pub mod metadata;
pub mod normalize;
pub mod path_hints;
pub mod mover;

use std::sync::Arc;
use std::time::Duration;

use crate::db;
use crate::web::AppState;

pub async fn run(state: Arc<AppState>) {
    let interval = Duration::from_secs(state.config.poll_interval_secs);
    tracing::info!("Ingest loop started, polling every {}s: {:?}", state.config.poll_interval_secs, state.config.inbox_dir);

    loop {
        match scan_inbox(&state).await {
            Ok(0) => {}
            Ok(count) => tracing::info!(count, "processed new files"),
            Err(e) => tracing::error!(?e, "inbox scan failed"),
        }
        // Re-process pending tracks (e.g. retried from admin UI)
        match reprocess_pending(&state).await {
            Ok(0) => {}
            Ok(count) => tracing::info!(count, "re-processed pending tracks"),
            Err(e) => tracing::error!(?e, "pending re-processing failed"),
        }
        // Process pending merge proposals
        match db::get_pending_merges_for_processing(&state.pool).await {
            Ok(merge_ids) => {
                for merge_id in merge_ids {
                    if let Err(e) = crate::merge::propose_merge(&state, merge_id).await {
                        tracing::error!(id = %merge_id, ?e, "Merge proposal failed");
                        let _ = db::update_merge_status(&state.pool, merge_id, "error", Some(&e.to_string())).await;
                    }
                }
            }
            Err(e) => tracing::error!(?e, "Failed to load pending merges"),
        }
        tokio::time::sleep(interval).await;
    }
}

async fn scan_inbox(state: &Arc<AppState>) -> anyhow::Result<usize> {
    let mut count = 0;
    let mut audio_files = Vec::new();
    let mut image_files = Vec::new();
    collect_files(&state.config.inbox_dir, &mut audio_files, &mut image_files).await?;

    if !audio_files.is_empty() || !image_files.is_empty() {
        tracing::info!("Scan found {} audio file(s) and {} image(s) in inbox", audio_files.len(), image_files.len());
    }

    for file_path in &audio_files {
        match process_file(state, file_path).await {
            Ok(true) => count += 1,
            Ok(false) => tracing::debug!(path = ?file_path, "skipped (already known)"),
            Err(e) => tracing::warn!(?e, path = ?file_path, "failed to process file"),
        }
    }

    // Process cover images after audio (so albums exist in DB)
    for image_path in &image_files {
        match process_cover_image(state, image_path).await {
            Ok(true) => {
                tracing::info!(path = ?image_path, "Cover image processed");
                count += 1;
            }
            Ok(false) => tracing::debug!(path = ?image_path, "cover image skipped"),
            Err(e) => tracing::warn!(?e, path = ?image_path, "failed to process cover image"),
        }
    }

    // Clean up empty directories in inbox
    if count > 0 {
        cleanup_empty_dirs(&state.config.inbox_dir).await;
    }

    Ok(count)
}

/// Re-process pending tracks from DB (e.g. tracks retried via admin UI).
/// These already have raw metadata and path hints stored — just need RAG + LLM.
async fn reprocess_pending(state: &Arc<AppState>) -> anyhow::Result<usize> {
    let pending = db::list_pending_for_processing(&state.pool, 10).await?;
    if pending.is_empty() {
        return Ok(0);
    }

    let mut count = 0;
    for pt in &pending {
        tracing::info!(id = %pt.id, title = pt.raw_title.as_deref().unwrap_or("?"), "Re-processing pending track");

        db::update_pending_status(&state.pool, pt.id, "processing", None).await?;

        // Build raw metadata and hints from stored DB fields
        let raw_meta = metadata::RawMetadata {
            title: pt.raw_title.clone(),
            artist: pt.raw_artist.clone(),
            album: pt.raw_album.clone(),
            track_number: pt.raw_track_number.map(|n| n as u32),
            year: pt.raw_year.map(|n| n as u32),
            genre: pt.raw_genre.clone(),
            duration_secs: pt.duration_secs,
        };

        let hints = db::PathHints {
            title: pt.path_title.clone(),
            artist: pt.path_artist.clone(),
            album: pt.path_album.clone(),
            year: pt.path_year,
            track_number: pt.path_track_number,
        };

        // RAG lookup
        let artist_query = raw_meta.artist.as_deref()
            .or(hints.artist.as_deref())
            .unwrap_or("");
        let album_query = raw_meta.album.as_deref()
            .or(hints.album.as_deref())
            .unwrap_or("");

        let similar_artists = if !artist_query.is_empty() {
            db::find_similar_artists(&state.pool, artist_query, 5).await.unwrap_or_default()
        } else {
            Vec::new()
        };

        let similar_albums = if !album_query.is_empty() {
            db::find_similar_albums(&state.pool, album_query, 5).await.unwrap_or_default()
        } else {
            Vec::new()
        };

        // LLM normalization (no folder context available for reprocessing from DB)
        match normalize::normalize(state, &raw_meta, &hints, &similar_artists, &similar_albums, None).await {
            Ok(normalized) => {
                let confidence = normalized.confidence.unwrap_or(0.0);
                let status = if confidence >= state.config.confidence_threshold {
                    "approved"
                } else {
                    "review"
                };

                tracing::info!(
                    id = %pt.id,
                    norm_artist = normalized.artist.as_deref().unwrap_or("-"),
                    norm_title = normalized.title.as_deref().unwrap_or("-"),
                    confidence,
                    status,
                    "Re-processing complete"
                );

                db::update_pending_normalized(&state.pool, pt.id, status, &normalized, None).await?;

                if status == "approved" {
                    let artist = normalized.artist.as_deref().unwrap_or("Unknown Artist");
                    let album = normalized.album.as_deref().unwrap_or("Unknown Album");
                    let title = normalized.title.as_deref().unwrap_or("Unknown Title");
                    let source = std::path::Path::new(&pt.inbox_path);
                    let ext = source.extension().and_then(|e| e.to_str()).unwrap_or("flac");
                    let track_num = normalized.track_number.unwrap_or(0);

                    let dest_filename = if track_num > 0 {
                        format!("{:02} - {}.{}", track_num, sanitize_filename(title), ext)
                    } else {
                        format!("{}.{}", sanitize_filename(title), ext)
                    };

                    // Check if already moved
                    let dest = state.config.storage_dir
                        .join(sanitize_filename(artist))
                        .join(sanitize_filename(album))
                        .join(&dest_filename);

                    let (storage_path, was_merged) = if dest.exists() && !source.exists() {
                        (dest.to_string_lossy().to_string(), false)
                    } else if source.exists() {
                        match mover::move_to_storage(
                            &state.config.storage_dir, artist, album, &dest_filename, source,
                        ).await {
                            Ok(mover::MoveOutcome::Moved(p)) => (p.to_string_lossy().to_string(), false),
                            Ok(mover::MoveOutcome::Merged(p)) => (p.to_string_lossy().to_string(), true),
                            Err(e) => {
                                tracing::error!(id = %pt.id, ?e, "Failed to move file");
                                db::update_pending_status(&state.pool, pt.id, "error", Some(&e.to_string())).await?;
                                continue;
                            }
                        }
                    } else {
                        tracing::error!(id = %pt.id, "Source file missing: {:?}", source);
                        db::update_pending_status(&state.pool, pt.id, "error", Some("Source file missing")).await?;
                        continue;
                    };

                    match db::approve_and_finalize(&state.pool, pt.id, &storage_path).await {
                        Ok(track_id) => {
                            if was_merged {
                                let _ = db::update_pending_status(&state.pool, pt.id, "merged", None).await;
                            }
                            tracing::info!(id = %pt.id, track_id, "Track finalized");
                        }
                        Err(e) => tracing::error!(id = %pt.id, ?e, "Failed to finalize"),
                    }
                }

                count += 1;
            }
            Err(e) => {
                tracing::error!(id = %pt.id, ?e, "LLM normalization failed");
                db::update_pending_status(&state.pool, pt.id, "error", Some(&e.to_string())).await?;
            }
        }
    }

    Ok(count)
}

/// Recursively remove empty directories inside the inbox.
/// Does not remove the inbox root itself.
async fn cleanup_empty_dirs(dir: &std::path::Path) -> bool {
    let mut entries = match tokio::fs::read_dir(dir).await {
        Ok(e) => e,
        Err(_) => return false,
    };

    let mut is_empty = true;
    while let Ok(Some(entry)) = entries.next_entry().await {
        let ft = match entry.file_type().await {
            Ok(ft) => ft,
            Err(_) => { is_empty = false; continue; }
        };
        if ft.is_dir() {
            let child_empty = Box::pin(cleanup_empty_dirs(&entry.path())).await;
            if child_empty {
                if let Err(e) = tokio::fs::remove_dir(&entry.path()).await {
                    tracing::warn!(?e, path = ?entry.path(), "Failed to remove empty directory");
                } else {
                    tracing::info!(path = ?entry.path(), "Removed empty inbox directory");
                }
            } else {
                is_empty = false;
            }
        } else {
            is_empty = false;
        }
    }
    is_empty
}

/// Recursively collect all audio files and image files under a directory.
async fn collect_files(dir: &std::path::Path, audio: &mut Vec<std::path::PathBuf>, images: &mut Vec<std::path::PathBuf>) -> anyhow::Result<()> {
    let mut entries = tokio::fs::read_dir(dir).await?;
    while let Some(entry) = entries.next_entry().await? {
        let name = entry.file_name().to_string_lossy().into_owned();
        if name.starts_with('.') {
            continue;
        }
        let ft = entry.file_type().await?;
        if ft.is_dir() {
            Box::pin(collect_files(&entry.path(), audio, images)).await?;
        } else if ft.is_file() {
            if is_audio_file(&name) {
                audio.push(entry.path());
            } else if is_cover_image(&name) {
                images.push(entry.path());
            }
        }
    }
    Ok(())
}

fn is_audio_file(name: &str) -> bool {
    let ext = name.rsplit('.').next().unwrap_or("").to_lowercase();
    matches!(
        ext.as_str(),
        "mp3" | "flac" | "ogg" | "opus" | "aac" | "m4a" | "wav" | "ape" | "wv" | "wma" | "tta" | "aiff" | "aif"
    )
}

fn is_cover_image(name: &str) -> bool {
    let ext = name.rsplit('.').next().unwrap_or("").to_lowercase();
    if !matches!(ext.as_str(), "jpg" | "jpeg" | "png" | "webp" | "bmp" | "gif") {
        return false;
    }
    let stem = std::path::Path::new(name)
        .file_stem()
        .and_then(|s| s.to_str())
        .unwrap_or("")
        .to_lowercase();
    matches!(
        stem.as_str(),
        "cover" | "front" | "folder" | "back" | "booklet" | "inlay" | "disc" | "cd"
        | "album" | "artwork" | "art" | "scan" | "thumb" | "thumbnail"
    )
}

fn classify_image(name: &str) -> &'static str {
    let stem = std::path::Path::new(name)
        .file_stem()
        .and_then(|s| s.to_str())
        .unwrap_or("")
        .to_lowercase();
    match stem.as_str() {
        "back" => "back",
        "booklet" | "inlay" | "scan" => "booklet",
        "disc" | "cd" => "disc",
        _ => "cover",
    }
}

fn mime_for_image(name: &str) -> &'static str {
    let ext = name.rsplit('.').next().unwrap_or("").to_lowercase();
    match ext.as_str() {
        "jpg" | "jpeg" => "image/jpeg",
        "png" => "image/png",
        "webp" => "image/webp",
        "gif" => "image/gif",
        "bmp" => "image/bmp",
        _ => "application/octet-stream",
    }
}

async fn process_file(state: &Arc<AppState>, file_path: &std::path::Path) -> anyhow::Result<bool> {
    let filename = file_path.file_name().and_then(|n| n.to_str()).unwrap_or("?");
    tracing::info!(file = filename, "Processing new file: {:?}", file_path);

    // Compute file hash for dedup
    tracing::info!(file = filename, "Computing file hash...");
    let path_clone = file_path.to_path_buf();
    let (hash, file_size) = tokio::task::spawn_blocking(move || -> anyhow::Result<(String, i64)> {
        let data = std::fs::read(&path_clone)?;
        let hash = blake3::hash(&data).to_hex().to_string();
        let size = data.len() as i64;
        Ok((hash, size))
    })
    .await??;
    tracing::info!(file = filename, hash = &hash[..16], size = file_size, "File hashed");

    // Skip if already known
    if db::file_hash_exists(&state.pool, &hash).await? {
        tracing::info!(file = filename, "Skipping: file hash already exists in database");
        return Ok(false);
    }

    // Extract raw metadata
    tracing::info!(file = filename, "Extracting metadata with Symphonia...");
    let path_for_meta = file_path.to_path_buf();
    let raw_meta = tokio::task::spawn_blocking(move || metadata::extract(&path_for_meta)).await??;
    tracing::info!(
        file = filename,
        artist = raw_meta.artist.as_deref().unwrap_or("-"),
        title = raw_meta.title.as_deref().unwrap_or("-"),
        album = raw_meta.album.as_deref().unwrap_or("-"),
        "Raw metadata extracted"
    );

    // Parse path hints relative to inbox dir
    let relative = file_path.strip_prefix(&state.config.inbox_dir).unwrap_or(file_path);
    let hints = path_hints::parse(relative);
    if hints.artist.is_some() || hints.album.is_some() || hints.year.is_some() {
        tracing::info!(
            file = filename,
            path_artist = hints.artist.as_deref().unwrap_or("-"),
            path_album = hints.album.as_deref().unwrap_or("-"),
            path_year = ?hints.year,
            "Path hints parsed"
        );
    }

    let inbox_path_str = file_path.to_string_lossy().to_string();

    // Insert pending record
    tracing::info!(file = filename, "Inserting pending track record...");
    let pending_id = db::insert_pending(
        &state.pool,
        &inbox_path_str,
        &hash,
        file_size,
        &db::RawFields {
            title: raw_meta.title.clone(),
            artist: raw_meta.artist.clone(),
            album: raw_meta.album.clone(),
            year: raw_meta.year.map(|y| y as i32),
            track_number: raw_meta.track_number.map(|t| t as i32),
            genre: raw_meta.genre.clone(),
        },
        &db::PathHints {
            title: hints.title.clone(),
            artist: hints.artist.clone(),
            album: hints.album.clone(),
            year: hints.year,
            track_number: hints.track_number,
        },
        raw_meta.duration_secs,
    )
    .await?;

    db::update_pending_status(&state.pool, pending_id, "processing", None).await?;

    // RAG: find similar entries in DB
    let artist_query = raw_meta.artist.as_deref()
        .or(hints.artist.as_deref())
        .unwrap_or("");
    let album_query = raw_meta.album.as_deref()
        .or(hints.album.as_deref())
        .unwrap_or("");

    tracing::info!(file = filename, "Searching database for similar artists/albums...");
    let similar_artists = if !artist_query.is_empty() {
        db::find_similar_artists(&state.pool, artist_query, 5).await.unwrap_or_default()
    } else {
        Vec::new()
    };

    let similar_albums = if !album_query.is_empty() {
        db::find_similar_albums(&state.pool, album_query, 5).await.unwrap_or_default()
    } else {
        Vec::new()
    };

    if !similar_artists.is_empty() {
        let names: Vec<&str> = similar_artists.iter().map(|a| a.name.as_str()).collect();
        tracing::info!(file = filename, matches = ?names, "Found similar artists in DB");
    }
    if !similar_albums.is_empty() {
        let names: Vec<&str> = similar_albums.iter().map(|a| a.name.as_str()).collect();
        tracing::info!(file = filename, matches = ?names, "Found similar albums in DB");
    }

    // Build folder context for the LLM
    let audio_extensions = ["flac", "mp3", "ogg", "wav", "aac", "m4a", "opus", "wma", "ape", "alac"];
    let folder_ctx = {
        let folder = file_path.parent().unwrap_or(file_path);
        let mut folder_files: Vec<String> = std::fs::read_dir(folder)
            .ok()
            .map(|rd| {
                rd.filter_map(|e| e.ok())
                  .filter_map(|e| {
                      let name = e.file_name().to_string_lossy().into_owned();
                      let ext = name.rsplit('.').next().unwrap_or("").to_lowercase();
                      if audio_extensions.contains(&ext.as_str()) { Some(name) } else { None }
                  })
                  .collect()
            })
            .unwrap_or_default();
        folder_files.sort();
        let track_count = folder_files.len();
        let folder_path = folder
            .strip_prefix(&state.config.inbox_dir)
            .unwrap_or(folder)
            .to_string_lossy()
            .into_owned();
        normalize::FolderContext { folder_path, folder_files, track_count }
    };

    // Call LLM for normalization
    tracing::info!(file = filename, model = %state.config.ollama_model, "Sending to LLM for normalization...");
    match normalize::normalize(state, &raw_meta, &hints, &similar_artists, &similar_albums, Some(&folder_ctx)).await {
        Ok(normalized) => {
            let confidence = normalized.confidence.unwrap_or(0.0);
            let status = if confidence >= state.config.confidence_threshold {
                "approved"
            } else {
                "review"
            };

            tracing::info!(
                file = filename,
                norm_artist = normalized.artist.as_deref().unwrap_or("-"),
                norm_title = normalized.title.as_deref().unwrap_or("-"),
                norm_album = normalized.album.as_deref().unwrap_or("-"),
                confidence,
                status,
                notes = normalized.notes.as_deref().unwrap_or("-"),
                "LLM normalization complete"
            );
            if !normalized.featured_artists.is_empty() {
                tracing::info!(
                    file = filename,
                    featured = ?normalized.featured_artists,
                    "Featured artists detected"
                );
            }

            db::update_pending_normalized(&state.pool, pending_id, status, &normalized, None).await?;

            // Auto-approve: move file to storage
            if status == "approved" {
                let artist = normalized.artist.as_deref().unwrap_or("Unknown Artist");
                let album = normalized.album.as_deref().unwrap_or("Unknown Album");
                let title = normalized.title.as_deref().unwrap_or("Unknown Title");
                let ext = file_path.extension().and_then(|e| e.to_str()).unwrap_or("flac");
                let track_num = normalized.track_number.unwrap_or(0);

                let dest_filename = if track_num > 0 {
                    format!("{:02} - {}.{}", track_num, sanitize_filename(title), ext)
                } else {
                    format!("{}.{}", sanitize_filename(title), ext)
                };

                tracing::info!(
                    file = filename,
                    dest_artist = artist,
                    dest_album = album,
                    dest_filename = %dest_filename,
                    "Auto-approved, moving to storage..."
                );

                match mover::move_to_storage(
                    &state.config.storage_dir,
                    artist,
                    album,
                    &dest_filename,
                    file_path,
                )
                .await
                {
                    Ok(outcome) => {
                        let (storage_path, was_merged) = match outcome {
                            mover::MoveOutcome::Moved(p) => (p, false),
                            mover::MoveOutcome::Merged(p) => (p, true),
                        };
                        let rel_path = storage_path.to_string_lossy().to_string();
                        match db::approve_and_finalize(&state.pool, pending_id, &rel_path).await {
                            Ok(track_id) => {
                                if was_merged {
                                    let _ = db::update_pending_status(&state.pool, pending_id, "merged", None).await;
                                }
                                tracing::info!(file = filename, track_id, storage = %rel_path, "Track finalized in database");
                            }
                            Err(e) => {
                                tracing::error!(file = filename, ?e, "Failed to finalize track in DB after move");
                            }
                        }
                    }
                    Err(e) => {
                        tracing::error!(file = filename, ?e, "Failed to move file to storage");
                        db::update_pending_status(&state.pool, pending_id, "error", Some(&e.to_string())).await?;
                    }
                }
            } else {
                tracing::info!(file = filename, confidence, "Sent to review queue (below threshold {})", state.config.confidence_threshold);
            }
        }
        Err(e) => {
            tracing::error!(file = filename, ?e, "LLM normalization failed");
            db::update_pending_status(&state.pool, pending_id, "error", Some(&e.to_string())).await?;
        }
    }

    Ok(true)
}

/// Process a cover image found in the inbox.
/// Uses path hints (Artist/Album/) to find the matching album in the DB,
/// then copies the image to the album's storage folder.
async fn process_cover_image(state: &Arc<AppState>, image_path: &std::path::Path) -> anyhow::Result<bool> {
    let filename = image_path.file_name().and_then(|n| n.to_str()).unwrap_or("?");

    // Hash for dedup
    let path_clone = image_path.to_path_buf();
    let (hash, file_size) = tokio::task::spawn_blocking(move || -> anyhow::Result<(String, i64)> {
        let data = std::fs::read(&path_clone)?;
        let hash = blake3::hash(&data).to_hex().to_string();
        let size = data.len() as i64;
        Ok((hash, size))
    })
    .await??;

    if db::image_hash_exists(&state.pool, &hash).await? {
        return Ok(false);
    }

    // Derive artist/album from path hints
    let relative = image_path.strip_prefix(&state.config.inbox_dir).unwrap_or(image_path);
    let components: Vec<&str> = relative
        .components()
        .filter_map(|c| c.as_os_str().to_str())
        .collect();

    tracing::info!(file = filename, path = ?relative, components = components.len(), "Processing cover image");

    // Supported structures:
    //   Artist/Album/image.jpg  (3+ components)
    //   Album/image.jpg         (2 components — album dir + image)
    if components.len() < 2 {
        tracing::info!(file = filename, "Cover image not inside an album folder, skipping");
        return Ok(false);
    }

    // The directory directly containing the image is always the album hint
    let album_raw = components[components.len() - 2];
    let path_artist = if components.len() >= 3 {
        Some(components[components.len() - 3])
    } else {
        None
    };

    let (album_name, _) = path_hints::parse_album_year_public(album_raw);

    tracing::info!(
        file = filename,
        path_artist = path_artist.unwrap_or("-"),
        album_hint = %album_name,
        "Looking up album in database..."
    );

    // Try to find album in DB — try with artist if available, then without
    let album_id = if let Some(artist) = path_artist {
        find_album_for_cover(&state.pool, artist, &album_name).await?
    } else {
        None
    };

    // If not found with artist, try fuzzy album name match across all artists
    let album_id = match album_id {
        Some(id) => Some(id),
        None => {
            let similar_albums = db::find_similar_albums(&state.pool, &album_name, 3).await.unwrap_or_default();
            if let Some(best) = similar_albums.first() {
                if best.similarity > 0.5 {
                    tracing::info!(file = filename, album = %best.name, similarity = best.similarity, "Matched album by fuzzy search");
                    Some(best.id)
                } else {
                    None
                }
            } else {
                None
            }
        }
    };

    let album_id = match album_id {
        Some(id) => id,
        None => {
            tracing::info!(
                file = filename,
                artist = path_artist.unwrap_or("-"),
                album = %album_name,
                "No matching album found in DB, skipping cover"
            );
            return Ok(false);
        }
    };

    // Determine image type and move to storage
    let image_type = classify_image(filename);
    let mime = mime_for_image(filename);

    // Get album's storage path from any track in that album
    let storage_dir_opt: Option<(String,)> = sqlx::query_as(
        "SELECT storage_path FROM tracks WHERE album_id = $1 LIMIT 1"
    )
    .bind(album_id)
    .fetch_optional(&state.pool)
    .await?;

    let album_storage_dir = match storage_dir_opt {
        Some((track_path,)) => {
            let p = std::path::Path::new(&track_path);
            match p.parent() {
                Some(dir) if dir.is_dir() => dir.to_path_buf(),
                _ => {
                    tracing::warn!(file = filename, track_path = %track_path, "Track storage path has no valid parent dir");
                    return Ok(false);
                }
            }
        }
        None => {
            tracing::info!(file = filename, album_id, "Album has no tracks in storage yet, skipping cover");
            return Ok(false);
        }
    };
    tracing::info!(file = filename, dest_dir = ?album_storage_dir, "Will copy cover to album storage dir");

    let dest = album_storage_dir.join(filename);
    if !dest.exists() {
        // Move or copy image
        match tokio::fs::rename(image_path, &dest).await {
            Ok(()) => {}
            Err(_) => {
                tokio::fs::copy(image_path, &dest).await?;
                tokio::fs::remove_file(image_path).await?;
            }
        }
    }

    let dest_str = dest.to_string_lossy().to_string();
    db::insert_album_image(&state.pool, album_id, image_type, &dest_str, &hash, mime, file_size).await?;

    tracing::info!(
        file = filename,
        album_id,
        image_type,
        dest = %dest_str,
        "Album image saved"
    );

    Ok(true)
}

/// Find an album in DB matching the path-derived artist and album name.
/// Tries exact match, then fuzzy artist + exact album, then fuzzy artist + fuzzy album.
async fn find_album_for_cover(pool: &sqlx::PgPool, path_artist: &str, album_name: &str) -> anyhow::Result<Option<i64>> {
    // Try exact match first
    if let Some(id) = db::find_album_id(pool, path_artist, album_name).await? {
        return Ok(Some(id));
    }

    // Try fuzzy artist, then exact or fuzzy album under that artist
    let similar_artists = db::find_similar_artists(pool, path_artist, 5).await.unwrap_or_default();
    for artist in &similar_artists {
        if artist.similarity < 0.3 {
            continue;
        }
        // Exact album under fuzzy artist
        if let Some(id) = db::find_album_id(pool, &artist.name, album_name).await? {
            return Ok(Some(id));
        }
        // Fuzzy album under this artist
        let similar_albums = db::find_similar_albums(pool, album_name, 3).await.unwrap_or_default();
        for album in &similar_albums {
            if album.artist_id == artist.id && album.similarity > 0.4 {
                return Ok(Some(album.id));
            }
        }
    }

    Ok(None)
}

/// Remove characters that are unsafe for filenames.
fn sanitize_filename(name: &str) -> String {
    name.chars()
        .map(|c| match c {
            '/' | '\\' | ':' | '*' | '?' | '"' | '<' | '>' | '|' => '_',
            _ => c,
        })
        .collect::<String>()
        .trim()
        .to_owned()
}