"use client";

import { useMemo, useState } from "react";
import Link from "next/link";
import { useParams } from "next/navigation";
import { PageLayout } from "@/components/layout/PageLayout";
import { SubCard } from "@/components/ui/sub-card";
import { DevicePhoneMobileIcon } from "@heroicons/react/24/outline";
import { simActionsService } from "@/features/subscriptions/services/sim-actions.service";
import { AlertBanner } from "@/components/common/AlertBanner";

const PLAN_CODES = ["PASI_5G", "PASI_10G", "PASI_25G", "PASI_50G"] as const;
type PlanCode = (typeof PLAN_CODES)[number];
const PLAN_LABELS: Record<PlanCode, string> = {
  PASI_5G: "5GB",
  PASI_10G: "10GB",
  PASI_25G: "25GB",
  PASI_50G: "50GB",
};

export function SimChangePlanContainer() {
  const params = useParams();
  const subscriptionId = parseInt(params.id as string);
  const [currentPlanCode] = useState<string>("");
  const [newPlanCode, setNewPlanCode] = useState<"" | PlanCode>("");
  const [assignGlobalIp, setAssignGlobalIp] = useState(false);
  const [scheduledAt, setScheduledAt] = useState("");
  const [message, setMessage] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [loading, setLoading] = useState(false);

  const options = useMemo(
    () => (PLAN_CODES as readonly PlanCode[]).filter(c => c !== (currentPlanCode as PlanCode)),
    [currentPlanCode]
  );

  const submit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!newPlanCode) {
      setError("Please select a new plan");
      return;
    }
    setLoading(true);
    setMessage(null);
    setError(null);
    try {
      await simActionsService.changePlan(subscriptionId, {
        newPlanCode,
        assignGlobalIp,
        scheduledAt: scheduledAt ? scheduledAt.replace(/-/g, "") : undefined,
      });
      setMessage("Plan change submitted successfully");
    } catch (e: unknown) {
      setError(e instanceof Error ? e.message : "Failed to change plan");
    } finally {
      setLoading(false);
    }
  };

  return (
    <PageLayout
      icon={<DevicePhoneMobileIcon />}
      title="Change Plan"
      description="Switch to a different data plan"
    >
      <div className="max-w-3xl mx-auto">
        <div className="mb-4">
          <Link
            href={`/subscriptions/${subscriptionId}#sim-management`}
            className="text-blue-600 hover:text-blue-700"
          >
            ← Back to SIM Management
          </Link>
        </div>

        <SubCard>
          <p className="text-sm text-gray-600 mb-6">
            Change Plan: Switch to a different data plan. Important: Plan changes must be requested
            before the 25th of the month. Changes will take effect on the 1st of the following
            month.
          </p>

          {message && (
            <div className="mb-4">
              <AlertBanner variant="success" title="Plan Change Submitted">
                {message}
              </AlertBanner>
            </div>
          )}
          {error && (
            <div className="mb-4">
              <AlertBanner variant="error" title="Plan Change Failed">
                {error}
              </AlertBanner>
            </div>
          )}

          <form onSubmit={e => void submit(e)} className="space-y-6">
            <div>
              <label className="block text-sm font-medium text-gray-700 mb-2">New Plan</label>
              <select
                value={newPlanCode}
                onChange={e => setNewPlanCode(e.target.value as PlanCode)}
                className="w-full px-3 py-2 border border-gray-300 rounded-md"
              >
                <option value="">Choose a plan</option>
                {options.map(code => (
                  <option key={code} value={code}>
                    {PLAN_LABELS[code]}
                  </option>
                ))}
              </select>
            </div>

            <div className="flex items-center">
              <input
                id="globalip"
                type="checkbox"
                checked={assignGlobalIp}
                onChange={e => setAssignGlobalIp(e.target.checked)}
                className="h-4 w-4 text-blue-600 border-gray-300 rounded"
              />
              <label htmlFor="globalip" className="ml-2 text-sm text-gray-700">
                Assign global IP
              </label>
            </div>

            <div>
              <label className="block text-sm font-medium text-gray-700 mb-2">
                Schedule (optional)
              </label>
              <input
                type="date"
                value={scheduledAt}
                onChange={e => setScheduledAt(e.target.value)}
                className="w-full px-3 py-2 border border-gray-300 rounded-md"
              />
            </div>

            <div className="flex gap-3">
              <button
                type="submit"
                disabled={loading}
                className="px-4 py-2 rounded-md bg-blue-600 text-white text-sm disabled:opacity-50"
              >
                {loading ? "Processing…" : "Submit Plan Change"}
              </button>
              <Link
                href={`/subscriptions/${subscriptionId}#sim-management`}
                className="px-4 py-2 rounded-md border border-gray-300 text-sm text-gray-700 bg-white hover:bg-gray-50"
              >
                Back
              </Link>
            </div>
          </form>
        </SubCard>
      </div>
    </PageLayout>
  );
}

export default SimChangePlanContainer;