"use client";

import React, { useEffect, useState } from "react";
import { AdminHeader, AlertBanner, Modal, ConfirmDeleteModal, getClientToken } from "../_components/AdminComponents";
import {
  adminGetMembers,
  adminCreateMember,
  adminUpdateMember,
  adminDeleteMember,
  adminGetAlumni,
  adminCreateAlumnus,
  adminUpdateAlumnus,
  adminDeleteAlumnus,
  AdminMember,
  AdminAlumnus,
} from "../../../lib/adminApi";

const MEMBER_DEGREES = [
  "Professor",
  "PhD",
  "PhDCandidate",
  "PhDStudent",
  "MSCandidate",
  "MSStudent",
];

const ALUMNI_DEGREES = ["PhD", "MS"];

export default function AdminMembersPage() {
  const [tab, setTab] = useState<"active" | "alumni">("active");
  const [members, setMembers] = useState<AdminMember[]>([]);
  const [alumni, setAlumni] = useState<AdminAlumnus[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [successMsg, setSuccessMsg] = useState<string | null>(null);

  // Active Member Modal State
  const [isMemberModalOpen, setIsMemberModalOpen] = useState(false);
  const [editingMember, setEditingMember] = useState<AdminMember | null>(null);
  const [memberForm, setMemberForm] = useState({
    name_ko: "",
    name_en: "",
    degree: "PhDStudent",
    affiliation: "",
    email: "",
    is_advisor: false,
    display_order: 0,
  });

  // Alumni Modal State
  const [isAlumniModalOpen, setIsAlumniModalOpen] = useState(false);
  const [editingAlumnus, setEditingAlumnus] = useState<AdminAlumnus | null>(null);
  const [alumniForm, setAlumniForm] = useState({
    name_ko: "",
    name_en: "",
    degree: "MS",
    graduated_at: "",
    major: "",
    current_position: "",
  });

  const [isSubmitting, setIsSubmitting] = useState(false);
  const [deletingMemberId, setDeletingMemberId] = useState<number | null>(null);
  const [deletingAlumniId, setDeletingAlumniId] = useState<number | null>(null);

  const loadData = async () => {
    try {
      setIsLoading(true);
      setError(null);
      const [mList, aList] = await Promise.all([adminGetMembers(), adminGetAlumni()]);
      setMembers(mList);
      setAlumni(aList);
    } catch (err: any) {
      setError(err?.message || "Failed to load members data.");
    } finally {
      setIsLoading(false);
    }
  };

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

  // Member Handlers
  const handleOpenMemberCreate = () => {
    setEditingMember(null);
    setMemberForm({
      name_ko: "",
      name_en: "",
      degree: "PhDStudent",
      affiliation: "",
      email: "",
      is_advisor: false,
      display_order: members.length + 1,
    });
    setIsMemberModalOpen(true);
  };

  const handleOpenMemberEdit = (m: AdminMember) => {
    setEditingMember(m);
    setMemberForm({
      name_ko: m.name_ko,
      name_en: m.name_en,
      degree: m.degree,
      affiliation: m.affiliation || "",
      email: m.email || "",
      is_advisor: m.is_advisor,
      display_order: m.display_order,
    });
    setIsMemberModalOpen(true);
  };

  const handleMemberSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    const token = getClientToken();
    if (!token) {
      setError("Unauthorized. Please log in.");
      return;
    }

    const payload = {
      name_ko: memberForm.name_ko.trim(),
      name_en: memberForm.name_en.trim(),
      degree: memberForm.degree,
      affiliation: memberForm.affiliation.trim() || undefined,
      email: memberForm.email.trim() || undefined,
      is_advisor: memberForm.is_advisor,
      display_order: Number(memberForm.display_order) || 0,
    };

    setIsSubmitting(true);
    setError(null);

    try {
      if (editingMember) {
        await adminUpdateMember(token, editingMember.id, payload);
        setSuccessMsg(`Member "${payload.name_ko}" updated successfully.`);
      } else {
        await adminCreateMember(token, payload);
        setSuccessMsg(`Member "${payload.name_ko}" created successfully.`);
      }
      setIsMemberModalOpen(false);
      await loadData();
    } catch (err: any) {
      setError(err?.message || "Failed to save member.");
    } finally {
      setIsSubmitting(false);
    }
  };

  const handleConfirmDeleteMember = async () => {
    if (!deletingMemberId) return;
    const token = getClientToken();
    if (!token) return;

    setIsSubmitting(true);
    try {
      await adminDeleteMember(token, deletingMemberId);
      setSuccessMsg("Member deleted successfully.");
      setDeletingMemberId(null);
      await loadData();
    } catch (err: any) {
      setError(err?.message || "Failed to delete member.");
    } finally {
      setIsSubmitting(false);
    }
  };

  // Alumni Handlers
  const handleOpenAlumniCreate = () => {
    setEditingAlumnus(null);
    setAlumniForm({
      name_ko: "",
      name_en: "",
      degree: "MS",
      graduated_at: "",
      major: "",
      current_position: "",
    });
    setIsAlumniModalOpen(true);
  };

  const handleOpenAlumniEdit = (a: AdminAlumnus) => {
    setEditingAlumnus(a);
    setAlumniForm({
      name_ko: a.name_ko,
      name_en: a.name_en,
      degree: a.degree,
      graduated_at: a.graduated_at,
      major: a.major || "",
      current_position: a.current_position || "",
    });
    setIsAlumniModalOpen(true);
  };

  const handleAlumniSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    const token = getClientToken();
    if (!token) return;

    const payload = {
      name_ko: alumniForm.name_ko.trim(),
      name_en: alumniForm.name_en.trim(),
      degree: alumniForm.degree,
      graduated_at: alumniForm.graduated_at.trim(),
      major: alumniForm.major.trim() || undefined,
      current_position: alumniForm.current_position.trim() || undefined,
    };

    setIsSubmitting(true);
    setError(null);

    try {
      if (editingAlumnus) {
        await adminUpdateAlumnus(token, editingAlumnus.id, payload);
        setSuccessMsg(`Alumnus "${payload.name_ko}" updated successfully.`);
      } else {
        await adminCreateAlumnus(token, payload);
        setSuccessMsg(`Alumnus "${payload.name_ko}" created successfully.`);
      }
      setIsAlumniModalOpen(false);
      await loadData();
    } catch (err: any) {
      setError(err?.message || "Failed to save alumnus.");
    } finally {
      setIsSubmitting(false);
    }
  };

  const handleConfirmDeleteAlumnus = async () => {
    if (!deletingAlumniId) return;
    const token = getClientToken();
    if (!token) return;

    setIsSubmitting(true);
    try {
      await adminDeleteAlumnus(token, deletingAlumniId);
      setSuccessMsg("Alumnus deleted successfully.");
      setDeletingAlumniId(null);
      await loadData();
    } catch (err: any) {
      setError(err?.message || "Failed to delete alumnus.");
    } finally {
      setIsSubmitting(false);
    }
  };

  return (
    <div>
      <AdminHeader
        title="Members & Alumni Management"
        description="Manage active laboratory researchers, advisors, and graduated alumni."
        action={
          <button
            onClick={tab === "active" ? handleOpenMemberCreate : handleOpenAlumniCreate}
            className="px-4 py-2 text-sm rounded bg-cobalt hover:bg-cobalt/90 text-white font-medium shadow-sm transition-colors"
          >
            {tab === "active" ? "+ Add Active Member" : "+ Add Alumnus"}
          </button>
        }
      />

      {/* Tabs */}
      <div className="flex border-b border-line mb-6 gap-6">
        <button
          onClick={() => setTab("active")}
          className={`pb-3 text-sm font-semibold border-b-2 transition-colors ${
            tab === "active" ? "border-cobalt text-cobalt" : "border-transparent text-ink/60 hover:text-ink"
          }`}
        >
          Active Members ({members.length})
        </button>
        <button
          onClick={() => setTab("alumni")}
          className={`pb-3 text-sm font-semibold border-b-2 transition-colors ${
            tab === "alumni" ? "border-cobalt text-cobalt" : "border-transparent text-ink/60 hover:text-ink"
          }`}
        >
          Alumni ({alumni.length})
        </button>
      </div>

      {error && <AlertBanner type="error" message={error} onClose={() => setError(null)} />}
      {successMsg && <AlertBanner type="success" message={successMsg} onClose={() => setSuccessMsg(null)} />}

      {isLoading ? (
        <div className="py-12 text-center text-sm text-ink/70">Loading records...</div>
      ) : tab === "active" ? (
        /* Active Members Table */
        <div className="bg-paper border border-line rounded-lg overflow-hidden shadow-sm">
          <table className="w-full text-left text-sm border-collapse">
            <thead>
              <tr className="bg-ivory border-b border-line text-xs font-semibold text-ink/70 uppercase">
                <th className="p-4 w-16">Order</th>
                <th className="p-4">Name (Ko / En)</th>
                <th className="p-4">Degree</th>
                <th className="p-4">Affiliation / Email</th>
                <th className="p-4 text-right">Actions</th>
              </tr>
            </thead>
            <tbody className="divide-y divide-line">
              {members.length === 0 ? (
                <tr>
                  <td colSpan={5} className="p-6 text-center text-ink/60">
                    No active members found.
                  </td>
                </tr>
              ) : (
                members.map((m) => (
                  <tr key={m.id} className="hover:bg-ivory/50">
                    <td className="p-4 text-xs font-mono text-ink/60">{m.display_order}</td>
                    <td className="p-4">
                      <div className="font-semibold text-ink flex items-center gap-2">
                        {m.name_ko} ({m.name_en})
                        {m.is_advisor && (
                          <span className="px-1.5 py-0.5 text-[10px] rounded bg-cobalt/10 text-cobalt font-bold">
                            Advisor
                          </span>
                        )}
                      </div>
                    </td>
                    <td className="p-4 text-xs font-medium text-ink/80">{m.degree}</td>
                    <td className="p-4 text-xs text-ink/70">
                      <div>{m.affiliation || "—"}</div>
                      <div className="text-ink/50">{m.email || "—"}</div>
                    </td>
                    <td className="p-4 text-right space-x-2">
                      <button
                        onClick={() => handleOpenMemberEdit(m)}
                        className="px-2.5 py-1 text-xs rounded border border-line hover:bg-ivory font-medium text-ink"
                      >
                        Edit
                      </button>
                      <button
                        onClick={() => setDeletingMemberId(m.id)}
                        className="px-2.5 py-1 text-xs rounded bg-red-50 hover:bg-red-100 text-red-600 border border-red-200 dark:bg-red-950/30 dark:hover:bg-red-950/60 dark:text-red-400 dark:border-red-900 font-medium"
                      >
                        Delete
                      </button>
                    </td>
                  </tr>
                ))
              )}
            </tbody>
          </table>
        </div>
      ) : (
        /* Alumni Table */
        <div className="bg-paper border border-line rounded-lg overflow-hidden shadow-sm">
          <table className="w-full text-left text-sm border-collapse">
            <thead>
              <tr className="bg-ivory border-b border-line text-xs font-semibold text-ink/70 uppercase">
                <th className="p-4">Graduation Date</th>
                <th className="p-4">Name (Ko / En)</th>
                <th className="p-4">Degree</th>
                <th className="p-4">Major / Current Position</th>
                <th className="p-4 text-right">Actions</th>
              </tr>
            </thead>
            <tbody className="divide-y divide-line">
              {alumni.length === 0 ? (
                <tr>
                  <td colSpan={5} className="p-6 text-center text-ink/60">
                    No alumni found.
                  </td>
                </tr>
              ) : (
                alumni.map((a) => (
                  <tr key={a.id} className="hover:bg-ivory/50">
                    <td className="p-4 text-xs font-mono text-ink/80">{a.graduated_at}</td>
                    <td className="p-4 font-semibold text-ink">
                      {a.name_ko} ({a.name_en})
                    </td>
                    <td className="p-4 text-xs font-medium text-ink/80">{a.degree}</td>
                    <td className="p-4 text-xs text-ink/70">
                      <div>{a.current_position || "—"}</div>
                      <div className="text-ink/50">{a.major || "—"}</div>
                    </td>
                    <td className="p-4 text-right space-x-2">
                      <button
                        onClick={() => handleOpenAlumniEdit(a)}
                        className="px-2.5 py-1 text-xs rounded border border-line hover:bg-ivory font-medium text-ink"
                      >
                        Edit
                      </button>
                      <button
                        onClick={() => setDeletingAlumniId(a.id)}
                        className="px-2.5 py-1 text-xs rounded bg-red-50 hover:bg-red-100 text-red-600 border border-red-200 dark:bg-red-950/30 dark:hover:bg-red-950/60 dark:text-red-400 dark:border-red-900 font-medium"
                      >
                        Delete
                      </button>
                    </td>
                  </tr>
                ))
              )}
            </tbody>
          </table>
        </div>
      )}

      {/* Member Modal */}
      <Modal
        isOpen={isMemberModalOpen}
        title={editingMember ? "Edit Active Member" : "Create Active Member"}
        onClose={() => setIsMemberModalOpen(false)}
      >
        <form onSubmit={handleMemberSubmit} className="space-y-4">
          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Korean Name *</label>
              <input
                type="text"
                value={memberForm.name_ko}
                onChange={(e) => setMemberForm({ ...memberForm, name_ko: e.target.value })}
                placeholder="e.g. 홍길동"
                required
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">English Name *</label>
              <input
                type="text"
                value={memberForm.name_en}
                onChange={(e) => setMemberForm({ ...memberForm, name_en: e.target.value })}
                placeholder="e.g. Gildong Hong"
                required
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
          </div>

          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Degree Level *</label>
              <select
                value={memberForm.degree}
                onChange={(e) => setMemberForm({ ...memberForm, degree: e.target.value })}
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              >
                {MEMBER_DEGREES.map((d) => (
                  <option key={d} value={d}>
                    {d}
                  </option>
                ))}
              </select>
            </div>
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Display Order</label>
              <input
                type="number"
                value={memberForm.display_order}
                onChange={(e) => setMemberForm({ ...memberForm, display_order: Number(e.target.value) })}
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
          </div>

          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Affiliation</label>
              <input
                type="text"
                value={memberForm.affiliation}
                onChange={(e) => setMemberForm({ ...memberForm, affiliation: e.target.value })}
                placeholder="e.g. School of Electronic Engineering"
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Email</label>
              <input
                type="email"
                value={memberForm.email}
                onChange={(e) => setMemberForm({ ...memberForm, email: e.target.value })}
                placeholder="e.g. user@knu.ac.kr"
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
          </div>

          <div className="flex items-center gap-2 pt-2">
            <input
              type="checkbox"
              id="is_advisor"
              checked={memberForm.is_advisor}
              onChange={(e) => setMemberForm({ ...memberForm, is_advisor: e.target.checked })}
              className="rounded text-cobalt focus:ring-cobalt"
            />
            <label htmlFor="is_advisor" className="text-xs font-semibold text-ink">
              Principal Investigator / Lab Advisor
            </label>
          </div>

          <div className="flex justify-end gap-3 pt-4 border-t border-line">
            <button
              type="button"
              onClick={() => setIsMemberModalOpen(false)}
              className="px-4 py-2 text-sm rounded border border-line hover:bg-ivory font-medium text-ink"
            >
              Cancel
            </button>
            <button
              type="submit"
              disabled={isSubmitting}
              className="px-4 py-2 text-sm rounded bg-cobalt hover:bg-cobalt/90 text-white font-medium disabled:opacity-50"
            >
              {isSubmitting ? "Saving..." : editingMember ? "Save Changes" : "Create Member"}
            </button>
          </div>
        </form>
      </Modal>

      {/* Alumni Modal */}
      <Modal
        isOpen={isAlumniModalOpen}
        title={editingAlumnus ? "Edit Alumnus" : "Create Alumnus"}
        onClose={() => setIsAlumniModalOpen(false)}
      >
        <form onSubmit={handleAlumniSubmit} className="space-y-4">
          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Korean Name *</label>
              <input
                type="text"
                value={alumniForm.name_ko}
                onChange={(e) => setAlumniForm({ ...alumniForm, name_ko: e.target.value })}
                placeholder="e.g. 홍길동"
                required
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">English Name *</label>
              <input
                type="text"
                value={alumniForm.name_en}
                onChange={(e) => setAlumniForm({ ...alumniForm, name_en: e.target.value })}
                placeholder="e.g. Gildong Hong"
                required
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
          </div>

          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Graduation Date (ISO 8601) *</label>
              <input
                type="text"
                value={alumniForm.graduated_at}
                onChange={(e) => setAlumniForm({ ...alumniForm, graduated_at: e.target.value })}
                placeholder="e.g. 2024-02"
                required
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              />
            </div>
            <div>
              <label className="block text-xs font-semibold text-ink mb-1">Degree *</label>
              <select
                value={alumniForm.degree}
                onChange={(e) => setAlumniForm({ ...alumniForm, degree: e.target.value })}
                className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
              >
                {ALUMNI_DEGREES.map((d) => (
                  <option key={d} value={d}>
                    {d}
                  </option>
                ))}
              </select>
            </div>
          </div>

          <div>
            <label className="block text-xs font-semibold text-ink mb-1">Current Position</label>
            <input
              type="text"
              value={alumniForm.current_position}
              onChange={(e) => setAlumniForm({ ...alumniForm, current_position: e.target.value })}
              placeholder="e.g. Samsung Electronics, Principal Engineer"
              className="w-full px-3 py-2 text-sm border border-line rounded bg-ivory text-ink focus:outline-none focus:ring-1 focus:ring-cobalt"
            />
          </div>

          <div className="flex justify-end gap-3 pt-4 border-t border-line">
            <button
              type="button"
              onClick={() => setIsAlumniModalOpen(false)}
              className="px-4 py-2 text-sm rounded border border-line hover:bg-ivory font-medium text-ink"
            >
              Cancel
            </button>
            <button
              type="submit"
              disabled={isSubmitting}
              className="px-4 py-2 text-sm rounded bg-cobalt hover:bg-cobalt/90 text-white font-medium disabled:opacity-50"
            >
              {isSubmitting ? "Saving..." : editingAlumnus ? "Save Changes" : "Create Alumnus"}
            </button>
          </div>
        </form>
      </Modal>

      <ConfirmDeleteModal
        isOpen={deletingMemberId !== null}
        onClose={() => setDeletingMemberId(null)}
        onConfirm={handleConfirmDeleteMember}
        isSubmitting={isSubmitting}
        title="Delete Member"
        description="Are you sure you want to delete this member?"
      />

      <ConfirmDeleteModal
        isOpen={deletingAlumniId !== null}
        onClose={() => setDeletingAlumniId(null)}
        onConfirm={handleConfirmDeleteAlumnus}
        isSubmitting={isSubmitting}
        title="Delete Alumnus"
        description="Are you sure you want to delete this alumnus?"
      />
    </div>
  );
}