feat: add teams (#848)

## Description

Add support for teams which will allow users to collaborate on
documents.

Teams features allows users to:

- Create, manage and transfer teams
- Manage team members
- Manage team emails
- Manage a shared team inbox and documents

These changes do NOT include the following, which are planned for a
future release:

- Team templates
- Team API
- Search menu integration

## Testing Performed

- Added E2E tests for general team management
- Added E2E tests to validate document counts

## Checklist

- [X] I have tested these changes locally and they work as expected.
- [X] I have added/updated tests that prove the effectiveness of these
changes.
- [ ] I have updated the documentation to reflect these changes, if
applicable.
- [X] I have followed the project's coding style guidelines.

packages/lib/server-only/team/delete-team-members.ts

@@ -0,0 +1,102 @@
+import { updateSubscriptionItemQuantity } from '@documenso/ee/server-only/stripe/update-subscription-item-quantity';
+import { IS_BILLING_ENABLED } from '@documenso/lib/constants/app';
+import { TEAM_MEMBER_ROLE_PERMISSIONS_MAP } from '@documenso/lib/constants/teams';
+import { AppError, AppErrorCode } from '@documenso/lib/errors/app-error';
+import { isTeamRoleWithinUserHierarchy } from '@documenso/lib/utils/teams';
+import { prisma } from '@documenso/prisma';
+
+export type DeleteTeamMembersOptions = {
+  /**
+   * The ID of the user who is initiating this action.
+   */
+  userId: number;
+
+  /**
+   * The ID of the team to remove members from.
+   */
+  teamId: number;
+
+  /**
+   * The IDs of the team members to remove.
+   */
+  teamMemberIds: number[];
+};
+
+export const deleteTeamMembers = async ({
+  userId,
+  teamId,
+  teamMemberIds,
+}: DeleteTeamMembersOptions) => {
+  await prisma.$transaction(async (tx) => {
+    // Find the team and validate that the user is allowed to remove members.
+    const team = await tx.team.findFirstOrThrow({
+      where: {
+        id: teamId,
+        members: {
+          some: {
+            userId,
+            role: {
+              in: TEAM_MEMBER_ROLE_PERMISSIONS_MAP['MANAGE_TEAM'],
+            },
+          },
+        },
+      },
+      include: {
+        members: {
+          select: {
+            id: true,
+            userId: true,
+            role: true,
+          },
+        },
+        subscription: true,
+      },
+    });
+
+    const currentTeamMember = team.members.find((member) => member.userId === userId);
+    const teamMembersToRemove = team.members.filter((member) => teamMemberIds.includes(member.id));
+
+    if (!currentTeamMember) {
+      throw new AppError(AppErrorCode.NOT_FOUND, 'Team member record does not exist');
+    }
+
+    if (teamMembersToRemove.find((member) => member.userId === team.ownerUserId)) {
+      throw new AppError(AppErrorCode.UNAUTHORIZED, 'Cannot remove the team owner');
+    }
+
+    const isMemberToRemoveHigherRole = teamMembersToRemove.some(
+      (member) => !isTeamRoleWithinUserHierarchy(currentTeamMember.role, member.role),
+    );
+
+    if (isMemberToRemoveHigherRole) {
+      throw new AppError(AppErrorCode.UNAUTHORIZED, 'Cannot remove a member with a higher role');
+    }
+
+    // Remove the team members.
+    await tx.teamMember.deleteMany({
+      where: {
+        id: {
+          in: teamMemberIds,
+        },
+        teamId,
+        userId: {
+          not: team.ownerUserId,
+        },
+      },
+    });
+
+    if (IS_BILLING_ENABLED && team.subscription) {
+      const numberOfSeats = await tx.teamMember.count({
+        where: {
+          teamId,
+        },
+      });
+
+      await updateSubscriptionItemQuantity({
+        priceId: team.subscription.priceId,
+        subscriptionId: team.subscription.planId,
+        quantity: numberOfSeats,
+      });
+    }
+  });
+};