"use client";

import React, { useEffect, useState } from "react";
import { useAuth } from "@/hooks/useAuth";
import { useRouter } from "next/navigation";
import { apiFetch } from "@/lib/api";
import { isValidZAPhone } from "@/lib/phone";
import { useDismissingState } from "@/hooks/useDismissingState";
import { User, Lock, ShieldAlert, Trash2, Clock, LogIn, KeyRound, RotateCcw } from "lucide-react";

type ActivityEvent = { id: string; type: "login" | "password_changed" | "password_reset"; device: string | null; createdAt: string };

const ACTIVITY_META: Record<ActivityEvent["type"], { label: (device: string | null) => string; icon: typeof LogIn }> = {
  login: { label: d => `Logged in${d ? ` from ${d}` : ""}`, icon: LogIn },
  password_changed: { label: () => "Password changed", icon: KeyRound },
  password_reset: { label: () => "Password reset via email link", icon: RotateCcw },
};

export default function UserProfilePage() {
  const { user, token, logout, updateToken } = useAuth();
  const router = useRouter();

  useEffect(() => {
    if (!user && !token) router.replace("/login");
  }, [user, token, router]);

  // ── Profile form ─────────────────────────────────────────────────────────
  const [name, setName] = useState("");
  const [email, setEmail] = useState("");
  const [phone, setPhone] = useState("");
  const [notifPref, setNotifPref] = useState<"email" | "whatsapp" | "both">("email");
  const [profileMsg, setProfileMsg] = useDismissingState<{ type: "ok" | "err"; text: string } | null>(null);
  const [savingProfile, setSavingProfile] = useState(false);

  const hasValidPhone = isValidZAPhone(phone);

  useEffect(() => {
    if (user) {
      setName(user.name || "");
      setEmail(user.email || "");
      setPhone(user.phoneNumber || "");
      setNotifPref(user.notificationPreference || "email");
    }
  }, [user]);

  const saveProfile = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!token) return;
    setSavingProfile(true);
    setProfileMsg(null);
    try {
      const res = await apiFetch<any>("/api/users/profile", {
        method: "PUT",
        authToken: token,
        body: {
          name,
          email,
          phoneNumber: phone || null,
          notificationPreference: hasValidPhone ? notifPref : "email",
        },
      });
      // Backend returns a refreshed token — save it so the session stays valid
      if (res?.token) updateToken(res.token);
      setProfileMsg({ type: "ok", text: "Profile updated." });
    } catch (e: any) {
      setProfileMsg({ type: "err", text: e?.message || "Failed to update profile." });
    } finally {
      setSavingProfile(false);
    }
  };

  // ── Password change ───────────────────────────────────────────────────────
  const [currentPassword, setCurrentPassword] = useState("");
  const [newPassword, setNewPassword] = useState("");
  const [confirmPassword, setConfirmPassword] = useState("");
  const [pwMsg, setPwMsg] = useDismissingState<{ type: "ok" | "err"; text: string } | null>(null);
  const [savingPw, setSavingPw] = useState(false);

  const changePassword = async (e: React.FormEvent) => {
    e.preventDefault();
    if (newPassword !== confirmPassword) {
      setPwMsg({ type: "err", text: "Passwords do not match." });
      return;
    }
    if (newPassword.length < 8) {
      setPwMsg({ type: "err", text: "Password must be at least 8 characters." });
      return;
    }
    if (!token) return;
    setSavingPw(true);
    setPwMsg(null);
    try {
      const res = await apiFetch<any>("/api/users/profile", {
        method: "PUT",
        authToken: token,
        body: { currentPassword, password: newPassword },
      });
      if (res?.token) updateToken(res.token);
      setCurrentPassword("");
      setNewPassword("");
      setConfirmPassword("");
      setPwMsg({ type: "ok", text: "Password changed." });
      loadActivity();
    } catch (e: any) {
      setPwMsg({ type: "err", text: e?.message || "Failed to change password." });
    } finally {
      setSavingPw(false);
    }
  };

  // ── Revoke sessions ───────────────────────────────────────────────────────
  const [revokeMsg, setRevokeMsg] = useDismissingState<{ type: "ok" | "err"; text: string } | null>(null);
  const [revoking, setRevoking] = useState(false);

  const revokeSessions = async () => {
    if (!confirm("This will sign you out of all other devices. You will need to log in again everywhere except here. Continue?")) return;
    if (!token) return;
    setRevoking(true);
    setRevokeMsg(null);
    try {
      const res = await apiFetch<any>("/api/users/revoke-sessions", {
        method: "POST",
        authToken: token,
      });
      // Revoking sessions invalidates the token this device was using too —
      // save the freshly issued one so this device stays signed in.
      if (res?.token) updateToken(res.token);
      setRevokeMsg({ type: "ok", text: res?.message || "All other sessions signed out." });
    } catch (e: any) {
      setRevokeMsg({ type: "err", text: e?.message || "Failed to revoke sessions." });
    } finally {
      setRevoking(false);
    }
  };

  // ── Account activity ──────────────────────────────────────────────────────
  const [activity, setActivity] = useState<ActivityEvent[]>([]);
  const [loadingActivity, setLoadingActivity] = useState(false);

  const loadActivity = async () => {
    if (!token) return;
    setLoadingActivity(true);
    try {
      const res = await apiFetch<ActivityEvent[]>("/api/users/activity", { authToken: token });
      setActivity(Array.isArray(res) ? res : []);
    } catch (e) {
      // Non-critical — just leave the list empty rather than showing an error banner.
    } finally {
      setLoadingActivity(false);
    }
  };

  useEffect(() => { loadActivity(); }, [token]);

  // ── Account closure ───────────────────────────────────────────────────────
  const [closeStep, setCloseStep] = useState<"idle" | "confirm">("idle");
  const [deleteData, setDeleteData] = useState(false);
  const [closePassword, setClosePassword] = useState("");
  const [closeMsg, setCloseMsg] = useDismissingState<{ type: "ok" | "err"; text: string } | null>(null);
  const [closing, setClosing] = useState(false);

  const submitAccountClosure = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!token) return;
    setClosing(true);
    setCloseMsg(null);
    try {
      const res = await apiFetch<any>("/api/users/close-account", {
        method: "POST",
        authToken: token,
        body: { password: closePassword, deleteData },
      });
      setCloseMsg({ type: "ok", text: res?.message || "Account closed." });
      // Slight delay so the user can read the message, then log out
      setTimeout(() => logout(), 2500);
    } catch (e: any) {
      setCloseMsg({ type: "err", text: e?.message || "Failed to close account." });
    } finally {
      setClosing(false);
    }
  };

  // ── Shared helpers ────────────────────────────────────────────────────────
  const Alert = ({ msg }: { msg: { type: "ok" | "err"; text: string } }) => (
    <div className={`mt-3 p-3 rounded-lg text-sm ${msg.type === "ok" ? "bg-green-50 text-green-800 border border-green-200" : "bg-red-50 text-red-800 border border-red-200"}`}>
      {msg.text}
    </div>
  );

  const inputCls = "w-full border rounded-lg px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-brand-500";

  const SectionHeader = ({ icon: Icon, title, tone = "brand" }: { icon: typeof User; title: string; tone?: "brand" | "amber" | "red" }) => {
    const toneCls = tone === "amber" ? "bg-amber-50 text-amber-600" : tone === "red" ? "bg-red-50 text-red-600" : "bg-brand-50 text-brand-600";
    return (
      <div className="flex items-center gap-2 mb-4">
        <div className={`w-9 h-9 rounded-lg flex items-center justify-center shrink-0 ${toneCls}`}>
          <Icon className="w-5 h-5" />
        </div>
        <h2 className="text-lg font-semibold text-gray-900">{title}</h2>
      </div>
    );
  };

  return (
    <div className="max-w-4xl mx-auto w-full">
      <div className="mb-6">
        <h1 className="text-2xl font-semibold text-gray-900">Profile &amp; Security</h1>
        <p className="text-sm text-gray-500 mt-1">Manage your personal information and keep your account secure.</p>
      </div>

      <div className="grid lg:grid-cols-2 gap-6 items-start">
        <div className="space-y-6">
          {/* ── Profile info ─────────────────────────────────────────────── */}
          <section className="border rounded-xl p-5 bg-white shadow-sm">
            <SectionHeader icon={User} title="Personal information" />
            <form onSubmit={saveProfile} className="space-y-4">
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">Full name</label>
                <input className={inputCls} value={name} onChange={e => setName(e.target.value)} required />
              </div>
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">Email address</label>
                <input type="email" className={inputCls} value={email} onChange={e => setEmail(e.target.value)} required />
              </div>
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">Phone number</label>
                <input type="tel" className={inputCls} value={phone} onChange={e => setPhone(e.target.value)} placeholder="e.g. 082 123 4567" />
              </div>

              {hasValidPhone && (
                <div>
                  <label className="block text-sm font-medium text-gray-700 mb-1">Notification preference</label>
                  <select className={inputCls} value={notifPref} onChange={e => setNotifPref(e.target.value as "email" | "whatsapp" | "both")}>
                    <option value="email">Email only</option>
                    <option value="whatsapp">WhatsApp only</option>
                    <option value="both">Email &amp; WhatsApp</option>
                  </select>
                  <p className="mt-1 text-xs text-gray-500">Security alerts (password reset, login notifications) are always sent via email regardless of this setting.</p>
                </div>
              )}

              <button type="submit" disabled={savingProfile} className="px-4 py-2 rounded-lg bg-brand-600 text-white text-sm font-medium hover:bg-brand-700 disabled:opacity-50">
                {savingProfile ? "Saving…" : "Save changes"}
              </button>
              {profileMsg && <Alert msg={profileMsg} />}
            </form>
          </section>

          {/* ── Account activity ─────────────────────────────────────────── */}
          <section className="border rounded-xl p-5 bg-white shadow-sm">
            <SectionHeader icon={Clock} title="Account activity" />
            {loadingActivity && activity.length === 0 ? (
              <p className="text-sm text-gray-400">Loading…</p>
            ) : activity.length === 0 ? (
              <p className="text-sm text-gray-500">No recent activity recorded yet.</p>
            ) : (
              <ul className="space-y-3">
                {activity.map(ev => {
                  const meta = ACTIVITY_META[ev.type] || ACTIVITY_META.login;
                  const Icon = meta.icon;
                  return (
                    <li key={ev.id} className="flex items-start gap-3">
                      <div className="w-7 h-7 rounded-full bg-gray-100 flex items-center justify-center shrink-0 mt-0.5">
                        <Icon className="w-3.5 h-3.5 text-gray-500" />
                      </div>
                      <div className="min-w-0 flex-1">
                        <div className="text-sm text-gray-800">{meta.label(ev.device)}</div>
                        <div className="text-xs text-gray-400">{new Date(ev.createdAt).toLocaleString()}</div>
                      </div>
                    </li>
                  );
                })}
              </ul>
            )}
          </section>
        </div>

        <div className="space-y-6">
          {/* ── Password ─────────────────────────────────────────────────── */}
          <section className="border rounded-xl p-5 bg-white shadow-sm">
            <SectionHeader icon={Lock} title="Change password" />
            <form onSubmit={changePassword} className="space-y-4">
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">Current password</label>
                <input type="password" className={inputCls} value={currentPassword} onChange={e => setCurrentPassword(e.target.value)} required autoComplete="current-password" />
              </div>
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">New password</label>
                <input type="password" className={inputCls} value={newPassword} onChange={e => setNewPassword(e.target.value)} required minLength={8} autoComplete="new-password" />
              </div>
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">Confirm new password</label>
                <input type="password" className={inputCls} value={confirmPassword} onChange={e => setConfirmPassword(e.target.value)} required autoComplete="new-password" />
              </div>
              <button type="submit" disabled={savingPw} className="px-4 py-2 rounded-lg bg-brand-600 text-white text-sm font-medium hover:bg-brand-700 disabled:opacity-50">
                {savingPw ? "Changing…" : "Change password"}
              </button>
              {pwMsg && <Alert msg={pwMsg} />}
            </form>
          </section>

          {/* ── Security ─────────────────────────────────────────────────── */}
          <section className="border rounded-xl p-5 bg-white shadow-sm">
            <SectionHeader icon={ShieldAlert} title="Security" tone="amber" />
            <p className="text-sm text-gray-500 mb-4">
              If you suspect someone else has access to your account, you can sign out of all other devices immediately.
              You will remain logged in on this device.
            </p>
            <button
              onClick={revokeSessions}
              disabled={revoking}
              className="px-4 py-2 rounded-lg bg-amber-500 text-white text-sm font-medium hover:bg-amber-600 disabled:opacity-50"
            >
              {revoking ? "Signing out…" : "Sign out all other devices"}
            </button>
            {revokeMsg && <Alert msg={revokeMsg} />}
          </section>

          {/* ── Danger zone ──────────────────────────────────────────────── */}
          <section className="border border-red-200 rounded-xl p-5 bg-white shadow-sm">
            <SectionHeader icon={Trash2} title="Close account" tone="red" />
            <p className="text-sm text-gray-500 mb-4">
              Closing your account will deactivate it immediately. You can also request that your personal
              information (name, email, phone number) be permanently deleted. Tickets and payment records
              will remain for accounting purposes but will show as &quot;Deleted User&quot;.
            </p>

            {closeStep === "idle" && (
              <button
                onClick={() => setCloseStep("confirm")}
                className="px-4 py-2 rounded-lg border border-red-600 text-red-600 text-sm font-medium hover:bg-red-50"
              >
                Close my account…
              </button>
            )}

            {closeStep === "confirm" && (
              <form onSubmit={submitAccountClosure} className="space-y-4">
                <div className="p-3 bg-red-50 border border-red-200 rounded-lg text-sm text-red-800">
                  <strong>This action cannot be undone.</strong> Please read carefully before continuing.
                </div>

                <label className="flex items-start gap-3 cursor-pointer">
                  <input
                    type="checkbox"
                    className="mt-0.5"
                    checked={deleteData}
                    onChange={e => setDeleteData(e.target.checked)}
                  />
                  <span className="text-sm text-gray-700">
                    <span className="font-medium">Also delete my personal data</span> — your name, email address,
                    and phone number will be permanently removed and cannot be recovered.
                  </span>
                </label>

                <div>
                  <label className="block text-sm font-medium text-gray-700 mb-1">
                    Confirm with your password
                  </label>
                  <input
                    type="password"
                    className="w-full border rounded-lg px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-red-500"
                    value={closePassword}
                    onChange={e => setClosePassword(e.target.value)}
                    required
                    placeholder="Enter your password to confirm"
                    autoComplete="current-password"
                  />
                </div>

                <div className="flex gap-3">
                  <button
                    type="button"
                    onClick={() => { setCloseStep("idle"); setClosePassword(""); setDeleteData(false); setCloseMsg(null); }}
                    className="px-4 py-2 rounded-lg bg-gray-100 text-sm font-medium hover:bg-gray-200"
                  >
                    Cancel
                  </button>
                  <button
                    type="submit"
                    disabled={closing || !closePassword}
                    className="px-4 py-2 rounded-lg bg-red-600 text-white text-sm font-medium hover:bg-red-700 disabled:opacity-50"
                  >
                    {closing ? "Processing…" : deleteData ? "Delete my data & close account" : "Close my account"}
                  </button>
                </div>
                {closeMsg && <Alert msg={closeMsg} />}
              </form>
            )}
          </section>
        </div>
      </div>
    </div>
  );
}