Add search iterator

src/main.rs

@@ -2,8 +2,8 @@ use std::error::Error;
 use std::path::PathBuf;
 
 use google_api_auth;
-use google_photoslibrary1;
-use google_photoslibrary1::schemas::SearchMediaItemsRequest;
+use google_photoslibrary1 as photos;
+use photos::schemas::{MediaItem, SearchMediaItemsRequest};
 use regex::Regex;
 use structopt::StructOpt;
 use yup_oauth2::{Authenticator, InstalledFlow};
@@ -43,7 +43,7 @@ struct Opt {
 fn new_client(
     credentials: &PathBuf,
     token_cache: &PathBuf,
-) -> Result<google_photoslibrary1::Client, Box<dyn Error>> {
+) -> Result<photos::Client, Box<dyn Error>> {
     let secret = yup_oauth2::read_application_secret(credentials)?;
 
     // Create an authenticator that uses an InstalledFlow to authenticate. The
@@ -58,53 +58,87 @@ fn new_client(
     .build()
     .unwrap();
 
-    let scopes = vec!["https://www.googleapis.com/auth/photoslibrary.readonly".to_string()];
+    let scopes = vec!["https://www.googleapis.com/auth/photoslibrary.readonly"];
 
     let auth = google_api_auth::yup_oauth2::from_authenticator(auth, scopes);
 
-    Ok(google_photoslibrary1::Client::new(auth))
+    Ok(photos::Client::new(auth))
 }
 
-fn search_media_items(
-    client: google_photoslibrary1::Client,
-    album_id: String,
-) -> Result<(), Box<dyn Error>> {
-    let mut page_token = None;
-    let mut total = 0;
-    loop {
-        let resp = client
-            .media_items()
-            .search(SearchMediaItemsRequest {
-                album_id: Some(album_id.clone()),
-                // 100 is the documented max.
-                page_size: Some(100),
-                page_token,
-                ..Default::default()
-            })
-            .execute_with_all_fields()?;
+struct SearchIter<'a> {
+    client: &'a photos::Client,
+    items: ::std::vec::IntoIter<MediaItem>,
+    finished: bool,
+    req: SearchMediaItemsRequest,
+}
 
-        let media_items = resp.media_items.ok_or("no results")?;
-        println!("got ({}) items", media_items.len());
-        total += media_items.len();
-        for mi in media_items {
-            println!(
-                "{} {}",
-                mi.id.unwrap_or("NO ID".to_string()),
-                mi.filename.unwrap_or("NO FILENAME".to_string())
-            );
-        }
-        page_token = resp.next_page_token;
-        if page_token.is_none() {
-            println!("({}) items total", total);
-            return Ok(());
+impl<'a> SearchIter<'a> {
+    fn new(client: &'a photos::Client, req: SearchMediaItemsRequest) -> Self {
+        SearchIter {
+            client,
+            items: Vec::new().into_iter(),
+            finished: false,
+            req,
         }
     }
 }
 
-fn list_albums(
-    client: google_photoslibrary1::Client,
-    title_filter: Option<Regex>,
-) -> Result<(), Box<dyn Error>> {
+impl<'a> Iterator for SearchIter<'a> {
+    type Item = Result<MediaItem, photos::Error>;
+
+    fn next(&mut self) -> Option<Result<MediaItem, photos::Error>> {
+        loop {
+            if let Some(v) = self.items.next() {
+                return Some(Ok(v));
+            }
+            if self.finished {
+                return None;
+            }
+            let resp = match self
+                .client
+                .media_items()
+                .search(self.req.clone())
+                .execute_with_default_fields()
+            {
+                Ok(resp) => resp,
+                Err(err) => return Some(Err(err)),
+            };
+            if resp.next_page_token.is_none() {
+                self.finished = true;
+            }
+            self.req.page_token = resp.next_page_token;
+            if let Some(items) = resp.media_items {
+                self.items = items.into_iter();
+            }
+        }
+    }
+}
+
+fn search_media_items(client: photos::Client, album_id: String) -> Result<(), Box<dyn Error>> {
+    let mut total = 0;
+    let media_items = SearchIter::new(
+        &client,
+        SearchMediaItemsRequest {
+            album_id: Some(album_id.clone()),
+            // 100 is the documented max.
+            page_size: Some(100),
+            ..Default::default()
+        },
+    );
+    for mi in media_items {
+        let mi = mi?;
+        total += 1;
+        println!(
+            "{} {}",
+            mi.id.unwrap_or("NO ID".to_string()),
+            mi.filename.unwrap_or("NO FILENAME".to_string())
+        );
+    }
+    println!("({}) items total", total);
+    Ok(())
+}
+
+fn list_albums(client: photos::Client, title_filter: Option<Regex>) -> Result<(), Box<dyn Error>> {
     for album in client
         .shared_albums()
         .list()