collage-maker/main.go

120 lines
2.7 KiB
Go

package main
import (
"crypto/rand"
"embed"
"encoding/json"
"flag"
"fmt"
"io"
"io/fs"
"net/http"
"os"
"path"
"sync/atomic"
"time"
"log/slog"
"go.balki.me/collage-maker/collage"
)
var (
imagesDir string
collageDir string
localAssets bool
)
//go:embed web/*
var webFS embed.FS
func main() {
flag.StringVar(&imagesDir, "images-dir", "images", "Sets the images dir")
flag.StringVar(&collageDir, "collages-dir", "collages", "Sets the collages dir")
flag.BoolVar(&localAssets, "local-assets", false, "Serve local assets for testing")
flag.Parse()
nameGen := NewNameGen()
imagesDirFs := os.DirFS(imagesDir)
imagesURLPath := "images"
collagesPath := "collages"
addFileServer := func(path, dir string) {
httpFileServer := http.FileServer(http.Dir(dir))
http.Handle("/"+path+"/", http.StripPrefix("/"+path, httpFileServer))
}
addFileServer(imagesURLPath, imagesDir)
addFileServer(collagesPath, collageDir)
if localAssets {
httpFileServer := http.FileServer(http.Dir("web"))
http.Handle("/", httpFileServer)
} else {
fs, err := fs.Sub(webFS, "web")
if err != nil {
panic(err)
}
httpFileServer := http.FileServer(http.FS(fs))
http.Handle("/", httpFileServer)
}
http.HandleFunc("/make-collage", func(w http.ResponseWriter, r *http.Request) {
collageReq := collage.Request{}
body, err := io.ReadAll(r.Body)
if err != nil {
slog.Error("failed to read request body", "error", err)
return
}
if err := json.Unmarshal(body, &collageReq); err != nil {
slog.Error("failed to unmarshal json request", "error", err)
return
}
collageFile := fmt.Sprintf("collage-%s.jpg", nameGen.Next())
out, err := os.Create(path.Join(collageDir, collageFile))
if err != nil {
slog.Error("failed to create collage output file", "error", err)
}
if err := collage.Make(collageReq, imagesDirFs, out); err != nil {
slog.Error("failed to make collage", "error", err)
return
}
w.Write([]byte(collageFile))
})
if err := http.ListenAndServe(":8767", nil); err != nil {
slog.Error("http ListenAndServe failed", "error", err)
}
}
type nameGen struct {
prefix string
counter atomic.Uint64
}
func NewNameGen() *nameGen {
currentTime := time.Now().Unix()
randBytes := make([]byte, 8)
_, err := rand.Read(randBytes)
if err != nil {
panic(err)
}
alpha := []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
uniqRunID := ""
for _, b := range randBytes {
uniqRunID += string(alpha[int(b)%len(alpha)])
}
return &nameGen{
prefix: fmt.Sprintf("%d-%s", currentTime, uniqRunID),
counter: atomic.Uint64{},
}
}
func (n *nameGen) Next() string {
return fmt.Sprintf("%s-%d", n.prefix, n.counter.Add(1))
}
// curl -D - --json @req.json http://localhost:8767/make-collage