import { useEffect, useMemo, useRef, useState } from "react";
import { Pencil, Plus, Search, Trash2 } from "lucide-react";
import type { ApiSettings, AuthInfo } from "@govoplan/core-webui";
import { createRole, deleteRole, fetchPermissionCatalog, fetchRolesDelta, updateRole, type PermissionItem, type RoleSummary } from "../../api/admin";
import { Button } from "@govoplan/core-webui";
import { DataGrid, type DataGridColumn } from "@govoplan/core-webui";
import { Dialog } from "@govoplan/core-webui";
import { FormField } from "@govoplan/core-webui";
import { StatusBadge } from "@govoplan/core-webui";
import { ConfirmDialog } from "@govoplan/core-webui";
import { AdminIconButton, AdminPageLayout, adminErrorMessage } from "@govoplan/core-webui";
import { hasTenantWildcard, i18nMessage, useDeltaWatermarks, useUnsavedDraftGuard } from "@govoplan/core-webui";
import { loadDeltaRows } from "./utils/deltaRows";

const emptyDraft = { slug: "", name: "", description: "", permissions: [] as string[], isAssignable: true };

export default function RolesPanel({ settings, auth, canDefine, onAuthRefresh }: {settings: ApiSettings;auth: AuthInfo;canDefine: boolean;onAuthRefresh: () => Promise<void>;}) {
  const [roles, setRoles] = useState<RoleSummary[]>([]);
  const [permissions, setPermissions] = useState<PermissionItem[]>([]);
  const rolesRef = useRef<RoleSummary[]>([]);
  const { getDeltaWatermark, setDeltaWatermark, resetDeltaWatermark } = useDeltaWatermarks();
  const [editing, setEditing] = useState<RoleSummary | "new" | null>(null);
  const [viewing, setViewing] = useState<RoleSummary | null>(null);
  const [draft, setDraft] = useState(emptyDraft);
  const [savedDraftKey, setSavedDraftKey] = useState(draftKey(emptyDraft));
  const [deleting, setDeleting] = useState<RoleSummary | null>(null);
  const [loading, setLoading] = useState(true);
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState("");
  const [success, setSuccess] = useState("");
  const dirty = editing !== null && draftKey(draft) !== savedDraftKey;

  useUnsavedDraftGuard({
    dirty,
    onSave: save,
    onDiscard: closeEditor
  });

  async function load() {
    setLoading(true);
    setError("");
    try {
      const [nextRoles, nextPermissions] = await Promise.all([
      loadDeltaRows(rolesRef.current, "access:roles", getDeltaWatermark, setDeltaWatermark, (since) => fetchRolesDelta(settings, { since }), (response) => response.roles, (role) => role.id, "access_role", sortTenantRoles),
      fetchPermissionCatalog(settings)]
      );
      rolesRef.current = nextRoles;
      setRoles(nextRoles);
      setPermissions(nextPermissions.filter((permission) => permission.level === "tenant"));
    } catch (err) {setError(adminErrorMessage(err));} finally
    {setLoading(false);}
  }

  useEffect(() => {
    rolesRef.current = [];
    resetDeltaWatermark();
    void load();
  }, [settings.accessToken, settings.apiBaseUrl, (auth.active_tenant ?? auth.tenant).id, resetDeltaWatermark]);

  const permissionGroups = useMemo(() => {
    const groups = new Map<string, PermissionItem[]>();
    for (const permission of permissions) groups.set(permission.category, [...(groups.get(permission.category) ?? []), permission]);
    return Array.from(groups.entries());
  }, [permissions]);

  function openCreate() {setDraft(emptyDraft);setSavedDraftKey(draftKey(emptyDraft));setEditing("new");setError("");}
  function openEdit(role: RoleSummary) {
    if (role.is_builtin || role.system_template_id) return;
    const nextDraft = { slug: role.slug, name: role.name, description: role.description || "", permissions: hasTenantWildcard(role.permissions) ? permissions.map((permission) => permission.scope) : role.permissions, isAssignable: role.is_assignable };
    setDraft(nextDraft);
    setSavedDraftKey(draftKey(nextDraft));
    setEditing(role);
    setError("");
  }

  function closeEditor() {
    setEditing(null);
    setDraft(emptyDraft);
    setSavedDraftKey(draftKey(emptyDraft));
  }
  function togglePermission(scope: string, checked: boolean) {
    const next = new Set(draft.permissions);
    if (checked) next.add(scope);else next.delete(scope);
    setDraft({ ...draft, permissions: Array.from(next) });
  }

  async function save(): Promise<boolean> {
    setBusy(true);
    setError("");
    try {
      if (editing === "new") {
        await createRole(settings, { slug: draft.slug, name: draft.name, description: draft.description || null, permissions: draft.permissions });
        setSuccess(i18nMessage("i18n:govoplan-access.role_value_created.2a964899", { value0: draft.name }));
      } else if (editing) {
        await updateRole(settings, editing.id, { name: draft.name, description: draft.description || null, permissions: draft.permissions, is_assignable: draft.isAssignable });
        setSuccess(i18nMessage("i18n:govoplan-access.role_value_updated.ec386eb0", { value0: draft.name }));
      }
      setEditing(null);
      await onAuthRefresh();
      await load();
      return true;
    } catch (err) {setError(adminErrorMessage(err));return false;} finally
    {setBusy(false);}
  }

  async function remove() {
    if (!deleting) return;
    setBusy(true);
    setError("");
    try {
      await deleteRole(settings, deleting.id);
      setSuccess(i18nMessage("i18n:govoplan-access.role_value_deleted.3bd819cf", { value0: deleting.name }));
      setDeleting(null);
      await onAuthRefresh();
      await load();
    } catch (err) {setError(adminErrorMessage(err));} finally
    {setBusy(false);}
  }

  const columns = useMemo<DataGridColumn<RoleSummary>[]>(() => [
  { id: "role", header: "i18n:govoplan-access.role.c3f104d1", width: "minmax(220px, 1fr)", minWidth: 190, resizable: true, sticky: "start", sortable: true, filterable: true, value: (row) => `${row.name} ${row.slug}`, render: (row) => <div><strong>{row.name}</strong><div className="muted small-note">{row.slug} {row.system_template_id && <span className="admin-managed-badge">i18n:govoplan-access.system.bc0792d8{row.system_required ? "i18n:govoplan-access.required.7c65879a" : ""}</span>}</div></div> },
  { id: "permissions", header: "i18n:govoplan-access.permissions.d06d5557", width: 170, resizable: false, sortable: true, filterable: true, filterType: "integer", value: (row) => row.effective_permission_count, render: (row) => hasTenantWildcard(row.permissions) ? `${row.effective_permission_count} (tenant:*)` : String(row.effective_permission_count) },
  { id: "assignments", header: "i18n:govoplan-access.assignments.057d58c7", width: 220, minWidth: 170, maxWidth: 420, resizable: true, fill: true, sortable: true, value: (row) => row.user_assignments + row.group_assignments, render: (row) => `${row.user_assignments} users / ${row.group_assignments} groups` },
  { id: "type", header: "i18n:govoplan-access.type.3deb7456", width: 140, resizable: false, sortable: true, filterable: true, value: (row) => row.is_builtin ? "built-in" : row.system_template_id ? "system-managed" : "custom", render: (row) => <StatusBadge status={row.is_builtin ? "built" : "active"} label={row.is_builtin ? "i18n:govoplan-access.built_in.20f409cc" : row.system_template_id ? "i18n:govoplan-access.system.bc0792d8" : "i18n:govoplan-access.custom.081ae3fd"} /> },
  { id: "actions", header: "i18n:govoplan-access.actions.c3cd636a", width: 150, sticky: "end", resizable: false, align: "right", render: (row) => <div className="admin-icon-actions">
      <AdminIconButton label={i18nMessage("i18n:govoplan-access.inspect_value.9d5d1071", { value0: row.name })} icon={<Search />} onClick={() => setViewing(row)} />
      <AdminIconButton label={i18nMessage("i18n:govoplan-access.edit_value.fad75899", { value0: row.name })} icon={<Pencil />} onClick={() => openEdit(row)} disabled={!canDefine || row.is_builtin || Boolean(row.system_template_id)} />
      <AdminIconButton label={i18nMessage("i18n:govoplan-access.delete_value.4d18989e", { value0: row.name })} icon={<Trash2 />} variant="danger" onClick={() => setDeleting(row)} disabled={!canDefine || row.is_builtin || Boolean(row.system_template_id) || row.user_assignments + row.group_assignments > 0} />
    </div> }],
  [canDefine, permissions]);

  return (
    <>
      <AdminPageLayout title="i18n:govoplan-access.tenant_roles.51aca82d" description="i18n:govoplan-access.roles_are_explicit_tenant_permission_bundles_bui.ce55fcaa" loading={loading} error={error} success={success} actions={<><Button onClick={() => void load()} disabled={loading}>i18n:govoplan-access.reload.cce71553</Button><AdminIconButton label="i18n:govoplan-access.add_role.d8d5d55c" icon={<Plus />} variant="primary" onClick={openCreate} disabled={!canDefine} /></>}>
        <div className="admin-table-surface"><DataGrid id="admin-roles-v3" rows={roles} columns={columns} initialFit="container" getRowKey={(row) => row.id} emptyText="i18n:govoplan-access.no_roles_found.70f7c0c9" /></div>
      </AdminPageLayout>

      <Dialog open={editing !== null} title={editing === "new" ? "i18n:govoplan-access.create_role.db859bad" : "i18n:govoplan-access.edit_role.61dd63e9"} onClose={() => !busy && setEditing(null)} className="admin-dialog admin-dialog-wide" footer={<><Button onClick={() => setEditing(null)} disabled={busy}>i18n:govoplan-access.cancel.77dfd213</Button><Button variant="primary" onClick={() => void save()} disabled={!canDefine || busy || !draft.name.trim() || !draft.slug.trim()}>{busy ? "i18n:govoplan-access.saving.56a2285c" : "i18n:govoplan-access.save_role.16fe10d1"}</Button></>}>
        <div className="admin-form-grid two-columns">
          <FormField label="i18n:govoplan-access.name.709a2322"><input value={draft.name} onChange={(event) => setDraft({ ...draft, name: event.target.value })} /></FormField>
          <FormField label="i18n:govoplan-access.slug.094da9b9"><input value={draft.slug} disabled={editing !== "new"} onChange={(event) => setDraft({ ...draft, slug: event.target.value })} /></FormField>
          <FormField label="i18n:govoplan-access.description.55f8ebc8"><textarea rows={3} value={draft.description} onChange={(event) => setDraft({ ...draft, description: event.target.value })} /></FormField>
          {editing !== "new" && <FormField label="i18n:govoplan-access.assignable.a88debc5"><select value={draft.isAssignable ? "yes" : "no"} onChange={(event) => setDraft({ ...draft, isAssignable: event.target.value === "yes" })}><option value="yes">i18n:govoplan-access.yes.5397e058</option><option value="no">i18n:govoplan-access.no.816c52fd</option></select></FormField>}
        </div>
        <div className="admin-permission-groups">{permissionGroups.map(([category, items]) => <fieldset key={category} className="admin-permission-group"><legend>{category}</legend>{items.map((permission) => <label key={permission.scope} className="admin-selection-item"><input type="checkbox" checked={draft.permissions.includes(permission.scope)} onChange={(event) => togglePermission(permission.scope, event.target.checked)} /><span><strong>{permission.label}</strong><small>{permission.description}<code>{permission.scope}</code></small></span></label>)}</fieldset>)}</div>
      </Dialog>

      <Dialog open={Boolean(viewing)} title="i18n:govoplan-access.role_details.a16b5d9f" onClose={() => setViewing(null)} className="admin-dialog admin-dialog-wide" footer={<Button onClick={() => setViewing(null)}>i18n:govoplan-access.close.bbfa773e</Button>}>
        {viewing && <><dl className="admin-details-grid">
          <div><dt>i18n:govoplan-access.role.c3f104d1</dt><dd>{viewing.name}</dd></div><div><dt>i18n:govoplan-access.slug.094da9b9</dt><dd>{viewing.slug}</dd></div>
          <div><dt>i18n:govoplan-access.type.3deb7456</dt><dd>{viewing.is_builtin ? "i18n:govoplan-access.built_in.20f409cc" : viewing.system_template_id ? i18nMessage("i18n:govoplan-access.system_managed_value.eb564eb1", { value0: viewing.system_required ? "i18n:govoplan-access.required.2e5396fd" : "i18n:govoplan-access.available.ce372771" }) : "i18n:govoplan-access.tenant_custom.4307081e"}</dd></div><div><dt>i18n:govoplan-access.assignable.a88debc5</dt><dd>{viewing.is_assignable ? "i18n:govoplan-access.yes.5397e058" : "i18n:govoplan-access.no.816c52fd"}</dd></div>
          <div><dt>i18n:govoplan-access.user_assignments.bc7cc801</dt><dd>{viewing.user_assignments}</dd></div><div><dt>i18n:govoplan-access.group_assignments.e534bb56</dt><dd>{viewing.group_assignments}</dd></div>
        </dl><h3>i18n:govoplan-access.permissions.d06d5557</h3><div className="admin-scope-list">{viewing.permissions.map((scope) => <code key={scope}>{scope}</code>)}</div></>}
      </Dialog>

      <ConfirmDialog open={Boolean(deleting)} title="i18n:govoplan-access.delete_role.fbf0667e" message={i18nMessage("i18n:govoplan-access.delete_value_only_unassigned_tenant_defined_role.e48b13e7", { value0: deleting?.name })} confirmLabel="i18n:govoplan-access.delete_role.fbf0667e" tone="danger" busy={busy} onCancel={() => setDeleting(null)} onConfirm={() => void remove()} />
    </>);

}

function draftKey(draft: typeof emptyDraft): string {
  return JSON.stringify(draft);
}

function sortTenantRoles(left: RoleSummary, right: RoleSummary): number {
  const builtinDelta = Number(right.is_builtin) - Number(left.is_builtin);
  if (builtinDelta !== 0) return builtinDelta;
  return left.name.localeCompare(right.name);
}