[Feature] 1-Key Live Stream Recording & Track Ripper (R)

[arkalon76]

📌 Feature Summary

Implement 1-Key Live Stream Recording & Track Ripping to allow users to record the active internet radio stream to an audio file on disk with a single keystroke (R), automatically tagging files with station and ICY song metadata.

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🎯 Motivation & User Story

"As an internet radio listener, I often encounter exclusive live DJ sets, underground electronic mixes, and acoustic radio broadcasts that are not available anywhere on Spotify or Apple Music. I want to press R to capture the stream directly to my music folder."

Stream recording is a classic, celebrated feature from legacy tools like PyRadio and streamripper. Integrating audio capture into halpradio allows users to archive their favorite radio moments effortlessly.

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⌨️ Proposed UX & Keybindings

• Trigger Key: Press R (Shift+r) to toggle recording on/off for the currently active stream.
• Recording Directory: Defaults to ~/Music/halpradio/ (creates directory if missing; configurable in config.yaml).
• Smart Filename & Tagging:
  • Auto-generates filenames based on active ICY metadata:

    ~/Music/halpradio/[StationName] - [Artist] - [Title] - 20260815_223000.mp3
    

  • If no track metadata is available:

    ~/Music/halpradio/[StationName] - Recording - 20260815_223000.mp3
    

• UI Feedback:
  • Playerbar displays a pulsing recording badge: 🔴 REC [00:02:45]
  • Status bar displays confirmation message upon completion:
    ✅ Saved recording to ~/Music/halpradio/SomaFM - Tycho - A Walk.mp3 (18.4 MB)

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🏗️ Technical & Architectural Guidelines

1. Audio Capture Strategies by Backend (pkg/player/):
   • mpv Backend: Send IPC command or launch with --record-file=<path> / stream dump command.
   • Native Go & FFmpeg Backends: Tee the incoming HTTP audio stream using an io.MultiWriter feeding both the audio decoder and an asynchronous buffered file writer.
2. Concurrency & Thread Safety:
   • Guard recording state, file handles, and byte counters behind player.Manager.mu.
   • Ensure disk I/O occurs on a background goroutine to prevent audio stutter or UI frame drops.
3. Graceful Teardown:
   • When user stops playback (s), switches stations, or quits (q), cleanly flush and close active recording files without corrupting the container header.

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✅ Acceptance Criteria

• Pressing R starts recording active audio stream without disrupting live audio playback.
• Pressing R again or stopping the station completes and closes the recording file cleanly.
• Active recording status and elapsed duration 🔴 REC [mm:ss] render dynamically in playerbar.go.
• Recorded audio files are playable in standard audio players (VLC, QuickTime, mpv).
• Unit tests for recording file path formatting, start/stop lifecycle, and error handling.