From 057771467dce4622513f6ce21a76c6c7f8ccaa69 Mon Sep 17 00:00:00 2001
From: Derek Stevens <nilix@nilfm.cc>
Date: Mon, 9 Jan 2023 22:23:25 -0700
Subject: [PATCH] wrote raven, a twtxt client

---
 .gitignore |   1 +
 config.go  | 176 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 feed.go    | 153 ++++++++++++++++++++++++++++++++++++++++++++++
 go.mod     |   3 +
 raven.go   |  55 +++++++++++++++++
 types.go   |  33 ++++++++++
 6 files changed, 421 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 config.go
 create mode 100644 feed.go
 create mode 100644 go.mod
 create mode 100644 raven.go
 create mode 100644 types.go

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..cc301e4
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/raven
\ No newline at end of file
diff --git a/config.go b/config.go
new file mode 100644
index 0000000..b40763a
--- /dev/null
+++ b/config.go
@@ -0,0 +1,176 @@
+package  main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+func GetConfigLocation() string {
+	home := os.Getenv("HOME")
+	appdata := os.Getenv("APPDATA")
+	switch runtime.GOOS {
+	case "windows":
+		return filepath.Join(appdata, "raven")
+	case "darwin":
+		return filepath.Join(home, "Library", "Application Support", "raven")
+	case "plan9":
+		return filepath.Join(home, "lib", "raven")
+	default:
+		return filepath.Join(home, ".config", "raven")
+	}
+}
+
+func ensureConfigLocationExists() {
+	fileInfo, err := os.Stat(GetConfigLocation())
+
+	if os.IsNotExist(err) {
+		os.MkdirAll(GetConfigLocation(), os.ModePerm)
+	} else if !fileInfo.IsDir() {
+		panic("Config location is not a directory!")
+	}
+}
+
+func ReadConfig() *Config {
+	ensureConfigLocationExists()
+	return parseConfig(filepath.Join(GetConfigLocation(), "raven.conf"))
+}
+
+func (self *Config) Write() error {
+	ensureConfigLocationExists()
+	return writeConfig(self, filepath.Join(GetConfigLocation(), "raven.conf"))
+}
+
+func (self *Config) IsNull() bool {
+	// zero-values for StaticShowHTML, StaticShowHidden, and StaticMaxUploadMB are valid
+	return len(self.Nick) == 0 || len(self.FeedFile) == 0 || len(self.FriendsFile) == 0
+}
+
+func (self *Config) RunWizard() {
+	fmt.Printf("All options are required.\n")
+	defer func(cfg *Config) {
+		if r := recover(); r != nil {
+			fmt.Printf("Invalid selection, starting over...")
+			cfg.RunWizard()
+		}
+	}(self)
+	inputBuf := ""
+
+	fmt.Printf("your nickname? ")
+	ensureNonEmptyOption(&inputBuf)
+	self.Nick = inputBuf
+
+	inputBuf = ""
+	fmt.Printf("your twtxt file location? ")
+	ensureNonEmptyOption(&inputBuf)
+	self.FeedFile = inputBuf
+
+	inputBuf = ""
+	fmt.Printf("your feed in ascending order? ")
+	self.FeedAscend = ensureBooleanOption(&inputBuf)
+
+	inputBuf = ""
+	fmt.Printf("file location containing your friends' feeds? ")
+	ensureNonEmptyOption(&inputBuf)
+	self.FriendsFile = inputBuf
+
+	inputBuf = ""
+	fmt.Printf("number of posts to store in memory? ")
+	self.MaxPosts = ensureNumberOption(&inputBuf)
+
+	fmt.Printf("Configuration complete!\n")
+	self.Write()
+}
+
+func ensureNonEmptyOption(buffer *string) {
+	for {
+		fmt.Scanln(buffer)
+		if len(strings.TrimSpace(*buffer)) != 0 {
+			break
+		}
+		fmt.Println("Please enter a nonempty value")
+	}
+}
+
+func ensureBooleanOption(buffer *string) bool {
+	for {
+		fmt.Scanln(buffer)
+		trimmedBuf := strings.TrimSpace(*buffer)
+		v, err := strconv.ParseBool(trimmedBuf)
+		if err == nil {
+			return v
+		}
+		fmt.Println("Please enter a true or false value")
+	}
+}
+
+func ensureNumberOption(buffer *string) int64 {
+	for {
+		fmt.Scanln(buffer)
+		trimmedBuf := strings.TrimSpace(*buffer)
+		v, err := strconv.ParseInt(trimmedBuf, 10, 64)
+		if err == nil && v >= 0 {
+			return v
+		}
+		fmt.Println("Please enter a nonnegative integer")
+	}
+}
+
+func writeConfig(cfg *Config, configFile string) error {
+	f, err := os.Create(configFile)
+	if err != nil {
+		return err
+	}
+
+	defer f.Close()
+	f.WriteString("nick=" + cfg.Nick + "\n")
+	f.WriteString("feedfile=" + cfg.FeedFile + "\n")
+	f.WriteString("feed_ascend=" + strconv.FormatBool(cfg.FeedAscend) + "\n")
+	f.WriteString("friendsfile=" + cfg.FriendsFile + "\n")
+	f.WriteString("max_posts=" + strconv.FormatInt(cfg.MaxPosts, 10) + "\n")
+	return nil
+}
+
+func parseConfig(configFile string) *Config {
+	f, err := os.ReadFile(configFile)
+	cfg := &Config{}
+	if err != nil {
+	   fmt.Println(err.Error())
+		return cfg
+	}
+
+	fileData := string(f[:])
+
+	lines := strings.Split(fileData, "\n")
+
+	for _, l := range lines {
+		if len(l) == 0 {
+			continue
+		}
+		if !strings.Contains(l, "=") {
+			panic("Malformed config not in INI format")
+		}
+
+		kvp := strings.Split(l, "=")
+		k := strings.TrimSpace(kvp[0])
+		v := strings.TrimSpace(kvp[1])
+		switch k {
+		case "feedfile":
+			cfg.FeedFile = v
+		case "feed_ascend":
+			cfg.FeedAscend, _ = strconv.ParseBool(v)
+		case "friendsfile":
+			cfg.FriendsFile = v
+		case "max_posts":
+			cfg.MaxPosts, _ = strconv.ParseInt(v, 10, 64)
+		case "nick":
+			cfg.Nick = v
+		default:
+			panic("Unrecognized config option: " + k)
+		}
+	}
+	return cfg
+}
\ No newline at end of file
diff --git a/feed.go b/feed.go
new file mode 100644
index 0000000..be23540
--- /dev/null
+++ b/feed.go
@@ -0,0 +1,153 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"sort"
+	"strings"
+	"time"
+)
+
+func appendToFile(filename, data string) error {
+	f, err := os.OpenFile(filename, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
+	if err != nil {
+		return err
+	}
+	f.WriteString(data)
+	f.Close()
+	return nil
+}
+
+func prependToFile(filename, data string) error {
+	ogData, err := os.ReadFile(filename)
+	if err != nil {
+		return err
+	}
+
+	fileData := string(ogData[:])
+
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	f.WriteString(data + fileData)
+	f.Close()
+	return nil
+}
+
+func Post(twt, feedFile string, ascend bool) error {
+	fileInfo, err := os.Stat(feedFile)
+	if err != nil {
+		os.Create(feedFile)
+	} else if fileInfo.IsDir() {
+		return errors.New("Feed file is a directory")
+	}
+
+	if ascend {
+		return appendToFile(feedFile, time.Now().Format(time.RFC3339)+"\t"+twt+"\n")
+	}
+	return prependToFile(feedFile, time.Now().Format(time.RFC3339)+"\t"+twt+"\n")
+}
+
+func buildFeedFromUrl(feed *Feed, nick, url string, max int64) error {
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+
+	defer resp.Body.Close()
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	return buildFeed(feed, nick, string(body[:]), max)
+}
+
+func buildFeedFromPath(feed *Feed, nick, filename string, max int64) error {
+	f, err := os.ReadFile(filename)
+	if err != nil {
+		return err
+	}
+
+	return buildFeed(feed, nick, string(f[:]), max)
+}
+
+func buildFeed(feed *Feed, nick, data string, max int64) error {
+	lines := strings.Split(data, "\n")
+
+	for i, l := range lines {
+	   if int64(i) > max {
+	     return nil
+	   }
+		parts := strings.Split(l, "\t")
+		t, err := time.Parse(time.RFC3339, parts[0])
+		if err != nil {
+		  continue
+		}
+		*feed = append(*feed, FeedEntry{
+			Nick:      nick,
+			Timestamp: t,
+			Post:      parts[1],
+		})
+	}
+	return nil
+}
+
+func printFeed(feed *Feed) {
+	sort.Sort(*feed)
+	for _, entry := range *feed {
+		fmt.Printf("[%s] <%s> %s\n", entry.Timestamp.Format(time.Stamp), entry.Nick, entry.Post)
+	}
+}
+
+func GetFeed(friend, friendsFile string, max int64) error {
+	feed := &Feed{}
+
+	f, err := os.ReadFile(friendsFile)
+	if err != nil {
+		return err
+	}
+
+	fileData := string(f[:])
+
+	lines := strings.Split(fileData, "\n")
+
+	for _, l := range lines {
+		if len(l) == 0 {
+			continue
+		}
+		if !strings.Contains(l, " ") {
+			return errors.New("Malformed friends file not in the format 'FRIEND_NAME https://friend.site/path/to/feed.txt'")
+		}
+
+		kvp := strings.Split(l, " ")
+		k := kvp[0]
+		v := kvp[1]
+
+		if k == friend || len(friend) == 0 {
+			err = buildFeedFromUrl(feed, k, v, max)
+			if err != nil {
+				return err
+			}
+			if len(friend) > 0 {
+			 break
+			}
+		}
+	}
+	printFeed(feed)
+	return nil
+}
+
+func GetOwnFeed(nick, feedFile string, max int64) error {
+	feed := &Feed{}
+	err := buildFeedFromPath(feed, nick, feedFile, max)
+	if err != nil {
+		return err
+	}
+	printFeed(feed)
+	return nil
+}
\ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..f42ee3f
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module nilfm.cc/git/raven
+
+go 1.19
diff --git a/raven.go b/raven.go
new file mode 100644
index 0000000..86b7dce
--- /dev/null
+++ b/raven.go
@@ -0,0 +1,55 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+)
+
+func helpMe(prog string) {
+	fmt.Printf("%s: twtxt client\n", prog)
+	fmt.Printf("usage: %s CMD <ARG>\n\n", prog)
+	fmt.Println("available commands are")
+	fmt.Println("  twt: post to your twtxt file")
+	fmt.Println("  feed: read the feed from all your friends, or the one named with ARG if given")
+	fmt.Println("  self: read your own feed\n")
+	fmt.Println("Config file is stored in " + GetConfigLocation() + " and is initialized automatically with a wizard")
+}
+
+func run(args []string) error {
+	cfg := ReadConfig()
+	if cfg.IsNull() {
+		cfg.RunWizard()
+	}
+
+	if len(args) == 1 || args[1] == "help" || args[1] == "-h" || args[1] == "--help" {
+		helpMe(args[0])
+		return nil
+	} else {
+		switch args[1] {
+		case "twt":
+			return Post(args[2], cfg.FeedFile, cfg.FeedAscend)
+		case "feed":
+			if len(args) > 2 {
+				return GetFeed(args[2], cfg.FriendsFile, cfg.MaxPosts)
+			} else {
+				return GetFeed("", cfg.FriendsFile, cfg.MaxPosts)
+			}
+		case "self":
+			return GetOwnFeed(cfg.Nick, cfg.FeedFile, cfg.MaxPosts)
+		default:
+			helpMe(args[0])
+			return errors.New("Unrecognized command line option: " + args[1] + "\n")
+		}
+	}
+}
+
+func main() {
+	err := run(os.Args)
+	if err == nil {
+		os.Exit(0)
+	} else {
+		fmt.Println(err.Error())
+		os.Exit(1)
+	}
+}
diff --git a/types.go b/types.go
new file mode 100644
index 0000000..9b2d9df
--- /dev/null
+++ b/types.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"time"
+)
+
+type Config struct {
+	FeedFile         string
+	FeedAscend       bool
+	FriendsFile      string
+	MaxPosts int64
+	Nick             string
+}
+
+type FeedEntry struct {
+	Nick      string
+	Timestamp time.Time
+	Post      string
+}
+
+type Feed []FeedEntry
+
+func (self Feed) Len() int {
+	return len(self)
+}
+
+func (self Feed) Swap(i, j int) {
+	self[i], self[j] = self[j], self[i]
+}
+
+func (self Feed) Less(i, j int) bool {
+	return self[i].Timestamp.After(self[j].Timestamp)
+}