Add file and chapter details fetching

Fetching file details allows us to download them to the correct location
later.

Chapter details are currently limited to is_skippable, which might be
used to determine whether to make the corresponding spine item
non-linear. Other details such as the title shall be fetched from the
spine and table-of-contents endpoints later.

2 files changed, 60 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index 165d6be..30f08ff 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,7 +4,7 @@ mod models;
 use anyhow::{Context, Result};
 use clap::Parser;
 use http_client::build_authenticated_client;
-use models::{EpubResponse, SearchResponse};
+use models::{Chapter, EpubResponse, FileEntry, Paginated, SearchResponse};
 use reqwest::Client;
 
 /// Download and generate an EPUB from Safari Books Online.
@@ -50,6 +50,34 @@ async fn fetch_epub_data(client: &Client, bookid: &str) -> Result<EpubResponse>
     Ok(response)
 }
 
+/// Fetch a paginated API.
+async fn fetch_all_pages<T>(client: &reqwest::Client, mut url: String) -> Result<Vec<T>>
+where
+    T: serde::de::DeserializeOwned,
+{
+    let mut items = Vec::new();
+    loop {
+        // GET current URL and deserialize into Paginated<T>.
+        let response = client
+            .get(&url)
+            .send()
+            .await?
+            .error_for_status()?
+            .json::<Paginated<T>>()
+            .await
+            .context("Failed to deserialize API response.")?;
+        // Extend items with the page's results.
+        items.extend(response.results);
+        // Set url to next page if available, else break.
+        if let Some(next) = response.next {
+            url = next;
+        } else {
+            break;
+        }
+    }
+    Ok(items)
+}
+
 #[tokio::main]
 async fn main() -> Result<()> {
     // Parse the command line arguments
@@ -81,5 +109,9 @@ async fn main() -> Result<()> {
     println!("Resources URL: {}", epub_data.files);
     println!("------------------\n");
 
+    println!("Fetching book structure...");
+    let chapters: Vec<Chapter> = fetch_all_pages(&client, epub_data.chapters.clone()).await?;
+    let file_entries: Vec<FileEntry> = fetch_all_pages(&client, epub_data.files.clone()).await?;
+
     Ok(())
 }
diff --git a/src/models.rs b/src/models.rs
index 77afeb2..174b983 100644
--- a/src/models.rs
+++ b/src/models.rs
@@ -23,3 +23,30 @@ pub struct EpubResponse {
     pub chapters: String, // This is a URL to the chapters list
     pub files: String,    // This is a URL to the resource files
 }
+
+// --- Generic Model for paginated API ---
+
+#[derive(Debug, serde::Deserialize)]
+pub struct Paginated<T> {
+    pub next: Option<String>,
+    pub results: Vec<T>,
+}
+
+/// Model for chapters API.
+#[derive(Debug, Deserialize)]
+pub struct Chapter {
+    pub ourn: String,
+    pub is_skippable: bool,
+}
+
+/// Model for files API.
+#[derive(Debug, Deserialize)]
+pub struct FileEntry {
+    pub ourn: String,
+    pub url: String,
+    pub full_path: String,
+    pub media_type: String,
+    pub filename: String,
+    pub filename_ext: String,
+    pub kind: String,
+}