v2: feature proposals

[raitonoberu]

Originally sptlrx was designed to only support Spotify, but was quickly updated with many other features. And the current Spotify-centric design makes it difficult to implement new features. I want to start from scratch.

In this issue, I'll be keeping a wishlist of features/ideas for sptlrx v2, which will eventually turn into a to-do list. You guys are welcome to discuss or add anything too :)

• Multi-player (DRAFT: Multi-player, Multi-lyric source enhancements (IN PROGRESS) #40, Support configuring several players #63). Iterate through enabled players and select the one that currently has something playing. Prioritization.
• Multi-source (DRAFT: Multi-player, Multi-lyric source enhancements (IN PROGRESS) #40). Iterate through the sources and select the one with the timesynced lyric. Prioritization. Same priority sources should all be queried and the best one should be selected.
• Improve local source. Attempt to find .lrc file based on track path (Add support for local lyric uri #53). Attempt to extract embedded lyrics.
• “No text” placeholder (Suggestion: Indicate when a lyric wasn't found #55). Make it optional.
• Remove support for lyricsapi. This has just been a fancy proxy to lrclib for a long time. So replace it with plain lrclib (+optional search logic described here).
• Improved .lrc file parser (Ignore LRC file tags #51). We may find some tags useful!
• Spotify authentication via API (Is it possible to authenticate using spotify api instead of cookie #56). The current implementation was made with using the internal API to retrieve song lyrics directly from Spotify in mind. However, there are now other ways to retrieve song lyrics that work just as well. Take advantage of them and use the public API just to get the title and position. May require a lot of work, so probably won't be in 2.0.
• Support for nscpot (Support for ncspot remote control (IPC) #38). Again, a lot of work for a potentially small number of users, so only if this gets enough votes.
• TOML config. The config structure is going to change a lot anyway, and I feel the yaml format is not flexible/convenient enough. Migration command.
• Sensible defaults. Now we show text on how to set up Spotify cookies on first run. Instead let's default to lrclib & mpris (unfortunately only for linux).
• Logging (Black screen #45). In its current state (ignoreErrors flag) it's just awful. Just write it somewhere, it won't hurt anyone.
• Test coverage... No comments here.

[raitonoberu]

This is how pretty our .toml config would look. Any thoughts?

[style]
align = "center"

[style.current]
foreground = 0xffc0cb

[players.spotify]
enabled = true
cookie = "qwerty"
priority = 1

[players.mpris]
enabled = true
whitelist = ["rhythmbox", "firefox"]
priority = 0

[source.spotify]
enabled = true
priority = 2

[sources.local]
enabled = true
directory = "~/Music"
priority = 1

[sources.lrclib]
enabled = true
priority = 0

[logging]
enabled = true
file = "/tmp/sptlrx.log"