feat: add irc-backed streamer split view

2026-04-29 00:40:35 +02:00
parent 01b044e305
commit ad1f5ec3ff
8 changed files with 1500 additions and 42 deletions
@@ -0,0 +1,252 @@
+// Package irc manages Twitch IRC chat connections for watched streamers.
+package irc
+
+import (
+	"bufio"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"strings"
+	"sync"
+	"time"
+)
+
+const DefaultAddr = "irc.chat.twitch.tv:6667"
+
+// ConnectionState describes the lifecycle state of one IRC connection.
+type ConnectionState string
+
+const (
+	StatePending      ConnectionState = "pending"
+	StateJoined       ConnectionState = "joined"
+	StateDisconnected ConnectionState = "disconnected"
+)
+
+// Event carries one IRC lifecycle change or log line for a streamer connection.
+type Event struct {
+	Streamer string
+	State    ConnectionState
+	Line     string
+}
+
+// EventSink consumes IRC events emitted by a client or manager.
+type EventSink func(Event)
+
+// Client maintains one Twitch IRC connection for a single streamer channel.
+type Client struct {
+	Addr        string
+	Login       string
+	Token       string
+	Streamer    string
+	Once        bool
+	Debug       bool
+	Out         io.Writer
+	Events      EventSink
+	DialContext func(context.Context, string, string) (net.Conn, error)
+}
+
+// Run connects, authenticates, joins the configured streamer channel, and stays connected.
+func (c *Client) Run(ctx context.Context) error {
+	if c.Login == "" {
+		return errors.New("missing Twitch login")
+	}
+	if c.Token == "" {
+		return errors.New("missing OAuth access token")
+	}
+	if c.Streamer == "" {
+		return errors.New("missing streamer")
+	}
+
+	addr := c.Addr
+	if addr == "" {
+		addr = DefaultAddr
+	}
+
+	c.status("Connecting to %s\n", addr)
+	conn, err := c.dial(ctx, addr)
+	if err != nil {
+		return fmt.Errorf("connect to Twitch IRC: %w", err)
+	}
+
+	session := &session{
+		conn:  conn,
+		out:   c.Out,
+		debug: c.Debug,
+	}
+	defer session.close()
+
+	done := make(chan struct{})
+	defer close(done)
+	go func() {
+		select {
+		case <-ctx.Done():
+			_ = session.send("QUIT :parasocial shutting down", false)
+			session.close()
+		case <-done:
+		}
+	}()
+
+	if err := session.send("PASS oauth:"+c.Token, true); err != nil {
+		return err
+	}
+	c.status("Sent PASS\n")
+	if err := session.send("NICK "+c.Login, false); err != nil {
+		return err
+	}
+	c.status("Sent NICK %s\n", c.Login)
+	if err := session.send("JOIN #"+c.Streamer, false); err != nil {
+		return err
+	}
+	c.status("Sent JOIN #%s\n", c.Streamer)
+
+	reader := bufio.NewReader(conn)
+	joined := false
+	for {
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			if ctx.Err() != nil {
+				return nil
+			}
+			if joined {
+				return fmt.Errorf("network interruption after join: %w", err)
+			}
+			return fmt.Errorf("IRC connection closed before join confirmation: %w", err)
+		}
+
+		line = strings.TrimRight(line, "\r\n")
+		session.debugIn(line)
+
+		if payload, ok := pingPayload(line); ok {
+			if err := session.send("PONG "+payload, false); err != nil {
+				return err
+			}
+			c.status("Responded to PING\n")
+			continue
+		}
+
+		if isAuthFailure(line) {
+			return fmt.Errorf("IRC authentication failure: %s", line)
+		}
+		if isJoinDenied(line, c.Streamer) {
+			return fmt.Errorf("IRC join denied: %s", line)
+		}
+		if isWelcome(line) {
+			c.status("IRC authentication accepted\n")
+			continue
+		}
+		if isJoinConfirmation(line, c.Login, c.Streamer) {
+			joinedLine := fmt.Sprintf("Joined #%s as %s", c.Streamer, c.Login)
+			c.status("%s\n", joinedLine)
+			c.emit(StateJoined, joinedLine)
+			joined = true
+			if c.Once {
+				if err := session.send("QUIT :parasocial --once complete", false); err != nil {
+					return err
+				}
+				return nil
+			}
+			continue
+		}
+		if joined {
+			c.status("%s\n", line)
+			c.emit("", line)
+		}
+	}
+}
+
+type session struct {
+	conn  net.Conn
+	out   io.Writer
+	debug bool
+	mu    sync.Mutex
+	once  sync.Once
+}
+
+func (s *session) send(line string, redact bool) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	debugLine := line
+	if redact {
+		debugLine = "PASS oauth:<redacted>"
+	}
+	if s.debug && s.out != nil {
+		fmt.Fprintf(s.out, "> %s\n", debugLine)
+	}
+	_, err := fmt.Fprintf(s.conn, "%s\r\n", line)
+	return err
+}
+
+func (s *session) debugIn(line string) {
+	if s.debug && s.out != nil {
+		fmt.Fprintf(s.out, "< %s\n", line)
+	}
+}
+
+func (s *session) close() {
+	s.once.Do(func() {
+		_ = s.conn.SetDeadline(time.Now())
+		_ = s.conn.Close()
+	})
+}
+
+func (c *Client) dial(ctx context.Context, addr string) (net.Conn, error) {
+	if c.DialContext != nil {
+		return c.DialContext(ctx, "tcp", addr)
+	}
+	dialer := &net.Dialer{Timeout: 30 * time.Second}
+	return dialer.DialContext(ctx, "tcp", addr)
+}
+
+func (c *Client) status(format string, args ...any) {
+	if c.Out == nil {
+		return
+	}
+	fmt.Fprintf(c.Out, format, args...)
+}
+
+func (c *Client) emit(state ConnectionState, line string) {
+	if c.Events == nil {
+		return
+	}
+	c.Events(Event{
+		Streamer: c.Streamer,
+		State:    state,
+		Line:     line,
+	})
+}
+
+func pingPayload(line string) (string, bool) {
+	if strings.HasPrefix(line, "PING ") {
+		return strings.TrimSpace(strings.TrimPrefix(line, "PING ")), true
+	}
+	return "", false
+}
+
+func isWelcome(line string) bool {
+	return strings.Contains(line, " 001 ")
+}
+
+func isAuthFailure(line string) bool {
+	lower := strings.ToLower(line)
+	return strings.Contains(lower, "login authentication failed") ||
+		strings.Contains(lower, "improperly formatted auth") ||
+		strings.Contains(lower, "error logging in")
+}
+
+func isJoinDenied(line, streamer string) bool {
+	lower := strings.ToLower(line)
+	channel := "#" + strings.ToLower(streamer)
+	return (strings.Contains(lower, " 403 ") && strings.Contains(lower, channel)) ||
+		(strings.Contains(lower, "notice "+channel) && strings.Contains(lower, "banned")) ||
+		(strings.Contains(lower, "notice "+channel) && strings.Contains(lower, "not permitted"))
+}
+
+func isJoinConfirmation(line, login, streamer string) bool {
+	lower := strings.ToLower(line)
+	channel := "#" + strings.ToLower(streamer)
+	return strings.Contains(lower, " join "+channel) &&
+		(strings.HasPrefix(lower, ":"+strings.ToLower(login)+"!") || strings.Contains(lower, "!"))
+}