"use client";

import { FormEvent, useCallback, useEffect, useState } from "react";
import Link from "next/link";
import { useParams } from "next/navigation";
import {
  api,
  ApiError,
  type Tenant,
  type TenantDomain,
  type Subscription,
  type Plan,
} from "@/lib/api";
import { getStoredToken } from "@/lib/auth";
import { identityApi, type AdminUser, type TenantMember } from "@/lib/identity";
import {
  AdminPageHeader,
  Banner,
  Button,
  Field,
  SelectField,
  StatusBadge,
  TextField,
  cardClass,
  inputClass,
} from "@/components/admin/controls";

const TENANT_STATUSES = [
  "draft",
  "pending_activation",
  "active",
  "suspended",
  "archived",
  "inactive",
].map((s) => ({ value: s, label: s }));

const SUBSCRIPTION_STATUSES = [
  "trialing",
  "active",
  "past_due",
  "canceled",
  "expired",
].map((s) => ({ value: s, label: s }));

export default function TenantDetailPage() {
  const params = useParams<{ id: string }>();
  const tenantId = params.id;

  const [tenant, setTenant] = useState<Tenant | null>(null);
  const [domains, setDomains] = useState<TenantDomain[]>([]);
  const [subscription, setSubscription] = useState<Subscription | null>(null);
  const [members, setMembers] = useState<TenantMember[]>([]);
  const [plans, setPlans] = useState<Plan[]>([]);
  const [users, setUsers] = useState<AdminUser[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState("");

  const load = useCallback(async () => {
    setLoading(true);
    setError("");
    const token = getStoredToken();
    try {
      const t = await api.platformTenants.get(tenantId);
      setTenant(t);
    } catch (e) {
      setError(e instanceof ApiError ? e.message : "دریافت Tenant ناموفق بود");
      setLoading(false);
      return;
    }
    const [d, sub, plansPage, mem, usersRes] = await Promise.allSettled([
      api.domains.listForTenant(tenantId),
      api.subscriptions.get(tenantId),
      api.plans.list(1, 100),
      token ? identityApi.listMembers(token, tenantId) : Promise.resolve([]),
      token ? identityApi.listUsers(token, { limit: 100 }) : Promise.resolve([]),
    ]);
    if (d.status === "fulfilled") setDomains(d.value);
    setSubscription(sub.status === "fulfilled" ? sub.value : null);
    if (plansPage.status === "fulfilled") setPlans(plansPage.value.items);
    if (mem.status === "fulfilled") setMembers(mem.value);
    if (usersRes.status === "fulfilled") setUsers(usersRes.value);
    setLoading(false);
  }, [tenantId]);

  useEffect(() => {
    void load();
  }, [load]);

  if (loading) {
    return <p className="text-sm text-gray-500">در حال بارگذاری...</p>;
  }

  if (!tenant) {
    return (
      <div className="space-y-4">
        <Banner variant="error">{error || "Tenant یافت نشد"}</Banner>
        <Link href="/admin/tenants" className="text-sm text-primary hover:underline">
          ← بازگشت به لیست
        </Link>
      </div>
    );
  }

  return (
    <div className="space-y-6">
      <div>
        <Link href="/admin/tenants" className="text-sm text-primary hover:underline">
          ← بازگشت به لیست
        </Link>
      </div>
      <AdminPageHeader
        title={tenant.name}
        subtitle={tenant.slug}
        action={<StatusBadge status={tenant.status} />}
      />

      {error && <Banner variant="error">{error}</Banner>}

      <div className="grid grid-cols-1 gap-6 lg:grid-cols-2">
        <TenantEditCard tenant={tenant} onUpdated={setTenant} onError={setError} />
        <DomainsCard tenantId={tenantId} domains={domains} onChanged={load} />
        <SubscriptionCard
          tenantId={tenantId}
          subscription={subscription}
          plans={plans}
          onChanged={load}
        />
        <MembersCard tenantId={tenantId} members={members} users={users} onChanged={load} />
      </div>
    </div>
  );
}

function TenantEditCard({
  tenant,
  onUpdated,
  onError,
}: {
  tenant: Tenant;
  onUpdated: (t: Tenant) => void;
  onError: (m: string) => void;
}) {
  const [name, setName] = useState(tenant.name);
  const [status, setStatus] = useState(tenant.status);
  const [ownerUserId, setOwnerUserId] = useState(tenant.owner_user_id || "");
  const [saving, setSaving] = useState(false);
  const [success, setSuccess] = useState("");

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    setSuccess("");
    onError("");
    setSaving(true);
    try {
      const updated = await api.platformTenants.update(tenant.id, {
        name,
        status,
        owner_user_id: ownerUserId.trim() || null,
      });
      onUpdated(updated);
      setSuccess("تغییرات ذخیره شد.");
    } catch (err) {
      onError(err instanceof ApiError ? err.message : "ذخیره ناموفق بود");
    } finally {
      setSaving(false);
    }
  };

  return (
    <form onSubmit={handleSubmit} className={`space-y-4 ${cardClass}`}>
      <h2 className="text-lg font-bold text-secondary">اطلاعات پایه</h2>
      <TextField label="نام" required value={name} onValue={setName} disabled={saving} />
      <SelectField
        label="وضعیت"
        value={status}
        onValue={setStatus}
        options={TENANT_STATUSES}
        disabled={saving}
      />
      <TextField
        label="شناسه کاربر مالک"
        dir="ltr"
        className="font-mono"
        value={ownerUserId}
        onValue={setOwnerUserId}
        disabled={saving}
        placeholder="UUID"
      />
      {success && <Banner variant="success">{success}</Banner>}
      <Button type="submit" loading={saving} loadingText="در حال ذخیره...">
        ذخیره تغییرات
      </Button>
    </form>
  );
}

function DomainsCard({
  tenantId,
  domains,
  onChanged,
}: {
  tenantId: string;
  domains: TenantDomain[];
  onChanged: () => void;
}) {
  const [domain, setDomain] = useState("");
  const [type, setType] = useState<"subdomain" | "custom_domain">("custom_domain");
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState("");

  const handleAdd = async (e: FormEvent) => {
    e.preventDefault();
    setError("");
    if (!domain.trim()) return;
    setSaving(true);
    try {
      await api.domains.create(tenantId, { domain: domain.trim(), domain_type: type });
      setDomain("");
      onChanged();
    } catch (err) {
      setError(err instanceof ApiError ? err.message : "افزودن دامنه ناموفق بود");
    } finally {
      setSaving(false);
    }
  };

  return (
    <div className={`space-y-4 ${cardClass}`}>
      <h2 className="text-lg font-bold text-secondary">دامنه‌ها</h2>
      {domains.length === 0 ? (
        <p className="text-sm text-gray-500">دامنه‌ای ثبت نشده است.</p>
      ) : (
        <ul className="space-y-2">
          {domains.map((d) => (
            <li
              key={d.id}
              className="flex items-center justify-between rounded-xl bg-gray-50 px-3 py-2 text-sm"
            >
              <span dir="ltr" className="font-mono text-gray-700">
                {d.domain}
              </span>
              <span className="flex items-center gap-2">
                <span className="text-xs text-gray-400">{d.domain_type}</span>
                <StatusBadge status={d.is_verified ? "active" : "pending_activation"} />
              </span>
            </li>
          ))}
        </ul>
      )}

      {error && <Banner variant="error">{error}</Banner>}

      <form onSubmit={handleAdd} className="space-y-3 border-t border-gray-100 pt-4">
        <TextField
          label="دامنه جدید"
          dir="ltr"
          className="font-mono"
          value={domain}
          onValue={setDomain}
          disabled={saving}
          placeholder="shop.example.com"
        />
        <SelectField
          label="نوع"
          value={type}
          onValue={(v) => setType(v as "subdomain" | "custom_domain")}
          options={[
            { value: "custom_domain", label: "دامنه اختصاصی" },
            { value: "subdomain", label: "زیردامنه" },
          ]}
          disabled={saving}
        />
        <Button type="submit" size="sm" loading={saving} loadingText="در حال افزودن...">
          افزودن دامنه
        </Button>
      </form>
    </div>
  );
}

function SubscriptionCard({
  tenantId,
  subscription,
  plans,
  onChanged,
}: {
  tenantId: string;
  subscription: Subscription | null;
  plans: Plan[];
  onChanged: () => void;
}) {
  const [planId, setPlanId] = useState(plans[0]?.id || "");
  const [status, setStatus] = useState("active");
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState("");

  useEffect(() => {
    if (!planId && plans[0]) setPlanId(plans[0].id);
  }, [plans, planId]);

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    setError("");
    if (!planId) {
      setError("ابتدا یک پلن انتخاب کنید.");
      return;
    }
    setSaving(true);
    try {
      await api.subscriptions.create(tenantId, {
        plan_id: planId,
        status: status as Subscription["status"],
      });
      onChanged();
    } catch (err) {
      setError(err instanceof ApiError ? err.message : "ثبت اشتراک ناموفق بود");
    } finally {
      setSaving(false);
    }
  };

  const planName = subscription
    ? plans.find((p) => p.id === subscription.plan_id)?.name || subscription.plan_id
    : null;

  return (
    <div className={`space-y-4 ${cardClass}`}>
      <h2 className="text-lg font-bold text-secondary">اشتراک</h2>
      {subscription ? (
        <div className="rounded-xl bg-gray-50 p-4 text-sm">
          <div className="flex items-center justify-between">
            <span className="text-gray-500">پلن</span>
            <span className="font-semibold text-secondary">{planName}</span>
          </div>
          <div className="mt-2 flex items-center justify-between">
            <span className="text-gray-500">وضعیت</span>
            <StatusBadge status={subscription.status} />
          </div>
        </div>
      ) : (
        <p className="text-sm text-gray-500">اشتراک فعالی ثبت نشده است.</p>
      )}

      {error && <Banner variant="error">{error}</Banner>}

      <form onSubmit={handleSubmit} className="space-y-3 border-t border-gray-100 pt-4">
        <p className="text-sm font-medium text-secondary">
          {subscription ? "تغییر/ثبت اشتراک جدید" : "ثبت اشتراک"}
        </p>
        {plans.length === 0 ? (
          <p className="text-xs text-amber-600">
            ابتدا از بخش «پلن‌ها» یک پلن بسازید.
          </p>
        ) : (
          <>
            <SelectField
              label="پلن"
              value={planId}
              onValue={setPlanId}
              options={plans.map((p) => ({ value: p.id, label: `${p.name} (${p.code})` }))}
              disabled={saving}
            />
            <SelectField
              label="وضعیت"
              value={status}
              onValue={setStatus}
              options={SUBSCRIPTION_STATUSES}
              disabled={saving}
            />
            <Button type="submit" size="sm" loading={saving} loadingText="در حال ثبت...">
              ثبت اشتراک
            </Button>
          </>
        )}
      </form>
    </div>
  );
}

function MembersCard({
  tenantId,
  members,
  users,
  onChanged,
}: {
  tenantId: string;
  members: TenantMember[];
  users: AdminUser[];
  onChanged: () => void;
}) {
  const [userId, setUserId] = useState("");
  const [role, setRole] = useState<"tenant_admin" | "tenant_member">("tenant_member");
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState("");

  const userLabel = (id: string) => {
    const u = users.find((x) => x.id === id);
    return u ? u.display_name || u.username || u.mobile || u.email : id;
  };

  const handleAdd = async (e: FormEvent) => {
    e.preventDefault();
    setError("");
    const token = getStoredToken();
    if (!token) {
      setError("توکن یافت نشد.");
      return;
    }
    if (!userId) {
      setError("یک کاربر انتخاب کنید.");
      return;
    }
    setSaving(true);
    try {
      await identityApi.addMember(token, tenantId, { user_id: userId, role });
      setUserId("");
      onChanged();
    } catch (err) {
      setError(err instanceof Error ? err.message : "افزودن عضو ناموفق بود");
    } finally {
      setSaving(false);
    }
  };

  return (
    <div className={`space-y-4 ${cardClass}`}>
      <h2 className="text-lg font-bold text-secondary">اعضا</h2>
      {members.length === 0 ? (
        <p className="text-sm text-gray-500">عضوی ثبت نشده است.</p>
      ) : (
        <ul className="space-y-2">
          {members.map((m) => (
            <li
              key={m.id}
              className="flex items-center justify-between rounded-xl bg-gray-50 px-3 py-2 text-sm"
            >
              <span className="text-gray-700">{userLabel(m.user_id)}</span>
              <span className="flex items-center gap-2">
                <span className="text-xs text-gray-400">
                  {m.role === "tenant_admin" ? "مدیر" : "عضو"}
                </span>
                <StatusBadge status={m.is_active ? "active" : "inactive"} />
              </span>
            </li>
          ))}
        </ul>
      )}

      {error && <Banner variant="error">{error}</Banner>}

      <form onSubmit={handleAdd} className="space-y-3 border-t border-gray-100 pt-4">
        <p className="text-sm font-medium text-secondary">افزودن عضو</p>
        {users.length === 0 ? (
          <p className="text-xs text-amber-600">
            کاربری برای افزودن یافت نشد. ابتدا از بخش «کاربران» کاربر بسازید.
          </p>
        ) : (
          <>
            <Field label="کاربر">
              <select
                className={inputClass}
                value={userId}
                onChange={(e) => setUserId(e.target.value)}
                disabled={saving}
              >
                <option value="">— انتخاب کاربر —</option>
                {users.map((u) => (
                  <option key={u.id} value={u.id}>
                    {u.display_name || u.username || u.mobile || u.email}
                  </option>
                ))}
              </select>
            </Field>
            <SelectField
              label="نقش"
              value={role}
              onValue={(v) => setRole(v as "tenant_admin" | "tenant_member")}
              options={[
                { value: "tenant_member", label: "عضو" },
                { value: "tenant_admin", label: "مدیر" },
              ]}
              disabled={saving}
            />
            <Button type="submit" size="sm" loading={saving} loadingText="در حال افزودن...">
              افزودن عضو
            </Button>
          </>
        )}
      </form>
    </div>
  );
}