ERP/internal/handlers/customers.go

package handlers

import (
	"fmt"
	"net/http"
	"strconv"

	"erp_system/internal/models"
)

func (h *Handler) CustomerList(w http.ResponseWriter, r *http.Request) {
	search := r.URL.Query().Get("search")
	page, _ := strconv.Atoi(r.URL.Query().Get("page"))
	if page < 1 {
		page = 1
	}
	limit := 10

	customers, total, err := models.CustomerGetPaginated(h.DB, search, page, limit)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	totalPages := (total + limit - 1) / limit

	data := map[string]interface{}{
		"Title":      "Customers",
		"Username":   h.getUsername(r),
		"ActivePage": "customers",
		"Customers":  customers,
		"Search":     search,
		"Page":       page,
		"TotalPages": totalPages,
		"HasPrev":    page > 1,
		"HasNext":    page < totalPages,
		"PrevPage":   page - 1,
		"NextPage":   page + 1,
	}

	// HTMX partial for search
	if r.Header.Get("HX-Request") == "true" && r.URL.Query().Get("partial") == "true" {
		// Construct clean URL for history
		u := fmt.Sprintf("/customers?page=%d", page)
		if search != "" {
			u += "&search=" + search
		}
		w.Header().Set("HX-Push-Url", u)

		h.renderPartial(w, "customers/list.html", "customer-table", data)
		return
	}

	h.render(w, r, []string{"layout.html", "customers/list.html"}, data)
}

func (h *Handler) CustomerNew(w http.ResponseWriter, r *http.Request) {
	data := map[string]interface{}{
		"Title":      "New Customer",
		"Username":   h.getUsername(r),
		"ActivePage": "customers",
		"Customer":   &models.Customer{},
		"IsNew":      true,
	}
	h.render(w, r, []string{"layout.html", "customers/form.html"}, data)
}

func (h *Handler) CustomerCreate(w http.ResponseWriter, r *http.Request) {
	c := &models.Customer{
		Name:    r.FormValue("name"),
		Email:   r.FormValue("email"),
		Phone:   r.FormValue("phone"),
		Address: r.FormValue("address"),
	}

	if c.Name == "" {
		data := map[string]interface{}{
			"Title":      "New Customer",
			"Username":   h.getUsername(r),
			"ActivePage": "customers",
			"Customer":   c,
			"IsNew":      true,
			"Error":      "Name is required",
		}
		h.render(w, r, []string{"layout.html", "customers/form.html"}, data)
		return
	}

	if err := models.CustomerInsert(h.DB, c); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	if r.Header.Get("HX-Request") == "true" {
		w.Header().Set("HX-Redirect", "/customers/"+strconv.Itoa(c.ID))
		return
	}
	http.Redirect(w, r, "/customers/"+strconv.Itoa(c.ID), http.StatusSeeOther)
}

func (h *Handler) CustomerDetail(w http.ResponseWriter, r *http.Request) {
	id, _ := strconv.Atoi(r.PathValue("id"))
	customer, err := models.CustomerGetByID(h.DB, id)
	if err != nil {
		http.Error(w, "Customer not found", http.StatusNotFound)
		return
	}

	// Get customer's orders
	orders, _ := models.OrderGetAll(h.DB, "")
	var customerOrders []models.Order
	for _, o := range orders {
		if o.CustomerID == id {
			customerOrders = append(customerOrders, o)
		}
	}

	// Get customer's invoices
	invoices, _ := models.InvoiceGetByCustomerID(h.DB, id)

	data := map[string]interface{}{
		"Title":      customer.Name,
		"Username":   h.getUsername(r),
		"ActivePage": "customers",
		"Customer":   customer,
		"Orders":     customerOrders,
		"Invoices":   invoices,
	}
	h.render(w, r, []string{"layout.html", "customers/detail.html"}, data)
}

func (h *Handler) CustomerEdit(w http.ResponseWriter, r *http.Request) {
	id, _ := strconv.Atoi(r.PathValue("id"))
	customer, err := models.CustomerGetByID(h.DB, id)
	if err != nil {
		http.Error(w, "Customer not found", http.StatusNotFound)
		return
	}

	data := map[string]interface{}{
		"Title":      "Edit " + customer.Name,
		"Username":   h.getUsername(r),
		"ActivePage": "customers",
		"Customer":   customer,
		"IsNew":      false,
	}
	h.render(w, r, []string{"layout.html", "customers/form.html"}, data)
}

func (h *Handler) CustomerUpdate(w http.ResponseWriter, r *http.Request) {
	id, _ := strconv.Atoi(r.PathValue("id"))
	c := &models.Customer{
		ID:      id,
		Name:    r.FormValue("name"),
		Email:   r.FormValue("email"),
		Phone:   r.FormValue("phone"),
		Address: r.FormValue("address"),
	}

	if c.Name == "" {
		data := map[string]interface{}{
			"Title":      "Edit Customer",
			"Username":   h.getUsername(r),
			"ActivePage": "customers",
			"Customer":   c,
			"IsNew":      false,
			"Error":      "Name is required",
		}
		h.render(w, r, []string{"layout.html", "customers/form.html"}, data)
		return
	}

	if err := models.CustomerUpdate(h.DB, c); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	if r.Header.Get("HX-Request") == "true" {
		w.Header().Set("HX-Redirect", "/customers/"+strconv.Itoa(id))
		return
	}
	http.Redirect(w, r, "/customers/"+strconv.Itoa(id), http.StatusSeeOther)
}

func (h *Handler) CustomerDelete(w http.ResponseWriter, r *http.Request) {
	id, _ := strconv.Atoi(r.PathValue("id"))
	if err := models.CustomerDelete(h.DB, id); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	if r.Header.Get("HX-Request") == "true" {
		w.Header().Set("HX-Redirect", "/customers")
		return
	}
	http.Redirect(w, r, "/customers", http.StatusSeeOther)
}