stream_app/main.go

package main

import (
	"encoding/json"
	"math"
	"net/http"
)

type Container struct {
	Length float64 `json:"length"`
	Width  float64 `json:"width"`
	Height float64 `json:"height"`
}

type Box struct {
	Length float64 `json:"length"`
	Width  float64 `json:"width"`
	Height float64 `json:"height"`
}

type Placement struct {
	X, Y, Z float64 `json:"x"`
}

type Response struct {
	Count            int         `json:"count"`
	Layout           []Placement `json:"layout"`
	BoxLength        float64     `json:"boxLength"`
	BoxWidth         float64     `json:"boxWidth"`
	BoxHeight        float64     `json:"boxHeight"`
	Strategy         string      `json:"strategy"`
	Density          float64     `json:"density"`
	SpaceUtilization float64     `json:"spaceUtilization"`
	UsedVolume       float64     `json:"usedVolume"`
}

func main() {
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, "index.html")
	})

	http.HandleFunc("/calculate", func(w http.ResponseWriter, r *http.Request) {
		var data struct {
			Container Container `json:"container"`
			Box       Box       `json:"box"`
		}
		json.NewDecoder(r.Body).Decode(&data)

		layout, bestRotation, strategy, density, spaceUtilization, usedVolume := optimizePacking(data.Container, data.Box)
		count := len(layout)

		response := Response{
			Count:            count,
			Layout:           layout,
			BoxLength:        bestRotation.Length,
			BoxWidth:         bestRotation.Width,
			BoxHeight:        bestRotation.Height,
			Strategy:         strategy,
			Density:          density,
			SpaceUtilization: spaceUtilization,
			UsedVolume:       usedVolume,
		}

		json.NewEncoder(w).Encode(response)
	})

	http.ListenAndServe(":8080", nil)
}

func optimizePacking(con Container, box Box) ([]Placement, Box, string, float64, float64, float64) {
	var bestLayout []Placement
	var bestRotation Box
	var bestStrategy string
	maxCount := 0
	var bestDensity float64
	var bestSpaceUtilization float64
	var bestUsedVolume float64

	rotations := generateRotations(box)
	conVolume := con.Length * con.Width * con.Height

	for _, r := range rotations {
		for _, strategy := range []string{"XY", "XZ", "YX", "YZ", "ZX", "ZY"} {
			var xCount, yCount, zCount float64
			switch strategy {
			case "XY":
				xCount = math.Floor(con.Length / r.Length)
				yCount = math.Floor(con.Width / r.Width)
				zCount = math.Floor(con.Height / r.Height)
			case "XZ":
				xCount = math.Floor(con.Length / r.Length)
				zCount = math.Floor(con.Height / r.Height)
				yCount = math.Floor(con.Width / r.Width)
			case "YX":
				yCount = math.Floor(con.Width / r.Length)
				xCount = math.Floor(con.Length / r.Width)
				zCount = math.Floor(con.Height / r.Height)
			case "YZ":
				yCount = math.Floor(con.Width / r.Length)
				zCount = math.Floor(con.Height / r.Height)
				xCount = math.Floor(con.Length / r.Width)
			case "ZX":
				zCount = math.Floor(con.Height / r.Length)
				xCount = math.Floor(con.Length / r.Width)
				yCount = math.Floor(con.Width / r.Height)
			case "ZY":
				zCount = math.Floor(con.Height / r.Length)
				yCount = math.Floor(con.Width / r.Height)
				xCount = math.Floor(con.Length / r.Width)
			}

			total := int(xCount * yCount * zCount)
			if total > maxCount && total > 0 {
				maxCount = total
				bestRotation = r
				bestStrategy = strategy
				bestLayout = generateLayout(r, xCount, yCount, zCount, strategy)

				boxVolume := r.Length * r.Width * r.Height
				bestUsedVolume = float64(total) * boxVolume
				bestDensity = (bestUsedVolume / conVolume) * 100
				bestSpaceUtilization = bestDensity
			}
		}
	}

	return bestLayout, bestRotation, bestStrategy, bestDensity, bestSpaceUtilization, bestUsedVolume
}

func generateRotations(box Box) []Box {
	return []Box{
		{box.Length, box.Width, box.Height},
		{box.Length, box.Height, box.Width},
		{box.Width, box.Length, box.Height},
		{box.Width, box.Height, box.Length},
		{box.Height, box.Length, box.Width},
		{box.Height, box.Width, box.Length},
	}
}

func generateLayout(r Box, xCount, yCount, zCount float64, strategy string) []Placement {
	var layout []Placement
	switch strategy {
	case "XY":
		for x := 0.0; x < xCount; x++ {
			for y := 0.0; y < yCount; y++ {
				for z := 0.0; z < zCount; z++ {
					layout = append(layout, Placement{
						X: x * r.Length,
						Y: z * r.Height,
						Z: y * r.Width,
					})
				}
			}
		}
	case "XZ":
		for x := 0.0; x < xCount; x++ {
			for z := 0.0; z < zCount; z++ {
				for y := 0.0; y < yCount; y++ {
					layout = append(layout, Placement{
						X: x * r.Length,
						Y: z * r.Height,
						Z: y * r.Width,
					})
				}
			}
		}
	case "YX":
		for y := 0.0; y < yCount; y++ {
			for x := 0.0; x < xCount; x++ {
				for z := 0.0; z < zCount; z++ {
					layout = append(layout, Placement{
						X: x * r.Width,
						Y: z * r.Height,
						Z: y * r.Length,
					})
				}
			}
		}
	case "YZ":
		for y := 0.0; y < yCount; y++ {
			for z := 0.0; z < zCount; z++ {
				for x := 0.0; x < xCount; x++ {
					layout = append(layout, Placement{
						X: x * r.Width,
						Y: z * r.Height,
						Z: y * r.Length,
					})
				}
			}
		}
	case "ZX":
		for z := 0.0; z < zCount; z++ {
			for x := 0.0; x < xCount; x++ {
				for y := 0.0; y < yCount; y++ {
					layout = append(layout, Placement{
						X: x * r.Width,
						Y: z * r.Length,
						Z: y * r.Height,
					})
				}
			}
		}
	case "ZY":
		for z := 0.0; z < zCount; z++ {
			for y := 0.0; y < yCount; y++ {
				for x := 0.0; x < xCount; x++ {
					layout = append(layout, Placement{
						X: x * r.Width,
						Y: z * r.Length,
						Z: y * r.Height,
					})
				}
			}
		}
	}
	return layout
}