Add record access strategy

backend/src/rbac/ability.factory.ts

@@ -0,0 +1,198 @@
+import { AbilityBuilder, PureAbility, AbilityClass } from '@casl/ability';
+import { Injectable } from '@nestjs/common';
+import { User } from '../models/user.model';
+import { RoleObjectPermission } from '../models/role-object-permission.model';
+import { RoleFieldPermission } from '../models/role-field-permission.model';
+import { RecordShare } from '../models/record-share.model';
+
+// Define action types
+export type Action = 'create' | 'read' | 'update' | 'delete' | 'view_all' | 'modify_all';
+
+// Define subject types - can be string (object API name) or actual object with fields
+export type Subject = string | { objectApiName: string; ownerId?: string; id?: string; [key: string]: any };
+
+// Define field actions
+export type FieldAction = 'read' | 'edit';
+
+export type AppAbility = PureAbility<[Action, Subject], { field?: string }>;
+
+@Injectable()
+export class AbilityFactory {
+  /**
+   * Build CASL ability for a user based on their roles and permissions
+   * This aggregates permissions from all roles the user has
+   */
+  async defineAbilityFor(
+    user: User & { roles?: Array<{ objectPermissions?: RoleObjectPermission[]; fieldPermissions?: RoleFieldPermission[] }> },
+    recordShares?: RecordShare[],
+  ): Promise<AppAbility> {
+    const { can, cannot, build } = new AbilityBuilder<AppAbility>(PureAbility as AbilityClass<AppAbility>);
+
+    if (!user.roles || user.roles.length === 0) {
+      // No roles = no permissions
+      return build();
+    }
+
+    // Aggregate object permissions from all roles
+    const objectPermissionsMap = new Map<string, {
+      canCreate: boolean;
+      canRead: boolean;
+      canEdit: boolean;
+      canDelete: boolean;
+      canViewAll: boolean;
+      canModifyAll: boolean;
+    }>();
+
+    // Aggregate field permissions from all roles
+    const fieldPermissionsMap = new Map<string, {
+      canRead: boolean;
+      canEdit: boolean;
+    }>();
+
+    // Process all roles
+    for (const role of user.roles) {
+      // Aggregate object permissions
+      if (role.objectPermissions) {
+        for (const perm of role.objectPermissions) {
+          const existing = objectPermissionsMap.get(perm.objectDefinitionId) || {
+            canCreate: false,
+            canRead: false,
+            canEdit: false,
+            canDelete: false,
+            canViewAll: false,
+            canModifyAll: false,
+          };
+
+          // Union of permissions (if any role grants it, user has it)
+          objectPermissionsMap.set(perm.objectDefinitionId, {
+            canCreate: existing.canCreate || perm.canCreate,
+            canRead: existing.canRead || perm.canRead,
+            canEdit: existing.canEdit || perm.canEdit,
+            canDelete: existing.canDelete || perm.canDelete,
+            canViewAll: existing.canViewAll || perm.canViewAll,
+            canModifyAll: existing.canModifyAll || perm.canModifyAll,
+          });
+        }
+      }
+
+      // Aggregate field permissions
+      if (role.fieldPermissions) {
+        for (const perm of role.fieldPermissions) {
+          const existing = fieldPermissionsMap.get(perm.fieldDefinitionId) || {
+            canRead: false,
+            canEdit: false,
+          };
+
+          fieldPermissionsMap.set(perm.fieldDefinitionId, {
+            canRead: existing.canRead || perm.canRead,
+            canEdit: existing.canEdit || perm.canEdit,
+          });
+        }
+      }
+    }
+
+    // Convert aggregated permissions to CASL rules
+    for (const [objectId, perms] of objectPermissionsMap) {
+      // Create permission
+      if (perms.canCreate) {
+        can('create', objectId);
+      }
+
+      // Read permission
+      if (perms.canRead) {
+        can('read', objectId);
+      }
+
+      // View all permission (can see all records regardless of ownership)
+      if (perms.canViewAll) {
+        can('view_all', objectId);
+      }
+
+      // Edit permission
+      if (perms.canEdit) {
+        can('update', objectId);
+      }
+
+      // Modify all permission (can edit all records regardless of ownership)
+      if (perms.canModifyAll) {
+        can('modify_all', objectId);
+      }
+
+      // Delete permission
+      if (perms.canDelete) {
+        can('delete', objectId);
+      }
+    }
+
+    // Add record sharing permissions
+    if (recordShares) {
+      for (const share of recordShares) {
+        // Only add if share is active (not expired, not revoked)
+        const now = new Date();
+        const isExpired = share.expiresAt && share.expiresAt < now;
+        const isRevoked = share.revokedAt !== null;
+
+        if (!isExpired && !isRevoked) {
+          // Note: Record-level sharing will be checked in authorization service
+          // CASL abilities are primarily for object-level permissions
+          // Individual record access is validated in applyScopeToQuery
+        }
+      }
+    }
+
+    return build();
+  }
+
+  /**
+   * Check if user can access a specific field
+   * Returns true if user has permission or if no restriction exists
+   */
+  canAccessField(
+    fieldDefinitionId: string,
+    action: FieldAction,
+    user: User & { roles?: Array<{ fieldPermissions?: RoleFieldPermission[] }> },
+  ): boolean {
+    if (!user.roles || user.roles.length === 0) {
+      return false;
+    }
+
+    // Collect all field permissions from all roles
+    const allFieldPermissions: RoleFieldPermission[] = [];
+    for (const role of user.roles) {
+      if (role.fieldPermissions) {
+        allFieldPermissions.push(...role.fieldPermissions);
+      }
+    }
+
+    // If there are NO field permissions configured at all, allow by default
+    if (allFieldPermissions.length === 0) {
+      return true;
+    }
+
+    // If field permissions exist, check for explicit grants (union of all roles)
+    for (const role of user.roles) {
+      if (role.fieldPermissions) {
+        const fieldPerm = role.fieldPermissions.find(fp => fp.fieldDefinitionId === fieldDefinitionId);
+        if (fieldPerm) {
+          if (action === 'read' && fieldPerm.canRead) return true;
+          if (action === 'edit' && fieldPerm.canEdit) return true;
+        }
+      }
+    }
+
+    // Field permissions exist but this field is not explicitly granted → deny
+    return false;
+  }
+
+  /**
+   * Filter fields based on user permissions
+   * Returns array of field IDs the user can access with the specified action
+   */
+  filterFields(
+    fieldDefinitionIds: string[],
+    action: FieldAction,
+    user: User & { roles?: Array<{ fieldPermissions?: RoleFieldPermission[] }> },
+  ): string[] {
+    return fieldDefinitionIds.filter(fieldId => this.canAccessField(fieldId, action, user));
+  }
+}