'use client';

import { useEffect, useState } from 'react';
import AdminLayout from '../../components/AdminLayout';
import { getSubscriptions } from '../../lib/api';

export default function SubscriptionsPage() {
  const [subscriptions, setSubscriptions] = useState([]);
  const [filter, setFilter] = useState('all');
  const [loading, setLoading] = useState(true);

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

  const loadSubscriptions = async () => {
    try {
      const data = await getSubscriptions();
      setSubscriptions(data.subscriptions || []);
    } catch (err) {
      console.error('Failed to load subscriptions:', err);
    } finally {
      setLoading(false);
    }
  };

  const filteredSubscriptions = subscriptions.filter((sub) => {
    if (filter === 'all') return true;
    if (filter === 'active') return sub.status === 'active';
    if (filter === 'premium') return sub.plan === 'premium' && sub.status === 'active';
    if (filter === 'canceled') return sub.status === 'canceled';
    return true;
  });

  const stats = {
    total: subscriptions.length,
    active: subscriptions.filter(s => s.status === 'active').length,
    premium: subscriptions.filter(s => s.plan === 'premium' && s.status === 'active').length,
    free: subscriptions.filter(s => s.plan === 'free').length,
    canceled: subscriptions.filter(s => s.status === 'canceled').length,
  };

  const mrr = stats.premium * 9.99;

  return (
    <AdminLayout>
      <div style={styles.header}>
        <h1 style={styles.title}>Subscriptions</h1>
        <div style={styles.filters}>
          {['all', 'active', 'premium', 'canceled'].map((f) => (
            <button
              key={f}
              onClick={() => setFilter(f)}
              style={{
                ...styles.filterBtn,
                ...(filter === f ? styles.filterBtnActive : {}),
              }}
            >
              {f.charAt(0).toUpperCase() + f.slice(1)}
            </button>
          ))}
        </div>
      </div>

      <div style={styles.statsGrid}>
        <StatCard label="MRR" value={`$${mrr.toFixed(2)}`} />
        <StatCard label="Active" value={stats.active} />
        <StatCard label="Premium" value={stats.premium} color="var(--primary)" />
        <StatCard label="Churned" value={stats.canceled} color="var(--error)" />
      </div>

      {loading ? (
        <p style={styles.loading}>Loading...</p>
      ) : (
        <div style={styles.table}>
          <div style={styles.tableHeader}>
            <span>User</span>
            <span>Plan</span>
            <span>Status</span>
            <span>Created</span>
            <span>Expires</span>
            <span>Stripe ID</span>
          </div>
          {filteredSubscriptions.length === 0 ? (
            <div style={styles.empty}>No subscriptions found</div>
          ) : (
            filteredSubscriptions.map((sub) => (
              <div key={sub.id} style={styles.tableRow}>
                <span style={styles.email}>
                  {sub.user?.email || '—'}
                </span>
                <span>
                  <PlanBadge plan={sub.plan} />
                </span>
                <span>
                  <StatusBadge status={sub.status} />
                </span>
                <span style={styles.date}>
                  {sub.created_at ? new Date(sub.created_at).toLocaleDateString() : '—'}
                </span>
                <span style={styles.date}>
                  {sub.expires_at ? new Date(sub.expires_at).toLocaleDateString() : '—'}
                </span>
                <span style={styles.stripeId}>
                  {sub.stripe_subscription_id || '—'}
                </span>
              </div>
            ))
          )}
        </div>
      )}
    </AdminLayout>
  );
}

function StatCard({ label, value, color }) {
  return (
    <div style={styles.statCard}>
      <div style={styles.statLabel}>{label}</div>
      <div style={{ ...styles.statValue, color: color || 'var(--text-primary)' }}>{value}</div>
    </div>
  );
}

function PlanBadge({ plan }) {
  const isPremium = plan === 'premium';
  return (
    <span style={{
      padding: '4px 10px',
      borderRadius: '12px',
      fontSize: '12px',
      fontWeight: '500',
      background: isPremium ? '#FEF3C7' : '#F3F4F6',
      color: isPremium ? '#92400E' : '#6B7280',
    }}>
      {plan || 'free'}
    </span>
  );
}

function StatusBadge({ status }) {
  const colors = {
    active: { bg: '#D1FAE5', color: '#065F46' },
    canceled: { bg: '#FEE2E2', color: '#991B1B' },
    expired: { bg: '#FEE2E2', color: '#991B1B' },
    trialing: { bg: '#DBEAFE', color: '#1E40AF' },
  };
  const style = colors[status] || colors.active;
  return (
    <span style={{
      padding: '4px 10px',
      borderRadius: '12px',
      fontSize: '12px',
      fontWeight: '500',
      background: style.bg,
      color: style.color,
    }}>
      {status || 'unknown'}
    </span>
  );
}

const styles = {
  header: {
    display: 'flex',
    justifyContent: 'space-between',
    alignItems: 'center',
    marginBottom: '24px',
  },
  title: {
    fontSize: '24px',
    fontWeight: '600',
  },
  filters: {
    display: 'flex',
    gap: '8px',
  },
  filterBtn: {
    padding: '8px 16px',
    fontSize: '13px',
    fontWeight: '500',
    border: '1px solid var(--border)',
    borderRadius: '6px',
    background: 'white',
    color: 'var(--text-secondary)',
    cursor: 'pointer',
  },
  filterBtnActive: {
    background: 'var(--primary)',
    color: 'white',
    borderColor: 'var(--primary)',
  },
  statsGrid: {
    display: 'grid',
    gridTemplateColumns: 'repeat(4, 1fr)',
    gap: '16px',
    marginBottom: '24px',
  },
  statCard: {
    background: 'white',
    borderRadius: '12px',
    padding: '20px',
    textAlign: 'center',
  },
  statLabel: {
    fontSize: '13px',
    color: 'var(--text-muted)',
    marginBottom: '4px',
  },
  statValue: {
    fontSize: '28px',
    fontWeight: '700',
  },
  loading: {
    color: 'var(--text-muted)',
  },
  table: {
    background: 'white',
    borderRadius: '12px',
    overflow: 'hidden',
  },
  tableHeader: {
    display: 'grid',
    gridTemplateColumns: '1.5fr 0.8fr 0.8fr 1fr 1fr 1.5fr',
    gap: '16px',
    padding: '16px 20px',
    background: 'var(--surface)',
    fontSize: '12px',
    fontWeight: '600',
    color: 'var(--text-muted)',
    textTransform: 'uppercase',
  },
  tableRow: {
    display: 'grid',
    gridTemplateColumns: '1.5fr 0.8fr 0.8fr 1fr 1fr 1.5fr',
    gap: '16px',
    padding: '16px 20px',
    borderBottom: '1px solid var(--border)',
    alignItems: 'center',
    fontSize: '14px',
  },
  email: {
    color: 'var(--text-secondary)',
  },
  date: {
    color: 'var(--text-muted)',
    fontSize: '13px',
  },
  stripeId: {
    fontFamily: 'monospace',
    fontSize: '11px',
    color: 'var(--text-muted)',
  },
  empty: {
    padding: '48px',
    textAlign: 'center',
    color: 'var(--text-muted)',
  },
};