feat(core): add output module

Author: atsyplenkov

src/core/output.rs

@@ -0,0 +1,104 @@
+use anyhow::Result;
+use serde_json::Value;
+use std::path::{Path, PathBuf};
+use std::time::{SystemTime, UNIX_EPOCH};
+use tokio::fs;
+use tokio::io::AsyncWriteExt;
+
+#[derive(Debug)]
+pub(crate) struct PreparedOutput {
+    pub(crate) output_dir: PathBuf,
+    pub(crate) figures_dir: PathBuf,
+    pub(crate) markdown_path: PathBuf,
+    pub(crate) log_path: PathBuf,
+}
+
+pub(crate) fn prepare_output_paths(
+    output_root: &Path,
+    pdf_path: &Path,
+    overwrite: bool,
+) -> Result<PreparedOutput> {
+    let stem = pdf_path
+        .file_stem()
+        .and_then(|s| s.to_str())
+        .ok_or_else(|| anyhow::anyhow!("Invalid PDF filename: {}", pdf_path.display()))?;
+
+    let output_dir = output_root.join(stem);
+    std::fs::create_dir_all(&output_dir)?;
+
+    let markdown_path = output_dir.join("index.md");
+    let figures_dir = output_dir.join("figures");
+    let log_path = output_dir.join("log.jsonl");
+
+    if !overwrite {
+        if markdown_path.exists() {
+            return Err(anyhow::anyhow!(
+                "Output already exists: {}. Re-run with --overwrite",
+                markdown_path.display()
+            ));
+        }
+        if figures_dir.exists() {
+            return Err(anyhow::anyhow!(
+                "Output already exists: {}. Re-run with --overwrite",
+                figures_dir.display()
+            ));
+        }
+    } else {
+        if markdown_path.exists() {
+            std::fs::remove_file(&markdown_path)?;
+        }
+        if figures_dir.exists() {
+            if figures_dir.is_dir() {
+                std::fs::remove_dir_all(&figures_dir)?;
+            } else {
+                std::fs::remove_file(&figures_dir)?;
+            }
+        }
+    }
+
+    std::fs::create_dir_all(&figures_dir)?;
+
+    Ok(PreparedOutput {
+        output_dir,
+        figures_dir,
+        markdown_path,
+        log_path,
+    })
+}
+
+pub(crate) async fn append_log(log_path: &Path, entry: Value) -> Result<()> {
+    if let Some(parent) = log_path.parent() {
+        fs::create_dir_all(parent).await?;
+    }
+    let mut file = fs::OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(log_path)
+        .await?;
+    let line = serde_json::to_string(&entry)?;
+    file.write_all(line.as_bytes()).await?;
+    file.write_all(b"\n").await?;
+    Ok(())
+}
+
+pub(crate) async fn atomic_write_text(path: &Path, content: &str) -> Result<()> {
+    atomic_write_bytes(path, content.as_bytes()).await
+}
+
+pub(crate) async fn atomic_write_bytes(path: &Path, content: &[u8]) -> Result<()> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent).await?;
+    }
+
+    let seed = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_nanos();
+    let temp_path = path.with_extension(format!("tmp-{}-{seed}", std::process::id()));
+    let mut temp_file = fs::File::create(&temp_path).await?;
+    temp_file.write_all(content).await?;
+    temp_file.flush().await?;
+    drop(temp_file);
+    fs::rename(&temp_path, path).await?;
+    Ok(())
+}