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

const API = '/api/gateway';

type Permission = { id: string; module: string; action: string };

async function loadPermissions(): Promise<Permission[]> {
  const res = await fetch(`${API}/api/admin/permissions`);
  if (!res.ok) return [];
  const data = await res.json();
  const rows = Array.isArray(data) ? data : (data.permissions || []);
  return rows;
}

export default function CreateInternalRolePage() {
  const navigate = useNavigate();
  const [permissions] = createResource(loadPermissions);

  const [roleName, setRoleName] = createSignal('');
  const [description, setDescription] = createSignal('');
  const [assignedModules, setAssignedModules] = createSignal<string[]>([]);
  const [permissionIds, setPermissionIds] = createSignal<string[]>([]);
  const [saving, setSaving] = createSignal(false);
  const [error, setError] = createSignal('');

  const permsByModule = createMemo(() => {
    const map: Record<string, Permission[]> = {};
    (permissions() || []).forEach((p) => {
      if (!map[p.module]) map[p.module] = [];
      map[p.module].push(p);
    });
    return map;
  });

  const allModules = createMemo(() => Object.keys(permsByModule()).sort());

  const toggleModule = (mod: string) => {
    const current = assignedModules();
    if (current.includes(mod)) {
      setAssignedModules(current.filter((m) => m !== mod));
      // remove permissions for this module
      const idsToRemove = (permsByModule()[mod] || []).map((p) => p.id);
      setPermissionIds(permissionIds().filter((id) => !idsToRemove.includes(id)));
    } else {
      setAssignedModules([...current, mod]);
    }
  };

  const togglePermission = (id: string) => {
    const current = permissionIds();
    if (current.includes(id)) {
      setPermissionIds(current.filter((p) => p !== id));
    } else {
      setPermissionIds([...current, id]);
    }
  };

  const handleSave = async () => {
    if (!roleName().trim()) { setError('Role name is required'); return; }
    if (assignedModules().length === 0) { setError('Select at least one module'); return; }
    if (permissionIds().length === 0) { setError('Assign at least one permission'); return; }

    try {
      setSaving(true);
      setError('');
      const res = await fetch(`${API}/api/admin/roles`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          name: roleName().trim(),
          description: description().trim(),
          audience: 'INTERNAL',
          modules: assignedModules(),
          permissionIds: permissionIds(),
        }),
      });
      if (!res.ok) {
        const body = await res.json().catch(() => ({}));
        throw new Error(body.message || 'Failed to create role');
      }
      navigate('/admin/roles');
    } catch (err: any) {
      setError(err.message || 'Failed to create role');
    } finally {
      setSaving(false);
    }
  };

  return (
    <AdminShell>
      <div class="page-actions">
        <div>
          <h1 class="page-title">Create Internal Role</h1>
          <p class="page-subtitle">Add a new internal role with module access and permissions.</p>
        </div>
        <a class="btn" href="/admin/roles">Back to Roles</a>
      </div>

      <Show when={error()}>
        <div class="error-box">{error()}</div>
      </Show>

      {/* Role Details */}
      <div class="role-form-section">
        <h3>Role Details</h3>
        <p>Start by giving the role a simple business name.</p>
        <div class="field-grid-2">
          <div class="field">
            <label>Name of the Role <span style="color:#ef4444">*</span></label>
            <input
              value={roleName()}
              onInput={(e) => setRoleName(e.currentTarget.value)}
              placeholder="e.g. Customer Support Rep"
            />
          </div>
          <div class="field">
            <label>Description</label>
            <input
              value={description()}
              onInput={(e) => setDescription(e.currentTarget.value)}
              placeholder="Short description of this role"
            />
          </div>
        </div>
      </div>

      {/* Module Access */}
      <div class="role-form-section">
        <h3>Module Access</h3>
        <p>Select which modules this role can access. Only selected modules will appear in the permission table below.</p>
        <Show when={permissions.loading}>
          <p class="notice">Loading modules...</p>
        </Show>
        <Show when={!permissions.loading && allModules().length > 0}>
          <div class="module-picker">
            {allModules().map((mod) => (
              <button
                type="button"
                class={`module-chip ${assignedModules().includes(mod) ? 'selected' : ''}`}
                onClick={() => toggleModule(mod)}
              >
                <span style={`width:14px;height:14px;border-radius:3px;border:2px solid ${assignedModules().includes(mod) ? '#c2410c' : '#cbd5e1'};background:${assignedModules().includes(mod) ? '#c2410c' : '#fff'};flex-shrink:0;display:inline-block`} />
                {mod}
              </button>
            ))}
          </div>
        </Show>
        <Show when={!permissions.loading && allModules().length === 0}>
          <p class="notice">No modules available. Is the backend running?</p>
        </Show>
      </div>

      {/* Permission Table */}
      <Show when={assignedModules().length > 0}>
        <div class="role-form-section">
          <h3>Permissions</h3>
          <p>Set Read / Create / Update / Delete access for each assigned module.</p>
          <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>
                {assignedModules().sort().map((mod) => {
                  const perms = permsByModule()[mod] || [];
                  const actionMap: Record<string, string> = {};
                  perms.forEach((p) => { actionMap[p.action] = p.id; });
                  const hasRead = !!actionMap['Read'] && permissionIds().includes(actionMap['Read']);
                  const hasCreate = !!actionMap['Create'] && permissionIds().includes(actionMap['Create']);
                  const hasUpdate = !!actionMap['Update'] && permissionIds().includes(actionMap['Update']);
                  const hasDelete = !!actionMap['Delete'] && permissionIds().includes(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={`${mod} no access`} /></td>
                      <td>{actionMap['Read'] ? <input type="checkbox" checked={hasRead} onChange={() => togglePermission(actionMap['Read'])} aria-label={`${mod} read`} /> : <span style="color:#cbd5e1">—</span>}</td>
                      <td>{actionMap['Create'] ? <input type="checkbox" checked={hasCreate} onChange={() => togglePermission(actionMap['Create'])} aria-label={`${mod} create`} /> : <span style="color:#cbd5e1">—</span>}</td>
                      <td>{actionMap['Update'] ? <input type="checkbox" checked={hasUpdate} onChange={() => togglePermission(actionMap['Update'])} aria-label={`${mod} update`} /> : <span style="color:#cbd5e1">—</span>}</td>
                      <td>{actionMap['Delete'] ? <input type="checkbox" checked={hasDelete} onChange={() => togglePermission(actionMap['Delete'])} aria-label={`${mod} delete`} /> : <span style="color:#cbd5e1">—</span>}</td>
                    </tr>
                  );
                })}
              </tbody>
            </table>
          </div>
        </div>
      </Show>

      {/* Save */}
      <div style="display:flex;justify-content:flex-end;margin-top:8px">
        <button
          class="btn navy"
          onClick={handleSave}
          disabled={saving() || !roleName().trim()}
        >
          {saving() ? 'Creating...' : 'Create Role'}
        </button>
      </div>
    </AdminShell>
  );
}