[feat] implement backend abstraction, dynamic backend selection, and GPU feature integration

crates/polyscribe-core/src/ui/progress.rs

@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2025 <COPYRIGHT HOLDER>. All rights reserved.
+
+use indicatif::{MultiProgress, ProgressBar, ProgressStyle};
+use std::io::IsTerminal as _;
+
+/// Manages a set of per-file progress bars plus a top aggregate bar.
+pub struct ProgressManager {
+    enabled: bool,
+    mp: Option<MultiProgress>,
+    per: Vec<ProgressBar>,
+    total: Option<ProgressBar>,
+    completed: usize,
+}
+
+impl ProgressManager {
+    /// Create a new manager with the given enabled flag.
+    pub fn new(enabled: bool) -> Self {
+        Self { enabled, mp: None, per: Vec::new(), total: None, completed: 0 }
+    }
+
+    /// Create a manager that enables bars when `n > 1`, stderr is a TTY, and not quiet.
+    pub fn default_for_files(n: usize) -> Self {
+        let enabled = n > 1 && std::io::stderr().is_terminal() && !crate::is_quiet() && !crate::is_no_progress();
+        Self::new(enabled)
+    }
+
+    /// Initialize bars for the given file labels. If disabled or single file, no-op.
+    pub fn init_files(&mut self, labels: &[String]) {
+        if !self.enabled || labels.len() <= 1 {
+            // No bars in single-file mode or when disabled
+            self.enabled = false;
+            return;
+        }
+        let mp = MultiProgress::new();
+        // Aggregate bar at the top
+        let total = mp.add(ProgressBar::new(labels.len() as u64));
+        total.set_style(ProgressStyle::with_template("{prefix} [{bar:40.cyan/blue}] {pos}/{len}")
+            .unwrap()
+            .progress_chars("=>-"));
+        total.set_prefix("Total");
+        self.total = Some(total);
+        // Per-file bars
+        for label in labels {
+            let pb = mp.add(ProgressBar::new(100));
+            pb.set_style(ProgressStyle::with_template("{prefix} [{bar:40.green/black}] {pos}% {msg}")
+                .unwrap()
+                .progress_chars("=>-"));
+            pb.set_position(0);
+            pb.set_prefix(label.clone());
+            self.per.push(pb);
+        }
+        self.mp = Some(mp);
+    }
+
+    /// Returns true when bars are enabled (multi-file TTY mode).
+    pub fn is_enabled(&self) -> bool { self.enabled }
+
+    /// Get a clone of the per-file progress bar at index, if enabled.
+    pub fn per_bar(&self, idx: usize) -> Option<ProgressBar> {
+        if !self.enabled { return None; }
+        self.per.get(idx).cloned()
+    }
+
+    /// Get a clone of the aggregate (total) progress bar, if enabled.
+    pub fn total_bar(&self) -> Option<ProgressBar> {
+        if !self.enabled { return None; }
+        self.total.as_ref().cloned()
+    }
+
+    /// Mark a file as finished (set to 100% and update total counter).
+    pub fn mark_file_done(&mut self, idx: usize) {
+        if !self.enabled { return; }
+        if let Some(pb) = self.per.get(idx) {
+            pb.set_position(100);
+            pb.finish_with_message("done");
+        }
+        self.completed += 1;
+        if let Some(total) = &self.total { total.set_position(self.completed as u64); }
+    }
+}