backbone-bucket 0.4.0

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

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

/// States for FileComment workflow
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum FileCommentState {
    /// Initial state
    Active,
    Resolved,
    /// Final state
    Deleted,
}

impl Default for FileCommentState {
    fn default() -> Self {
        Self::Active
    }
}

impl std::fmt::Display for FileCommentState {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Active => write!(f, "active"),
            Self::Resolved => write!(f, "resolved"),
            Self::Deleted => write!(f, "deleted"),
        }
    }
}

impl FromStr for FileCommentState {
    type Err = StateMachineError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s.to_lowercase().as_str() {
            "active" => Ok(Self::Active),
            "resolved" => Ok(Self::Resolved),
            "deleted" => Ok(Self::Deleted),
            _ => Err(StateMachineError::InvalidState(s.to_string())),
        }
    }
}

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

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

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

/// Transitions for FileComment workflow
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum FileCommentTransition {
    /// active -> resolved
    Resolve,
    /// active -> active
    Edit,
    /// active -> deleted
    DeleteActive,
    /// resolved -> active
    Reopen,
    /// resolved -> deleted
    DeleteResolved,
}

impl std::fmt::Display for FileCommentTransition {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Resolve => write!(f, "resolve"),
            Self::Edit => write!(f, "edit"),
            Self::DeleteActive => write!(f, "delete_active"),
            Self::Reopen => write!(f, "reopen"),
            Self::DeleteResolved => write!(f, "delete_resolved"),
        }
    }
}

impl FromStr for FileCommentTransition {
    type Err = StateMachineError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s.to_lowercase().as_str() {
            "resolve" => Ok(Self::Resolve),
            "edit" => Ok(Self::Edit),
            "delete_active" => Ok(Self::DeleteActive),
            "reopen" => Ok(Self::Reopen),
            "delete_resolved" => Ok(Self::DeleteResolved),
            _ => Err(StateMachineError::InvalidTransition(s.to_string())),
        }
    }
}

impl FileCommentTransition {
    /// Get the target state of this transition
    pub fn target_state(&self) -> FileCommentState {
        match self {
            Self::Resolve => FileCommentState::Resolved,
            Self::Edit => FileCommentState::Active,
            Self::DeleteActive => FileCommentState::Deleted,
            Self::Reopen => FileCommentState::Active,
            Self::DeleteResolved => FileCommentState::Deleted,
        }
    }

    /// Get all transitions
    pub fn all() -> Vec<Self> {
        vec![
            Self::Resolve,
            Self::Edit,
            Self::DeleteActive,
            Self::Reopen,
            Self::DeleteResolved,
        ]
    }

    /// Get allowed roles for this transition
    pub fn allowed_roles(&self) -> &'static [&'static str] {
        match self {
            Self::Resolve => &["owner", "file_owner"],
            Self::Edit => &["owner"],
            Self::DeleteActive => &["owner", "file_owner"],
            Self::Reopen => &["user"],
            Self::DeleteResolved => &["owner", "file_owner"],
        }
    }
}

use super::StateMachineError;

/// State machine for FileComment workflow
#[derive(Debug, Clone)]
pub struct FileCommentStateMachine {
    current_state: FileCommentState,
}

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

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

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

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

        match (self.current_state, transition) {
            (FileCommentState::Active, FileCommentTransition::Resolve) => true,
            (FileCommentState::Active, FileCommentTransition::Edit) => true,
            (FileCommentState::Active, FileCommentTransition::DeleteActive) => true,
            (FileCommentState::Resolved, FileCommentTransition::Reopen) => true,
            (FileCommentState::Resolved, FileCommentTransition::DeleteResolved) => true,
            _ => false,
        }
    }

    /// Check if a transition is allowed for a given role
    pub fn can_transition_with_role(&self, transition: FileCommentTransition, 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: FileCommentTransition) -> Result<FileCommentState, 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: FileCommentTransition, role: &str) -> Result<FileCommentState, 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<FileCommentTransition> {
        FileCommentTransition::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<FileCommentTransition> {
        FileCommentTransition::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: FileCommentState) -> Result<FileCommentState, StateMachineError> {
        let valid = FileCommentTransition::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 FileCommentStateMachine {
    fn default() -> Self {
        Self::new()
    }
}

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

    #[test]
    fn test_initial_state() {
        let sm = FileCommentStateMachine::new();
        assert_eq!(sm.current_state(), FileCommentState::Active);
        assert!(sm.current_state().is_initial());
    }

    #[test]
    fn test_valid_transition() {
        let mut sm = FileCommentStateMachine::from_state(FileCommentState::Active);
        assert!(sm.can_transition(FileCommentTransition::Resolve));
        let result = sm.transition(FileCommentTransition::Resolve);
        assert!(result.is_ok());
        assert_eq!(sm.current_state(), FileCommentState::Resolved);
    }

    #[test]
    fn test_invalid_transition() {
        let mut sm = FileCommentStateMachine::from_state(FileCommentState::Active);
        // Reopen is not valid from Active state
        let result = sm.transition(FileCommentTransition::Reopen);
        assert!(result.is_err());
    }

    #[test]
    fn test_state_parsing() {
        let state: FileCommentState = "active".parse().unwrap();
        assert_eq!(state, FileCommentState::Active);
    }

    #[test]
    fn test_available_transitions() {
        let sm = FileCommentStateMachine::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());
    }
}