Files
cull-gmail/src/eol_action.rs
2025-10-20 14:08:17 +01:00

525 lines
17 KiB
Rust

//! # End-of-Life Action Module
//!
//! This module defines the actions that can be performed on Gmail messages
//! when they reach their end-of-life criteria based on configured rules.
//!
//! ## Overview
//!
//! The `EolAction` enum specifies how messages should be handled when they
//! meet the criteria for removal from a Gmail account. The module provides
//! two primary actions:
//!
//! - **Trash**: Moves messages to the trash folder (reversible)
//! - **Delete**: Permanently deletes messages (irreversible)
//!
//! ## Safety Considerations
//!
//! - **Trash** action allows message recovery from Gmail's trash folder
//! - **Delete** action permanently removes messages and cannot be undone
//! - Always test rules carefully before applying delete actions
//!
//! ## Usage Examples
//!
//! ### Basic Usage
//!
//! ```rust
//! use cull_gmail::EolAction;
//!
//! // Default action is Trash (safer option)
//! let action = EolAction::default();
//! assert_eq!(action, EolAction::Trash);
//!
//! // Parse from string
//! let delete_action = EolAction::parse("delete").unwrap();
//! assert_eq!(delete_action, EolAction::Delete);
//!
//! // Display as string
//! println!("Action: {}", delete_action); // Prints: "Action: delete"
//! ```
//!
//! ### Integration with Rules
//!
//! ```rust,no_run
//! use cull_gmail::EolAction;
//!
//! fn configure_rule_action(action_str: &str) -> Option<EolAction> {
//! match EolAction::parse(action_str) {
//! Some(action) => {
//! println!("Configured action: {}", action);
//! Some(action)
//! }
//! None => {
//! eprintln!("Invalid action: {}", action_str);
//! None
//! }
//! }
//! }
//! ```
//!
//! ## String Representation
//!
//! The enum implements both parsing from strings and display formatting:
//!
//! | Variant | String | Description |
//! |---------|--------|--------------|
//! | `Trash` | "trash" | Move to trash (recoverable) |
//! | `Delete` | "delete" | Permanent deletion |
//!
//! Parsing is case-insensitive, so "TRASH", "Trash", and "trash" are all valid.
use std::fmt;
/// Represents the action to take on Gmail messages that meet end-of-life criteria.
///
/// This enum defines the two possible actions for handling messages when they
/// reach the end of their lifecycle based on configured retention rules.
///
/// # Variants
///
/// - [`Trash`](EolAction::Trash) - Move messages to Gmail's trash folder (default, reversible)
/// - [`Delete`](EolAction::Delete) - Permanently delete messages (irreversible)
///
/// # Default Behavior
///
/// The default action is [`Trash`](EolAction::Trash), which provides a safety net
/// by allowing message recovery from the trash folder.
///
/// # Examples
///
/// ```rust
/// use cull_gmail::EolAction;
///
/// // Using the default (Trash)
/// let safe_action = EolAction::default();
/// assert_eq!(safe_action, EolAction::Trash);
///
/// // Comparing actions
/// let delete = EolAction::Delete;
/// let trash = EolAction::Trash;
/// assert_ne!(delete, trash);
///
/// // Converting to string for logging/display
/// println!("Action: {}", delete); // Prints: "delete"
/// ```
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
pub enum EolAction {
/// Move the message to Gmail's trash folder.
///
/// This is the default and safer option as it allows message recovery.
/// Messages in the trash are automatically deleted by Gmail after 30 days.
///
/// # Safety
///
/// This action is reversible - messages can be recovered from the trash folder
/// until they are automatically purged or manually deleted from trash.
#[default]
Trash,
/// Permanently delete the message immediately.
///
/// This action bypasses the trash folder and permanently removes the message.
///
/// # Warning
///
/// This action is **irreversible**. Once deleted, messages cannot be recovered.
/// Use with extreme caution and thorough testing of rule criteria.
///
/// # Use Cases
///
/// - Sensitive data that should not remain in trash
/// - Storage optimization where trash recovery is not needed
/// - Automated cleanup of known disposable messages
Delete,
}
impl fmt::Display for EolAction {
/// Formats the `EolAction` as a lowercase string.
///
/// This implementation provides a consistent string representation
/// for logging, configuration, and user interfaces.
///
/// # Returns
///
/// - `"trash"` for [`EolAction::Trash`]
/// - `"delete"` for [`EolAction::Delete`]
///
/// # Examples
///
/// ```rust
/// use cull_gmail::EolAction;
///
/// assert_eq!(EolAction::Trash.to_string(), "trash");
/// assert_eq!(EolAction::Delete.to_string(), "delete");
///
/// // Useful for logging
/// let action = EolAction::default();
/// println!("Performing action: {}", action);
/// ```
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
EolAction::Trash => write!(f, "trash"),
EolAction::Delete => write!(f, "delete"),
}
}
}
impl EolAction {
/// Parses a string into an `EolAction` variant.
///
/// This method provides case-insensitive parsing from string representations
/// to `EolAction` variants. It's useful for configuration file parsing,
/// command-line arguments, and user input validation.
///
/// # Arguments
///
/// * `input` - A string slice to parse. Case is ignored.
///
/// # Returns
///
/// - `Some(EolAction)` if the string matches a valid variant
/// - `None` if the string is not recognized
///
/// # Valid Input Strings
///
/// - `"trash"`, `"Trash"`, `"TRASH"` → [`EolAction::Trash`]
/// - `"delete"`, `"Delete"`, `"DELETE"` → [`EolAction::Delete`]
///
/// # Examples
///
/// ```rust
/// use cull_gmail::EolAction;
///
/// // Valid parsing (case-insensitive)
/// assert_eq!(EolAction::parse("trash"), Some(EolAction::Trash));
/// assert_eq!(EolAction::parse("TRASH"), Some(EolAction::Trash));
/// assert_eq!(EolAction::parse("Delete"), Some(EolAction::Delete));
///
/// // Invalid input
/// assert_eq!(EolAction::parse("invalid"), None);
/// assert_eq!(EolAction::parse(""), None);
/// ```
///
/// # Use Cases
///
/// ```rust
/// use cull_gmail::EolAction;
///
/// fn parse_user_action(input: &str) -> Result<EolAction, String> {
/// EolAction::parse(input)
/// .ok_or_else(|| format!("Invalid action: '{}'. Use 'trash' or 'delete'.", input))
/// }
///
/// assert!(parse_user_action("trash").is_ok());
/// assert!(parse_user_action("invalid").is_err());
/// ```
pub fn parse(input: &str) -> Option<Self> {
match input.trim().to_lowercase().as_str() {
"trash" => Some(EolAction::Trash),
"delete" => Some(EolAction::Delete),
_ => None,
}
}
/// Returns `true` if the action is reversible (can be undone).
///
/// This method helps determine if an action allows for message recovery,
/// which is useful for safety checks and user confirmations.
///
/// # Returns
///
/// - `true` for [`EolAction::Trash`] (messages can be recovered from trash)
/// - `false` for [`EolAction::Delete`] (messages are permanently deleted)
///
/// # Examples
///
/// ```rust
/// use cull_gmail::EolAction;
///
/// assert!(EolAction::Trash.is_reversible());
/// assert!(!EolAction::Delete.is_reversible());
///
/// // Use in safety checks
/// let action = EolAction::Delete;
/// if !action.is_reversible() {
/// println!("Warning: This action cannot be undone!");
/// }
/// ```
pub fn is_reversible(&self) -> bool {
match self {
EolAction::Trash => true,
EolAction::Delete => false,
}
}
/// Returns all possible `EolAction` variants.
///
/// This method is useful for generating help text, validation lists,
/// or iterating over all possible actions.
///
/// # Returns
///
/// An array containing all `EolAction` variants in declaration order.
///
/// # Examples
///
/// ```rust
/// use cull_gmail::EolAction;
///
/// let all_actions = EolAction::variants();
/// assert_eq!(all_actions.len(), 2);
/// assert_eq!(all_actions[0], EolAction::Trash);
/// assert_eq!(all_actions[1], EolAction::Delete);
///
/// // Generate help text
/// println!("Available actions:");
/// for action in EolAction::variants() {
/// println!(" {} - {}", action,
/// if action.is_reversible() { "reversible" } else { "irreversible" });
/// }
/// ```
pub fn variants() -> &'static [EolAction] {
&[EolAction::Trash, EolAction::Delete]
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_default_action_is_trash() {
let action = EolAction::default();
assert_eq!(action, EolAction::Trash);
}
#[test]
fn test_copy_and_equality() {
let trash1 = EolAction::Trash;
let trash2 = trash1; // Copy semantics
assert_eq!(trash1, trash2);
let delete1 = EolAction::Delete;
let delete2 = delete1; // Copy semantics
assert_eq!(delete1, delete2);
assert_ne!(trash1, delete1);
}
#[test]
fn test_debug_formatting() {
assert_eq!(format!("{:?}", EolAction::Trash), "Trash");
assert_eq!(format!("{:?}", EolAction::Delete), "Delete");
}
#[test]
fn test_display_formatting() {
assert_eq!(EolAction::Trash.to_string(), "trash");
assert_eq!(EolAction::Delete.to_string(), "delete");
assert_eq!(format!("{}", EolAction::Trash), "trash");
assert_eq!(format!("{}", EolAction::Delete), "delete");
}
#[test]
fn test_parse_valid_inputs() {
// Test lowercase
assert_eq!(EolAction::parse("trash"), Some(EolAction::Trash));
assert_eq!(EolAction::parse("delete"), Some(EolAction::Delete));
// Test uppercase
assert_eq!(EolAction::parse("TRASH"), Some(EolAction::Trash));
assert_eq!(EolAction::parse("DELETE"), Some(EolAction::Delete));
// Test mixed case
assert_eq!(EolAction::parse("Trash"), Some(EolAction::Trash));
assert_eq!(EolAction::parse("Delete"), Some(EolAction::Delete));
assert_eq!(EolAction::parse("TrAsH"), Some(EolAction::Trash));
assert_eq!(EolAction::parse("dElEtE"), Some(EolAction::Delete));
// Test with whitespace
assert_eq!(EolAction::parse(" trash "), Some(EolAction::Trash));
assert_eq!(EolAction::parse("\tdelete\n"), Some(EolAction::Delete));
assert_eq!(EolAction::parse(" TRASH "), Some(EolAction::Trash));
}
#[test]
fn test_parse_invalid_inputs() {
// Invalid strings
assert_eq!(EolAction::parse("invalid"), None);
assert_eq!(EolAction::parse("remove"), None);
assert_eq!(EolAction::parse("destroy"), None);
assert_eq!(EolAction::parse("archive"), None);
// Empty and whitespace
assert_eq!(EolAction::parse(""), None);
assert_eq!(EolAction::parse(" "), None);
assert_eq!(EolAction::parse("\t\n"), None);
// Partial matches
assert_eq!(EolAction::parse("tras"), None);
assert_eq!(EolAction::parse("delet"), None);
assert_eq!(EolAction::parse("trashh"), None);
assert_eq!(EolAction::parse("deletee"), None);
// Special characters
assert_eq!(EolAction::parse("trash!"), None);
assert_eq!(EolAction::parse("delete?"), None);
assert_eq!(EolAction::parse("trash-delete"), None);
}
#[test]
fn test_parse_edge_cases() {
// Unicode variations
assert_eq!(EolAction::parse("trash"), Some(EolAction::Trash)); // Unicode 't'
// Numbers and symbols
assert_eq!(EolAction::parse("trash123"), None);
assert_eq!(EolAction::parse("123delete"), None);
assert_eq!(EolAction::parse("t@rash"), None);
}
#[test]
fn test_is_reversible() {
assert!(EolAction::Trash.is_reversible());
assert!(!EolAction::Delete.is_reversible());
}
#[test]
fn test_variants() {
let variants = EolAction::variants();
assert_eq!(variants.len(), 2);
assert_eq!(variants[0], EolAction::Trash);
assert_eq!(variants[1], EolAction::Delete);
// Ensure all enum variants are included
assert!(variants.contains(&EolAction::Trash));
assert!(variants.contains(&EolAction::Delete));
}
#[test]
fn test_variants_completeness() {
// Verify that variants() returns all possible enum values
let variants = EolAction::variants();
// Test that we can parse back to all variants
for variant in variants {
let string_repr = variant.to_string();
let parsed = EolAction::parse(&string_repr);
assert_eq!(parsed, Some(*variant));
}
}
#[test]
fn test_hash_trait() {
use std::collections::HashMap;
let mut map = HashMap::new();
map.insert(EolAction::Trash, "safe");
map.insert(EolAction::Delete, "dangerous");
assert_eq!(map.get(&EolAction::Trash), Some(&"safe"));
assert_eq!(map.get(&EolAction::Delete), Some(&"dangerous"));
}
#[test]
fn test_round_trip_conversion() {
// Test that display -> parse -> display is consistent
let actions = [EolAction::Trash, EolAction::Delete];
for action in actions {
let string_repr = action.to_string();
let parsed = EolAction::parse(&string_repr).expect("Should parse successfully");
assert_eq!(action, parsed);
assert_eq!(string_repr, parsed.to_string());
}
}
#[test]
fn test_safety_properties() {
// Verify safety properties are as expected
assert!(
EolAction::Trash.is_reversible(),
"Trash should be reversible for safety"
);
assert!(
!EolAction::Delete.is_reversible(),
"Delete should be irreversible"
);
assert_eq!(
EolAction::default(),
EolAction::Trash,
"Default should be the safer option"
);
}
#[test]
fn test_string_case_insensitive_parsing() {
let test_cases = [
("trash", Some(EolAction::Trash)),
("TRASH", Some(EolAction::Trash)),
("Trash", Some(EolAction::Trash)),
("TrAsH", Some(EolAction::Trash)),
("delete", Some(EolAction::Delete)),
("DELETE", Some(EolAction::Delete)),
("Delete", Some(EolAction::Delete)),
("DeLeTe", Some(EolAction::Delete)),
("invalid", None),
("INVALID", None),
("", None),
];
for (input, expected) in test_cases {
assert_eq!(
EolAction::parse(input),
expected,
"Failed for input: '{input}'"
);
}
}
#[test]
fn test_practical_usage_scenarios() {
// Test common usage patterns
// Configuration parsing scenario
let config_value = "delete";
let action = EolAction::parse(config_value).unwrap_or_default();
assert_eq!(action, EolAction::Delete);
// Invalid config falls back to default (safe)
let invalid_config = "invalid_action";
let safe_action = EolAction::parse(invalid_config).unwrap_or_default();
assert_eq!(safe_action, EolAction::Trash);
// Logging/display scenario
let action = EolAction::Delete;
let log_message = format!("Executing {action} action");
assert_eq!(log_message, "Executing delete action");
// Safety check scenario
let dangerous_action = EolAction::Delete;
if !dangerous_action.is_reversible() {
// This would prompt user confirmation in real usage
// Test that we can detect dangerous actions
}
}
#[test]
fn test_error_handling_patterns() {
// Test error handling patterns that might be used with this enum
fn parse_with_error(input: &str) -> Result<EolAction, String> {
EolAction::parse(input)
.ok_or_else(|| format!("Invalid action: '{input}'. Valid options: trash, delete"))
}
// Valid cases
assert!(parse_with_error("trash").is_ok());
assert!(parse_with_error("delete").is_ok());
// Error cases
let error = parse_with_error("invalid").unwrap_err();
assert!(error.contains("Invalid action: 'invalid'"));
assert!(error.contains("trash, delete"));
}
}