import { CHAT_PERMISSIONS } from "@hivegrid/chat";
import { createGroupChat, getOrCreateDirectMessage } from "@hivegrid/chat/lifecycle.server";
import { withTenantScope } from "@hivegrid/foundation";
import {
  buildChatChannelCreateVM,
  type ChatChannelCreateMode,
  type ChatChannelCreateSubmission,
  type ChatChannelCreateVM,
  type ChatPermissionGroupOptionInput,
  type ChatTenantUserOptionInput,
} from "@hivegrid/view-models";

import { TenantUserStatus } from "~/application/enums/tenants/TenantUserStatus";
import { withTenantRLS } from "~/utils/db/.server/tenantRls.server";

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

export async function loadChatChannelCreatePage(input: {
  readonly context: ChatRouteContext;
  readonly requestedMode?: ChatChannelCreateMode;
}): Promise<ChatChannelCreateVM> {
  const permissions = {
    canCreateGroup: chatHasPermission(input.context, CHAT_PERMISSIONS.createChannel),
    canCreateDm: chatHasPermission(input.context, CHAT_PERMISSIONS.createDm),
  };

  const options =
    permissions.canCreateGroup || permissions.canCreateDm
      ? await loadChatChannelCreateOptions(input.context, permissions.canCreateGroup)
      : { tenantUsers: [], tenantGroups: [] };

  return buildChatChannelCreateVM({
    currentUserId: input.context.userId,
    tenantUsers: options.tenantUsers,
    tenantGroups: options.tenantGroups,
    permissions,
    requestedMode: input.requestedMode,
  });
}

export async function createChatChannel(input: {
  readonly context: ChatRouteContext;
  readonly requestId: string;
  readonly submission: ChatChannelCreateSubmission;
}): Promise<{ readonly chatId: string }> {
  if (input.submission.mode === "group") {
    const context = requireChatPermission(input.context, CHAT_PERMISSIONS.createChannel);
    return createGroupChat({
      tenantId: context.tenantId,
      userId: context.userId,
      permissions: context.permissions,
      requestId: input.requestId,
      name: input.submission.name,
      description: input.submission.description,
      isPrivate: input.submission.privacy === "private",
      notificationDefault: "all_messages",
      initialMemberUserIds: input.submission.initialUserIds,
      initialGroupIds: input.submission.initialGroupIds,
      syncGroupMembership: input.submission.syncGroupMembership,
    });
  }

  const context = requireChatPermission(input.context, CHAT_PERMISSIONS.createDm);
  return getOrCreateDirectMessage({
    tenantId: context.tenantId,
    userId: context.userId,
    permissions: context.permissions,
    requestId: input.requestId,
    peerUserId: input.submission.peerUserId,
  });
}

async function loadChatChannelCreateOptions(
  context: ChatRouteContext,
  includeGroups: boolean
): Promise<Readonly<{ tenantUsers: readonly ChatTenantUserOptionInput[]; tenantGroups: readonly ChatPermissionGroupOptionInput[] }>> {
  const { memberships, groups } = await withTenantRLS(context.tenantId, async (tx) => {
    const membershipsPromise = tx.tenantUser.findMany({
      where: {
        tenantId: context.tenantId,
        status: TenantUserStatus.ACTIVE,
        user: {
          active: true,
          pendingDeletion: false,
          pseudonymized: false,
        },
      },
      select: {
        userId: true,
        user: {
          select: {
            email: true,
            firstName: true,
            lastName: true,
            avatar: true,
          },
        },
      },
      orderBy: [{ user: { firstName: "asc" } }, { user: { lastName: "asc" } }, { user: { email: "asc" } }],
    });
    const groupsPromise = includeGroups
      ? tx.group.findMany({
          where: withTenantScope(context.tenantId, {}),
          select: {
            id: true,
            name: true,
            description: true,
            users: {
              where: {
                user: {
                  active: true,
                  pendingDeletion: false,
                  pseudonymized: false,
                  tenants: { some: withTenantScope(context.tenantId, { status: TenantUserStatus.ACTIVE }) },
                },
              },
              select: { userId: true },
            },
          },
          orderBy: [{ name: "asc" }, { id: "asc" }],
        })
      : Promise.resolve([]);
    const [memberships, groups] = await Promise.all([membershipsPromise, groupsPromise]);
    return { memberships, groups };
  });

  const tenantUsers = memberships.map(({ userId, user }) => {
    const displayName =
      [user.firstName, user.lastName]
        .map((part) => part?.trim())
        .filter((part): part is string => Boolean(part))
        .join(" ") || user.email;
    const fallbackLabel =
      [user.firstName?.trim().slice(0, 1), user.lastName?.trim().slice(0, 1)]
        .filter((part): part is string => Boolean(part))
        .join("")
        .toLocaleUpperCase() ||
      user.email.slice(0, 1).toLocaleUpperCase() ||
      "?";

    return {
      userId,
      displayName,
      email: user.email,
      avatar: {
        imageUrl: user.avatar?.trim() || null,
        fallbackLabel,
      },
    };
  });
  const tenantGroups = groups.map((group) => ({
    groupId: group.id,
    name: group.name,
    description: group.description,
    memberCount: group.users.length,
  }));
  return { tenantUsers, tenantGroups };
}