diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index cc6d0ac..d40e803 100644
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -14,51 +14,140 @@ datasource db {
 }
 
 model Users {
-  user_id       Int     @id @default(autoincrement())
-  first_name    String
-  last_name     String
-  email         String?  @unique
-  phone_number  Int     @unique
-  residence     String?
+  id                 String             @id @default(uuid())
+  first_name         String
+  last_name          String
+  email              String?            @unique
+  phone_number       Int                @unique
+  residence          String?
+  role               Roles              @default(GUEST)
 
 
-  employee      Employees? @relation("UserEmployee")
-  customer      Customers? @relation("UserCustomer")
+  employee           Employees?         @relation("UserEmployee")
+  customer           Customers?         @relation("UserCustomer")
+  oauth_access_token OAuthAccessTokens? @relation("UserOAuthAccessToken")
 
   @@map("users")
 }
 
 model Employees {
-  employee_id          Int     @id @default(autoincrement())
-  user                 Users   @relation("UserEmployee", fields: [user_id], references:[user_id])
-  user_id              Int     @unique
-  external_payroll_id  Int     @unique
+  id                   Int            @id @default(autoincrement())
+  user                 Users          @relation("UserEmployee", fields: [user_id], references:[id])
+  user_id              String         @unique
+  external_payroll_id  Int            @unique
   company_code         Int     
   first_work_day       DateTime
   last_work_day        DateTime?
-  role                 Roles   @default(EMPLOYEE)
+
+  timesheet            Timesheets?    @relation("TimesheetEmployee")
+  leave_request        LeaveRequests? @relation("LeaveRequestEmployee")
 
   @@map("employees")
 }
 
 model Customers {
-  customer_id         Int     @id @default(autoincrement())
-  user                Users   @relation("UserCustomer", fields: [user_id], references:[user_id])
-  user_id             Int     @unique
-  invoice_id          Int?     @unique
-  role                Roles   @default(CUSTOMER)
+  id                  Int     @id @default(autoincrement())
+  user                Users   @relation("UserCustomer", fields: [user_id], references:[id])
+  user_id             String  @unique
+  invoice_id          Int?    @unique
 
   @@map("customers")
 }
 
+model LeaveRequests {
+  id              Int                 @id @default(autoincrement())
+  employee        Employees           @relation("LeaveRequestEmployee", fields: [employee_id], references:[id])
+  employee_id     Int                 @unique
+  leave_type      LeaveTypes
+  start_date_time DateTime
+  end_date_time   DateTime?
+  comment         String
+  approval_status LeaveApprovalStatus @default(PENDING)
+
+  @@map("leave_requests")
+}
+
+model Timesheets {
+  id            Int         @id @default(autoincrement())
+  employee      Employees   @relation("TimesheetEmployee", fields: [employee_id], references:[id])
+  employee_id   Int         @unique
+  is_approved   Boolean     @default(false)
+
+
+  shift         Shifts?     @relation("ShiftTimesheet")
+
+  @@map("timesheets")
+}
+
+model Shifts {
+  id            Int         @id @default(autoincrement())
+  timesheet     Timesheets  @relation("ShiftTimesheet", fields: [timesheet_id], references: [id])
+  timesheet_id  Int         @unique
+  shift_code    ShiftCodes  @relation("ShiftShiftCode", fields: [shift_code_id], references: [id])
+  shift_code_id Int         @unique
+  date          DateTime
+  start_time    DateTime
+  end_time      DateTime
+
+  @@map("shifts")
+}
+
+model ShiftCodes {
+  id          Int     @id @default(autoincrement())
+  shift_type  String
+  bank_code   String
+
+
+  shift       Shifts? @relation("ShiftShiftCode")
+
+  @@map("shift_codes")
+}
+
+model OAuthAccessTokens {
+  id                    String    @id @default(cuid())
+  user                  Users     @relation("UserOAuthAccessToken", fields: [user_id], references: [id])
+  user_id               String    @unique
+  access_token          String    @unique
+  refresh_token         String    @unique
+  access_token_expiry   DateTime
+  refresh_token_expiry  DateTime?
+  scopes                Json      @default("[]")
+  created_at            DateTime  @default(now())
+  updated_at            DateTime?
+
+  @@map("refresh_tokens")
+}
+
 enum Roles {
   ADMIN
-  CUSTOMER
-  DEALER
-  EMPLOYEE
-  HR
   SUPERVISOR
+  HR
   ACCOUNTING
+  EMPLOYEE
+  DEALER
+  CUSTOMER
+  GUEST
 
   @@map("roles")
+}
+
+enum LeaveTypes {
+  SICK            // maladie ou repos
+  VACATION        // paye
+  UNPAID          // non-paye
+  BEREAVEMENT     // deuil de famille
+  PARENTAL        // maternite/paternite/adoption
+  LEGAL           // obligations legales comme devoir de juree
+
+  @@map("leave_types")
+}
+
+enum LeaveApprovalStatus {
+  PENDING
+  APPROVED
+  DENIED
+  CANCELLED
+  ESCALATED
+
+  @@map("leave_approval_status")
 }
\ No newline at end of file