Implement application layer

- Add DTOs with validation
- Implement use cases for create and get operations
- Add unit tests for use cases
- Update progress tracking

Author: codevalley

jump/Cargo.toml

@@ -19,6 +19,9 @@ tokio = { version = "1.32", features = ["full"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 
+# Validation
+validator = { version = "0.16", features = ["derive"] }
+
 # Logging and tracing
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

jump/src/application/dtos.rs

@@ -0,0 +1,148 @@
+//! Data Transfer Objects (DTOs) for the application layer.
+//!
+//! This module contains all the DTOs used for:
+//! - API request/response objects
+//! - Data validation
+//! - Serialization/deserialization of payloads
+//! 
+//! DTOs are designed to be API-version specific and decouple the domain model
+//! from the external interface.
+
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use validator::Validate;
+
+/// Request DTO for creating a new payload.
+/// 
+/// This struct represents the expected JSON structure for POST /api/v1/payloads
+/// 
+/// # Example JSON
+/// ```json
+/// {
+///   "content": "Your payload content here",
+///   "mime_type": "text/plain",
+///   "expiry_time": "2024-03-14T12:00:00Z"
+/// }
+/// ```
+#[derive(Debug, Deserialize, Validate)]
+pub struct CreatePayloadRequest {
+    /// The content to be shared. Must not be empty.
+    #[validate(length(min = 1, message = "Content cannot be empty"))]
+    #[validate(length(max = 1048576, message = "Content cannot exceed 1MB"))]
+    pub content: String,
+
+    /// Optional MIME type of the content. If not provided, defaults to "text/plain".
+    #[validate(regex(
+        path = "MIME_TYPE_REGEX",
+        message = "Invalid MIME type format"
+    ))]
+    pub mime_type: Option<String>,
+
+    /// Optional expiry time. If not provided, defaults to 24 hours from creation.
+    pub expiry_time: Option<DateTime<Utc>>,
+}
+
+/// Response DTO for successful payload creation.
+/// 
+/// This struct represents the JSON structure returned after successfully
+/// creating a new payload.
+#[derive(Debug, Serialize)]
+pub struct CreatePayloadResponse {
+    /// The unique identifier for accessing the payload
+    pub hash_id: String,
+    
+    /// The stored content
+    pub content: String,
+    
+    /// The MIME type of the content
+    pub mime_type: String,
+    
+    /// When the payload was created
+    pub created_at: DateTime<Utc>,
+    
+    /// When the payload was last updated
+    pub updated_at: DateTime<Utc>,
+    
+    /// When the payload was last viewed (if ever)
+    pub viewed_at: Option<DateTime<Utc>>,
+    
+    /// When the payload will expire
+    pub expiry_time: DateTime<Utc>,
+}
+
+/// Response DTO for retrieving a payload.
+/// 
+/// This struct represents the JSON structure returned when retrieving
+/// an existing payload.
+#[derive(Debug, Serialize)]
+pub struct GetPayloadResponse {
+    /// The unique identifier of the payload
+    pub hash_id: String,
+    
+    /// The stored content
+    pub content: String,
+    
+    /// The MIME type of the content
+    pub mime_type: String,
+    
+    /// When the payload was created
+    pub created_at: DateTime<Utc>,
+    
+    /// When the payload was last updated
+    pub updated_at: DateTime<Utc>,
+    
+    /// When the payload was last viewed (if ever)
+    pub viewed_at: Option<DateTime<Utc>>,
+    
+    /// When the payload will expire
+    pub expiry_time: DateTime<Utc>,
+}
+
+/// Error response DTO.
+/// 
+/// This struct represents the JSON structure returned when an error occurs.
+#[derive(Debug, Serialize)]
+pub struct ErrorResponse {
+    /// The error message
+    pub error: String,
+    
+    /// Optional field for rate limit errors, indicating when to retry
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub retry_after: Option<i32>,
+}
+
+/// Regular expression for validating MIME types
+static MIME_TYPE_REGEX: &str = r"^[a-z]+/[a-z0-9.+-]+$";
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use validator::Validate;
+
+    #[test]
+    fn test_create_payload_request_validation() {
+        // Valid request
+        let valid_request = CreatePayloadRequest {
+            content: "Test content".to_string(),
+            mime_type: Some("text/plain".to_string()),
+            expiry_time: None,
+        };
+        assert!(valid_request.validate().is_ok());
+
+        // Empty content
+        let empty_content = CreatePayloadRequest {
+            content: "".to_string(),
+            mime_type: None,
+            expiry_time: None,
+        };
+        assert!(empty_content.validate().is_err());
+
+        // Invalid MIME type
+        let invalid_mime = CreatePayloadRequest {
+            content: "Test content".to_string(),
+            mime_type: Some("invalid-mime-type".to_string()),
+            expiry_time: None,
+        };
+        assert!(invalid_mime.validate().is_err());
+    }
+}