import { useEffect, useMemo } from "react";
import { useSearchParams } from "react-router";
import type {
  AdminSectionContribution,
  AdminSectionsUiCapability,
  ApiSettings,
  AuthInfo,
  AuthUpdate,
  FilesConnectorsUiCapability,
  MailProfilesUiCapability,
  OrganizationFunctionPickerUiCapability
} from "@govoplan/core-webui";
import { fetchShellAuth } from "@govoplan/core-webui";
import { ActionBlockerHint } from "@govoplan/core-webui";
import { PageLayout, WorkspaceLayout } from "@govoplan/core-webui";
import { PageScrollViewport } from "@govoplan/core-webui";
import {
  TreeSubnav,
  type TreeSubnavNode
} from "@govoplan/core-webui";
import { adminReadScopes, hasAnyScope, hasScope } from "@govoplan/core-webui";
import SystemUsersPanel from "./SystemUsersPanel";
import SystemRolesPanel from "./SystemRolesPanel";
import UsersPanel from "./UsersPanel";
import GroupsPanel from "./GroupsPanel";
import RolesPanel from "./RolesPanel";
import ExternalFunctionRoleMappingsPanel from "./ExternalFunctionRoleMappingsPanel";
import ApiKeysPanel from "./ApiKeysPanel";
import ServiceAccountsPanel from "./ServiceAccountsPanel";
import FileConnectorsPanel from "./FileConnectorsPanel";
import MailProfilesPanel from "./MailProfilesPanel";
import CredentialEnvelopesPanel from "./CredentialEnvelopesPanel";
import {
  ACCESS_INTERFACE_I18N,
  ACCESS_WORKFLOW_DOCUMENTATION
} from "./interfacePatterns";
import {
  isViewSurfaceVisible,
  useEffectiveView,
  usePlatformUiCapabilities,
  usePlatformUiCapability,
  useViewSurfaces
} from "@govoplan/core-webui";

type AdminSection = string;
type OrderedAdminNavItem = {
  id: AdminSection;
  label: string;
  order: number;
  moduleId?: string;
  kind?: "management" | "settings";
};
type AdminNavGroup = {
  id: string;
  title: string;
  items: OrderedAdminNavItem[];
};

const handledAdminSectionIds = new Set<string>([
  "overview",
  "system-settings",
  "system-configuration-changes",
  "system-configuration-packages",
  "system-modules",
  "system-roles",
  "system-role-templates",
  "system-groups",
  "system-users",
  "system-file-connectors",
  "system-mail-servers",
  "system-credentials",
  "tenant-roles",
  "tenant-function-role-mappings",
  "tenant-groups",
  "tenant-users",
  "tenant-file-connectors",
  "tenant-mail-servers",
  "tenant-credentials",
  "tenant-api-keys",
  "tenant-service-accounts",
  "tenant-group-file-connectors",
  "tenant-group-mail-servers",
  "tenant-group-credentials",
  "tenant-user-file-connectors",
  "tenant-user-mail-servers",
  "tenant-user-credentials"
]);

const builtInAdminSurfaceIds: Record<string, string> = {
  "system-roles": "access.admin.system-roles",
  "system-users": "access.admin.system-users",
  "system-credentials": "access.admin.system-credentials",
  "tenant-roles": "access.admin.tenant-roles",
  "tenant-function-role-mappings": "access.admin.tenant-function-mappings",
  "tenant-groups": "access.admin.tenant-groups",
  "tenant-users": "access.admin.tenant-users",
  "tenant-credentials": "access.admin.tenant-credentials",
  "tenant-api-keys": "access.admin.tenant-api-keys",
  "tenant-service-accounts": "access.admin.tenant-service-accounts",
  "tenant-group-credentials": "access.admin.group-credentials",
  "tenant-user-credentials": "access.admin.user-credentials",
  "system-mail-servers": "mail.admin.system-servers",
  "tenant-mail-servers": "mail.admin.tenant-servers",
  "tenant-group-mail-servers": "mail.admin.group-servers",
  "tenant-user-mail-servers": "mail.admin.user-servers",
  "tenant-group-file-connectors": "files.admin.group-connectors",
  "tenant-user-file-connectors": "files.admin.user-connectors"
};

const builtInAdminSectionMetadata: Record<
  string,
  Pick<OrderedAdminNavItem, "moduleId" | "kind">
> = {
  "system-settings": { moduleId: "admin", kind: "settings" },
  "system-file-connectors": { moduleId: "files", kind: "settings" },
  "system-mail-servers": { moduleId: "mail", kind: "settings" },
  "system-credentials": { moduleId: "access", kind: "settings" },
  "tenant-file-connectors": { moduleId: "files", kind: "settings" },
  "tenant-mail-servers": { moduleId: "mail", kind: "settings" },
  "tenant-credentials": { moduleId: "access", kind: "settings" },
  "tenant-group-file-connectors": { moduleId: "files", kind: "settings" },
  "tenant-group-mail-servers": { moduleId: "mail", kind: "settings" },
  "tenant-group-credentials": { moduleId: "access", kind: "settings" },
  "tenant-user-file-connectors": { moduleId: "files", kind: "settings" },
  "tenant-user-mail-servers": { moduleId: "mail", kind: "settings" },
  "tenant-user-credentials": { moduleId: "access", kind: "settings" }
};

export default function AdminPage({
  settings,
  auth,
  onAuthChange
}: {
  settings: ApiSettings;
  auth: AuthInfo;
  onAuthChange: (auth: AuthUpdate | null, accessToken?: string) => void;
}) {
  const mailProfilesUi = usePlatformUiCapability<MailProfilesUiCapability>("mail.profiles");
  const fileConnectorsUi = usePlatformUiCapability<FilesConnectorsUiCapability>("files.connectors");
  const organizationFunctionPicker = usePlatformUiCapability<OrganizationFunctionPickerUiCapability>("organizations.functionPicker");
  const adminSectionCapabilities = usePlatformUiCapabilities<AdminSectionsUiCapability>("admin.sections");
  const effectiveView = useEffectiveView();
  const viewSurfaces = useViewSurfaces();
  const mailProfilesAvailable = Boolean(mailProfilesUi);
  const fileConnectorsAvailable = Boolean(fileConnectorsUi);
  const contributedSections = useMemo(
    () =>
      adminSectionCapabilities
        .flatMap((capability) => capability.sections)
        .filter((section) =>
          isViewSurfaceVisible(
            effectiveView,
            section.surfaceId,
            viewSurfaces
          )
        )
        .sort((left, right) => (left.order ?? 100) - (right.order ?? 100)),
    [adminSectionCapabilities, effectiveView, viewSurfaces]
  );
  const contributionById = useMemo(() => {
    const mapped = new Map<string, AdminSectionContribution>();
    for (const section of contributedSections) {
      if (!mapped.has(section.id)) mapped.set(section.id, section);
    }
    return mapped;
  }, [contributedSections]);

  const available = useMemo(() => {
    const sections = new Set<AdminSection>();
    for (const section of contributedSections) {
      if (canUseContributedSection(auth, section)) sections.add(section.id);
    }
    if (hasScope(auth, "system:settings:read")) {
      if (mailProfilesAvailable) sections.add("system-mail-servers");
    }
    if (hasAnyScope(auth, ["system:settings:read", "access:system_credential:read"])) {
      sections.add("system-credentials");
    }
    if (hasAnyScope(auth, ["system:accounts:read", "system:access:read"])) sections.add("system-users");
    if (hasAnyScope(auth, ["system:roles:read", "system:access:read"])) sections.add("system-roles");
    if (hasScope(auth, "admin:users:read")) sections.add("tenant-users");
    if (hasScope(auth, "admin:groups:read")) sections.add("tenant-groups");
    if (hasScope(auth, "admin:roles:read")) sections.add("tenant-roles");
    if (organizationFunctionPicker && hasAnyScope(auth, ["admin:roles:read", "access:function:read", "access:role:read"])) sections.add("tenant-function-role-mappings");
    if (hasScope(auth, "admin:api_keys:read")) sections.add("tenant-api-keys");
    if (hasScope(auth, "access:service_account:read")) sections.add("tenant-service-accounts");
    if (mailProfilesAvailable && hasAnyScope(auth, ["mail_servers:read", "admin:policies:read"])) {
      sections.add("tenant-mail-servers");
      if (hasScope(auth, "admin:users:read")) sections.add("tenant-user-mail-servers");
      if (hasScope(auth, "admin:groups:read")) sections.add("tenant-group-mail-servers");
    }
    if (fileConnectorsAvailable && hasAnyScope(auth, ["files:file:admin", "admin:settings:read"])) {
      if (hasScope(auth, "admin:users:read")) sections.add("tenant-user-file-connectors");
      if (hasScope(auth, "admin:groups:read")) sections.add("tenant-group-file-connectors");
    }
    if (hasAnyScope(auth, ["admin:settings:read", "access:credential:read"])) {
      sections.add("tenant-credentials");
      if (hasScope(auth, "admin:users:read")) sections.add("tenant-user-credentials");
      if (hasScope(auth, "admin:groups:read")) sections.add("tenant-group-credentials");
    }
    return new Set(
      [...sections].filter((sectionId) =>
        isViewSurfaceVisible(
          effectiveView,
          builtInAdminSurfaceIds[sectionId],
          viewSurfaces
        )
      )
    );
  }, [auth, contributedSections, effectiveView, fileConnectorsAvailable, mailProfilesAvailable, organizationFunctionPicker, viewSurfaces]);
  const [searchParams, setSearchParams] = useSearchParams();
  const requestedSection = searchParams.get("section") as AdminSection | null;
  const fallbackSection = available.has("overview") ? "overview" : (Array.from(available)[0] ?? "overview");
  const active: AdminSection = requestedSection && available.has(requestedSection) ? requestedSection : fallbackSection;

  function selectSection(section: AdminSection) {
    const next = new URLSearchParams(searchParams);
    if (section === "overview") next.delete("section");
    else next.set("section", section);
    setSearchParams(next, { replace: true });
  }

  useEffect(() => {
    if (requestedSection && !available.has(requestedSection)) selectSection(fallbackSection);
  }, [requestedSection, available, fallbackSection]);

  async function refreshAuth() {
    onAuthChange(await fetchShellAuth(settings));
  }

  if (!hasAnyScope(auth, adminReadScopes)) {
    return (
      <PageScrollViewport>
        <div className="content-pad">
          <ActionBlockerHint
            tone="warning"
            reason={{
              summary: "i18n:govoplan-access.administration_unavailable.b86d4cb5",
              details: "i18n:govoplan-access.your_current_roles_do_not_grant_administrative_a.6eafee69",
              requiredAction: ACCESS_INTERFACE_I18N.requestAdministrationAccess,
              actor: ACCESS_INTERFACE_I18N.accessAdministrator,
              target: ACCESS_INTERFACE_I18N.accessAdministration
            }}
            labels={{
              requiredAction: ACCESS_INTERFACE_I18N.requiredAction,
              actor: ACCESS_INTERFACE_I18N.actor,
              target: ACCESS_INTERFACE_I18N.destinationLabel
            }}
            documentation={ACCESS_WORKFLOW_DOCUMENTATION}
          />
        </div>
      </PageScrollViewport>
    );
  }

  const adminNavGroups: AdminNavGroup[] = [
    {
      id: "administration",
      title: "i18n:govoplan-access.admin.4e7afebc",
      items: sortNavItems([
          ...contributedNavItems(contributedSections, available, "ROOT"),
          visibleNavItem(available, "system-modules", "i18n:govoplan-access.modules.04e9462c", 10),
          visibleNavItem(available, "system-configuration-packages", "i18n:govoplan-access.packages.0a999012", 20),
          visibleNavItem(available, "system-settings", "i18n:govoplan-access.maintenance.94de303b", 30),
          visibleNavItem(available, "system-configuration-changes", "i18n:govoplan-access.changes.8aa57de6", 40),
          ...contributedNavItems(contributedSections, available, "ADMINISTRATION", handledAdminSectionIds)
        ])
    },
    {
      id: "global",
      title: "i18n:govoplan-access.global",
      items: sortNavItems([
          visibleNavItem(available, "system-roles", "i18n:govoplan-access.system_roles.a9461aa6", 20),
          visibleNavItem(available, "system-role-templates", "i18n:govoplan-access.tenant_role_templates", 30),
          visibleNavItem(available, "system-groups", "i18n:govoplan-access.group_templates", 40),
          visibleNavItem(available, "system-users", "i18n:govoplan-access.users.57f2b181", 50),
          visibleNavItem(available, "system-file-connectors", "i18n:govoplan-access.file_connections.1e362326", 60),
          visibleNavItem(available, "system-mail-servers", "i18n:govoplan-access.mail_servers.d627326a", 70),
          visibleNavItem(available, "system-credentials", "i18n:govoplan-core.credentials.dd097a22", 80),
          ...contributedNavItems(contributedSections, available, "GLOBAL", handledAdminSectionIds),
          ...contributedNavItems(contributedSections, available, "SYSTEM", handledAdminSectionIds)
        ])
    },
    {
      id: "tenant",
      title: "i18n:govoplan-access.tenant.3ca93c78",
      items: sortNavItems([
          visibleNavItem(available, "tenant-roles", "i18n:govoplan-access.roles.47dcc27d", 10),
          visibleNavItem(available, "tenant-function-role-mappings", "i18n:govoplan-access.function_role_mappings.2b64e9c3", 20),
          visibleNavItem(available, "tenant-groups", "i18n:govoplan-access.groups.ae9629f4", 30),
          visibleNavItem(available, "tenant-users", "i18n:govoplan-access.users.57f2b181", 40),
          visibleNavItem(available, "tenant-file-connectors", "i18n:govoplan-access.file_connections.1e362326", 50),
          visibleNavItem(available, "tenant-mail-servers", "i18n:govoplan-access.mail_servers.d627326a", 60),
          visibleNavItem(available, "tenant-credentials", "i18n:govoplan-core.credentials.dd097a22", 70),
          visibleNavItem(available, "tenant-api-keys", "i18n:govoplan-access.api_keys.94fcf3c2", 80),
          visibleNavItem(available, "tenant-service-accounts", "Service accounts", 90),
          ...contributedNavItems(contributedSections, available, "TENANT", handledAdminSectionIds)
        ])
    },
    {
      id: "group",
      title: "i18n:govoplan-access.group.171a0606",
      items: sortNavItems([
          visibleNavItem(available, "tenant-group-file-connectors", "i18n:govoplan-access.file_connections.1e362326", 10),
          visibleNavItem(available, "tenant-group-mail-servers", "i18n:govoplan-access.mail_servers.d627326a", 20),
          visibleNavItem(available, "tenant-group-credentials", "i18n:govoplan-core.credentials.dd097a22", 30),
          ...contributedNavItems(contributedSections, available, "GROUP", handledAdminSectionIds)
        ])
    },
    {
      id: "user",
      title: "i18n:govoplan-access.user.9f8a2389",
      items: sortNavItems([
          visibleNavItem(available, "tenant-user-file-connectors", "i18n:govoplan-access.file_connections.1e362326", 10),
          visibleNavItem(available, "tenant-user-mail-servers", "i18n:govoplan-access.mail_servers.d627326a", 20),
          visibleNavItem(available, "tenant-user-credentials", "i18n:govoplan-core.credentials.dd097a22", 30),
          ...contributedNavItems(contributedSections, available, "USER", handledAdminSectionIds)
        ])
    }
  ].filter((group) => group.items.length > 0);
  const adminTree = adminNavigationTree(adminNavGroups);
  const contributedSection = contributionById.get(active);
  const contributionContext = { settings, auth, onAuthChange, refreshAuth, availableSections: available, selectSection };

  return (
    <WorkspaceLayout
      className="module-workspace"
      primary={(
        <TreeSubnav
          active={active}
          nodes={adminTree}
          onSelect={selectSection}
          ariaLabel="i18n:govoplan-access.admin.4e7afebc"
        />
      )}
      primaryLabel="i18n:govoplan-access.admin.4e7afebc"
      contentLabel="i18n:govoplan-access.admin.4e7afebc"
      documentationType="admin"
    >
      <PageLayout
        archetype="workspace"
        title="i18n:govoplan-access.admin.4e7afebc"
        mode="workspace"
        showHeader={false}
        documentationType="admin"
      >
          {contributedSection && contributedSection.render(contributionContext)}
          {!contributedSection && active === "system-mail-servers" && (
            <MailProfilesPanel settings={settings} scopeType="system" canWriteProfiles={hasScope(auth, "system:settings:write")} canManageCredentials={hasScope(auth, "system:settings:write")} canWritePolicy={hasScope(auth, "system:settings:write")} />
          )}
          {!contributedSection && active === "system-credentials" && (
            <CredentialEnvelopesPanel
              settings={settings}
              scopeType="system"
              canWrite={hasAnyScope(auth, ["system:settings:write", "access:system_credential:write"])}
            />
          )}
          {!contributedSection && active === "system-users" && (
            <SystemUsersPanel
              settings={settings}
              canCreate={hasScope(auth, "system:accounts:create")}
              canUpdate={hasScope(auth, "system:accounts:update")}
              canSuspend={hasScope(auth, "system:accounts:suspend")}
              canAssignRoles={hasAnyScope(auth, ["system:roles:assign", "system:access:assign"])}
              canManageMemberships={hasScope(auth, "system:accounts:update") && hasScope(auth, "system:access:assign")}
              onAuthRefresh={refreshAuth}
            />
          )}
          {!contributedSection && active === "system-roles" && <SystemRolesPanel settings={settings} canWrite={hasScope(auth, "system:roles:write")} onAuthRefresh={refreshAuth} />}
          {!contributedSection && active === "tenant-users" && <UsersPanel settings={settings} auth={auth} canCreate={hasScope(auth, "admin:users:create")} canUpdate={hasScope(auth, "admin:users:update")} canSuspend={hasScope(auth, "admin:users:suspend")} canManageGroups={hasScope(auth, "admin:groups:manage_members")} canAssignRoles={hasScope(auth, "admin:roles:assign")} canRevokeSessions={hasAnyScope(auth, ["admin:users:update", "access:membership:update"])} onAuthRefresh={refreshAuth} />}
          {!contributedSection && active === "tenant-groups" && <GroupsPanel settings={settings} auth={auth} canDefine={hasScope(auth, "admin:groups:write")} canManageMembers={hasScope(auth, "admin:groups:manage_members")} canAssignRoles={hasScope(auth, "admin:roles:assign")} onAuthRefresh={refreshAuth} />}
          {!contributedSection && active === "tenant-roles" && <RolesPanel settings={settings} auth={auth} canDefine={hasScope(auth, "admin:roles:write")} onAuthRefresh={refreshAuth} />}
          {!contributedSection && active === "tenant-function-role-mappings" && organizationFunctionPicker && <ExternalFunctionRoleMappingsPanel settings={settings} auth={auth} functionPicker={organizationFunctionPicker} canWrite={hasAnyScope(auth, ["admin:roles:write", "access:function:write", "access:role:assign"])} onAuthRefresh={refreshAuth} />}
          {!contributedSection && active === "tenant-api-keys" && <ApiKeysPanel settings={settings} auth={auth} canCreate={hasScope(auth, "admin:api_keys:create")} canRevoke={hasScope(auth, "admin:api_keys:revoke")} />}
          {!contributedSection && active === "tenant-service-accounts" && <ServiceAccountsPanel settings={settings} auth={auth} canWrite={hasScope(auth, "access:service_account:write")} />}
          {!contributedSection && active === "tenant-mail-servers" && <MailProfilesPanel settings={settings} scopeType="tenant" canWriteProfiles={hasScope(auth, "mail_servers:write")} canManageCredentials={hasScope(auth, "mail_servers:manage_credentials")} canWritePolicy={hasScope(auth, "admin:policies:write")} />}
          {!contributedSection && active === "tenant-credentials" && <CredentialEnvelopesPanel settings={settings} scopeType="tenant" canWrite={hasAnyScope(auth, ["admin:settings:write", "access:credential:write"])} />}
          {!contributedSection && active === "tenant-user-mail-servers" && <MailProfilesPanel settings={settings} scopeType="user" canWriteProfiles={hasScope(auth, "mail_servers:write")} canManageCredentials={hasScope(auth, "mail_servers:manage_credentials")} canWritePolicy={hasAnyScope(auth, ["admin:policies:write", "mail_servers:write"])} />}
          {!contributedSection && active === "tenant-group-mail-servers" && <MailProfilesPanel settings={settings} scopeType="group" canWriteProfiles={hasScope(auth, "mail_servers:write")} canManageCredentials={hasScope(auth, "mail_servers:manage_credentials")} canWritePolicy={hasAnyScope(auth, ["admin:policies:write", "mail_servers:write"])} />}
          {!contributedSection && active === "tenant-user-credentials" && <CredentialEnvelopesPanel settings={settings} scopeType="user" canWrite={hasAnyScope(auth, ["admin:settings:write", "access:credential:write"])} />}
          {!contributedSection && active === "tenant-group-credentials" && <CredentialEnvelopesPanel settings={settings} scopeType="group" canWrite={hasAnyScope(auth, ["admin:settings:write", "access:credential:write"])} />}
          {!contributedSection && active === "tenant-user-file-connectors" && <FileConnectorsPanel settings={settings} scopeType="user" canWrite={hasAnyScope(auth, ["files:file:admin", "admin:settings:write"])} />}
          {!contributedSection && active === "tenant-group-file-connectors" && <FileConnectorsPanel settings={settings} scopeType="group" canWrite={hasAnyScope(auth, ["files:file:admin", "admin:settings:write"])} />}
      </PageLayout>
    </WorkspaceLayout>
  );
}

function canUseContributedSection(auth: AuthInfo, section: AdminSectionContribution): boolean {
  if (section.allOf?.length && !section.allOf.every((scope) => hasScope(auth, scope))) return false;
  if (section.anyOf?.length && !hasAnyScope(auth, section.anyOf)) return false;
  return true;
}

function contributedNavItems(
  sections: AdminSectionContribution[],
  available: ReadonlySet<string>,
  group: string,
  excludedIds: ReadonlySet<string> = new Set()
): OrderedAdminNavItem[] {
  return sections
    .filter((section) => (section.group ?? "SYSTEM") === group && available.has(section.id) && !excludedIds.has(section.id))
    .map((section) => ({
      id: section.id,
      label: section.label,
      order: section.order ?? 100,
      moduleId: section.moduleId,
      kind: section.kind
    }));
}

function visibleNavItem(available: ReadonlySet<string>, id: AdminSection, label: string, order: number): OrderedAdminNavItem | null {
  return available.has(id)
    ? { id, label, order, ...builtInAdminSectionMetadata[id] }
    : null;
}

function sortNavItems(items: Array<OrderedAdminNavItem | null>): OrderedAdminNavItem[] {
  return items.filter((item): item is OrderedAdminNavItem => item !== null).sort((left, right) => left.order - right.order);
}

function adminNavigationTree(
  groups: AdminNavGroup[]
): TreeSubnavNode<AdminSection>[] {
  return groups.map((group) => {
    const managementItems = group.items.filter(
      (item) => item.kind !== "settings"
    );
    const settingsItems = group.items.filter(
      (item) => item.kind === "settings"
    );
    const children: TreeSubnavNode<AdminSection>[] = managementItems.map(
      ({ id, label }) => ({ id, label })
    );
    if (settingsItems.length > 0) {
      const byModule = new Map<string, OrderedAdminNavItem[]>();
      for (const item of settingsItems) {
        const moduleId = item.moduleId ?? "platform";
        byModule.set(moduleId, [...(byModule.get(moduleId) ?? []), item]);
      }
      children.push({
        branchId: `admin-${group.id}-settings`,
        label: "i18n:govoplan-core.settings.c7f73bb5",
        defaultExpanded: false,
        children: [...byModule.entries()]
          .sort(([left], [right]) => left.localeCompare(right))
          .map(([moduleId, items]) => ({
            branchId: `admin-${group.id}-settings-${moduleId}`,
            label: moduleLabel(moduleId),
            defaultExpanded: items.some(
              (item) => item.id === "system-settings"
            ),
            children: items.map(({ id, label }) => ({ id, label }))
          }))
      });
    }
    return {
      branchId: `admin-${group.id}`,
      label: group.title,
      defaultExpanded: group.id === "administration",
      children
    };
  });
}

function moduleLabel(moduleId: string): string {
  if (moduleId === "platform") return "i18n:govoplan-access.platform_administration";
  if (moduleId === "access") return "i18n:govoplan-access.access.2f81a22d";
  if (moduleId === "admin") return "i18n:govoplan-access.admin.4e7afebc";
  if (moduleId === "files") return "i18n:govoplan-access.files.6ce6c512";
  if (moduleId === "mail") return "i18n:govoplan-access.mail_servers.d627326a";
  return moduleId
    .split(/[-_]/)
    .filter(Boolean)
    .map((part) => part[0].toUpperCase() + part.slice(1))
    .join(" ");
}