initial version

src/main.rs

@@ -1,3 +1,46 @@
-fn main() {
-    println!("Hello, world!");
+mod backup;
+mod store;
+
+use crate::backup::Backup;
+use crate::store::Store;
+use main_error::MainError;
+use md5::Digest;
+use std::cmp::max;
+use std::collections::HashMap;
+use std::path::PathBuf;
+use thiserror::Error;
+
+mod api;
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("Request failed: {0}")]
+    Request(#[from] std::io::Error),
+    #[error("MD5 digest mismatch for downloaded demo, expected {expected:?}, received {got:?}")]
+    DigestMismatch { expected: Digest, got: Digest },
+}
+
+fn main() -> Result<(), MainError> {
+    let mut args: HashMap<_, _> = dotenv::vars().collect();
+    let store = Store::new(args.get("STORAGE_ROOT").expect("no STORAGE_ROOT set"));
+    let state_path = PathBuf::from(args.remove("STATE_FILE").expect("no STATE_FILE set"));
+    let backup = Backup::new(store);
+
+    let last_page = if state_path.is_file() {
+        max(
+            std::fs::read_to_string(&state_path)?
+                .trim()
+                .parse::<u32>()?
+                - 1,
+            1,
+        )
+    } else {
+        1u32
+    };
+
+    let current_page = backup.backup_from(last_page)?;
+
+    std::fs::write(&state_path, format!("{}", current_page))?;
+
+    Ok(())
 }