feat(config): only download when changed

resolves #5176

src/engine/migrate_glyphs.go

@@ -8,7 +8,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/jandedobbeleer/oh-my-posh/src/platform"
+	"github.com/jandedobbeleer/oh-my-posh/src/platform/net"
 )
 
 type codePoints map[uint64]uint64
@@ -24,7 +24,7 @@ func getGlyphCodePoints() (codePoints, error) {
 		return codePoints, &ConnectionError{reason: err.Error()}
 	}
 
-	response, err := platform.Client.Do(request)
+	response, err := net.HTTPClient.Do(request)
 	if err != nil {
 		return codePoints, err
 	}

src/font/download.go

@@ -11,7 +11,7 @@ import (
 	"net/http"
 	"net/url"
 
-	"github.com/jandedobbeleer/oh-my-posh/src/platform"
+	"github.com/jandedobbeleer/oh-my-posh/src/platform/net"
 )
 
 func Download(fontPath string) ([]byte, error) {
@@ -42,7 +42,7 @@ func getRemoteFile(location string) (data []byte, err error) {
 	if err != nil {
 		return nil, err
 	}
-	resp, err := platform.Client.Do(req)
+	resp, err := net.HTTPClient.Do(req)
 	if err != nil {
 		return
 	}

src/font/fonts.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/jandedobbeleer/oh-my-posh/src/platform"
+	"github.com/jandedobbeleer/oh-my-posh/src/platform/net"
 )
 
 type release struct {
@@ -57,7 +57,7 @@ func fetchFontAssets(repo string) ([]*Asset, error) {
 	}
 
 	req.Header.Add("Accept", "application/vnd.github.v3+json")
-	response, err := platform.Client.Do(req)
+	response, err := net.HTTPClient.Do(req)
 	if err != nil || response.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("failed to get %s release", repo)
 	}

src/log/log.go

@@ -22,30 +22,27 @@ func Plain() {
 	plain = true
 }
 
-func Info(message string) {
-	if !enabled {
-		return
-	}
-	log.WriteString(message)
-}
-
 func Trace(start time.Time, args ...string) {
 	if !enabled {
 		return
 	}
+
 	elapsed := time.Since(start)
 	fn, _ := funcSpec()
 	header := fmt.Sprintf("%s(%s) - %s", fn, strings.Join(args, " "), Text(elapsed.String()).Yellow().Plain())
+
 	printLn(trace, header)
 }
 
-func Debug(message string) {
+func Debug(message ...string) {
 	if !enabled {
 		return
 	}
+
 	fn, line := funcSpec()
 	header := fmt.Sprintf("%s:%d", fn, line)
-	printLn(debug, header, message)
+
+	printLn(debug, header, strings.Join(message, " "))
 }
 
 func Error(err error) {
@@ -54,6 +51,7 @@ func Error(err error) {
 	}
 	fn, line := funcSpec()
 	header := fmt.Sprintf("%s:%d", fn, line)
+
 	printLn(bug, header, err.Error())
 }
 
@@ -66,11 +64,14 @@ func funcSpec() (string, int) {
 	if !OK {
 		return "", 0
 	}
+
 	fn := runtime.FuncForPC(pc).Name()
 	fn = fn[strings.LastIndex(fn, ".")+1:]
 	file = filepath.Base(file)
+
 	if strings.HasPrefix(fn, "func") {
 		return file, line
 	}
+
 	return fmt.Sprintf("%s:%s", file, fn), line
 }

src/platform/config/download.go

@@ -0,0 +1,118 @@
+package config
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/jandedobbeleer/oh-my-posh/src/log"
+	"github.com/jandedobbeleer/oh-my-posh/src/platform/net"
+)
+
+func Download(cachePath, url string) (string, error) {
+	defer log.Trace(time.Now(), cachePath, url)
+
+	configPath, shouldUpdate := shouldUpdate(cachePath, url)
+	if !shouldUpdate {
+		return configPath, nil
+	}
+
+	log.Debug("downloading config from ", url, " to ", configPath)
+
+	ctx, cncl := context.WithTimeout(context.Background(), time.Second*time.Duration(5))
+	defer cncl()
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		log.Error(err)
+		return "", err
+	}
+
+	response, err := net.HTTPClient.Do(request)
+	if err != nil {
+		log.Error(err)
+		return "", err
+	}
+
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusOK {
+		err := fmt.Errorf("unexpected status code: %d", response.StatusCode)
+		log.Error(err)
+		return "", err
+	}
+
+	if len(configPath) == 0 {
+		configPath = formatConfigPath(url, response.Header.Get("Etag"), cachePath)
+		log.Debug("config path not set yet, using ", configPath)
+	}
+
+	out, err := os.Create(configPath)
+	if err != nil {
+		log.Error(err)
+		return "", err
+	}
+
+	defer out.Close()
+
+	_, err = io.Copy(out, response.Body)
+	if err != nil {
+		log.Error(err)
+		return "", err
+	}
+
+	log.Debug("config updated to ", configPath)
+
+	return configPath, nil
+}
+
+func shouldUpdate(cachePath, url string) (string, bool) {
+	defer log.Trace(time.Now(), cachePath, url)
+
+	ctx, cncl := context.WithTimeout(context.Background(), time.Second*time.Duration(5))
+	defer cncl()
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodHead, url, nil)
+	if err != nil {
+		log.Error(err)
+		return "", true
+	}
+
+	response, err := net.HTTPClient.Do(request)
+	if err != nil {
+		log.Error(err)
+		return "", true
+	}
+
+	defer response.Body.Close()
+
+	etag := response.Header.Get("Etag")
+	if len(etag) == 0 {
+		log.Debug("no etag found, updating config")
+		return "", true
+	}
+
+	configPath := formatConfigPath(url, etag, cachePath)
+
+	_, err = os.Stat(configPath)
+	if err != nil {
+		log.Debug("configfile ", configPath, " doest not exist, updating config")
+		return configPath, true
+	}
+
+	log.Debug("config found at", configPath, " skipping update")
+	return configPath, false
+}
+
+func formatConfigPath(url, etag, cachePath string) string {
+	ext := filepath.Ext(url)
+	etag = strings.TrimLeft(etag, `W/`)
+	etag = strings.Trim(etag, `"`)
+	filename := fmt.Sprintf("config.%s.omp%s", etag, ext)
+	return filepath.Join(cachePath, filename)
+}

src/platform/httpclient.go → src/platform/net/http.go

@@ -1,4 +1,4 @@
-package platform
+package net
 
 import (
 	"net"
@@ -31,5 +31,6 @@ var (
 		TLSHandshakeTimeout:   10 * time.Second,
 		ResponseHeaderTimeout: 10 * time.Second,
 	}
-	Client httpClient = &http.Client{Transport: defaultTransport}
+
+	HTTPClient httpClient = &http.Client{Transport: defaultTransport}
 )

src/platform/shell.go

@@ -1,9 +1,7 @@
 package platform
 
 import (
-	"bytes"
 	"context"
-	"encoding/base64"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -22,6 +20,8 @@ import (
 	"github.com/jandedobbeleer/oh-my-posh/src/log"
 	"github.com/jandedobbeleer/oh-my-posh/src/platform/battery"
 	"github.com/jandedobbeleer/oh-my-posh/src/platform/cmd"
+	"github.com/jandedobbeleer/oh-my-posh/src/platform/config"
+	"github.com/jandedobbeleer/oh-my-posh/src/platform/net"
 	"github.com/jandedobbeleer/oh-my-posh/src/regex"
 
 	disk "github.com/shirou/gopsutil/v3/disk"
@@ -239,65 +239,46 @@ func (env *Shell) Init() {
 
 func (env *Shell) resolveConfigPath() {
 	defer env.Trace(time.Now())
+
 	if len(env.CmdFlags.Config) == 0 {
 		env.CmdFlags.Config = env.Getenv("POSH_THEME")
 	}
+
 	if len(env.CmdFlags.Config) == 0 {
 		env.Debug("No config set, fallback to default config")
 		return
 	}
+
 	if strings.HasPrefix(env.CmdFlags.Config, "https://") {
-		if err := env.downloadConfig(env.CmdFlags.Config); err != nil {
-			// make it use default config when download fails
+		filePath, err := config.Download(env.CachePath(), env.CmdFlags.Config)
+		if err != nil {
 			env.Error(err)
 			env.CmdFlags.Config = ""
 			return
 		}
+
+		env.CmdFlags.Config = filePath
+		return
 	}
+
 	// Cygwin path always needs the full path as we're on Windows but not really.
 	// Doing filepath actions will convert it to a Windows path and break the init script.
 	if env.Platform() == WINDOWS && env.Shell() == "bash" {
 		env.Debug("Cygwin detected, using full path for config")
 		return
 	}
+
 	configFile := env.CmdFlags.Config
 	if strings.HasPrefix(configFile, "~") {
 		configFile = strings.TrimPrefix(configFile, "~")
 		configFile = filepath.Join(env.Home(), configFile)
 	}
+
 	if !filepath.IsAbs(configFile) {
 		configFile = filepath.Join(env.Pwd(), configFile)
 	}
-	env.CmdFlags.Config = filepath.Clean(configFile)
-}
 
-func (env *Shell) downloadConfig(location string) error {
-	defer env.Trace(time.Now(), location)
-	ext := filepath.Ext(location)
-	fileHash := base64.StdEncoding.EncodeToString([]byte(location))
-	filename := fmt.Sprintf("config.%s.omp%s", fileHash, ext)
-	configPath := filepath.Join(env.CachePath(), filename)
-	cfg, err := env.HTTPRequest(location, nil, 5000)
-	if err != nil {
-		if _, osErr := os.Stat(configPath); !os.IsNotExist(osErr) {
-			// use the already cached config
-			env.CmdFlags.Config = configPath
-			return nil
-		}
-
-		return err
-	}
-	out, err := os.Create(configPath)
-	if err != nil {
-		return err
-	}
-	defer out.Close()
-	_, err = io.Copy(out, bytes.NewReader(cfg))
-	if err != nil {
-		return err
-	}
-	env.CmdFlags.Config = configPath
-	return nil
+	env.CmdFlags.Config = filepath.Clean(configFile)
 }
 
 func (env *Shell) Trace(start time.Time, args ...string) {
@@ -639,38 +620,48 @@ func (env *Shell) unWrapError(err error) error {
 
 func (env *Shell) HTTPRequest(targetURL string, body io.Reader, timeout int, requestModifiers ...HTTPRequestModifier) ([]byte, error) {
 	defer env.Trace(time.Now(), targetURL)
+
 	ctx, cncl := context.WithTimeout(context.Background(), time.Millisecond*time.Duration(timeout))
 	defer cncl()
+
 	request, err := http.NewRequestWithContext(ctx, http.MethodGet, targetURL, body)
 	if err != nil {
 		return nil, err
 	}
+
 	for _, modifier := range requestModifiers {
 		modifier(request)
 	}
+
 	if env.CmdFlags.Debug {
 		dump, _ := httputil.DumpRequestOut(request, true)
 		env.Debug(string(dump))
 	}
-	response, err := Client.Do(request)
+
+	response, err := net.HTTPClient.Do(request)
 	if err != nil {
 		env.Error(err)
 		return nil, env.unWrapError(err)
 	}
+
 	// anything inside the range [200, 299] is considered a success
 	if response.StatusCode < 200 || response.StatusCode >= 300 {
 		message := "HTTP status code " + strconv.Itoa(response.StatusCode)
 		err := errors.New(message)
 		env.Error(err)
 		return nil, err
 	}
+
 	defer response.Body.Close()
+
 	responseBody, err := io.ReadAll(response.Body)
 	if err != nil {
 		env.Error(err)
 		return nil, err
 	}
+
 	env.Debug(string(responseBody))
+
 	return responseBody, nil
 }