add command parsing

2021-03-16 10:20:31 -06:00
parent f82e090577
commit 91e663c0f0
6 changed files with 221 additions and 0 deletions
@@ -0,0 +1,118 @@
+// Copyright (C) 2021 nytpu
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// For more license details, see LICENSE or <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+// comitium is a feed aggregator for gemini. see README.md for more details and
+// doc/comitium.1.scd for a manual page.
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/mitchellh/go-homedir"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprint(os.Stderr, "Please provide a command.\n\n")
+		usage()
+		os.Exit(1)
+	}
+
+	// these are special cases where we shouldn't bother to do anything else
+	if os.Args[1] == "help" {
+		usage()
+		os.Exit(0)
+	}
+	if os.Args[1] == "version" {
+		fmt.Printf("comitium v%v, commit %v\n", Version, Commit)
+		os.Exit(0)
+	}
+
+	c, ok := commands[os.Args[1]]
+	if !ok {
+		fmt.Fprint(os.Stderr, "Unrecognized Command.\n\n")
+		usage()
+		os.Exit(1)
+	}
+
+	c.AddFlagSet(globalFs)
+	c.Parse(os.Args[2:])
+
+	// dataPath is the location where all the data (list of subs, cached hashes,
+	// etcetera) are stored
+	dataPath := getDataPath()
+
+	switch os.Args[1] {
+	case "refresh":
+		fmt.Println("Refresh")
+	case "list":
+		fmt.Println("List")
+	case "add":
+		fmt.Println("Add")
+		fmt.Printf("Format: %v\n", *addTypeFlag)
+	case "remove":
+		fmt.Println("Remove")
+	}
+
+	fmt.Printf("Detected data path: %v\n", dataPath)
+}
+
+// verifyPath will expand ~ if neccessary and will clean the path.
+func verifyPath(p string) string {
+	if n, err := homedir.Expand(p); err != nil {
+		return filepath.Clean(p)
+	} else {
+		return filepath.Clean(n)
+	}
+}
+
+// getDataPath will return a data path in a gracefully degrading tree, picking
+// the first that exists:
+// --data flag, $COMITIUM_DATA, $XDG_DATA_HOME/comitium,
+// $HOME/.local/share/comitium, $HOME/.comitium, $PWD (last resort)
+func getDataPath() string {
+	if *dataFlag != "" {
+		return verifyPath(*dataFlag)
+	}
+
+	if env := os.Getenv("COMITIUM_DATA"); env != "" {
+		return verifyPath(env)
+	}
+	if env := os.Getenv("XDG_DATA_HOME"); env != "" {
+		return verifyPath(env + "/comitium")
+	}
+
+	home, err := homedir.Dir()
+	if err == nil {
+		if _, err := os.Stat(verifyPath(home + "/.local")); !os.IsNotExist(err) {
+			return verifyPath(home + "/.local/share/comitium")
+		}
+		return verifyPath(home + "/.comitium")
+	}
+
+	log.Printf("Error finding a suitable directory! Falling back to the current working directory. See \"comitium help\" or comitium(1) for more information.")
+	return verifyPath("comitium")
+}
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "Usage:\n")
+	fmt.Fprintf(os.Stderr, "  %v <command> [FLAGS] [ARGUMENTS]\n\n", os.Args[0])
+
+	fmt.Fprint(os.Stderr, "Commands:\n")
+	for _, v := range commandInfo {
+		// FIXME: find a way to dynamically match the spacing that
+		// flag.PrintDefaults() outputs (instead of hardcoding "-20")
+		fmt.Fprintf(os.Stderr, "  %-20s%s\n", v.Name, v.Usage)
+	}
+
+	fmt.Fprintf(os.Stderr, "\nGlobal Flags:\n%v", globalFs.FlagUsages())
+	// command-specific flags should be printed here
+	fmt.Fprintf(os.Stderr, "Flags for \"add\":\n%v\n", commands["add"].FlagUsages())
+
+	//fmt.Fprintf(os.Stderr, "To see specific details for a command, run \"%v <command> -h\"\n", os.Args[0])
+	fmt.Fprint(os.Stderr, "For more help, see comitium(1).\n")
+}
@@ -0,0 +1,31 @@
+// Copyright (C) 2021 nytpu
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// For more license details, see LICENSE or <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+package main
+
+import (
+	"testing"
+)
+
+func TestVerifyPath(t *testing.T) {
+	given := []string{
+		"~////../hello-world////",
+		"/home/~/../test/../..",
+		"/test/torture/../../../../test/./././torture/./0011/",
+		".local/share/comitium/",
+		"/home/test/.local/share/comitium",
+	}
+	want := []string{
+		"/home/hello-world",
+		"/",
+		"/test/torture/0011",
+		".local/share/comitium",
+		"/home/test/.local/share/comitium",
+	}
+	for i, v := range given {
+		if result := verifyPath(v); result != want[i] {
+			t.Fatalf(`verifyPath("%v") = %v, want %v`, v, result, want[i])
+		}
+	}
+}
@@ -0,0 +1,49 @@
+// Copyright (C) 2021 nytpu
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// For more license details, see LICENSE or <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+package main
+
+import flag "github.com/spf13/pflag"
+
+// globalFs contains the flags that are used in every command.
+var (
+	globalFs = flag.NewFlagSet("global", flag.ContinueOnError)
+
+	dataFlag = globalFs.StringP("data", "d", "", "The data directory where comitium will store its files")
+)
+
+// command holds fields used for printing information about a command.
+type command struct {
+	Name  string
+	Usage string
+}
+
+// info about all the accepted commands
+var commandInfo = []command{
+	{"refresh", "Check for new updates to subscriptions"},
+	{"list", "List all subscriptions"},
+	{"add", "Add a new subscription"},
+	{"remove", "Remove a subscription"},
+	{"help", "Print usage information"},
+	{"version", "Print version information"},
+}
+
+var commands = map[string]*flag.FlagSet{
+	"refresh": flag.NewFlagSet("refresh", flag.ExitOnError),
+	"list":    flag.NewFlagSet("list", flag.ExitOnError),
+	"add":     flag.NewFlagSet("add", flag.ExitOnError),
+	"remove":  flag.NewFlagSet("remove", flag.ExitOnError),
+}
+
+// set up various flags for each individual command
+var (
+	// add
+	addTypeFlag = commands["add"].StringP(
+		"type", "t", // long and shorthand flag
+		"g", // default
+		`Select which type a subscription is. Can be "g" for a
+Gemini feed; "a" for Atom, RSS, & JSON; or "c" to watch
+the page for changes.`,
+	)
+)
@@ -0,0 +1,8 @@
+module golang.nytpu.com/comitium
+
+go 1.16
+
+require (
+	github.com/mitchellh/go-homedir v1.1.0
+	github.com/spf13/pflag v1.0.5
+)
@@ -0,0 +1,4 @@
+github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
+github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
@@ -0,0 +1,11 @@
+// Copyright (C) 2021 nytpu
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// For more license details, see LICENSE or <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+package main
+
+// These variables are set by the linker. They can be modified in the Makefile.
+var (
+	Version = "Unknown"
+	Commit  = "Unknown"
+)