Reference of v4 song info

arguments	description	optional
songname	any song name for fuzzy search	NO

Explain

Search and return the song info.

Return data

format follows the songlist file

• title_localized.ja maybe null and title_localized.en always exist
• Append ratingReal in the difficulties which contains the real song rating
• Append ratingPlus to tag the song level which has + suffix, like 9+, 10+
• Replace audioPreview and audioPreviewEnd into audioTimeSec
• Append totalNotes

{
    "status": 0,
    "content": {
        "id": "ifi",
        "title_localized": {
            "en": "#1f1e33"
        },
        "artist": "かめりあ(EDP)",
        "bpm": "181",
        "bpm_base": 181,
        "set": "vs",
        "audioTimeSec": 163,
        "side": 1,
        "remote_dl": true,
        "world_unlock": false,
        "date": 1590537604,
        "version": "3.0",
        "difficulties": [
            {
                "ratingClass": 0,
                "chartDesigner": "夜浪",
                "jacketDesigner": "望月けい",
                "rating": 5,
                "ratingReal": 5.5,
		"totalNotes": 765
            },
            {
                "ratingClass": 1,
                "chartDesigner": "夜浪",
                "jacketDesigner": "望月けい",
                "rating": 9,
                "ratingReal": 9.2,
		"totalNotes": 1144
            },
            {
                "ratingClass": 2,
                "chartDesigner": "夜浪 VS 東星 \"Convergence\"",
                "jacketDesigner": "望月けい",
                "rating": 10,
                "ratingReal": 10.9,
                "ratingPlus": true,
		"totalNotes": 1576
            }
        ]
    }
}

Error status

status	description
0	everything is OK
-1	invalid songname
-2	this song is not recorded in the database
-3	too many records
-233	unknown error occurred