Mediatypes support (#134)

Co-authored-by: makeworld <25111343+makeworld-the-better-one@users.noreply.github.com>
Co-authored-by: Stephen Robinson <stephen@drsudo.com>

README.md

@@ -116,6 +116,8 @@ Features in *italics* are in the master branch, but not in the latest release.
   - Disabled by default, enable in config
 - [x] Proxying
   - Schemes like Gopher or HTTP can be proxied through a Gemini server
+- [x] *Configure applications to open particular mediatypes*
+    - [ ] Allow piping/streaming content instead of downloading it first
 - [x] Client certificate support
   - [ ] Full client certificate UX within the client
     - Create transient and permanent certs within the client, per domain

config/config.go

@@ -38,6 +38,7 @@ var bkmkDir string
 var bkmkPath string
 
 var DownloadsDir string
+var TempDownloadsDir string
 
 // Subscriptions
 var subscriptionDir string
@@ -46,6 +47,13 @@ var SubscriptionPath string
 // Command for opening HTTP(S) URLs in the browser, from "a-general.http" in config.
 var HTTPCommand []string
 
+type MediaHandler struct {
+	Cmd      []string
+	NoPrompt bool
+}
+
+var MediaHandlers = make(map[string]MediaHandler)
+
 func Init() error {
 
 	// *** Set paths ***
@@ -194,6 +202,36 @@ func Init() error {
 		DownloadsDir = dDir
 	}
 
+	// Setup temporary downloads dir
+	if viper.GetString("a-general.temp_downloads") == "" {
+		TempDownloadsDir = filepath.Join(os.TempDir(), "amfora_temp")
+
+		// Make sure it exists
+		err = os.MkdirAll(TempDownloadsDir, 0755)
+		if err != nil {
+			return fmt.Errorf("temp downloads path could not be created: %s", TempDownloadsDir)
+		}
+	} else {
+		// Validate path
+		dDir := viper.GetString("a-general.temp_downloads")
+		di, err := os.Stat(dDir)
+		if err == nil {
+			if !di.IsDir() {
+				return fmt.Errorf("temp downloads path specified is not a directory: %s", dDir)
+			}
+		} else if os.IsNotExist(err) {
+			// Try to create path
+			err = os.MkdirAll(dDir, 0755)
+			if err != nil {
+				return fmt.Errorf("temp downloads path could not be created: %s", dDir)
+			}
+		} else {
+			// Some other error
+			return fmt.Errorf("couldn't access temp downloads directory: %s", dDir)
+		}
+		TempDownloadsDir = dDir
+	}
+
 	// *** Setup vipers ***
 
 	TofuStore.SetConfigFile(tofuDBPath)
@@ -228,6 +266,7 @@ func Init() error {
 	viper.SetDefault("a-general.left_margin", 0.15)
 	viper.SetDefault("a-general.max_width", 100)
 	viper.SetDefault("a-general.downloads", "")
+	viper.SetDefault("a-general.temp_downloads", "")
 	viper.SetDefault("a-general.page_max_size", 2097152)
 	viper.SetDefault("a-general.page_max_time", 10)
 	viper.SetDefault("a-general.emoji_favicons", false)
@@ -279,5 +318,26 @@ func Init() error {
 		HTTPCommand = strings.Fields(viper.GetString("a-general.http"))
 	}
 
+	var rawMediaHandlers []struct {
+		Cmd      []string `mapstructure:"cmd"`
+		Types    []string `mapstructure:"types"`
+		NoPrompt bool     `mapstructure:"no_prompt"`
+	}
+	err = viper.UnmarshalKey("mediatype-handlers", &rawMediaHandlers)
+	if err != nil {
+		return fmt.Errorf("couldn't parse mediatype-handlers section in config: %w", err)
+	}
+	for _, rawMediaHandler := range rawMediaHandlers {
+		for _, typ := range rawMediaHandler.Types {
+			if _, ok := MediaHandlers[typ]; ok {
+				return fmt.Errorf("multiple mediatype-handlers defined for %v", typ)
+			}
+			MediaHandlers[typ] = MediaHandler{
+				Cmd:      rawMediaHandler.Cmd,
+				NoPrompt: rawMediaHandler.NoPrompt,
+			}
+		}
+	}
+
 	return nil
 }

config/default.go

@@ -115,6 +115,54 @@ shift_numbers = "!@#$%^&*()"
 other = 'off'
 
 
+# [[mediatype-handlers]]
+# Specify what applications will open certain media types.
+# By default your default application will be used to open the file when you select "Open".
+# You only need to configure this section if you want to override your default application,
+# or do special things like streaming.
+#
+# To open jpeg files with the feh command:
+#   [[mediatype-handlers]]
+#   cmd = ["feh"]
+#   types = ["image/jpeg"]
+#
+# Each command that you specify must come under its own [[mediatype-handlers]]. You may
+# specify as many [[mediatype-handlers]] as you want to setup multiple commands.
+#
+# If the subtype is omitted then the specified command will be used for the
+# entire type:
+#   [[mediatype-handlers]]
+#   command = ["vlc", "--flag"]
+#   types = ["audio", "video"]
+#
+# A catch-all handler can by specified with "*".
+# Note that there are already catch-all handlers in place for all OSes,
+# that open the file using your default application. This is only if you
+# want to override that.
+#   [[mediatype-handlers]]
+#   cmd = ["some-command"]
+#   types = [
+#           "application/pdf",
+#           "*",
+#   ]
+#
+# If you want to always open a type in its viewer without the download or open
+# prompt appearing, you can add no_prompt = true
+#
+#   [[mediatype-handlers]]
+#   cmd = ["feh"]
+#   types = ["image"]
+#   no_prompt = true
+#
+# Note: Multiple handlers cannot be defined for the same full media type, but
+# still there needs to be an order for which handlers are used. The following
+# order applies regardless of the order written in the config:
+#
+# 1. Full media type: "image/jpeg"
+# 2. Just type: "image"
+# 3. Catch-all: "*"
+
+
 [cache]
 # Options for page cache - which is only for text/gemini pages
 # Increase the cache size to speed up browsing at the expense of memory

config/default.sh

@@ -1,6 +1,10 @@
 #!/usr/bin/env bash
 
-head -n 3 default.go | tee default.go > /dev/null
+cat > default.go <<-EOF
+package config
+
+//go:generate ./default.sh
+EOF
 echo -n 'var defaultConf = []byte(`' >> default.go
 cat ../default-config.toml >> default.go
-echo '`)' >> default.go
+echo '`)' >> default.go

default-config.toml

@@ -112,6 +112,54 @@ shift_numbers = "!@#$%^&*()"
 other = 'off'
 
 
+# [[mediatype-handlers]]
+# Specify what applications will open certain media types.
+# By default your default application will be used to open the file when you select "Open".
+# You only need to configure this section if you want to override your default application,
+# or do special things like streaming.
+#
+# To open jpeg files with the feh command:
+#   [[mediatype-handlers]]
+#   cmd = ["feh"]
+#   types = ["image/jpeg"]
+#
+# Each command that you specify must come under its own [[mediatype-handlers]]. You may
+# specify as many [[mediatype-handlers]] as you want to setup multiple commands.
+#
+# If the subtype is omitted then the specified command will be used for the
+# entire type:
+#   [[mediatype-handlers]]
+#   command = ["vlc", "--flag"]
+#   types = ["audio", "video"]
+#
+# A catch-all handler can by specified with "*".
+# Note that there are already catch-all handlers in place for all OSes,
+# that open the file using your default application. This is only if you
+# want to override that.
+#   [[mediatype-handlers]]
+#   cmd = ["some-command"]
+#   types = [
+#           "application/pdf",
+#           "*",
+#   ]
+#
+# If you want to always open a type in its viewer without the download or open
+# prompt appearing, you can add no_prompt = true
+#
+#   [[mediatype-handlers]]
+#   cmd = ["feh"]
+#   types = ["image"]
+#   no_prompt = true
+#
+# Note: Multiple handlers cannot be defined for the same full media type, but
+# still there needs to be an order for which handlers are used. The following
+# order applies regardless of the order written in the config:
+#
+# 1. Full media type: "image/jpeg"
+# 2. Just type: "image"
+# 3. Catch-all: "*"
+
+
 [cache]
 # Options for page cache - which is only for text/gemini pages
 # Increase the cache size to speed up browsing at the expense of memory

display/download.go

@@ -4,8 +4,10 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"mime"
 	"net/url"
 	"os"
+	"os/exec"
 	"path"
 	"path/filepath"
 	"strconv"
@@ -15,15 +17,16 @@ import (
 	"github.com/gdamore/tcell"
 	"github.com/makeworld-the-better-one/amfora/config"
 	"github.com/makeworld-the-better-one/amfora/structs"
+	"github.com/makeworld-the-better-one/amfora/sysopen"
 	"github.com/makeworld-the-better-one/go-gemini"
 	"github.com/makeworld-the-better-one/progressbar/v3"
 	"github.com/spf13/viper"
 	"gitlab.com/tslocum/cview"
 )
 
-// For choosing between download and the portal - copy of YesNo basically
+// For choosing between download and opening - copy of YesNo basically
 var dlChoiceModal = cview.NewModal().
-	AddButtons([]string{"Download", "Open in portal", "Cancel"})
+	AddButtons([]string{"Open", "Download", "Cancel"})
 
 // Channel to indicate what choice they made using the button text
 var dlChoiceCh = make(chan string)
@@ -83,46 +86,62 @@ func dlInit() {
 	})
 }
 
+func getMediaHandler(resp *gemini.Response) config.MediaHandler {
+	def := config.MediaHandler{
+		Cmd:      nil,
+		NoPrompt: false,
+	}
+
+	mediatype, _, err := mime.ParseMediaType(resp.Meta)
+	if err != nil {
+		return def
+	}
+
+	if ret, ok := config.MediaHandlers[mediatype]; ok {
+		return ret
+	}
+
+	splitType := strings.Split(mediatype, "/")[0]
+	if ret, ok := config.MediaHandlers[splitType]; ok {
+		return ret
+	}
+
+	if ret, ok := config.MediaHandlers["*"]; ok {
+		return ret
+	}
+
+	return def
+}
+
 // dlChoice displays the download choice modal and acts on the user's choice.
 // It should run in a goroutine.
 func dlChoice(text, u string, resp *gemini.Response) {
 	defer resp.Body.Close()
 
-	parsed, err := url.Parse(u)
-	if err != nil {
-		Error("URL Error", err.Error())
-		return
+	mediaHandler := getMediaHandler(resp)
+	var choice string
+
+	if mediaHandler.NoPrompt {
+		choice = "Open"
+	} else {
+		dlChoiceModal.SetText(text)
+		tabPages.ShowPage("dlChoice")
+		tabPages.SendToFront("dlChoice")
+		App.SetFocus(dlChoiceModal)
+		App.Draw()
+		choice = <-dlChoiceCh
 	}
 
-	dlChoiceModal.SetText(text)
-	tabPages.ShowPage("dlChoice")
-	tabPages.SendToFront("dlChoice")
-	App.SetFocus(dlChoiceModal)
-	App.Draw()
-
-	choice := <-dlChoiceCh
 	if choice == "Download" {
 		tabPages.HidePage("dlChoice")
 		App.Draw()
-		downloadURL(u, resp)
+		downloadURL(config.DownloadsDir, u, resp)
 		return
 	}
-	if choice == "Open in portal" {
-		// Open in mozz's proxy
-		portalURL := u
-		if parsed.RawQuery != "" {
-			// Remove query and add encoded version on the end
-			query := parsed.RawQuery
-			parsed.RawQuery = ""
-			portalURL = parsed.String() + "%3F" + query
-		}
-		portalURL = strings.TrimPrefix(portalURL, "gemini://") + "?raw=1"
-		ok := handleHTTP("https://portal.mozz.us/gemini/"+portalURL, false)
-		if ok {
-			tabPages.SwitchToPage(strconv.Itoa(curTab))
-			App.SetFocus(tabs[curTab].view)
-			App.Draw()
-		}
+	if choice == "Open" {
+		tabPages.HidePage("dlChoice")
+		App.Draw()
+		open(u, resp)
 		return
 	}
 	tabPages.SwitchToPage(strconv.Itoa(curTab))
@@ -130,9 +149,43 @@ func dlChoice(text, u string, resp *gemini.Response) {
 	App.Draw()
 }
 
+// open performs the same actions as downloadURL except it also opens the file.
+// If there is no system viewer configured for the particular mediatype, it opens it
+// with the default system viewer.
+func open(u string, resp *gemini.Response) {
+	mediaHandler := getMediaHandler(resp)
+	path := downloadURL(config.TempDownloadsDir, u, resp)
+	if path == "" {
+		return
+	}
+	tabPages.SwitchToPage(strconv.Itoa(curTab))
+	App.SetFocus(tabs[curTab].view)
+	App.Draw()
+	if mediaHandler.Cmd == nil {
+		// Open with system default viewer
+		_, err := sysopen.Open(path)
+		if err != nil {
+			Error("System Viewer Error", err.Error())
+			return
+		}
+		Info("Opened in default system viewer")
+	} else {
+		cmd := mediaHandler.Cmd
+		err := exec.Command(cmd[0], append(cmd[1:], path)...).Start()
+		if err != nil {
+			Error("File Opening Error", "Error executing custom command: "+err.Error())
+			return
+		}
+		Info("Opened with " + cmd[0])
+	}
+	App.SetFocus(dlModal)
+	App.Draw()
+}
+
 // downloadURL pulls up a modal to show download progress and saves the URL content.
 // downloadPage should be used for Page content.
-func downloadURL(u string, resp *gemini.Response) {
+// Returns location downloaded to or an empty string on error.
+func downloadURL(dir, u string, resp *gemini.Response) string {
 	_, _, width, _ := dlModal.GetInnerRect()
 	// Copy of progressbar.DefaultBytesSilent with custom width
 	bar := progressbar.NewOptions64(
@@ -146,15 +199,15 @@ func downloadURL(u string, resp *gemini.Response) {
 	)
 	bar.RenderBlank() //nolint:errcheck
 
-	savePath, err := downloadNameFromURL(u, "")
+	savePath, err := downloadNameFromURL(dir, u, "")
 	if err != nil {
 		Error("Download Error", "Error deciding on file name: "+err.Error())
-		return
+		return ""
 	}
 	f, err := os.OpenFile(savePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
 	if err != nil {
 		Error("Download Error", "Error creating download file: "+err.Error())
-		return
+		return ""
 	}
 	defer f.Close()
 
@@ -184,7 +237,7 @@ func downloadURL(u string, resp *gemini.Response) {
 		Error("Download Error", err.Error())
 		f.Close()
 		os.Remove(savePath) // Remove partial file
-		return
+		return ""
 	}
 	dlModal.SetText(fmt.Sprintf("Download complete! File saved to %s.", savePath))
 	dlModal.ClearButtons()
@@ -192,6 +245,8 @@ func downloadURL(u string, resp *gemini.Response) {
 	dlModal.GetForm().SetFocus(100)
 	App.SetFocus(dlModal)
 	App.Draw()
+
+	return savePath
 }
 
 // downloadPage saves the passed Page to a file.
@@ -202,9 +257,9 @@ func downloadPage(p *structs.Page) (string, error) {
 	var err error
 
 	if p.Mediatype == structs.TextGemini {
-		savePath, err = downloadNameFromURL(p.URL, ".gmi")
+		savePath, err = downloadNameFromURL(config.DownloadsDir, p.URL, ".gmi")
 	} else {
-		savePath, err = downloadNameFromURL(p.URL, ".txt")
+		savePath, err = downloadNameFromURL(config.DownloadsDir, p.URL, ".txt")
 	}
 	if err != nil {
 		return "", err
@@ -221,13 +276,13 @@ func downloadPage(p *structs.Page) (string, error) {
 // downloadNameFromURL takes a URl and returns a safe download path that will not overwrite any existing file.
 // ext is an extension that will be added if the file has no extension, and for domain only URLs.
 // It should include the dot.
-func downloadNameFromURL(u string, ext string) (string, error) {
+func downloadNameFromURL(dir, u, ext string) (string, error) {
 	var name string
 	var err error
 	parsed, _ := url.Parse(u)
 	if parsed.Path == "" || path.Base(parsed.Path) == "/" {
 		// No file, just the root domain
-		name, err = getSafeDownloadName(parsed.Hostname()+ext, true, 0)
+		name, err = getSafeDownloadName(dir, parsed.Hostname()+ext, true, 0)
 		if err != nil {
 			return "", err
 		}
@@ -238,23 +293,23 @@ func downloadNameFromURL(u string, ext string) (string, error) {
 			// No extension
 			name += ext
 		}
-		name, err = getSafeDownloadName(name, false, 0)
+		name, err = getSafeDownloadName(dir, name, false, 0)
 		if err != nil {
 			return "", err
 		}
 	}
-	return filepath.Join(config.DownloadsDir, name), nil
+	return filepath.Join(dir, name), nil
 }
 
 // getSafeDownloadName is used by downloads.go only.
-// It returns a modified name that is unique for the downloads folder.
+// It returns a modified name that is unique for the specified folder.
 // This way duplicate saved files will not overwrite each other.
 //
 // lastDot should be set to true if the number added to the name should come before
 // the last dot in the filename instead of the first.
 //
 // n should be set to 0, it is used for recursiveness.
-func getSafeDownloadName(name string, lastDot bool, n int) (string, error) {
+func getSafeDownloadName(dir, name string, lastDot bool, n int) (string, error) {
 	// newName("test.txt", 3) -> "test(3).txt"
 	newName := func() string {
 		if n <= 0 {
@@ -271,7 +326,7 @@ func getSafeDownloadName(name string, lastDot bool, n int) (string, error) {
 		return name[:idx] + "(" + strconv.Itoa(n) + ")" + name[idx:]
 	}
 
-	d, err := os.Open(config.DownloadsDir)
+	d, err := os.Open(dir)
 	if err != nil {
 		return "", err
 	}
@@ -285,7 +340,7 @@ func getSafeDownloadName(name string, lastDot bool, n int) (string, error) {
 	for i := range files {
 		if nn == files[i] {
 			d.Close()
-			return getSafeDownloadName(name, lastDot, n+1)
+			return getSafeDownloadName(dir, name, lastDot, n+1)
 		}
 	}
 	d.Close()

sysopen/open_browser_darwin.go

@@ -0,0 +1,14 @@
+// +build darwin
+
+package sysopen
+
+import "os/exec"
+
+// Open opens `path` in default system viewer.
+func Open(path string) (string, error) {
+	err := exec.Command("open", path).Start()
+	if err != nil {
+		return "", err
+	}
+	return "Opened in default system viewer", nil
+}

sysopen/open_browser_other.go

@@ -0,0 +1,11 @@
+// +build !linux,!darwin,!windows,!freebsd,!netbsd,!openbsd
+
+package sysopen
+
+import "fmt"
+
+// Open opens `path` in default system viewer, but not on this OS.
+func Open(path string) (string, error) {
+	return "", fmt.Errorf("unsupported OS for default system viewer. " +
+		"Set a catch-all [[mediatype-handlers]] command in the config")
+}

sysopen/open_browser_unix.go

@@ -0,0 +1,35 @@
+// +build linux freebsd netbsd openbsd
+
+//nolint:goerr113
+package sysopen
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+// Open opens `path` in default system viewer. It tries to do so using
+// xdg-open. It only works if there is a display server working.
+func Open(path string) (string, error) {
+	var (
+		xorgDisplay                     = os.Getenv("DISPLAY")
+		waylandDisplay                  = os.Getenv("WAYLAND_DISPLAY")
+		xdgOpenPath, xdgOpenNotFoundErr = exec.LookPath("xdg-open")
+	)
+	switch {
+	case xorgDisplay == "" && waylandDisplay == "":
+		return "", fmt.Errorf("no display server was found. " +
+			"You may set a default [[mediatype-handlers]] command in the config")
+	case xdgOpenNotFoundErr == nil:
+		// Use start rather than run or output in order
+		// to make application run in background.
+		if err := exec.Command(xdgOpenPath, path).Start(); err != nil {
+			return "", err
+		}
+		return "Opened in default system viewer", nil
+	default:
+		return "", fmt.Errorf("could not determine default system viewer. " +
+			"Set a catch-all [[mediatype-handlers]] command in the config")
+	}
+}

sysopen/open_browser_windows.go

@@ -0,0 +1,15 @@
+// +build windows
+// +build !linux !darwin !freebsd !netbsd !openbsd
+
+package sysopen
+
+import "os/exec"
+
+// Open opens `path` in default system vierwer.
+func Open(path string) (string, error) {
+	err := exec.Command("rundll32", "url.dll,FileProtocolHandler", path).Start()
+	if err != nil {
+		return "", err
+	}
+	return "Opened in default system viewer", nil
+}