add command parsing

comitium.go

@@ -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")
+}