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294package main
import (
"bytes"
"crypto/md5"
"encoding/base64"
"fmt"
"image/png"
"io/ioutil"
"os"
"path"
"path/filepath"
"regexp"
"sort"
"strings"
"time"
"github.com/chai2010/webp"
"github.com/rjeczalik/notify"
"github.com/tdewolff/minify/v2"
"github.com/tdewolff/minify/v2/css"
"github.com/tdewolff/minify/v2/js"
"github.com/tdewolff/minify/v2/json"
"gopkg.in/kothar/brotli-go.v0/enc"
)
type Asset struct {
Br, Data, WebP []byte
Mime string
}
var cssAssetURL = regexp.MustCompile(`asset-url\('(.*?)'\)`)
var cssSVGEmbed = regexp.MustCompile(`svg-embed\('(.*?)'(?:,(.*?))?\)`)
var cssVariable = regexp.MustCompile(`var\(--(.*?)\)`)
var jsAssetPath = regexp.MustCompile(`assetPath\('(.*?)'\)`)
var manifestSrc = regexp.MustCompile(`"src":"(.*?)"`)
var mimes = map[string]string{
".css": "text/css",
".jpg": "image/jpeg",
".js": "application/javascript",
".png": "image/png",
".svg": "image/svg+xml",
".webmanifest": "application/manifest+json",
".woff2": "font/woff2",
}
var variables = map[string][]byte{
"blue": []byte("#007bff"),
"green": []byte("#28a745"),
"green-dark": []byte("#155724"),
"green-light": []byte("#d4edda"),
"grey": []byte("#ced4da"),
"grey-dark": []byte("#343a40"),
"grey-light": []byte("#f8f9fa"),
"red": []byte("#dc3545"),
"red-dark": []byte("#721c24"),
"red-light": []byte("#f8d7da"),
"yellow": []byte("#ffc107"),
"yellow-light": []byte("#fff3cd"),
"yellow-dark": []byte("#856404"),
}
var assets map[string]Asset
var dev = os.Getenv("DEV") == "1"
var min = minify.New()
var paths map[string]string
func cssAssetURLFunc(match []byte) []byte {
file := cssAssetURL.FindStringSubmatch(string(match))[1]
return []byte("url(" + paths[file] + ")")
}
func cssSVGEmbedFunc(match []byte) []byte {
matches := cssSVGEmbed.FindStringSubmatch(string(match))
svg, err := ioutil.ReadFile(matches[1])
if err != nil {
panic(err)
}
if matches[2] != "" {
svg = bytes.ReplaceAll(svg, []byte("FILL"), []byte(matches[2]))
}
svg = cssVariable.ReplaceAllFunc(svg, cssVariableFunc)
svg = bytes.ReplaceAll(svg, []byte{'"'}, []byte{'\''})
svg = bytes.ReplaceAll(svg, []byte{'#'}, []byte("%23"))
return append([]byte(`url("data:image/svg+xml,`), append(svg, '"', ')')...)
}
func cssVariableFunc(match []byte) []byte {
return variables[cssVariable.FindStringSubmatch(string(match))[1]]
}
func jsAssetPathFunc(match []byte) []byte {
file := jsAssetPath.FindStringSubmatch(string(match))[1]
return []byte("'" + paths[file] + "'")
}
func manifestSrcFunc(match []byte) []byte {
file := manifestSrc.FindStringSubmatch(string(match))[1]
return []byte(`"src":"` + paths[file] + `"`)
}
func main() {
min.AddFunc("application/javascript", js.Minify)
min.AddFunc("application/manifest+json", json.Minify)
min.AddFunc("text/css", css.Minify)
if err := os.Chdir("assets"); err != nil {
panic(err)
}
run()
if dev {
c := make(chan notify.EventInfo, 1)
if err := notify.Watch("./...", c, notify.All); err != nil {
panic(err)
}
var lastRun time.Time
for {
event := <-c
// Very crude debouncing.
if time.Since(lastRun) > time.Millisecond {
fmt.Println(event)
run()
}
lastRun = time.Now()
}
}
}
func run() {
start := time.Now()
var files []string
assets = map[string]Asset{}
paths = map[string]string{}
if err := filepath.Walk(".", func(file string, fi os.FileInfo, err error) error {
if !fi.IsDir() && !strings.HasPrefix(path.Base(file), "_") {
files = append(files, file)
}
return err
}); err != nil {
panic(err)
}
// Process images first because they could be referenced in other assets.
sort.Slice(files, func(i, j int) bool {
iImg := strings.HasPrefix(files[i], "images/")
jImg := strings.HasPrefix(files[j], "images/")
if iImg != jImg {
return iImg
}
iServiceWorker := strings.HasSuffix(files[i], "service-worker.js")
jServiceWorker := strings.HasSuffix(files[j], "service-worker.js")
if iServiceWorker != jServiceWorker {
return iServiceWorker
}
return files[i] < files[j]
})
for _, file := range files {
ext := filepath.Ext(file)
if ext == ".go" {
continue
}
asset := Asset{Mime: mimes[ext]}
if asset.Mime == "" {
panic("Unsupported: " + file)
}
var err error
if asset.Data, err = ioutil.ReadFile(file); err != nil {
panic(err)
}
switch ext {
case ".css":
asset.Data = cssAssetURL.ReplaceAllFunc(asset.Data, cssAssetURLFunc)
asset.Data = cssVariable.ReplaceAllFunc(asset.Data, cssVariableFunc)
fallthrough
case ".js", ".webmanifest":
asset.Data = jsAssetPath.ReplaceAllFunc(asset.Data, jsAssetPathFunc)
// Minify
if asset.Data, err = min.Bytes(asset.Mime, asset.Data); err != nil {
panic(err)
}
switch ext {
case ".css":
// FIXME After minify because https://github.com/tdewolff/minify/issues/180
asset.Data = cssSVGEmbed.ReplaceAllFunc(asset.Data, cssSVGEmbedFunc)
case ".webmanifest":
asset.Data = manifestSrc.ReplaceAllFunc(asset.Data, manifestSrcFunc)
}
case ".svg":
asset.Data = cssVariable.ReplaceAllFunc(asset.Data, cssVariableFunc)
}
if !dev {
// Brotli or WebP
switch ext {
case ".css", ".js", ".svg":
if asset.Br, err = enc.CompressBuffer(nil, asset.Data, nil); err != nil {
panic(err)
}
case ".png":
img, err := png.Decode(bytes.NewBuffer(asset.Data))
if err != nil {
panic(err)
}
var buf bytes.Buffer
if err := webp.Encode(&buf, img, &webp.Options{Lossless: true}); err != nil {
panic(err)
}
asset.WebP = buf.Bytes()
}
}
hash := md5.Sum(asset.Data)
fingerprint := base64.RawURLEncoding.EncodeToString(hash[:])
assets[fingerprint] = asset
paths[file] = "/assets/" + fingerprint
}
file, err := os.Create("assets.go")
if err != nil {
panic(err)
}
if _, err := file.WriteString("package assets;var Paths=map[string]string{"); err != nil {
panic(err)
}
for path, hash := range paths {
if _, err := fmt.Fprintf(file, "%#v:%#v,", path, hash); err != nil {
panic(err)
}
}
if _, err := file.WriteString(
"};var Assets=map[string]struct{Br,Data,WebP[]byte;Mime string}{",
); err != nil {
panic(err)
}
for hash, asset := range assets {
if _, err := fmt.Fprintf(
file,
"%#v:{[]byte(%#v),[]byte(%#v),[]byte(%#v),%#v},",
hash,
string(asset.Br),
string(asset.Data),
string(asset.WebP),
asset.Mime,
); err != nil {
panic(err)
}
}
if _, err := file.WriteString("}"); err != nil {
panic(err)
}
if err := file.Close(); err != nil {
panic(err)
}
fmt.Println("Processed", len(files), "assets in", time.Since(start))
}