import { CHAT_PERMISSIONS } from "@hivegrid/chat";
import { loadChatChannelSettings, type ChatChannelSettingsRecord } from "@hivegrid/chat/channel-settings.server";
import {
  archiveChatChannel as archiveManagedChatChannel,
  leaveGroupChat,
  removeChatChannelMember as removeManagedChatChannelMember,
  setChatChannelMember,
  setGroupChatPrivacy,
} from "@hivegrid/chat/lifecycle.server";
import { buildChatChannelSettingsVM, type ChatChannelSettingsVM } from "@hivegrid/view-models";

import { withTenantRLS } from "~/utils/db/.server/tenantRls.server";
import { projectDetailPath } from "~/utils/integrations/projects/projectRoutePaths";

import { requireChatPermission, type ChatRouteContext } from "../routes/chatAccess.server";

export type ChatChannelSettingsLabels = Readonly<{
  directMessage: string;
  unnamedGroup: string;
  unnamedProject: string;
  unknownProjectStage: string;
}>;

export async function loadChatChannelSettingsPage(input: {
  readonly context: ChatRouteContext;
  readonly tenantSlug: string;
  readonly chatId: string;
  readonly labels: ChatChannelSettingsLabels;
}): Promise<ChatChannelSettingsVM> {
  const context = requireChatPermission(input.context, CHAT_PERMISSIONS.readOwnChannels);
  const record = await loadChatChannelSettings({
    tenantId: context.tenantId,
    userId: context.userId,
    permissions: context.permissions,
    chatId: input.chatId,
  });
  const project = record.channel.projectId
    ? await loadProjectSummary(context.tenantId, input.tenantSlug, record.channel.projectId, input.labels)
    : null;

  return buildChatChannelSettingsVM({
    currentUserId: context.userId,
    channel: {
      id: record.channel.id,
      kind: record.channel.kind,
      title: channelTitle(record, context.userId, project?.label ?? null, input.labels),
      description: record.channel.description,
      isPrivate: record.channel.privacy !== "public",
      isArchived: record.channel.archivedAtIso !== null,
      project,
    },
    members: record.members.map((member) => ({
      user: profileInput(member),
      role: member.roleInChat,
      isProjectManaged: member.provenance.isProjectManaged,
      isManualGuest: member.provenance.isManualMember,
      manualRole: member.provenance.manualRoleInChat,
    })),
    tenantUsers: record.candidateUsers.map(profileInput),
    permissions: {
      canManageMembers: record.capabilities.canManageMembers,
      canManageAdmins: record.capabilities.canManageAdmins,
      canChangePrivacy: record.capabilities.canChangePrivacy,
      canLeave: record.capabilities.canLeave,
      canManageManualGuests: record.capabilities.canManageManualGuests,
      canArchive: record.capabilities.canArchive,
    },
  });
}

export async function addChatChannelMember(input: MutationInput & { readonly memberUserId: string }): Promise<void> {
  await setChatChannelMember({ ...repositoryContext(input.context), chatId: input.chatId, requestId: input.requestId, memberUserId: input.memberUserId, roleInChat: "member" });
}

export async function changeChatChannelMemberRole(
  input: MutationInput & { readonly memberUserId: string; readonly roleInChat: "admin" | "member" }
): Promise<void> {
  await setChatChannelMember({
    ...repositoryContext(input.context),
    chatId: input.chatId,
    requestId: input.requestId,
    memberUserId: input.memberUserId,
    roleInChat: input.roleInChat,
  });
}

export async function removeChatChannelMember(input: MutationInput & { readonly memberUserId: string }): Promise<void> {
  await removeManagedChatChannelMember({
    ...repositoryContext(input.context),
    chatId: input.chatId,
    requestId: input.requestId,
    memberUserId: input.memberUserId,
  });
}

export async function changeChatChannelPrivacy(input: MutationInput & { readonly privacy: "public" | "private" }): Promise<void> {
  await setGroupChatPrivacy({
    ...repositoryContext(input.context),
    chatId: input.chatId,
    requestId: input.requestId,
    isPrivate: input.privacy === "private",
  });
}

export async function leaveChatChannel(input: MutationInput): Promise<void> {
  await leaveGroupChat({ ...repositoryContext(input.context), chatId: input.chatId, requestId: input.requestId });
}

export async function archiveChatChannel(input: MutationInput): Promise<void> {
  await archiveManagedChatChannel({ ...repositoryContext(input.context), chatId: input.chatId, requestId: input.requestId });
}

type MutationInput = Readonly<{
  context: ChatRouteContext;
  chatId: string;
  requestId: string;
}>;

function repositoryContext(context: ChatRouteContext) {
  return { tenantId: context.tenantId, userId: context.userId, permissions: context.permissions };
}

function profileInput(profile: {
  readonly userId: string;
  readonly displayName: string;
  readonly email: string;
  readonly avatarUrl: string | null;
}) {
  return {
    userId: profile.userId,
    displayName: profile.displayName,
    email: profile.email,
    avatar: {
      imageUrl: profile.avatarUrl,
      fallbackLabel: fallbackLabel(profile.displayName, profile.email),
    },
  };
}

function fallbackLabel(displayName: string, email: string): string {
  const initials = displayName
    .split(/\s+/u)
    .filter(Boolean)
    .slice(0, 2)
    .map((part) => part.slice(0, 1))
    .join("")
    .toLocaleUpperCase();
  return initials || email.slice(0, 1).toLocaleUpperCase() || "?";
}

function channelTitle(
  record: ChatChannelSettingsRecord,
  currentUserId: string,
  projectLabel: string | null,
  labels: ChatChannelSettingsLabels
): string {
  if (record.channel.kind === "group") return record.channel.name ?? labels.unnamedGroup;
  if (record.channel.kind === "project") return projectLabel ?? record.channel.name ?? labels.unnamedProject;
  return record.members.find((member) => member.userId !== currentUserId)?.displayName ?? labels.directMessage;
}

async function loadProjectSummary(
  tenantId: string,
  tenantSlug: string,
  projectId: string,
  labels: ChatChannelSettingsLabels
) {
  const project = await withTenantRLS(tenantId, (tx) =>
    tx.projekt.findFirst({
      where: { tenantId, id: projectId },
      select: {
        id: true,
        projektNummer: true,
        projektname: true,
        stage: { select: { name: true } },
      },
    })
  );
  return {
    id: projectId,
    number: project?.projektNummer ?? projectId,
    label: project?.projektname?.trim() || labels.unnamedProject,
    stageLabel: project?.stage.name?.trim() || labels.unknownProjectStage,
    href: projectDetailPath(tenantSlug, projectId),
  };
}