backbone-bucket 0.4.0

//! State machine for StoredFile workflow
//!
//! Generated by metaphor-schema

use serde::{Deserialize, Serialize};
use std::str::FromStr;

/// States for StoredFile workflow
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum StoredFileState {
    /// Initial state
    Uploading,
    Processing,
    Active,
    Quarantined,
    Deleted,
    /// Final state
    Purged,
}

impl Default for StoredFileState {
    fn default() -> Self {
        Self::Uploading
    }
}

impl std::fmt::Display for StoredFileState {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Uploading => write!(f, "uploading"),
            Self::Processing => write!(f, "processing"),
            Self::Active => write!(f, "active"),
            Self::Quarantined => write!(f, "quarantined"),
            Self::Deleted => write!(f, "deleted"),
            Self::Purged => write!(f, "purged"),
        }
    }
}

impl FromStr for StoredFileState {
    type Err = StateMachineError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s.to_lowercase().as_str() {
            "uploading" => Ok(Self::Uploading),
            "processing" => Ok(Self::Processing),
            "active" => Ok(Self::Active),
            "quarantined" => Ok(Self::Quarantined),
            "deleted" => Ok(Self::Deleted),
            "purged" => Ok(Self::Purged),
            _ => Err(StateMachineError::InvalidState(s.to_string())),
        }
    }
}

impl StoredFileState {
    /// Check if this is the initial state
    pub fn is_initial(&self) -> bool {
        matches!(self, Self::Uploading)
    }

    /// Check if this is a final state
    pub fn is_final(&self) -> bool {
        matches!(self, Self::Purged)
    }

    /// Get all possible states
    pub fn all() -> Vec<Self> {
        vec![
            Self::Uploading,
            Self::Processing,
            Self::Active,
            Self::Quarantined,
            Self::Deleted,
            Self::Purged,
        ]
    }
}

/// Transitions for StoredFile workflow
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum StoredFileTransition {
    /// uploading -> processing
    CompleteUpload,
    /// processing -> active
    MarkSafe,
    /// processing -> quarantined
    Quarantine,
    /// quarantined -> active
    MarkSafeByAdmin,
    /// active, quarantined -> deleted
    SoftDelete,
    /// deleted -> active
    Restore,
    /// deleted -> purged
    Purge,
}

impl std::fmt::Display for StoredFileTransition {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::CompleteUpload => write!(f, "complete_upload"),
            Self::MarkSafe => write!(f, "mark_safe"),
            Self::Quarantine => write!(f, "quarantine"),
            Self::MarkSafeByAdmin => write!(f, "mark_safe_by_admin"),
            Self::SoftDelete => write!(f, "soft_delete"),
            Self::Restore => write!(f, "restore"),
            Self::Purge => write!(f, "purge"),
        }
    }
}

impl FromStr for StoredFileTransition {
    type Err = StateMachineError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s.to_lowercase().as_str() {
            "complete_upload" => Ok(Self::CompleteUpload),
            "mark_safe" => Ok(Self::MarkSafe),
            "quarantine" => Ok(Self::Quarantine),
            "mark_safe_by_admin" => Ok(Self::MarkSafeByAdmin),
            "soft_delete" => Ok(Self::SoftDelete),
            "restore" => Ok(Self::Restore),
            "purge" => Ok(Self::Purge),
            _ => Err(StateMachineError::InvalidTransition(s.to_string())),
        }
    }
}

impl StoredFileTransition {
    /// Get the target state of this transition
    pub fn target_state(&self) -> StoredFileState {
        match self {
            Self::CompleteUpload => StoredFileState::Processing,
            Self::MarkSafe => StoredFileState::Active,
            Self::Quarantine => StoredFileState::Quarantined,
            Self::MarkSafeByAdmin => StoredFileState::Active,
            Self::SoftDelete => StoredFileState::Deleted,
            Self::Restore => StoredFileState::Active,
            Self::Purge => StoredFileState::Purged,
        }
    }

    /// Get all transitions
    pub fn all() -> Vec<Self> {
        vec![
            Self::CompleteUpload,
            Self::MarkSafe,
            Self::Quarantine,
            Self::MarkSafeByAdmin,
            Self::SoftDelete,
            Self::Restore,
            Self::Purge,
        ]
    }

    /// Get allowed roles for this transition
    pub fn allowed_roles(&self) -> &'static [&'static str] {
        match self {
            Self::CompleteUpload => &["system"],
            Self::MarkSafe => &["system"],
            Self::Quarantine => &["system"],
            Self::MarkSafeByAdmin => &["admin"],
            Self::SoftDelete => &["admin", "owner"],
            Self::Restore => &["admin", "owner"],
            Self::Purge => &["admin", "system"],
        }
    }
}

use super::StateMachineError;

/// State machine for StoredFile workflow
#[derive(Debug, Clone)]
pub struct StoredFileStateMachine {
    current_state: StoredFileState,
}

impl StoredFileStateMachine {
    /// Create a new state machine with initial state
    pub fn new() -> Self {
        Self {
            current_state: StoredFileState::default(),
        }
    }

    /// Create from an existing state
    pub fn from_state(state: StoredFileState) -> Self {
        Self { current_state: state }
    }

    /// Get the current state
    pub fn current_state(&self) -> StoredFileState {
        self.current_state
    }

    /// Check if a transition is allowed from the current state
    pub fn can_transition(&self, transition: StoredFileTransition) -> bool {
        if matches!(self.current_state, StoredFileState::Purged) {
            return false;
        }

        match (self.current_state, transition) {
            (StoredFileState::Uploading, StoredFileTransition::CompleteUpload) => true,
            (StoredFileState::Processing, StoredFileTransition::MarkSafe) => true,
            (StoredFileState::Processing, StoredFileTransition::Quarantine) => true,
            (StoredFileState::Quarantined, StoredFileTransition::MarkSafeByAdmin) => true,
            (StoredFileState::Active, StoredFileTransition::SoftDelete) => true,
            (StoredFileState::Quarantined, StoredFileTransition::SoftDelete) => true,
            (StoredFileState::Deleted, StoredFileTransition::Restore) => true,
            (StoredFileState::Deleted, StoredFileTransition::Purge) => true,
            _ => false,
        }
    }

    /// Check if a transition is allowed for a given role
    pub fn can_transition_with_role(&self, transition: StoredFileTransition, role: &str) -> bool {
        if !self.can_transition(transition) {
            return false;
        }

        let allowed_roles = transition.allowed_roles();
        if allowed_roles.is_empty() {
            return true; // No role restriction
        }

        allowed_roles.iter().any(|r| *r == role || *r == "*")
    }

    /// Apply a transition, returning the new state
    pub fn transition(&mut self, transition: StoredFileTransition) -> Result<StoredFileState, StateMachineError> {
        if !self.can_transition(transition) {
            return Err(StateMachineError::TransitionNotAllowed {
                transition: transition.to_string(),
                from: self.current_state.to_string(),
            });
        }

        self.current_state = transition.target_state();
        Ok(self.current_state)
    }

    /// Apply a transition with role check
    pub fn transition_with_role(&mut self, transition: StoredFileTransition, role: &str) -> Result<StoredFileState, StateMachineError> {
        // Check basic transition validity first
        if !self.can_transition(transition) {
            return Err(StateMachineError::TransitionNotAllowed {
                transition: transition.to_string(),
                from: self.current_state.to_string(),
            });
        }

        // Check role authorization
        if !self.can_transition_with_role(transition, role) {
            return Err(StateMachineError::RoleNotAuthorized {
                role: role.to_string(),
                transition: transition.to_string(),
            });
        }

        self.current_state = transition.target_state();
        Ok(self.current_state)
    }

    /// Get all available transitions from the current state
    pub fn available_transitions(&self) -> Vec<StoredFileTransition> {
        StoredFileTransition::all()
            .into_iter()
            .filter(|t| self.can_transition(*t))
            .collect()
    }

    /// Get all available transitions for a given role
    pub fn available_transitions_for_role(&self, role: &str) -> Vec<StoredFileTransition> {
        StoredFileTransition::all()
            .into_iter()
            .filter(|t| self.can_transition_with_role(*t, role))
            .collect()
    }

    /// Attempt to transition directly to a target state.
    ///
    /// Finds any transition that leads to the target state and applies it.
    /// Returns Err if no valid transition leads from current state to target.
    pub fn transition_to_state(&mut self, target: StoredFileState) -> Result<StoredFileState, StateMachineError> {
        let valid = StoredFileTransition::all().into_iter()
            .filter(|t| self.can_transition(*t))
            .find(|t| t.target_state() == target);
        match valid {
            Some(t) => self.transition(t),
            None => Err(StateMachineError::TransitionNotAllowed {
                transition: target.to_string(),
                from: self.current_state.to_string(),
            }),
        }
    }
}

impl Default for StoredFileStateMachine {
    fn default() -> Self {
        Self::new()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_initial_state() {
        let sm = StoredFileStateMachine::new();
        assert_eq!(sm.current_state(), StoredFileState::Uploading);
        assert!(sm.current_state().is_initial());
    }

    #[test]
    fn test_valid_transition() {
        let mut sm = StoredFileStateMachine::from_state(StoredFileState::Uploading);
        assert!(sm.can_transition(StoredFileTransition::CompleteUpload));
        let result = sm.transition(StoredFileTransition::CompleteUpload);
        assert!(result.is_ok());
        assert_eq!(sm.current_state(), StoredFileState::Processing);
    }

    #[test]
    fn test_invalid_transition() {
        let mut sm = StoredFileStateMachine::from_state(StoredFileState::Uploading);
        // MarkSafe is not valid from Uploading state
        let result = sm.transition(StoredFileTransition::MarkSafe);
        assert!(result.is_err());
    }

    #[test]
    fn test_state_parsing() {
        let state: StoredFileState = "uploading".parse().unwrap();
        assert_eq!(state, StoredFileState::Uploading);
    }

    #[test]
    fn test_available_transitions() {
        let sm = StoredFileStateMachine::new();
        let available = sm.available_transitions();
        // Should have at least some transitions available from initial state
        assert!(!available.is_empty() || sm.current_state().is_final());
    }
}