From 8e1df934b3f69074020e1667da1c24b99dad5aaa Mon Sep 17 00:00:00 2001
From: kalipso <kalipso@c3d2.de>
Date: Sun, 29 Jun 2025 16:57:51 +0200
Subject: [PATCH] WIP cost calculation

---
 controllers/printController.go | 74 ++++++++++++++++++++++++++++++++--
 utils/utils.go                 | 41 +++++++++++++++++++
 2 files changed, 111 insertions(+), 4 deletions(-)

diff --git a/controllers/printController.go b/controllers/printController.go
index f917cd2..9fa5bda 100644
--- a/controllers/printController.go
+++ b/controllers/printController.go
@@ -2,11 +2,13 @@ package controllers
 
 import (
 	"fmt"
+	"math"
 	"net/http"
 	"strconv"
 
 	"git.dynamicdiscord.de/kalipso/zineshop/models"
 	"git.dynamicdiscord.de/kalipso/zineshop/repositories"
+	"git.dynamicdiscord.de/kalipso/zineshop/utils"
 	"github.com/gin-gonic/gin"
 )
 
@@ -63,7 +65,14 @@ func (rc *printController) PrintCartView(c *gin.Context) {
 		return
 	}
 
+	paper, err := repositories.Papers.GetAll()
+	if err != nil {
+		c.HTML(http.StatusBadRequest, "error.html", gin.H{"data": gin.H{"error": err}})
+		return
+	}
+
 	data := CreateSessionData(c, gin.H{
+		"paper":     paper,
 		"cartItems": cartItems,
 	})
 
@@ -78,9 +87,16 @@ func (rc *printController) PrintOrderView(c *gin.Context) {
 		return
 	}
 
+	paper, err := repositories.Papers.GetAll()
+	if err != nil {
+		c.HTML(http.StatusBadRequest, "error.html", gin.H{"data": gin.H{"error": err}})
+		return
+	}
+
 	cartItems := order.CartItems
 
 	data := CreateSessionData(c, gin.H{
+		"paper":     paper,
 		"cartItems": cartItems,
 	})
 
@@ -90,6 +106,7 @@ func (rc *printController) PrintOrderView(c *gin.Context) {
 func (rc *printController) PrintHandler(c *gin.Context) {
 	variantIds := c.PostFormArray("variant-id[]")
 	variantAmounts := c.PostFormArray("variant-amount[]")
+	variantPapertypes := c.PostFormArray("variant-papertype[]")
 	variantCoverPages := c.PostFormArray("variant-coverpage[]")
 
 	if len(variantIds) != len(variantAmounts) || len(variantIds) != len(variantCoverPages) {
@@ -113,9 +130,53 @@ func (rc *printController) PrintHandler(c *gin.Context) {
 			return
 		}
 
-		coverPage := false
-		if variantCoverPages[idx] == "1" {
-			coverPage = true
+		paperType, err := repositories.Papers.GetById(fmt.Sprintf("%v", variantPapertypes[idx]))
+		if err != nil {
+			c.HTML(http.StatusBadRequest, "error.html", gin.H{"data": gin.H{"error": err}})
+			return
+		}
+
+		var coverPage models.Paper
+		doPrintCoverpage := false
+		if variantCoverPages[idx] != "0" {
+			coverPage, err = repositories.Papers.GetById(fmt.Sprintf("%v", variantCoverPages[idx]))
+			if err != nil {
+				c.HTML(http.StatusBadRequest, "error.html", gin.H{"data": gin.H{"error": err}})
+				return
+			}
+
+			doPrintCoverpage = true
+		}
+
+		calculatePrintCosts := func(shopItem models.ShopItem, paperType models.Paper, coverPagePaperType models.Paper, colored bool, amount int) (float64, error) {
+			pageCount := utils.CountPagesAtPath(shopItem.Pdf)
+			printMode := models.GetPrintMode(shopItem.PrintMode)
+
+			//Get actual pagecount depending on printmode
+			actualPageCount := pageCount
+
+			if printMode == models.CreateBooklet {
+				dividedCount := float64(pageCount) / 4.0
+				actualPageCount = int(math.Ceil(dividedCount))
+			}
+
+			if printMode == models.LongEdge || printMode == models.ShortEdge {
+				dividedCount := float64(pageCount) / 2.0
+				actualPageCount = int(math.Ceil(dividedCount))
+			}
+
+			PPC := 0.002604
+			partCost := 0.0067
+			if colored {
+				partCost = 0.0478
+			}
+			printingCosts := float64(actualPageCount) * paperType.Price
+			printingCosts += float64(actualPageCount/2) * PPC
+			printingCosts += partCost * float64(actualPageCount)
+
+			fmt.Printf("Printing Costs per Zine: %v\n", printingCosts)
+			fmt.Printf("Printing Costs Total: %v\n", printingCosts*float64(amount))
+			return printingCosts, nil
 		}
 
 		variantAmount, err := strconv.Atoi(variantAmounts[idx])
@@ -124,7 +185,12 @@ func (rc *printController) PrintHandler(c *gin.Context) {
 			return
 		}
 
-		printJob, err := models.NewPrintJob(shopItem, variant, coverPage, uint(variantAmount))
+		fmt.Println("Printing Costs:")
+
+		colored := variant.Name == "Colored"
+		calculatePrintCosts(shopItem, paperType, coverPage, colored, int(variantAmount))
+
+		printJob, err := models.NewPrintJob(shopItem, variant, doPrintCoverpage, uint(variantAmount))
 
 		if err != nil {
 			c.HTML(http.StatusBadRequest, "error.html", gin.H{"data": gin.H{"error": err}})
diff --git a/utils/utils.go b/utils/utils.go
index 66c4d20..107aaac 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -1,8 +1,11 @@
 package utils
 
 import (
+	"bufio"
 	"crypto/rand"
 	"encoding/hex"
+	"io"
+	"os"
 )
 
 func GenerateSessionId(length int) string {
@@ -17,3 +20,41 @@ func GenerateSessionId(length int) string {
 func GenerateToken() string {
 	return GenerateSessionId(16)
 }
+
+const match = "/Page\x00"
+
+// Pages reads the given io.ByteReader until EOF is reached, returning the
+// number of pages encountered.
+func Pages(reader io.ByteReader) (pages int) {
+	i := 0
+	for {
+		b, err := reader.ReadByte()
+		if err != nil {
+			return
+		}
+	check:
+		switch match[i] {
+		case 0:
+			if !(b >= 'A' && b <= 'Z' || b >= 'a' && b <= 'z') {
+				pages++
+			}
+			i = 0
+			goto check
+		case b:
+			i++
+		default:
+			i = 0
+		}
+	}
+}
+
+// PagesAtPath opens a PDF file at the given file path, returning the number
+// of pages found.
+func CountPagesAtPath(path string) (pages int) {
+	if reader, err := os.Open(path); err == nil {
+		reader.Chdir()
+		pages = Pages(bufio.NewReader(reader))
+		reader.Close()
+	}
+	return
+}