backbone-bucket 0.2.1

//! FileUpload flow implementation
//!
//! Generated by metaphor-schema
//!
//! Complete file upload workflow including:
//! - Quota validation
//! - File validation
//! - Content deduplication
//! - Virus scanning
//! - Thumbnail generation (images and video)
//! - Document preview generation
//! - CDN URL generation
//! - Quota update
//! - Event emission

use serde::{Deserialize, Serialize};
use std::sync::Arc;
use chrono;
use backbone_core::flow::{WorkflowStep, WorkflowContext};

/// Error type for flow execution
#[derive(Debug, Clone, thiserror::Error)]
pub enum FlowError {
    #[error("No current step to execute")]
    NoCurrentStep,

    #[error("Step execution failed: {0}")]
    StepFailed(String),

    #[error("Condition evaluation failed: {0}")]
    ConditionFailed(String),

    #[error("Compensation failed: {0}")]
    CompensationFailed(String),

    #[error("Flow timed out")]
    Timeout,

    #[error("Flow cancelled")]
    Cancelled,

    #[error("Invalid state transition: {from} -> {to}")]
    InvalidTransition { from: String, to: String },
}

/// Execution status for FileUpload flow
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum FileUploadFlowStatus {
    /// Flow is pending execution
    Pending,
    /// Flow is currently running
    Running,
    /// Flow is waiting for an event or condition
    Waiting,
    /// Flow completed successfully
    Completed,
    /// Flow failed
    Failed,
    /// Flow was cancelled
    Cancelled,
    /// Flow is compensating (rolling back)
    Compensating,
}

/// Steps in FileUpload flow
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum FileUploadFlowStep {
    /// load_bucket
    LoadBucket,
    /// check_bucket_active
    CheckBucketActive,
    /// check_deduplication_enabled
    CheckDeduplicationEnabled,
    /// calculate_checksum
    CalculateChecksum,
    /// check_duplicate_content
    CheckDuplicateContent,
    /// use_existing_content
    UseExistingContent,
    /// detect_mime_type
    DetectMimeType,
    /// validate_file_type
    ValidateFileType,
    /// validate_file_size
    ValidateFileSize,
    /// load_quota
    LoadQuota,
    /// create_default_quota
    CreateDefaultQuota,
    /// check_quota
    CheckQuota,
    /// create_file_record
    CreateFileRecord,
    /// check_should_store_content
    CheckShouldStoreContent,
    /// store_content
    StoreContent,
    /// create_content_hash
    CreateContentHash,
    /// link_content_hash
    LinkContentHash,
    /// update_file_processing
    UpdateFileProcessing,
    /// scan_file
    ScanFile,
    /// check_scan_result
    CheckScanResult,
    /// update_scan_complete
    UpdateScanComplete,
    /// check_cdn_enabled
    CheckCdnEnabled,
    /// generate_cdn_url
    GenerateCdnUrl,
    /// update_cdn_info
    UpdateCdnInfo,
    /// mark_file_active
    MarkFileActive,
    /// update_quota
    UpdateQuota,
    /// update_bucket_stats
    UpdateBucketStats,
    /// emit_uploaded_event
    EmitUploadedEvent,
    /// complete
    Complete,
    /// quarantine_file
    QuarantineFile,
    /// emit_threat_event
    EmitThreatEvent,
    /// notify_threat
    NotifyThreat,
    /// complete_quarantine
    CompleteQuarantine,
    /// bucket_not_found
    BucketNotFound,
    /// bucket_not_active
    BucketNotActive,
    /// mime_type_not_allowed
    MimeTypeNotAllowed,
    /// file_too_large
    FileTooLarge,
    /// quota_exceeded
    QuotaExceeded,
    /// quota_exceeded_terminal
    QuotaExceededTerminal,
    /// rollback_file_record
    RollbackFileRecord,
    /// storage_failed
    StorageFailed,
}

/// Instance of FileUpload flow execution
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct FileUploadFlowInstance {
    /// Unique instance ID
    pub id: String,
    /// Current status
    pub status: FileUploadFlowStatus,
    /// Current step
    pub current_step: Option<FileUploadFlowStep>,
    /// Flow context (variables)
    pub context: serde_json::Value,
    /// Completed steps
    pub completed_steps: Vec<FileUploadFlowStep>,
    /// Error if failed
    pub error: Option<String>,
    /// Created timestamp
    pub created_at: chrono::DateTime<chrono::Utc>,
    /// Updated timestamp
    pub updated_at: chrono::DateTime<chrono::Utc>,
}

impl FileUploadFlowInstance {
    /// Create a new flow instance
    pub fn new(id: impl Into<String>) -> Self {
        let now = chrono::Utc::now();
        Self {
            id: id.into(),
            status: FileUploadFlowStatus::Pending,
            current_step: None,
            context: serde_json::json!({}),
            completed_steps: Vec::new(),
            error: None,
            created_at: now,
            updated_at: now,
        }
    }

    /// Check if flow is complete
    pub fn is_complete(&self) -> bool {
        matches!(
            self.status,
            FileUploadFlowStatus::Completed | FileUploadFlowStatus::Failed | FileUploadFlowStatus::Cancelled
        )
    }

    /// Check if flow is running
    pub fn is_running(&self) -> bool {
        matches!(
            self.status,
            FileUploadFlowStatus::Running | FileUploadFlowStatus::Waiting
        )
    }

    /// Set a context variable
    pub fn set_context(&mut self, key: &str, value: serde_json::Value) {
        if let serde_json::Value::Object(ref mut map) = self.context {
            map.insert(key.to_string(), value);
        }
        self.updated_at = chrono::Utc::now();
    }

    /// Get a context variable
    pub fn get_context(&self, key: &str) -> Option<&serde_json::Value> {
        if let serde_json::Value::Object(ref map) = self.context {
            map.get(key)
        } else {
            None
        }
    }
}

// Phase 1: FlowInstance satisfies backbone_core::flow::WorkflowContext.
// The entity() accessor requires the entity to be carried in the instance;
// add `pub entity: FileUpload` in the // <<< CUSTOM section and remove the todo!.
#[allow(unused_variables)]
impl WorkflowContext<FileUploadFlowInstance> for FileUploadFlowInstance {
    fn entity(&self) -> &FileUploadFlowInstance { self }
    fn set_var(&mut self, key: &str, value: serde_json::Value) {
        self.set_context(key, value);
    }
    fn get_var(&self, key: &str) -> Option<&serde_json::Value> {
        self.get_context(key)
    }
}

/// Step handler trait for FileUpload flow
#[async_trait::async_trait]
pub trait FileUploadStepHandler: Send + Sync {
    /// Handle load_bucket step
    async fn handle_load_bucket(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Evaluate condition for check_bucket_active step
    async fn evaluate_check_bucket_active(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Evaluate condition for check_deduplication_enabled step
    async fn evaluate_check_deduplication_enabled(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Handle calculate_checksum step
    async fn handle_calculate_checksum(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle check_duplicate_content step
    async fn handle_check_duplicate_content(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle use_existing_content step
    async fn handle_use_existing_content(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle detect_mime_type step
    async fn handle_detect_mime_type(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Evaluate condition for validate_file_type step
    async fn evaluate_validate_file_type(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Evaluate condition for validate_file_size step
    async fn evaluate_validate_file_size(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Handle load_quota step
    async fn handle_load_quota(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle create_default_quota step
    async fn handle_create_default_quota(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Evaluate condition for check_quota step
    async fn evaluate_check_quota(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Handle create_file_record step
    async fn handle_create_file_record(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Evaluate condition for check_should_store_content step
    async fn evaluate_check_should_store_content(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Handle store_content step
    async fn handle_store_content(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle create_content_hash step
    async fn handle_create_content_hash(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle link_content_hash step
    async fn handle_link_content_hash(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle update_file_processing step
    async fn handle_update_file_processing(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle scan_file step
    async fn handle_scan_file(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Evaluate condition for check_scan_result step
    async fn evaluate_check_scan_result(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Handle update_scan_complete step
    async fn handle_update_scan_complete(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Evaluate condition for check_cdn_enabled step
    async fn evaluate_check_cdn_enabled(
        &self,
        instance: &FileUploadFlowInstance,
    ) -> Result<FileUploadFlowStep, FlowError>;

    /// Handle generate_cdn_url step
    async fn handle_generate_cdn_url(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle update_cdn_info step
    async fn handle_update_cdn_info(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle mark_file_active step
    async fn handle_mark_file_active(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle update_quota step
    async fn handle_update_quota(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle update_bucket_stats step
    async fn handle_update_bucket_stats(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle emit_uploaded_event step
    async fn handle_emit_uploaded_event(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle terminal step complete
    async fn handle_complete(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Handle quarantine_file step
    async fn handle_quarantine_file(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle emit_threat_event step
    async fn handle_emit_threat_event(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle notify_threat step
    async fn handle_notify_threat(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle terminal step complete_quarantine
    async fn handle_complete_quarantine(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Handle terminal step bucket_not_found
    async fn handle_bucket_not_found(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Handle terminal step bucket_not_active
    async fn handle_bucket_not_active(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Handle terminal step mime_type_not_allowed
    async fn handle_mime_type_not_allowed(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Handle terminal step file_too_large
    async fn handle_file_too_large(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Handle quota_exceeded step
    async fn handle_quota_exceeded(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle terminal step quota_exceeded_terminal
    async fn handle_quota_exceeded_terminal(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Handle rollback_file_record step
    async fn handle_rollback_file_record(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<Option<FileUploadFlowStep>, FlowError>;

    /// Handle terminal step storage_failed
    async fn handle_storage_failed(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

    /// Execute compensation (rollback)
    async fn compensate(
        &self,
        instance: &mut FileUploadFlowInstance,
    ) -> Result<(), FlowError>;

}

/// Executor for FileUpload flow
pub struct FileUploadFlowExecutor<H: FileUploadStepHandler> {
    handler: Arc<H>,
}

impl<H: FileUploadStepHandler> FileUploadFlowExecutor<H> {
    /// Create a new flow executor
    pub fn new(handler: Arc<H>) -> Self {
        Self { handler }
    }

    /// Start a new flow instance
    pub async fn start(&self, instance_id: impl Into<String>) -> Result<FileUploadFlowInstance, FlowError> {
        let mut instance = FileUploadFlowInstance::new(instance_id);
        instance.status = FileUploadFlowStatus::Running;
        instance.current_step = Some(FileUploadFlowStep::LoadBucket);
        Ok(instance)
    }

    /// Execute the current step
    pub async fn execute_step(&self, instance: &mut FileUploadFlowInstance) -> Result<(), FlowError> {
        let current_step = match instance.current_step {
            Some(step) => step,
            None => return Err(FlowError::NoCurrentStep),
        };

        let next_step = match current_step {
            FileUploadFlowStep::LoadBucket => {
                self.handler.handle_load_bucket(instance).await?
            }
            FileUploadFlowStep::CheckBucketActive => {
                let next = self.handler.evaluate_check_bucket_active(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::CheckDeduplicationEnabled => {
                let next = self.handler.evaluate_check_deduplication_enabled(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::CalculateChecksum => {
                self.handler.handle_calculate_checksum(instance).await?
            }
            FileUploadFlowStep::CheckDuplicateContent => {
                self.handler.handle_check_duplicate_content(instance).await?
            }
            FileUploadFlowStep::UseExistingContent => {
                self.handler.handle_use_existing_content(instance).await?
            }
            FileUploadFlowStep::DetectMimeType => {
                self.handler.handle_detect_mime_type(instance).await?
            }
            FileUploadFlowStep::ValidateFileType => {
                let next = self.handler.evaluate_validate_file_type(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::ValidateFileSize => {
                let next = self.handler.evaluate_validate_file_size(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::LoadQuota => {
                self.handler.handle_load_quota(instance).await?
            }
            FileUploadFlowStep::CreateDefaultQuota => {
                self.handler.handle_create_default_quota(instance).await?
            }
            FileUploadFlowStep::CheckQuota => {
                let next = self.handler.evaluate_check_quota(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::CreateFileRecord => {
                self.handler.handle_create_file_record(instance).await?
            }
            FileUploadFlowStep::CheckShouldStoreContent => {
                let next = self.handler.evaluate_check_should_store_content(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::StoreContent => {
                self.handler.handle_store_content(instance).await?
            }
            FileUploadFlowStep::CreateContentHash => {
                self.handler.handle_create_content_hash(instance).await?
            }
            FileUploadFlowStep::LinkContentHash => {
                self.handler.handle_link_content_hash(instance).await?
            }
            FileUploadFlowStep::UpdateFileProcessing => {
                self.handler.handle_update_file_processing(instance).await?
            }
            FileUploadFlowStep::ScanFile => {
                self.handler.handle_scan_file(instance).await?
            }
            FileUploadFlowStep::CheckScanResult => {
                let next = self.handler.evaluate_check_scan_result(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::UpdateScanComplete => {
                self.handler.handle_update_scan_complete(instance).await?
            }
            FileUploadFlowStep::CheckCdnEnabled => {
                let next = self.handler.evaluate_check_cdn_enabled(instance).await?;
                Some(next)
            }
            FileUploadFlowStep::GenerateCdnUrl => {
                self.handler.handle_generate_cdn_url(instance).await?
            }
            FileUploadFlowStep::UpdateCdnInfo => {
                self.handler.handle_update_cdn_info(instance).await?
            }
            FileUploadFlowStep::MarkFileActive => {
                self.handler.handle_mark_file_active(instance).await?
            }
            FileUploadFlowStep::UpdateQuota => {
                self.handler.handle_update_quota(instance).await?
            }
            FileUploadFlowStep::UpdateBucketStats => {
                self.handler.handle_update_bucket_stats(instance).await?
            }
            FileUploadFlowStep::EmitUploadedEvent => {
                self.handler.handle_emit_uploaded_event(instance).await?
            }
            FileUploadFlowStep::Complete => {
                self.handler.handle_complete(instance).await?;
                None // Terminal step
            }
            FileUploadFlowStep::QuarantineFile => {
                self.handler.handle_quarantine_file(instance).await?
            }
            FileUploadFlowStep::EmitThreatEvent => {
                self.handler.handle_emit_threat_event(instance).await?
            }
            FileUploadFlowStep::NotifyThreat => {
                self.handler.handle_notify_threat(instance).await?
            }
            FileUploadFlowStep::CompleteQuarantine => {
                self.handler.handle_complete_quarantine(instance).await?;
                None // Terminal step
            }
            FileUploadFlowStep::BucketNotFound => {
                self.handler.handle_bucket_not_found(instance).await?;
                None // Terminal step
            }
            FileUploadFlowStep::BucketNotActive => {
                self.handler.handle_bucket_not_active(instance).await?;
                None // Terminal step
            }
            FileUploadFlowStep::MimeTypeNotAllowed => {
                self.handler.handle_mime_type_not_allowed(instance).await?;
                None // Terminal step
            }
            FileUploadFlowStep::FileTooLarge => {
                self.handler.handle_file_too_large(instance).await?;
                None // Terminal step
            }
            FileUploadFlowStep::QuotaExceeded => {
                self.handler.handle_quota_exceeded(instance).await?
            }
            FileUploadFlowStep::QuotaExceededTerminal => {
                self.handler.handle_quota_exceeded_terminal(instance).await?;
                None // Terminal step
            }
            FileUploadFlowStep::RollbackFileRecord => {
                self.handler.handle_rollback_file_record(instance).await?
            }
            FileUploadFlowStep::StorageFailed => {
                self.handler.handle_storage_failed(instance).await?;
                None // Terminal step
            }
        };

        // Mark current step as completed
        instance.completed_steps.push(current_step);

        // Move to next step
        match next_step {
            Some(next) => {
                instance.current_step = Some(next);
            }
            None => {
                instance.current_step = None;
                instance.status = FileUploadFlowStatus::Completed;
            }
        }

        instance.updated_at = chrono::Utc::now();
        Ok(())
    }

    /// Run the flow to completion
    pub async fn run(&self, instance: &mut FileUploadFlowInstance) -> Result<(), FlowError> {
        while !instance.is_complete() && instance.status != FileUploadFlowStatus::Waiting {
            self.execute_step(instance).await?;
        }
        Ok(())
    }

    /// Cancel the flow
    pub fn cancel(&self, instance: &mut FileUploadFlowInstance) {
        instance.status = FileUploadFlowStatus::Cancelled;
        instance.updated_at = chrono::Utc::now();
    }

    /// Mark flow as failed
    pub fn fail(&self, instance: &mut FileUploadFlowInstance, error: impl Into<String>) {
        instance.status = FileUploadFlowStatus::Failed;
        instance.error = Some(error.into());
        instance.updated_at = chrono::Utc::now();
    }
}

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

    #[test]
    fn test_flow_instance_creation() {
        let instance = FileUploadFlowInstance::new("test-1");
        assert_eq!(instance.id, "test-1");
        assert_eq!(instance.status, FileUploadFlowStatus::Pending);
        assert!(!instance.is_complete());
    }

    #[test]
    fn test_flow_context() {
        let mut instance = FileUploadFlowInstance::new("test-2");
        instance.set_context("key", serde_json::json!("value"));
        let value = instance.get_context("key");
        assert_eq!(value, Some(&serde_json::json!("value")));
    }

    #[test]
    fn test_flow_status_transitions() {
        let mut instance = FileUploadFlowInstance::new("test-3");
        assert!(!instance.is_running());

        instance.status = FileUploadFlowStatus::Running;
        assert!(instance.is_running());
        assert!(!instance.is_complete());

        instance.status = FileUploadFlowStatus::Completed;
        assert!(instance.is_complete());
        assert!(!instance.is_running());
    }
}