// components/GroupsExplorer.tsx
// Client component: list groups, create/edit/delete.

"use client";

import { useState, useEffect } from "react";
import Link from "next/link";
import { useQueryClient } from "@tanstack/react-query";
import { pbList, pbPatch, pbCreate, pbDelete } from "@/lib/api";
import type { YsterbaardGroup, PBList } from "@/lib/types";

interface Props {
  initial: PBList<YsterbaardGroup>;
}

interface EditForm {
  id?: string;
  name: string;
  description: string;
}

export default function GroupsExplorer({ initial }: Props) {
  const qc = useQueryClient();
  const [groups, setGroups] = useState<YsterbaardGroup[]>(initial.items);
  const [showCreate, setShowCreate] = useState(false);
  const [editingId, setEditingId] = useState<string | null>(null);
  const [deleteId, setDeleteId] = useState<string | null>(null);
  const [form, setForm] = useState<EditForm>({ name: "", description: "" });
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [deleteSaving, setDeleteSaving] = useState(false);

  // Reset form when closing create
  useEffect(() => {
    if (!showCreate) setForm({ name: "", description: "" });
  }, [showCreate]);

  // Populate form for editing
  function startEdit(g: YsterbaardGroup) {
    setEditingId(g.id);
    setForm({ name: g.name, description: g.description ?? "" });
  }

  function cancelEdit() {
    setEditingId(null);
    setForm({ name: "", description: "" });
  }

  async function handleSave() {
    if (!form.name.trim()) {
      setError("Group name is required.");
      return;
    }
    setError(null);
    setSaving(true);
    try {
      if (editingId) {
        // Update existing
        await pbPatch({
          collection: "groups",
          id: editingId,
          fields: {
            name: form.name.trim(),
            description: form.description.trim() || "",
          },
        });
        setGroups((prev) =>
          prev.map((g) =>
            g.id === editingId
              ? { ...g, name: form.name.trim(), description: form.description.trim() || null }
              : g
          )
        );
        cancelEdit();
      } else {
        // Create new
        const created = await pbCreate({
          collection: "groups",
          fields: {
            name: form.name.trim(),
            description: form.description.trim() || "",
          },
        });
        const newGroup = (created as YsterbaardGroup);
        setGroups((prev) => [...prev, newGroup].sort((a, b) => a.name.localeCompare(b.name)));
        setShowCreate(false);
      }
      await qc.invalidateQueries({ queryKey: ["pb-list", "groups"] });
    } catch (err) {
      setError(err instanceof Error ? err.message : "Save failed.");
    } finally {
      setSaving(false);
    }
  }

  async function handleDelete() {
    if (!deleteId) return;
    setDeleteSaving(true);
    try {
      await pbDelete({ collection: "groups", id: deleteId });
      setGroups((prev) => prev.filter((g) => g.id !== deleteId));
      setDeleteId(null);
      await qc.invalidateQueries({ queryKey: ["pb-list", "groups"] });
    } catch (err) {
      setError(err instanceof Error ? err.message : "Delete failed.");
    } finally {
      setDeleteSaving(false);
    }
  }

  return (
    <div className="flex flex-col gap-6">

      {/* Create button */}
      {!showCreate && editingId === null ? (
        <div className="flex justify-end">
          <button
            onClick={() => setShowCreate(true)}
            className="px-4 py-2.5 rounded-lg bg-accent text-accent-on text-sm font-bold hover:bg-accent-hover transition-colors"
          >
            + New Group
          </button>
        </div>
      ) : null}

      {/* Create form */}
      {showCreate ? (
        <div className="bg-surface border border-border rounded-lg p-6">
          <h3 className="text-base font-semibold text-fg mb-4">Create Group</h3>
          {error && (
            <div className="mb-4 px-4 py-3 rounded-lg bg-red-500/10 border border-red-500/30 text-sm text-red-400">
              {error}
            </div>
          )}
          <div className="space-y-3">
            <div>
              <label className="block text-sm font-semibold text-fg mb-1.5" htmlFor="group-name">
                Group Name <span className="text-red-400">*</span>
              </label>
              <input
                id="group-name"
                type="text"
                value={form.name}
                onChange={(e) => setForm((f) => ({ ...f, name: e.target.value.toUpperCase() }))}
                placeholder="e.g. CNL"
                autoFocus
                className="w-full rounded-lg border border-border bg-surface-warm px-3 py-2.5 text-sm text-fg focus:outline-none focus:border-accent focus:ring-1 focus:ring-accent"
              />
            </div>
            <div>
              <label className="block text-sm font-semibold text-fg mb-1.5" htmlFor="group-desc">
                Description <span className="text-xs text-muted font-normal">(optional)</span>
              </label>
              <input
                id="group-desc"
                type="text"
                value={form.description}
                onChange={(e) => setForm((f) => ({ ...f, description: e.target.value }))}
                placeholder="e.g. CNL Group of Companies"
                className="w-full rounded-lg border border-border bg-surface-warm px-3 py-2.5 text-sm text-fg focus:outline-none focus:border-accent focus:ring-1 focus:ring-accent"
              />
            </div>
          </div>
          <div className="mt-4 flex gap-3">
            <button
              onClick={() => { setShowCreate(false); setError(null); }}
              className="px-4 py-2.5 rounded-lg border border-border bg-surface-warm text-sm font-semibold text-fg hover:bg-surface"
            >
              Cancel
            </button>
            <button
              onClick={handleSave}
              disabled={saving}
              className="px-4 py-2.5 rounded-lg bg-accent text-accent-on text-sm font-bold hover:bg-accent-hover transition-colors disabled:opacity-60"
            >
              {saving ? "Saving..." : "Create Group"}
            </button>
          </div>
        </div>
      ) : null}

      {/* Error banner */}
      {error && !showCreate ? (
        <div className="px-4 py-3 rounded-lg bg-red-500/10 border border-red-500/30 text-sm text-red-400">
          {error}
        </div>
      ) : null}

      {/* Groups list */}
      {groups.length === 0 && !showCreate ? (
        <div className="bg-surface border border-border rounded-lg p-12 text-center text-muted">
          No groups yet. Click &ldquo;New Group&rdquo; to create one.
        </div>
      ) : (
        <div className="bg-surface border border-border rounded-lg overflow-hidden">
          <table className="w-full text-sm">
            <thead className="bg-surface-warm text-muted">
              <tr>
                <th className="text-left font-semibold px-5 py-3">Group Name</th>
                <th className="text-left font-semibold px-5 py-3">Description</th>
                <th className="px-5 py-3"></th>
              </tr>
            </thead>
            <tbody>
              {groups.map((g) => (
                <tr key={g.id} className="border-t border-border hover:bg-surface-warm/50 transition-colors">
                  {editingId === g.id ? (
                    // Editing row
                    <>
                      <td className="px-5 py-3">
                        <input
                          type="text"
                          value={form.name}
                          onChange={(e) => setForm((f) => ({ ...f, name: e.target.value.toUpperCase() }))}
                          className="w-full rounded border border-border bg-surface-warm px-3 py-2 text-sm text-fg focus:outline-none focus:border-accent"
                          autoFocus
                        />
                      </td>
                      <td className="px-5 py-3">
                        <input
                          type="text"
                          value={form.description}
                          onChange={(e) => setForm((f) => ({ ...f, description: e.target.value }))}
                          className="w-full rounded border border-border bg-surface-warm px-3 py-2 text-sm text-fg focus:outline-none focus:border-accent"
                        />
                      </td>
                      <td className="px-5 py-3">
                        <div className="flex gap-2 justify-end">
                          <button
                            onClick={cancelEdit}
                            className="text-xs px-3 py-1.5 rounded border border-border bg-surface-warm text-fg hover:bg-surface"
                          >
                            Cancel
                          </button>
                          <button
                            onClick={handleSave}
                            disabled={saving}
                            className="text-xs px-3 py-1.5 rounded bg-accent text-accent-on font-semibold hover:bg-accent-hover disabled:opacity-60"
                          >
                            {saving ? "..." : "Save"}
                          </button>
                        </div>
                      </td>
                    </>
                  ) : (
                    // Display row
                    <>
                      <td className="px-5 py-3">
                        <span className="font-semibold text-fg">{g.name}</span>
                      </td>
                      <td className="px-5 py-3 text-fg-2">
                        {g.description || <span className="text-muted italic">—</span>}
                      </td>
                      <td className="px-5 py-3">
                        <div className="flex gap-2 justify-end">
                          <a
                            href={`/groups/${g.id}/report`}
                            className="text-xs px-3 py-1.5 rounded border border-border bg-surface-warm text-fg no-underline hover:border-accent hover:text-accent transition-colors"
                          >
                            Report
                          </a>
                          <a
                            href={`/api/group-report/${g.id}/pdf`}
                            target="_blank"
                            className="text-xs px-3 py-1.5 rounded border border-border bg-surface-warm text-fg no-underline hover:border-accent hover:text-accent transition-colors"
                          >
                            View PDF
                          </a>
                          <button
                            onClick={() => {
                              const email = prompt("Enter email address to send the group PDF to:");
                              if (!email) return;
                              if (!confirm(`Send group PDF for "${g.name}" to ${email}?`)) return;
                              fetch(`/api/group-report/${g.id}/email`, {
                                method: "POST",
                                headers: { "Content-Type": "application/json" },
                                body: JSON.stringify({ to: email }),
                              })
                                .then(r => r.json())
                                .then(d => d.ok ? alert(`Sent to ${email}`) : alert(`Failed: ${d.error}`))
                                .catch(e => alert(`Error: ${e}`));
                            }}
                            className="text-xs px-3 py-1.5 rounded border border-border bg-surface-warm text-fg hover:border-accent hover:text-accent transition-colors"
                          >
                            Mail PDF
                          </button>
                          <button
                            onClick={() => startEdit(g)}
                            className="text-xs px-3 py-1.5 rounded border border-border bg-surface-warm text-fg hover:border-accent hover:text-accent transition-colors"
                          >
                            Edit
                          </button>
                          <button
                            onClick={() => setDeleteId(g.id)}
                            className="text-xs px-3 py-1.5 rounded border border-red-500/30 bg-red-500/5 text-red-400 hover:bg-red-500/15 transition-colors"
                          >
                            Delete
                          </button>
                        </div>
                      </td>
                    </>
                  )}
                </tr>
              ))}
            </tbody>
          </table>
        </div>
      )}

      {/* Delete confirmation modal */}
      {deleteId ? (
        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 backdrop-blur-sm p-4">
          <div className="bg-surface border border-border rounded-xl shadow-2xl w-full max-w-sm p-6">
            <h3 className="text-base font-bold text-fg mb-2">Delete Group?</h3>
            <p className="text-sm text-fg-2 mb-1">
              This will <strong>remove this group from all companies</strong> that are linked to it.
            </p>
            <p className="text-sm text-muted mb-5">
              The group record will be deleted. Companies are not deleted.
            </p>
            <div className="flex gap-3">
              <button
                onClick={() => { setDeleteId(null); setError(null); }}
                className="flex-1 px-4 py-2.5 rounded-lg border border-border bg-surface-warm text-sm font-semibold text-fg hover:bg-surface"
              >
                Cancel
              </button>
              <button
                onClick={handleDelete}
                disabled={deleteSaving}
                className="flex-1 px-4 py-2.5 rounded-lg bg-red-600 text-white text-sm font-bold hover:bg-red-700 disabled:opacity-60"
              >
                {deleteSaving ? "Deleting..." : "Delete Group"}
              </button>
            </div>
          </div>
        </div>
      ) : null}
    </div>
  );
}