import { A, useParams } from '@solidjs/router';
import { createMemo, createResource, Show } from 'solid-js';
import AdminShell from '~/components/AdminShell';

const API = '/api/gateway';

type Permission = { id: string; module: string; action: string };
type Role = { id: string; name: string; description?: string; permissions: Permission[] };

async function loadRoleDetail(id: string) {
  try {
    const [roleRes, permsRes] = await Promise.all([
      fetch(`${API}/api/admin/roles/${id}`),
      fetch(`${API}/api/admin/permissions`),
    ]);
    if (!roleRes.ok) return null;
    const role: Role = await roleRes.json();
    const permsData = permsRes.ok ? await permsRes.json() : { permissions: [] };
    const allPerms: Permission[] = Array.isArray(permsData) ? permsData : (permsData.permissions || []);
    return { role, allPerms };
  } catch {
    return null;
  }
}

export default function RoleDetailPage() {
  const params = useParams();
  const [data] = createResource(() => params.id, loadRoleDetail);

  const grouped = createMemo(() => {
    if (!data()?.allPerms) return {};
    const map: Record<string, Permission[]> = {};
    (data()!.allPerms).forEach((p) => {
      if (!map[p.module]) map[p.module] = [];
      map[p.module].push(p);
    });
    return map;
  });

  const rolePermIds = createMemo(() => new Set((data()?.role?.permissions || []).map((p) => p.id)));

  const modules = createMemo(() => Object.keys(grouped()).sort());

  return (
    <AdminShell>
      <div class="page-hero-card page-actions">
        <div>
          <h1 class="page-title">Role Details</h1>
          <p class="page-subtitle">View role information and assigned permissions.</p>
        </div>
        <div class="page-actions-right">
          <A class="btn" href="/admin/roles">Back to List</A>
          <Show when={data()?.role}>
            <A class="btn navy" href={`/admin/roles/${params.id}/edit`}>Edit Role</A>
          </Show>
        </div>
      </div>

      <nav class="admin-link-tabs" aria-label="Role Management Navigation">
        <A class="admin-link-tab active" href="/admin/roles">Internal Roles</A>
        <A class="admin-link-tab" href="/admin/runtime-roles">External Runtime Roles</A>
        <A class="admin-link-tab" href="/admin/onboarding-schemas">Onboarding Schemas</A>
      </nav>

      <Show when={data.loading}>
        <div class="card">
          <p class="notice">Loading role details...</p>
        </div>
      </Show>

      <Show when={data.error}>
        <div class="error-box">Failed to load role. Check that the backend is running.</div>
      </Show>

      <Show when={data()?.role}>
        {/* Role Info */}
        <div class="role-detail-card">
          <div class="field-grid-2">
            <div class="field">
              <label>Role Name</label>
              <input class="role-field-readonly" value={data()!.role.name} readOnly disabled />
            </div>
            <div class="field">
              <label>Description</label>
              <input class="role-field-readonly" value={data()!.role.description || '—'} readOnly disabled />
            </div>
          </div>
        </div>

        {/* Permission Matrix */}
        <div class="card" style="padding: 0; overflow: hidden;">
          <div class="table-wrap">
            <table class="perm-table">
              <thead>
                <tr>
                  <th style="width:45%">Name of the module</th>
                  <th style="width:11%">No Access</th>
                  <th style="width:11%">Read</th>
                  <th style="width:11%">Create</th>
                  <th style="width:11%">Update</th>
                  <th style="width:11%">Delete</th>
                </tr>
              </thead>
              <tbody>
                <Show when={modules().length === 0}>
                  <tr>
                    <td colspan="6" style="text-align:center;padding:24px;color:#94a3b8;">No permissions defined.</td>
                  </tr>
                </Show>
                {modules().map((mod) => {
                  const perms = grouped()[mod] || [];
                  const actionMap: Record<string, string> = {};
                  perms.forEach((p) => { actionMap[p.action] = p.id; });
                  const hasRead = !!actionMap['Read'] && rolePermIds().has(actionMap['Read']);
                  const hasCreate = !!actionMap['Create'] && rolePermIds().has(actionMap['Create']);
                  const hasUpdate = !!actionMap['Update'] && rolePermIds().has(actionMap['Update']);
                  const hasDelete = !!actionMap['Delete'] && rolePermIds().has(actionMap['Delete']);
                  const noAccess = !hasRead && !hasCreate && !hasUpdate && !hasDelete;
                  return (
                    <tr>
                      <td style="font-weight:500">{mod}</td>
                      <td><input type="checkbox" checked={noAccess} disabled aria-label={`${mod} no access`} /></td>
                      <td>{actionMap['Read'] ? <input type="checkbox" checked={hasRead} disabled aria-label={`${mod} read`} /> : <span style="color:#cbd5e1">—</span>}</td>
                      <td>{actionMap['Create'] ? <input type="checkbox" checked={hasCreate} disabled aria-label={`${mod} create`} /> : <span style="color:#cbd5e1">—</span>}</td>
                      <td>{actionMap['Update'] ? <input type="checkbox" checked={hasUpdate} disabled aria-label={`${mod} update`} /> : <span style="color:#cbd5e1">—</span>}</td>
                      <td>{actionMap['Delete'] ? <input type="checkbox" checked={hasDelete} disabled aria-label={`${mod} delete`} /> : <span style="color:#cbd5e1">—</span>}</td>
                    </tr>
                  );
                })}
              </tbody>
            </table>
          </div>
        </div>
      </Show>
    </AdminShell>
  );
}