Added AI agent to manage metadata

furumi-agent/src/ingest/metadata.rs

@@ -0,0 +1,129 @@
+use std::path::Path;
+
+use symphonia::core::{
+    codecs::CODEC_TYPE_NULL,
+    formats::FormatOptions,
+    io::MediaSourceStream,
+    meta::{MetadataOptions, StandardTagKey},
+    probe::Hint,
+};
+
+#[derive(Debug, Default)]
+pub struct RawMetadata {
+    pub title: Option<String>,
+    pub artist: Option<String>,
+    pub album: Option<String>,
+    pub track_number: Option<u32>,
+    pub year: Option<u32>,
+    pub genre: Option<String>,
+    pub duration_secs: Option<f64>,
+}
+
+/// Extract metadata from an audio file using Symphonia.
+/// Must be called from a blocking context (spawn_blocking).
+pub fn extract(path: &Path) -> anyhow::Result<RawMetadata> {
+    let file = std::fs::File::open(path)?;
+    let mss = MediaSourceStream::new(Box::new(file), Default::default());
+
+    let mut hint = Hint::new();
+    if let Some(ext) = path.extension().and_then(|e| e.to_str()) {
+        hint.with_extension(ext);
+    }
+
+    let mut probed = symphonia::default::get_probe().format(
+        &hint,
+        mss,
+        &FormatOptions { enable_gapless: false, ..Default::default() },
+        &MetadataOptions::default(),
+    )?;
+
+    let mut meta = RawMetadata::default();
+
+    // Check metadata side-data (e.g., ID3 tags probed before format)
+    if let Some(rev) = probed.metadata.get().as_ref().and_then(|m| m.current()) {
+        extract_tags(rev.tags(), &mut meta);
+    }
+
+    // Also check format-embedded metadata
+    if let Some(rev) = probed.format.metadata().current() {
+        if meta.title.is_none() {
+            extract_tags(rev.tags(), &mut meta);
+        }
+    }
+
+    // Duration
+    meta.duration_secs = probed
+        .format
+        .tracks()
+        .iter()
+        .find(|t| t.codec_params.codec != CODEC_TYPE_NULL)
+        .and_then(|t| {
+            let n_frames = t.codec_params.n_frames?;
+            let tb = t.codec_params.time_base?;
+            Some(n_frames as f64 * tb.numer as f64 / tb.denom as f64)
+        });
+
+    Ok(meta)
+}
+
+fn extract_tags(tags: &[symphonia::core::meta::Tag], meta: &mut RawMetadata) {
+    for tag in tags {
+        let value = fix_encoding(tag.value.to_string());
+        if let Some(key) = tag.std_key {
+            match key {
+                StandardTagKey::TrackTitle => {
+                    if meta.title.is_none() {
+                        meta.title = Some(value);
+                    }
+                }
+                StandardTagKey::Artist | StandardTagKey::Performer => {
+                    if meta.artist.is_none() {
+                        meta.artist = Some(value);
+                    }
+                }
+                StandardTagKey::Album => {
+                    if meta.album.is_none() {
+                        meta.album = Some(value);
+                    }
+                }
+                StandardTagKey::TrackNumber => {
+                    if meta.track_number.is_none() {
+                        meta.track_number = value.parse().ok();
+                    }
+                }
+                StandardTagKey::Date | StandardTagKey::OriginalDate => {
+                    if meta.year.is_none() {
+                        meta.year = value[..4.min(value.len())].parse().ok();
+                    }
+                }
+                StandardTagKey::Genre => {
+                    if meta.genre.is_none() {
+                        meta.genre = Some(value);
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+}
+
+/// Heuristic to fix mojibake (CP1251 bytes interpreted as Latin-1/Windows-1252).
+fn fix_encoding(s: String) -> String {
+    let bytes: Vec<u8> = s.chars().map(|c| c as u32).filter(|&c| c <= 255).map(|c| c as u8).collect();
+
+    if bytes.len() != s.chars().count() {
+        return s;
+    }
+
+    let has_mojibake = bytes.iter().any(|&b| b >= 0xC0);
+    if !has_mojibake {
+        return s;
+    }
+
+    let (decoded, _, errors) = encoding_rs::WINDOWS_1251.decode(&bytes);
+    if errors {
+        return s;
+    }
+
+    decoded.into_owned()
+}