package handlers

import (
	"fmt"
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/oklog/ulid/v2"
	"github.com/timetracker/backend/internal/api/utils"
	dto "github.com/timetracker/backend/internal/dtos"
	"github.com/timetracker/backend/internal/models"
)

// CustomerHandler handles customer-related API endpoints
type CustomerHandler struct{}

// NewCustomerHandler creates a new CustomerHandler
func NewCustomerHandler() *CustomerHandler {
	return &CustomerHandler{}
}

// GetCustomers handles GET /customers
//
//	@Summary		Get all customers
//	@Description	Get a list of all customers
//	@Tags			customers
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Success		200	{object}	utils.Response{data=[]dto.CustomerDto}
//	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/customers [get]
func (h *CustomerHandler) GetCustomers(c *gin.Context) {
	// Get customers from the database
	customers, err := models.GetAllCustomers(c.Request.Context())
	if err != nil {
		utils.InternalErrorResponse(c, "Error retrieving customers: "+err.Error())
		return
	}

	// Convert to DTOs
	customerDTOs := make([]dto.CustomerDto, len(customers))
	for i, customer := range customers {
		customerDTOs[i] = convertCustomerToDTO(&customer)
	}

	utils.SuccessResponse(c, http.StatusOK, customerDTOs)
}

// GetCustomerByID handles GET /customers/:id
//
//	@Summary		Get customer by ID
//	@Description	Get a customer by its ID
//	@Tags			customers
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			id	path		string	true	"Customer ID"
//	@Success		200	{object}	utils.Response{data=dto.CustomerDto}
//	@Failure		400	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		404	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/customers/{id} [get]
func (h *CustomerHandler) GetCustomerByID(c *gin.Context) {
	// Parse ID from URL
	idStr := c.Param("id")
	id, err := ulid.Parse(idStr)
	if err != nil {
		utils.BadRequestResponse(c, "Invalid customer ID format")
		return
	}

	// Get customer from the database
	customer, err := models.GetCustomerByID(c.Request.Context(), models.FromULID(id))
	if err != nil {
		utils.InternalErrorResponse(c, "Error retrieving customer: "+err.Error())
		return
	}

	if customer == nil {
		utils.NotFoundResponse(c, "Customer not found")
		return
	}

	// Convert to DTO
	customerDTO := convertCustomerToDTO(customer)

	utils.SuccessResponse(c, http.StatusOK, customerDTO)
}

// GetCustomersByCompanyID handles GET /customers/company/:companyId
//
//	@Summary		Get customers by company ID
//	@Description	Get a list of customers for a specific company
//	@Tags			customers
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			companyId	path		int	true	"Company ID"
//	@Success		200			{object}	utils.Response{data=[]dto.CustomerDto}
//	@Failure		400			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500			{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/customers/company/{companyId} [get]
func (h *CustomerHandler) GetCustomersByCompanyID(c *gin.Context) {
	// Parse company ID from URL
	companyIDStr := c.Param("companyId")
	companyID, err := parseCompanyID(companyIDStr)
	if err != nil {
		utils.BadRequestResponse(c, "Invalid company ID format")
		return
	}

	// Get customers from the database
	customers, err := models.GetCustomersByCompanyID(c.Request.Context(), companyID)
	if err != nil {
		utils.InternalErrorResponse(c, "Error retrieving customers: "+err.Error())
		return
	}

	// Convert to DTOs
	customerDTOs := make([]dto.CustomerDto, len(customers))
	for i, customer := range customers {
		customerDTOs[i] = convertCustomerToDTO(&customer)
	}

	utils.SuccessResponse(c, http.StatusOK, customerDTOs)
}

// CreateCustomer handles POST /customers
//
//	@Summary		Create a new customer
//	@Description	Create a new customer
//	@Tags			customers
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			customer	body		dto.CustomerCreateDto	true	"Customer data"
//	@Success		201			{object}	utils.Response{data=dto.CustomerDto}
//	@Failure		400			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500			{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/customers [post]
func (h *CustomerHandler) CreateCustomer(c *gin.Context) {
	// Parse request body
	var customerCreateDTO dto.CustomerCreateDto
	if err := c.ShouldBindJSON(&customerCreateDTO); err != nil {
		utils.BadRequestResponse(c, "Invalid request body: "+err.Error())
		return
	}

	// Convert DTO to model
	customerCreate := convertCreateCustomerDTOToModel(customerCreateDTO)

	// Create customer in the database
	customer, err := models.CreateCustomer(c.Request.Context(), customerCreate)
	if err != nil {
		utils.InternalErrorResponse(c, "Error creating customer: "+err.Error())
		return
	}

	// Convert to DTO
	customerDTO := convertCustomerToDTO(customer)

	utils.SuccessResponse(c, http.StatusCreated, customerDTO)
}

// UpdateCustomer handles PUT /customers/:id
//
//	@Summary		Update a customer
//	@Description	Update an existing customer
//	@Tags			customers
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			id			path		string					true	"Customer ID"
//	@Param			customer	body		dto.CustomerUpdateDto	true	"Customer data"
//	@Success		200			{object}	utils.Response{data=dto.CustomerDto}
//	@Failure		400			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		404			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500			{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/customers/{id} [put]
func (h *CustomerHandler) UpdateCustomer(c *gin.Context) {
	// Parse ID from URL
	idStr := c.Param("id")
	id, err := ulid.Parse(idStr)
	if err != nil {
		utils.BadRequestResponse(c, "Invalid customer ID format")
		return
	}

	// Parse request body
	var customerUpdateDTO dto.CustomerUpdateDto
	if err := c.ShouldBindJSON(&customerUpdateDTO); err != nil {
		utils.BadRequestResponse(c, "Invalid request body: "+err.Error())
		return
	}

	// Set ID from URL
	customerUpdateDTO.ID = id.String()

	// Convert DTO to model
	customerUpdate := convertUpdateCustomerDTOToModel(customerUpdateDTO)

	// Update customer in the database
	customer, err := models.UpdateCustomer(c.Request.Context(), customerUpdate)
	if err != nil {
		utils.InternalErrorResponse(c, "Error updating customer: "+err.Error())
		return
	}

	if customer == nil {
		utils.NotFoundResponse(c, "Customer not found")
		return
	}

	// Convert to DTO
	customerDTO := convertCustomerToDTO(customer)

	utils.SuccessResponse(c, http.StatusOK, customerDTO)
}

// DeleteCustomer handles DELETE /customers/:id
//
//	@Summary		Delete a customer
//	@Description	Delete a customer by its ID
//	@Tags			customers
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			id	path		string	true	"Customer ID"
//	@Success		204	{object}	utils.Response
//	@Failure		400	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/customers/{id} [delete]
func (h *CustomerHandler) DeleteCustomer(c *gin.Context) {
	// Parse ID from URL
	idStr := c.Param("id")
	id, err := ulid.Parse(idStr)
	if err != nil {
		utils.BadRequestResponse(c, "Invalid customer ID format")
		return
	}

	// Delete customer from the database
	err = models.DeleteCustomer(c.Request.Context(), models.FromULID(id))
	if err != nil {
		utils.InternalErrorResponse(c, "Error deleting customer: "+err.Error())
		return
	}

	utils.SuccessResponse(c, http.StatusNoContent, nil)
}

// Helper functions for DTO conversion

func convertCustomerToDTO(customer *models.Customer) dto.CustomerDto {
	return dto.CustomerDto{
		ID:        customer.ID.String(),
		CreatedAt: customer.CreatedAt,
		UpdatedAt: customer.UpdatedAt,
		Name:      customer.Name,
		CompanyID: customer.CompanyID,
	}
}

func convertCreateCustomerDTOToModel(dto dto.CustomerCreateDto) models.CustomerCreate {
	return models.CustomerCreate{
		Name:      dto.Name,
		CompanyID: dto.CompanyID,
	}
}

func convertUpdateCustomerDTOToModel(dto dto.CustomerUpdateDto) models.CustomerUpdate {
	id, _ := ulid.Parse(dto.ID)
	update := models.CustomerUpdate{
		ID: models.FromULID(id),
	}

	if dto.Name != nil {
		update.Name = dto.Name
	}

	if dto.CompanyID != nil {
		update.CompanyID = dto.CompanyID
	}

	return update
}

// Helper function to parse company ID from string
func parseCompanyID(idStr string) (int, error) {
	var id int
	_, err := fmt.Sscanf(idStr, "%d", &id)
	return id, err
}