'use client';

import { useState } from 'react';
import { RouteSettingsDialog } from './RouteSettingsDialog';
import { RouteRulesDialog } from './RouteRulesDialog';

type ForwardFormat = 'THREADED' | 'DIGEST' | 'SUMMARY';
type ForwardFrequency = 'INSTANT' | 'FIVE_MIN' | 'FIFTEEN_MIN' | 'ONE_HOUR' | 'ONE_DAY' | 'SEVEN_DAYS';
type ApprovalMode = 'MANUAL' | 'AUTO';

interface AssignedRule {
  id: string;
  matchType: string;
  matchValue: string;
  ruleIntent: 'POSITIVE' | 'NEGATIVE';
}

interface Route {
  id: string;
  sourceGroupId: string;
  targetGroupId: string;
  sourceGroup: { name: string };
  targetGroup: { name: string };
  forwardFormat: ForwardFormat;
  withAttachment: boolean;
  frequency: ForwardFrequency;
  approvalMode: ApprovalMode;
  isActive: boolean;
  assignedRules?: Array<{ tenantRule: AssignedRule }>;
}

interface Group {
  id: string;
  name: string;
  platform: string;
  isActive: boolean;
}

const FREQ_LABELS: Record<ForwardFrequency, string> = {
  INSTANT: 'Instant', FIVE_MIN: '5 min', FIFTEEN_MIN: '15 min',
  ONE_HOUR: '1h', ONE_DAY: '1d', SEVEN_DAYS: '7d',
};
const FORMAT_LABELS: Record<ForwardFormat, string> = {
  THREADED: 'Threaded', DIGEST: 'Digest', SUMMARY: 'Summary',
};

export function RouteManager({
  groups,
  initialRoutes,
}: {
  groups: Group[];
  initialRoutes: Route[];
}) {
  const [routes, setRoutes] = useState<Route[]>(initialRoutes);
  const [sourceId, setSourceId] = useState('');
  const [targetIds, setTargetIds] = useState<Set<string>>(new Set());
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [settingsRoute, setSettingsRoute] = useState<Route | null>(null);
  const [rulesRoute, setRulesRoute] = useState<Route | null>(null);

  const grouped = new Map<string, { sourceId: string; targets: Route[] }>();
  for (const r of routes) {
    const key = r.sourceGroup.name;
    if (!grouped.has(key)) grouped.set(key, { sourceId: r.sourceGroupId, targets: [] });
    grouped.get(key)!.targets.push(r);
  }

  function toggleTarget(id: string) {
    setTargetIds((prev) => {
      const next = new Set(prev);
      if (next.has(id)) next.delete(id); else next.add(id);
      return next;
    });
    setError(null);
  }

  async function addRoutes() {
    if (!sourceId || targetIds.size === 0) return;
    setBusy(true); setError(null);
    try {
      const res = await fetch('/api/routes/batch', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ sourceGroupId: sourceId, targetGroupIds: [...targetIds] }),
      });
      if (res.status === 409) { setError((await res.json()).message ?? 'Routes already exist'); return; }
      if (!res.ok) { setError('Failed to create routes'); return; }
      const created: Route[] = await res.json();
      setRoutes((prev) => [...created, ...prev]);
      setSourceId(''); setTargetIds(new Set());
    } finally { setBusy(false); }
  }

  async function deleteRoute(id: string) {
    const res = await fetch(`/api/routes/${id}`, { method: 'DELETE' });
    if (res.ok || res.status === 204) setRoutes((prev) => prev.filter((r) => r.id !== id));
  }

  const eligibleTargets = groups.filter((g) => g.id !== sourceId && g.platform === 'whatsapp' && g.isActive);

  return (
    <div className="flex flex-col gap-6">
      <section>
        <h2 className="text-base font-semibold mb-3">Active sync routes</h2>
        {routes.length === 0 ? (
          <p className="text-sm text-gray-400">No routes configured.</p>
        ) : (
          <div className="overflow-x-auto rounded-lg border border-gray-200">
            <table className="w-full text-sm">
              <thead>
                <tr className="border-b border-gray-200 bg-gray-50 text-left text-xs text-gray-500">
                  <th className="px-4 py-2.5">Source</th>
                  <th className="px-4 py-2.5">Target</th>
                  <th className="px-4 py-2.5">Rules</th>
                  <th className="px-4 py-2.5">Frequency</th>
                  <th className="px-4 py-2.5">Format</th>
                  <th className="px-4 py-2.5">Approval</th>
                  <th className="px-4 py-2.5" />
                </tr>
              </thead>
              <tbody>
                {routes.map((r) => {
                  const ruleCount = r.assignedRules?.length ?? 0;
                  return (
                    <tr key={r.id} className="border-b border-gray-100 last:border-0 hover:bg-gray-50">
                      <td className="px-4 py-2.5 font-medium text-gray-700">{r.sourceGroup.name}</td>
                      <td className="px-4 py-2.5 text-gray-600">{r.targetGroup.name}</td>
                      <td className="px-4 py-2.5">
                        <span className={`text-xs rounded px-2 py-0.5 ${ruleCount > 0 ? 'bg-blue-50 text-blue-700' : 'bg-gray-100 text-gray-400'}`}>
                          {ruleCount} rule{ruleCount !== 1 ? 's' : ''}
                        </span>
                      </td>
                      <td className="px-4 py-2.5 text-gray-600">{FREQ_LABELS[r.frequency] ?? r.frequency}</td>
                      <td className="px-4 py-2.5 text-gray-600">
                        {FORMAT_LABELS[r.forwardFormat] ?? r.forwardFormat}
                        {r.withAttachment && <span className="ml-1 text-[10px] text-gray-400">+attach</span>}
                      </td>
                      <td className="px-4 py-2.5">
                        <span className={`text-xs rounded px-2 py-0.5 ${r.approvalMode === 'AUTO' ? 'bg-green-100 text-green-700' : 'bg-yellow-50 text-yellow-700'}`}>
                          {r.approvalMode === 'AUTO' ? 'Auto' : 'Manual'}
                        </span>
                      </td>
                      <td className="px-4 py-2.5">
                        <div className="flex items-center gap-2">
                          <button
                            onClick={() => setSettingsRoute(r)}
                            className="text-xs text-gray-400 hover:text-blue-600"
                            title="Edit settings"
                          >
                            ✏️
                          </button>
                          <button
                            onClick={() => setRulesRoute(r)}
                            className="text-xs text-gray-400 hover:text-blue-600"
                            title="Manage rules"
                          >
                            📋
                          </button>
                          <button
                            onClick={() => void deleteRoute(r.id)}
                            className="text-xs text-gray-400 hover:text-red-600"
                            title="Delete route"
                          >
                            🗑️
                          </button>
                        </div>
                      </td>
                    </tr>
                  );
                })}
              </tbody>
            </table>
          </div>
        )}
      </section>

      <section>
        <h2 className="text-base font-semibold mb-3">Add routes</h2>
        <div className="flex flex-col gap-3">
          <div className="flex gap-2 items-center">
            <select
              value={sourceId}
              onChange={(e) => { setSourceId(e.target.value); setTargetIds(new Set()); setError(null); }}
              className="rounded-lg border border-gray-200 px-3 py-2 text-sm"
            >
              <option value="">Source group…</option>
              {groups.filter((g) => g.platform === 'whatsapp' && g.isActive).map((g) => (
                <option key={g.id} value={g.id}>{g.name}</option>
              ))}
            </select>
            <span className="text-gray-400 text-sm">→</span>
            <span className="text-xs text-gray-500">{targetIds.size} target{targetIds.size !== 1 ? 's' : ''} selected</span>
          </div>

          {sourceId && eligibleTargets.length > 0 && (
            <div className="rounded-lg border border-gray-200 bg-white p-3 max-h-48 overflow-y-auto">
              {eligibleTargets.map((g) => (
                <label
                  key={g.id}
                  className={`flex items-center gap-2 px-2 py-1.5 rounded cursor-pointer text-sm transition-colors ${
                    targetIds.has(g.id) ? 'bg-blue-50 text-blue-700' : 'hover:bg-gray-50'
                  }`}
                >
                  <input
                    type="checkbox"
                    checked={targetIds.has(g.id)}
                    onChange={() => toggleTarget(g.id)}
                    className="rounded border-gray-300"
                  />
                  {g.name}
                </label>
              ))}
            </div>
          )}

          {error && (
            <p className="text-sm text-red-600 bg-red-50 border border-red-200 rounded px-3 py-2">{error}</p>
          )}

          <button
            onClick={() => void addRoutes()}
            disabled={!sourceId || targetIds.size === 0 || busy}
            className="self-start rounded-lg bg-blue-600 px-4 py-2 text-sm font-medium text-white hover:bg-blue-700 disabled:opacity-50"
          >
            {busy ? 'Creating…' : `Create ${targetIds.size} route${targetIds.size !== 1 ? 's' : ''}`}
          </button>
        </div>
      </section>

      {settingsRoute && (
        <RouteSettingsDialog
          route={settingsRoute}
          onSaved={(updates) => {
            setRoutes((prev) => prev.map((r) => r.id === settingsRoute.id ? { ...r, ...updates } : r));
          }}
          onClose={() => setSettingsRoute(null)}
        />
      )}

      {rulesRoute && (
        <RouteRulesDialog
          routeId={rulesRoute.id}
          targetGroupName={rulesRoute.targetGroup.name}
          onClose={() => setRulesRoute(null)}
        />
      )}
    </div>
  );
}