feat: Implement course-level asset management and interactive media markers.

services/cms-service/src/exporter.rs

@@ -2,7 +2,10 @@ use chrono::{DateTime, Utc};
 use common::models::{Course, Lesson, Module};
 use serde::{Deserialize, Serialize};
 use sqlx::PgPool;
+use std::io::Cursor;
+use std::io::Write;
 use uuid::Uuid;
+use zip::write::FileOptions;
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct CourseExport {
@@ -63,3 +66,50 @@ pub async fn get_course_data(pool: &PgPool, course_id: Uuid) -> anyhow::Result<C
         exported_at: Utc::now(),
     })
 }
+
+pub async fn generate_course_zip(pool: &PgPool, course_id: Uuid) -> anyhow::Result<Vec<u8>> {
+    let course_data = get_course_data(pool, course_id).await?;
+    let assets =
+        sqlx::query_as::<_, common::models::Asset>("SELECT * FROM assets WHERE course_id = $1")
+            .bind(course_id)
+            .fetch_all(pool)
+            .await?;
+
+    let mut buf = Vec::new();
+    let mut zip = zip::ZipWriter::new(Cursor::new(&mut buf));
+
+    let options = FileOptions::default()
+        .compression_method(zip::CompressionMethod::Stored)
+        .unix_permissions(0o755);
+
+    // 1. Add course.json
+    zip.start_file("course.json", options)?;
+    let json_bytes = serde_json::to_vec_pretty(&course_data)?;
+    zip.write_all(&json_bytes)?;
+
+    // 2. Add Assets
+    for asset in assets {
+        // Use the internal storage filename (UUID.ext) to avoid collisions
+        let storage_filename = asset
+            .storage_path
+            .split('/')
+            .last()
+            .unwrap_or(&asset.filename);
+        let zip_path = format!("assets/{}", storage_filename);
+
+        if let Ok(file_content) = tokio::fs::read(&asset.storage_path).await {
+            zip.start_file(zip_path, options)?;
+            zip.write_all(&file_content)?;
+        } else {
+            tracing::warn!(
+                "Failed to read asset file for export: {}",
+                asset.storage_path
+            );
+        }
+    }
+
+    zip.finish()?;
+    drop(zip);
+
+    Ok(buf)
+}