xs text-on-surface-variant">
                <span className="material-symbols-outlined text-[15px] text-emerald-400">
                  download
                </span>
                <span>Total Received</span>
              </div>
              <div className="text-xl font-bold font-mono text-on-surface">
                {formatBytes(network?.bytes_received ?? null)}
              </div>
              <p className="text-[10px] text-outline font-mono">
                {network?.bytes_received ? `${network.bytes_received.toLocaleString()} bytes` : 'N/A'}
              </p>
            </div>

            <div className="p-3.5 rounded-lg bg-surface-container-lowest border border-outline-variant/15 space-y-1">
              <div className="flex items-center gap-1.5 text-xs text-on-surface-variant">
                <span className="material-symbols-outlined text-[15px] text-primary-container">
                  upload
                </span>
                <span>Total Transmitted</span>
              </div>
              <div className="text-xl font-bold font-mono text-on-surface">
                {formatBytes(network?.bytes_transmitted ?? null)}
              </div>
              <p className="text-[10px] text-outline font-mono">
                {network?.bytes_transmitted ? `${network.bytes_transmitted.toLocaleString()} bytes` : 'N/A'}
              </p>
            </div>
          </div>

          <div className="p-2.5 rounded-lg bg-surface-container-lowest/60 border border-outline-variant/10 text-[11px] text-outline flex items-center gap-2">
            <span className="material-symbols-outlined text-[14px] text-primary-fixed-dim">
              info
            </span>
            <span>
              Cumulative Total Since Boot across physical network interfaces. Instantaneous bandwidth rates are not tracked.
            </span>
          </div>
        </div>

        {/* Deployment Health Foundations */}
        <div className="p-5 rounded-xl bg-surface-container-low border border-outline-variant/20 space-y-4">
          <div className="flex items-center justify-between">
            <div className="flex items-center gap-2">
              <span className="material-symbols-outlined text-primary-container text-xl">
                deployed_code
              </span>
              <div>
                <h3 className="text-sm font-bold text-on-surface">
                  Deployment Health Foundations
                </h3>
                <p className="text-[11px] text-outline">
                  Active code revision and subsystem runtime readiness
                </p>
              </div>
            </div>
            <span className="px-2 py-0.5 rounded text-[10px] font-mono bg-surface-container-high text-on-surface-variant border border-outline-variant/30">
              Foundation
            </span>
          </div>

          <div className="space-y-3 pt-1">
            {/* Active Git Revision */}
            <div className="p-3 rounded-lg bg-surface-container-lowest border border-outline-variant/15 flex items-center justify-between">
              <div>
                <div className="text-xs text-on-surface-variant">Active Git Revision</div>
                <div className="flex items-center gap-2 mt-1">
                  <span className="font-mono text-sm font-bold text-on-surface">
                    {deployment?.short_revision || 'Unavailable'}
                  </span>
                  {deployment?.git_revision && (
                    <button
                      type="button"
                      onClick={() => handleCopySha(deployment.git_revision!)}
                      title="Copy full SHA"
                      className="p-1 rounded text-outline hover:text-on-surface hover:bg-surface-container transition-colors"
                    >
                      <span className="material-symbols-outlined text-[14px]">
                        {copiedSha ? 'check' : 'content_copy'}
                      </span>
                    </button>
                  )}
                </div>
              </div>
              <div className="flex items-center gap-1.5 font-mono text-[11px]">
                <span
                  className={`w-2 h-2 rounded-full ${
                    deployment?.revision_status === 'known' ? 'bg-emerald-400' : 'bg-slate-500'
                  }`}
                />
                <span className="capitalize text-outline">
                  {deployment?.revision_status ?? 'unavailable'}
                </span>
              </div>
            </div>

            {/* Health indicators */}
            <div className="grid grid-cols-2 gap-3">
              <div className="p-3 rounded-lg bg-surface-container-lowest border border-outline-variant/15">
                <div className="text-xs text-on-surface-variant mb-1">Website Ingress</div>
                {(() => {
                  const badge = getComponentHealthBadge(deployment?.website_health ?? 'unknown');
                  return (
                    <div
                      className={`inline-flex items-center gap-1.5 px-2 py-0.5 rounded-full text-[10px] font-mono border ${badge.classes}`}
                    >
                      <span className="material-symbols-outlined text-[12px]">{badge.icon}</span>
                      <span>{badge.label}</span>
                    </div>
                  );
                })()}
              </div>

              <div className="p-3 rounded-lg bg-surface-container-lowest border border-outline-variant/15">
                <div className="text-xs text-on-surface-variant mb-1">API Readiness</div>
                {(() => {
                  const badge = getComponentHealthBadge(deployment?.api_health ?? 'unknown');
                  return (
                    <div
                      className={`inline-flex items-center gap-1.5 px-2 py-0.5 rounded-full text-[10px] font-mono border ${badge.classes}`}
                    >
                      <span className="material-symbols-outlined text-[12px]">{badge.icon}</span>
                      <span>{badge.label}</span>
                    </div>
                  );
                })()}
              </div>
            </div>

            {/* Deployment History Status */}
            <div className="p-2.5 rounded-lg bg-surface-container-lowest/60 border border-outline-variant/10 text-[11px] text-outline flex items-center justify-between">
              <span className="font-mono">Deployment History:</span>
              <span className="text-primary-fixed-dim font-mono">Audited in Phase 2</span>
            </div>
          </div>
        </div>
      </div>

      {/* Operations Actions & Deployment Controls */}
      <div className="mt-8 pt-6 border-t border-outline-variant/20">
        <OperationsActions role={role} onActionCompleted={fetchData} />
      </div>
    </div>
  );
}