package service

import (
	"context"
	"database/sql"
	"fmt"

	"boc/repository"
)

// HRService handles business logic for HR operations
type HRService struct {
	repo *repository.HRRepository
	db   *sql.DB
}

func NewHRService(db *sql.DB) *HRService {
	return &HRService{
		repo: repository.NewHRRepository(db),
		db:   db,
	}
}

// ListEmployees returns all employees
func (s *HRService) ListEmployees(ctx context.Context) ([]repository.Employee, error) {
	return s.repo.ListEmployees(ctx)
}

// GetEmployee returns a single employee by ID
func (s *HRService) GetEmployee(ctx context.Context, id string) (*repository.Employee, error) {
	return s.repo.GetEmployee(ctx, id)
}

// CreateEmployee creates a new employee with validation
func (s *HRService) CreateEmployee(ctx context.Context, e *repository.Employee) error {
	if e.Name == "" {
		return fmt.Errorf("employee name is required")
	}
	if e.Email == "" {
		return fmt.Errorf("employee email is required")
	}
	if e.Status == "" {
		e.Status = "active"
	}
	return s.repo.CreateEmployee(ctx, e)
}

// UpdateEmployee updates an existing employee
func (s *HRService) UpdateEmployee(ctx context.Context, id string, e *repository.Employee) error {
	if e.Name == "" {
		return fmt.Errorf("employee name is required")
	}
	return s.repo.UpdateEmployee(ctx, id, e)
}

// ListLeaves returns all leave requests
func (s *HRService) ListLeaves(ctx context.Context) ([]repository.Leave, error) {
	return s.repo.ListLeaves(ctx)
}

// CreateLeave creates a new leave request with validation
func (s *HRService) CreateLeave(ctx context.Context, l *repository.Leave) error {
	if l.EmployeeID == "" {
		return fmt.Errorf("employee ID is required")
	}
	if l.Type == "" {
		return fmt.Errorf("leave type is required")
	}
	if l.Status == "" {
		l.Status = "pending"
	}
	return s.repo.CreateLeave(ctx, l)
}

// ListTimesheets returns all timesheet entries
func (s *HRService) ListTimesheets(ctx context.Context) ([]repository.Timesheet, error) {
	return s.repo.ListTimesheets(ctx)
}

// CreateTimesheet creates a new timesheet entry with validation
func (s *HRService) CreateTimesheet(ctx context.Context, t *repository.Timesheet) error {
	if t.EmployeeID == "" {
		return fmt.Errorf("employee ID is required")
	}
	if t.Hours <= 0 {
		return fmt.Errorf("hours must be positive")
	}
	if t.Status == "" {
		t.Status = "pending"
	}
	return s.repo.CreateTimesheet(ctx, t)
}