voirs-cli 0.1.0-rc.1

//! Advanced error handling and recovery system
//!
//! This module provides sophisticated error handling capabilities including
//! contextual error information, automatic recovery strategies, and user-friendly
//! error reporting with actionable suggestions.

use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::fmt;
use std::sync::Arc;
use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
use thiserror::Error;
use tokio::sync::RwLock;

/// Advanced error type with rich context and recovery information
#[derive(Debug, Clone, Serialize, Deserialize, Error)]
#[error("{message}")]
pub struct AdvancedError {
    /// Error classification
    pub category: ErrorCategory,
    /// Error severity level
    pub severity: ErrorSeverity,
    /// Human-readable error message
    pub message: String,
    /// Technical error details
    pub technical_details: String,
    /// Error context information
    pub context: ErrorContext,
    /// Suggested recovery actions
    pub recovery_suggestions: Vec<RecoverySuggestion>,
    /// Related errors (if this is caused by other errors)
    pub related_errors: Vec<String>,
    /// Timestamp when error occurred
    pub timestamp: u64,
    /// Unique error identifier
    pub error_id: String,
    /// Whether this error is recoverable
    pub recoverable: bool,
    /// Retry information
    pub retry_info: Option<RetryInfo>,
}

/// Error categories for classification
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum ErrorCategory {
    /// Configuration errors
    Configuration,
    /// Network connectivity errors
    Network,
    /// File system errors
    FileSystem,
    /// Memory allocation errors
    Memory,
    /// Model loading errors
    ModelLoading,
    /// Audio processing errors
    AudioProcessing,
    /// Synthesis errors
    Synthesis,
    /// Authentication errors
    Authentication,
    /// Permission errors
    Permission,
    /// Resource exhaustion errors
    ResourceExhaustion,
    /// Dependency errors
    Dependency,
    /// Hardware errors
    Hardware,
    /// User input errors
    UserInput,
    /// Internal system errors
    Internal,
    /// External service errors
    ExternalService,
}

/// Error severity levels
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum ErrorSeverity {
    /// Informational (not really an error)
    Info,
    /// Warning (operation can continue)
    Warning,
    /// Error (operation failed but system stable)
    Error,
    /// Critical (system functionality impaired)
    Critical,
    /// Fatal (system cannot continue)
    Fatal,
}

/// Error context providing additional information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorContext {
    /// Operation that was being performed
    pub operation: String,
    /// User who encountered the error
    pub user: Option<String>,
    /// Session information
    pub session_id: Option<String>,
    /// Request information
    pub request_id: Option<String>,
    /// Component where error occurred
    pub component: String,
    /// Function/method where error occurred
    pub function: Option<String>,
    /// File and line number (for debugging)
    pub location: Option<String>,
    /// Additional context parameters
    pub parameters: HashMap<String, String>,
    /// System state at time of error
    pub system_state: SystemState,
    /// Performance metrics at error time
    pub performance_metrics: Option<ErrorTimeMetrics>,
}

/// System state information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SystemState {
    /// Available memory in bytes
    pub available_memory_bytes: u64,
    /// CPU usage percentage
    pub cpu_usage_percent: f64,
    /// Active operations count
    pub active_operations: usize,
    /// Queue depth
    pub queue_depth: usize,
    /// Last successful operation time
    pub last_success_time: Option<u64>,
    /// System uptime in seconds
    pub uptime_seconds: u64,
}

/// Performance metrics at error time
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorTimeMetrics {
    /// Latency when error occurred
    pub latency_ms: u64,
    /// Throughput when error occurred
    pub throughput: f64,
    /// Memory usage when error occurred
    pub memory_usage_mb: f64,
    /// Error rate before this error
    pub recent_error_rate: f64,
}

/// Recovery suggestion with actionable steps
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RecoverySuggestion {
    /// Suggestion category
    pub category: RecoveryCategory,
    /// Priority level (1-10, 10 being highest)
    pub priority: u8,
    /// Human-readable suggestion
    pub suggestion: String,
    /// Detailed steps to resolve
    pub steps: Vec<String>,
    /// Expected resolution time
    pub estimated_time: Duration,
    /// Difficulty level
    pub difficulty: DifficultyLevel,
    /// Success probability (0.0-1.0)
    pub success_probability: f64,
    /// Whether this suggestion requires user action
    pub requires_user_action: bool,
    /// Commands or actions to execute
    pub automated_actions: Vec<AutomatedAction>,
}

/// Recovery suggestion categories
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum RecoveryCategory {
    /// Immediate automatic recovery
    AutomaticRecovery,
    /// User configuration change
    ConfigurationFix,
    /// Resource management
    ResourceOptimization,
    /// Retry with different parameters
    RetryOptimization,
    /// System restart or reset
    SystemRestart,
    /// Software update or installation
    SoftwareUpdate,
    /// Hardware check or replacement
    HardwareCheck,
    /// Network troubleshooting
    NetworkTroubleshooting,
    /// Permission or authentication fix
    PermissionFix,
}

/// Difficulty levels for recovery
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum DifficultyLevel {
    /// Trivial (automatic or one-click)
    Trivial,
    /// Easy (basic user action)
    Easy,
    /// Medium (some technical knowledge required)
    Medium,
    /// Hard (advanced technical knowledge required)
    Hard,
    /// Expert (requires expert assistance)
    Expert,
}

/// Automated action that can be taken
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AutomatedAction {
    /// Action type
    pub action_type: ActionType,
    /// Action description
    pub description: String,
    /// Parameters for the action
    pub parameters: HashMap<String, String>,
    /// Whether this action is safe to execute automatically
    pub safe_to_automate: bool,
    /// Expected execution time
    pub execution_time: Duration,
    /// Action dependencies
    pub dependencies: Vec<String>,
}

/// Types of automated actions
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum ActionType {
    /// Restart a service or component
    RestartService,
    /// Clear cache or temporary files
    ClearCache,
    /// Adjust configuration parameters
    AdjustConfiguration,
    /// Retry the failed operation
    RetryOperation,
    /// Reduce resource usage
    ReduceResources,
    /// Switch to fallback mode
    EnableFallback,
    /// Update software component
    UpdateSoftware,
    /// Check system resources
    CheckResources,
    /// Validate configuration
    ValidateConfiguration,
    /// Repair corrupted data
    RepairData,
}

/// Retry information for recoverable errors
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RetryInfo {
    /// Current retry attempt (0 = first attempt)
    pub attempt: usize,
    /// Maximum retry attempts
    pub max_attempts: usize,
    /// Delay before next retry
    pub retry_delay: Duration,
    /// Backoff strategy
    pub backoff_strategy: BackoffStrategy,
    /// Last retry time
    pub last_retry: Option<u64>,
    /// Retry success history
    pub success_history: Vec<bool>,
}

/// Backoff strategies for retries
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum BackoffStrategy {
    /// Fixed delay between retries
    Fixed,
    /// Linear increase in delay
    Linear,
    /// Exponential backoff
    Exponential,
    /// Fibonacci sequence
    Fibonacci,
    /// Custom delay sequence
    Custom(Vec<u64>),
}

/// Error pattern for detection and analysis
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorPattern {
    /// Pattern identifier
    pub pattern_id: String,
    /// Pattern description
    pub description: String,
    /// Error categories involved
    pub categories: Vec<ErrorCategory>,
    /// Minimum occurrences to trigger pattern
    pub min_occurrences: usize,
    /// Time window for pattern detection
    pub time_window: Duration,
    /// Pattern-specific recovery strategy
    pub recovery_strategy: RecoveryStrategy,
    /// Pattern confidence score
    pub confidence: f64,
}

/// Recovery strategies for error patterns
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RecoveryStrategy {
    /// Strategy name
    pub name: String,
    /// Automatic recovery actions
    pub automatic_actions: Vec<AutomatedAction>,
    /// Manual recovery steps
    pub manual_steps: Vec<String>,
    /// Conditions for applying this strategy
    pub conditions: Vec<String>,
    /// Expected success rate
    pub success_rate: f64,
    /// Recovery time estimate
    pub recovery_time: Duration,
}

/// Advanced error handler with pattern detection and recovery
pub struct AdvancedErrorHandler {
    /// Error history for pattern analysis
    error_history: Arc<RwLock<Vec<AdvancedError>>>,
    /// Detected error patterns
    detected_patterns: Arc<RwLock<HashMap<String, ErrorPattern>>>,
    /// Recovery success statistics
    recovery_stats: Arc<RwLock<RecoveryStatistics>>,
    /// Configuration for error handling
    config: ErrorHandlerConfig,
    /// Pattern detection rules
    pattern_rules: Vec<ErrorPattern>,
    /// Recovery action handlers
    action_handlers: HashMap<ActionType, Box<dyn ActionHandler>>,
}

/// Recovery statistics tracking
#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct RecoveryStatistics {
    /// Total errors encountered
    pub total_errors: u64,
    /// Total recovery attempts
    pub recovery_attempts: u64,
    /// Successful recoveries
    pub successful_recoveries: u64,
    /// Recovery success rate
    pub success_rate: f64,
    /// Average recovery time
    pub avg_recovery_time_ms: f64,
    /// Error category statistics
    pub category_stats: HashMap<ErrorCategory, CategoryStats>,
    /// Pattern detection statistics
    pub pattern_stats: HashMap<String, PatternStats>,
}

/// Statistics per error category
#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct CategoryStats {
    /// Total occurrences
    pub count: u64,
    /// Recovery success rate for this category
    pub recovery_rate: f64,
    /// Average time to recover
    pub avg_recovery_time_ms: f64,
    /// Most effective recovery method
    pub best_recovery_method: Option<RecoveryCategory>,
}

/// Statistics per error pattern
#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct PatternStats {
    /// Times this pattern was detected
    pub detection_count: u64,
    /// Times recovery was attempted for this pattern
    pub recovery_attempts: u64,
    /// Successful recoveries for this pattern
    pub successful_recoveries: u64,
    /// Pattern-specific success rate
    pub success_rate: f64,
}

/// Configuration for error handler
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorHandlerConfig {
    /// Enable pattern detection
    pub enable_pattern_detection: bool,
    /// Enable automatic recovery
    pub enable_auto_recovery: bool,
    /// Maximum error history size
    pub max_error_history: usize,
    /// Pattern detection sensitivity (0.0-1.0)
    pub pattern_sensitivity: f64,
    /// Maximum automatic recovery attempts
    pub max_auto_recovery_attempts: usize,
    /// Error reporting configuration
    pub reporting_config: ErrorReportingConfig,
    /// Recovery timeout
    pub recovery_timeout: Duration,
}

/// Error reporting configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorReportingConfig {
    /// Enable detailed error logging
    pub detailed_logging: bool,
    /// Log file path
    pub log_file_path: Option<String>,
    /// Enable error telemetry
    pub enable_telemetry: bool,
    /// Telemetry endpoint
    pub telemetry_endpoint: Option<String>,
    /// Enable user notifications
    pub enable_notifications: bool,
    /// Notification severity threshold
    pub notification_threshold: ErrorSeverity,
}

/// Action handler trait for automated recovery
pub trait ActionHandler: Send + Sync {
    /// Execute the automated action
    fn execute(&self, action: &AutomatedAction) -> Result<ActionResult, ActionError>;

    /// Validate if action can be executed
    fn can_execute(&self, action: &AutomatedAction) -> bool;

    /// Get estimated execution time
    fn estimated_time(&self, action: &AutomatedAction) -> Duration;
}

/// Result of an automated action
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ActionResult {
    /// Whether action succeeded
    pub success: bool,
    /// Result message
    pub message: String,
    /// Execution time
    pub execution_time: Duration,
    /// Additional result data
    pub data: HashMap<String, String>,
}

/// Error from automated action execution
#[derive(Debug, Error)]
pub enum ActionError {
    #[error("Action execution failed: {message}")]
    ExecutionFailed { message: String },
    #[error("Action not supported: {action_type:?}")]
    NotSupported { action_type: ActionType },
    #[error("Action timed out after {timeout:?}")]
    Timeout { timeout: Duration },
    #[error("Action dependencies not met: {missing:?}")]
    DependenciesMissing { missing: Vec<String> },
}

impl AdvancedErrorHandler {
    /// Create a new advanced error handler
    pub fn new(config: ErrorHandlerConfig) -> Self {
        Self {
            error_history: Arc::new(RwLock::new(Vec::new())),
            detected_patterns: Arc::new(RwLock::new(HashMap::new())),
            recovery_stats: Arc::new(RwLock::new(RecoveryStatistics::default())),
            config,
            pattern_rules: Self::default_pattern_rules(),
            action_handlers: Self::default_action_handlers(),
        }
    }

    /// Handle an error with advanced processing
    pub async fn handle_error(&self, error: AdvancedError) -> ErrorHandlingResult {
        tracing::error!(
            "Handling advanced error: {} ({})",
            error.message,
            error.error_id
        );

        // Record error in history
        self.record_error(&error).await;

        // Update statistics
        self.update_statistics(&error).await;

        // Detect patterns
        let detected_patterns = if self.config.enable_pattern_detection {
            self.detect_patterns(&error).await
        } else {
            Vec::new()
        };

        // Attempt recovery
        let recovery_result = if self.config.enable_auto_recovery && error.recoverable {
            self.attempt_recovery(&error).await
        } else {
            RecoveryResult::NotAttempted
        };

        // Generate user-friendly report
        let user_report = self
            .generate_user_report(&error, &detected_patterns, &recovery_result)
            .await;

        ErrorHandlingResult {
            error_id: error.error_id.clone(),
            handled: true,
            recovery_result,
            detected_patterns,
            user_report,
            automated_actions_taken: self.get_automated_actions(&error).await,
            recommendations: error.recovery_suggestions.clone(),
        }
    }

    /// Record error in history
    async fn record_error(&self, error: &AdvancedError) {
        let mut history = self.error_history.write().await;
        history.push(error.clone());

        // Maintain history size limit
        if history.len() > self.config.max_error_history {
            history.remove(0);
        }
    }

    /// Update recovery statistics
    async fn update_statistics(&self, error: &AdvancedError) {
        let mut stats = self.recovery_stats.write().await;
        stats.total_errors += 1;

        // Update category statistics
        let category_stats = stats.category_stats.entry(error.category).or_default();
        category_stats.count += 1;
    }

    /// Detect error patterns
    async fn detect_patterns(&self, current_error: &AdvancedError) -> Vec<String> {
        let mut detected = Vec::new();
        let history = self.error_history.read().await;

        for pattern in &self.pattern_rules {
            if self.matches_pattern(pattern, current_error, &history) {
                detected.push(pattern.pattern_id.clone());

                // Record pattern detection
                let mut patterns = self.detected_patterns.write().await;
                patterns.insert(pattern.pattern_id.clone(), pattern.clone());
            }
        }

        detected
    }

    /// Check if error matches a pattern
    fn matches_pattern(
        &self,
        pattern: &ErrorPattern,
        error: &AdvancedError,
        history: &[AdvancedError],
    ) -> bool {
        // Check if error category matches pattern
        if !pattern.categories.contains(&error.category) {
            return false;
        }

        // Count recent occurrences of similar errors
        let cutoff_time = SystemTime::now()
            .duration_since(SystemTime::UNIX_EPOCH)
            .unwrap_or_default()
            .as_secs()
            .saturating_sub(pattern.time_window.as_secs());

        let recent_similar_errors = history
            .iter()
            .filter(|e| e.timestamp >= cutoff_time)
            .filter(|e| pattern.categories.contains(&e.category))
            .count();

        recent_similar_errors >= pattern.min_occurrences
    }

    /// Attempt automatic recovery
    async fn attempt_recovery(&self, error: &AdvancedError) -> RecoveryResult {
        tracing::info!(
            "Attempting automatic recovery for error: {}",
            error.error_id
        );

        let mut stats = self.recovery_stats.write().await;
        stats.recovery_attempts += 1;
        drop(stats);

        // Try recovery suggestions in priority order
        let mut sorted_suggestions = error.recovery_suggestions.clone();
        sorted_suggestions.sort_by_key(|b| std::cmp::Reverse(b.priority));

        for suggestion in sorted_suggestions {
            if suggestion.category == RecoveryCategory::AutomaticRecovery {
                match self
                    .execute_recovery_actions(&suggestion.automated_actions)
                    .await
                {
                    Ok(results) => {
                        if results.iter().all(|r| r.success) {
                            let mut stats = self.recovery_stats.write().await;
                            stats.successful_recoveries += 1;
                            stats.success_rate =
                                stats.successful_recoveries as f64 / stats.recovery_attempts as f64;

                            return RecoveryResult::Successful {
                                method: suggestion.category,
                                actions_taken: results,
                                recovery_time: suggestion.estimated_time,
                            };
                        }
                    }
                    Err(e) => {
                        tracing::warn!("Recovery action failed: {}", e);
                    }
                }
            }
        }

        RecoveryResult::Failed {
            reason: "No successful automatic recovery method found".to_string(),
            attempted_methods: error
                .recovery_suggestions
                .iter()
                .map(|s| s.category.clone())
                .collect(),
        }
    }

    /// Execute recovery actions
    async fn execute_recovery_actions(
        &self,
        actions: &[AutomatedAction],
    ) -> Result<Vec<ActionResult>, ActionError> {
        let mut results = Vec::new();

        for action in actions {
            if let Some(handler) = self.action_handlers.get(&action.action_type) {
                if handler.can_execute(action) {
                    match handler.execute(action) {
                        Ok(result) => results.push(result),
                        Err(e) => return Err(e),
                    }
                } else {
                    return Err(ActionError::NotSupported {
                        action_type: action.action_type.clone(),
                    });
                }
            }
        }

        Ok(results)
    }

    /// Generate user-friendly error report
    async fn generate_user_report(
        &self,
        error: &AdvancedError,
        patterns: &[String],
        recovery: &RecoveryResult,
    ) -> UserErrorReport {
        UserErrorReport {
            title: self.generate_user_friendly_title(error),
            summary: self.generate_error_summary(error),
            impact: self.assess_user_impact(error),
            what_happened: self.explain_what_happened(error),
            why_it_happened: self.explain_why_it_happened(error, patterns),
            what_we_did: self.explain_recovery_actions(recovery),
            what_you_can_do: self.generate_user_actions(error),
            prevention_tips: self.generate_prevention_tips(error),
            technical_details: if self.config.reporting_config.detailed_logging {
                Some(error.technical_details.clone())
            } else {
                None
            },
            support_info: self.generate_support_info(error),
        }
    }

    /// Generate user-friendly error title
    fn generate_user_friendly_title(&self, error: &AdvancedError) -> String {
        match error.category {
            ErrorCategory::Network => "Network Connection Issue".to_string(),
            ErrorCategory::Memory => "Memory Issue Detected".to_string(),
            ErrorCategory::ModelLoading => "Model Loading Problem".to_string(),
            ErrorCategory::AudioProcessing => "Audio Processing Error".to_string(),
            ErrorCategory::Synthesis => "Voice Synthesis Issue".to_string(),
            ErrorCategory::Configuration => "Configuration Problem".to_string(),
            ErrorCategory::FileSystem => "File System Error".to_string(),
            ErrorCategory::Authentication => "Authentication Issue".to_string(),
            ErrorCategory::Permission => "Permission Error".to_string(),
            ErrorCategory::ResourceExhaustion => "System Resources Low".to_string(),
            ErrorCategory::Dependency => "Dependency Issue".to_string(),
            ErrorCategory::Hardware => "Hardware Problem Detected".to_string(),
            ErrorCategory::UserInput => "Input Validation Error".to_string(),
            ErrorCategory::Internal => "Internal System Error".to_string(),
            ErrorCategory::ExternalService => "External Service Issue".to_string(),
        }
    }

    /// Generate error summary
    fn generate_error_summary(&self, error: &AdvancedError) -> String {
        match error.severity {
            ErrorSeverity::Info => format!("Information: {}", error.message),
            ErrorSeverity::Warning => {
                format!("Warning: {} This may affect performance.", error.message)
            }
            ErrorSeverity::Error => format!(
                "Error: {} The current operation could not be completed.",
                error.message
            ),
            ErrorSeverity::Critical => format!(
                "Critical Issue: {} System functionality may be impaired.",
                error.message
            ),
            ErrorSeverity::Fatal => format!(
                "Fatal Error: {} System cannot continue normal operation.",
                error.message
            ),
        }
    }

    /// Assess user impact
    fn assess_user_impact(&self, error: &AdvancedError) -> UserImpact {
        match (error.severity, error.category) {
            (ErrorSeverity::Fatal, _) => UserImpact::Severe,
            (ErrorSeverity::Critical, _) => UserImpact::High,
            (ErrorSeverity::Error, ErrorCategory::Synthesis) => UserImpact::Medium,
            (ErrorSeverity::Error, ErrorCategory::AudioProcessing) => UserImpact::Medium,
            (ErrorSeverity::Warning, _) => UserImpact::Low,
            (ErrorSeverity::Info, _) => UserImpact::None,
            _ => UserImpact::Medium,
        }
    }

    /// Explain what happened
    fn explain_what_happened(&self, error: &AdvancedError) -> String {
        format!(
            "While performing '{}', an issue occurred in the {} component. {}",
            error.context.operation,
            error.context.component,
            match error.category {
                ErrorCategory::Network =>
                    "The system could not connect to the required network service.",
                ErrorCategory::Memory => "The system ran low on available memory.",
                ErrorCategory::ModelLoading => "The voice model could not be loaded properly.",
                ErrorCategory::AudioProcessing =>
                    "The audio data could not be processed as expected.",
                ErrorCategory::Synthesis => "The voice synthesis process encountered an issue.",
                _ => "An unexpected condition was encountered.",
            }
        )
    }

    /// Explain why it happened
    fn explain_why_it_happened(&self, error: &AdvancedError, patterns: &[String]) -> String {
        if !patterns.is_empty() {
            format!(
                "This appears to be part of a known pattern: {}. Common causes include resource constraints, network instability, or configuration issues.",
                patterns.join(", ")
            )
        } else {
            match error.category {
                ErrorCategory::Network => "This could be due to internet connectivity issues, firewall restrictions, or service outages.".to_string(),
                ErrorCategory::Memory => "This typically happens when the system is processing large amounts of data or when other applications are using significant memory.".to_string(),
                ErrorCategory::ModelLoading => "This may occur if model files are corrupted, missing, or incompatible with the current system.".to_string(),
                _ => "The exact cause is being investigated. This may be a temporary issue.".to_string(),
            }
        }
    }

    /// Explain recovery actions taken
    fn explain_recovery_actions(&self, recovery: &RecoveryResult) -> String {
        match recovery {
            RecoveryResult::Successful {
                method,
                actions_taken,
                ..
            } => {
                format!(
                    "We automatically attempted to resolve this issue using {} and took {} recovery actions. The issue appears to be resolved.",
                    Self::recovery_method_description(method),
                    actions_taken.len()
                )
            }
            RecoveryResult::Failed {
                attempted_methods, ..
            } => {
                format!(
                    "We attempted automatic recovery using {} methods, but the issue persists and requires manual intervention.",
                    attempted_methods.len()
                )
            }
            RecoveryResult::NotAttempted => {
                "No automatic recovery was attempted for this type of issue.".to_string()
            }
        }
    }

    /// Generate user actions
    fn generate_user_actions(&self, error: &AdvancedError) -> Vec<String> {
        let mut actions = Vec::new();

        // Add general actions based on error category
        match error.category {
            ErrorCategory::Network => {
                actions.push("Check your internet connection".to_string());
                actions.push("Try again in a few moments".to_string());
                actions.push("Check if any firewalls are blocking the connection".to_string());
            }
            ErrorCategory::Memory => {
                actions.push("Close other applications to free up memory".to_string());
                actions.push("Try processing smaller amounts of data at once".to_string());
                actions.push("Restart the application if the issue persists".to_string());
            }
            ErrorCategory::ModelLoading => {
                actions.push("Verify that all required model files are present".to_string());
                actions.push("Try re-downloading the models if available".to_string());
                actions.push("Check available disk space".to_string());
            }
            _ => {
                actions.push("Try the operation again".to_string());
                actions.push("Check the system logs for more details".to_string());
            }
        }

        // Add specific recovery suggestions
        for suggestion in &error.recovery_suggestions {
            if suggestion.requires_user_action && suggestion.difficulty == DifficultyLevel::Easy {
                actions.push(suggestion.suggestion.clone());
            }
        }

        actions
    }

    /// Generate prevention tips
    fn generate_prevention_tips(&self, error: &AdvancedError) -> Vec<String> {
        match error.category {
            ErrorCategory::Network => vec![
                "Ensure stable internet connection before starting operations".to_string(),
                "Consider using offline mode when available".to_string(),
            ],
            ErrorCategory::Memory => vec![
                "Close unnecessary applications before processing large tasks".to_string(),
                "Process data in smaller batches".to_string(),
                "Consider upgrading system memory if this occurs frequently".to_string(),
            ],
            ErrorCategory::ModelLoading => vec![
                "Regularly verify model file integrity".to_string(),
                "Keep models updated to the latest versions".to_string(),
                "Ensure sufficient disk space for model storage".to_string(),
            ],
            _ => vec![
                "Keep the application updated to the latest version".to_string(),
                "Monitor system resources during heavy operations".to_string(),
            ],
        }
    }

    /// Generate support information
    fn generate_support_info(&self, error: &AdvancedError) -> SupportInfo {
        SupportInfo {
            error_id: error.error_id.clone(),
            timestamp: error.timestamp,
            component: error.context.component.clone(),
            severity: error.severity,
            category: error.category,
            session_id: error.context.session_id.clone(),
            request_id: error.context.request_id.clone(),
            support_url: Some("https://support.voirs.com".to_string()),
            documentation_links: self.get_relevant_documentation_links(&error.category),
        }
    }

    /// Get automated actions taken
    async fn get_automated_actions(&self, error: &AdvancedError) -> Vec<String> {
        error
            .recovery_suggestions
            .iter()
            .filter(|s| s.category == RecoveryCategory::AutomaticRecovery)
            .flat_map(|s| s.automated_actions.iter())
            .map(|a| a.description.clone())
            .collect()
    }

    /// Get relevant documentation links
    fn get_relevant_documentation_links(&self, category: &ErrorCategory) -> Vec<String> {
        match category {
            ErrorCategory::Network => vec![
                "https://docs.voirs.com/troubleshooting/network".to_string(),
                "https://docs.voirs.com/configuration/connectivity".to_string(),
            ],
            ErrorCategory::Memory => vec![
                "https://docs.voirs.com/performance/memory-optimization".to_string(),
                "https://docs.voirs.com/troubleshooting/performance".to_string(),
            ],
            ErrorCategory::ModelLoading => vec![
                "https://docs.voirs.com/models/installation".to_string(),
                "https://docs.voirs.com/troubleshooting/models".to_string(),
            ],
            _ => vec!["https://docs.voirs.com/troubleshooting".to_string()],
        }
    }

    /// Get recovery method description
    fn recovery_method_description(method: &RecoveryCategory) -> &'static str {
        match method {
            RecoveryCategory::AutomaticRecovery => "automatic system recovery",
            RecoveryCategory::ConfigurationFix => "configuration adjustment",
            RecoveryCategory::ResourceOptimization => "resource optimization",
            RecoveryCategory::RetryOptimization => "intelligent retry",
            RecoveryCategory::SystemRestart => "system restart",
            RecoveryCategory::SoftwareUpdate => "software update",
            RecoveryCategory::HardwareCheck => "hardware validation",
            RecoveryCategory::NetworkTroubleshooting => "network diagnostics",
            RecoveryCategory::PermissionFix => "permission correction",
        }
    }

    /// Get default pattern rules
    fn default_pattern_rules() -> Vec<ErrorPattern> {
        vec![
            ErrorPattern {
                pattern_id: "network_instability".to_string(),
                description: "Repeated network connection failures".to_string(),
                categories: vec![ErrorCategory::Network, ErrorCategory::ExternalService],
                min_occurrences: 3,
                time_window: Duration::from_secs(300), // 5 minutes
                recovery_strategy: RecoveryStrategy {
                    name: "Network Recovery".to_string(),
                    automatic_actions: vec![AutomatedAction {
                        action_type: ActionType::RetryOperation,
                        description: "Retry with exponential backoff".to_string(),
                        parameters: HashMap::new(),
                        safe_to_automate: true,
                        execution_time: Duration::from_secs(30),
                        dependencies: vec![],
                    }],
                    manual_steps: vec!["Check network connection".to_string()],
                    conditions: vec!["Network errors > 3 in 5 minutes".to_string()],
                    success_rate: 0.8,
                    recovery_time: Duration::from_secs(60),
                },
                confidence: 0.9,
            },
            ErrorPattern {
                pattern_id: "memory_pressure".to_string(),
                description: "System running low on memory".to_string(),
                categories: vec![ErrorCategory::Memory, ErrorCategory::ResourceExhaustion],
                min_occurrences: 2,
                time_window: Duration::from_secs(120), // 2 minutes
                recovery_strategy: RecoveryStrategy {
                    name: "Memory Optimization".to_string(),
                    automatic_actions: vec![
                        AutomatedAction {
                            action_type: ActionType::ClearCache,
                            description: "Clear system caches".to_string(),
                            parameters: HashMap::new(),
                            safe_to_automate: true,
                            execution_time: Duration::from_secs(10),
                            dependencies: vec![],
                        },
                        AutomatedAction {
                            action_type: ActionType::ReduceResources,
                            description: "Reduce memory usage".to_string(),
                            parameters: HashMap::new(),
                            safe_to_automate: true,
                            execution_time: Duration::from_secs(5),
                            dependencies: vec![],
                        },
                    ],
                    manual_steps: vec!["Close unnecessary applications".to_string()],
                    conditions: vec!["Memory errors in short timespan".to_string()],
                    success_rate: 0.7,
                    recovery_time: Duration::from_secs(30),
                },
                confidence: 0.85,
            },
        ]
    }

    /// Get default action handlers
    fn default_action_handlers() -> HashMap<ActionType, Box<dyn ActionHandler>> {
        // In a real implementation, these would be actual handlers
        HashMap::new()
    }
}

/// Result of error handling
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorHandlingResult {
    /// Error identifier
    pub error_id: String,
    /// Whether error was handled
    pub handled: bool,
    /// Recovery result
    pub recovery_result: RecoveryResult,
    /// Detected error patterns
    pub detected_patterns: Vec<String>,
    /// User-friendly error report
    pub user_report: UserErrorReport,
    /// Automated actions that were taken
    pub automated_actions_taken: Vec<String>,
    /// Recovery recommendations
    pub recommendations: Vec<RecoverySuggestion>,
}

/// Result of recovery attempt
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum RecoveryResult {
    /// Recovery was successful
    Successful {
        method: RecoveryCategory,
        actions_taken: Vec<ActionResult>,
        recovery_time: Duration,
    },
    /// Recovery failed
    Failed {
        reason: String,
        attempted_methods: Vec<RecoveryCategory>,
    },
    /// Recovery was not attempted
    NotAttempted,
}

/// User-friendly error report
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct UserErrorReport {
    /// User-friendly title
    pub title: String,
    /// Brief summary
    pub summary: String,
    /// Impact on user
    pub impact: UserImpact,
    /// What happened explanation
    pub what_happened: String,
    /// Why it happened explanation
    pub why_it_happened: String,
    /// What the system did automatically
    pub what_we_did: String,
    /// What the user can do
    pub what_you_can_do: Vec<String>,
    /// Prevention tips
    pub prevention_tips: Vec<String>,
    /// Technical details (optional)
    pub technical_details: Option<String>,
    /// Support information
    pub support_info: SupportInfo,
}

/// User impact levels
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum UserImpact {
    /// No impact on user experience
    None,
    /// Minor impact, barely noticeable
    Low,
    /// Moderate impact, some functionality affected
    Medium,
    /// High impact, significant functionality affected
    High,
    /// Severe impact, system unusable
    Severe,
}

/// Support information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SupportInfo {
    /// Error identifier for support
    pub error_id: String,
    /// Error timestamp
    pub timestamp: u64,
    /// Component that failed
    pub component: String,
    /// Error severity
    pub severity: ErrorSeverity,
    /// Error category
    pub category: ErrorCategory,
    /// Session identifier
    pub session_id: Option<String>,
    /// Request identifier
    pub request_id: Option<String>,
    /// Support URL
    pub support_url: Option<String>,
    /// Relevant documentation links
    pub documentation_links: Vec<String>,
}

impl Default for ErrorHandlerConfig {
    fn default() -> Self {
        Self {
            enable_pattern_detection: true,
            enable_auto_recovery: true,
            max_error_history: 1000,
            pattern_sensitivity: 0.8,
            max_auto_recovery_attempts: 3,
            reporting_config: ErrorReportingConfig::default(),
            recovery_timeout: Duration::from_secs(60),
        }
    }
}

impl Default for ErrorReportingConfig {
    fn default() -> Self {
        Self {
            detailed_logging: true,
            log_file_path: Some("voirs-errors.log".to_string()),
            enable_telemetry: false,
            telemetry_endpoint: None,
            enable_notifications: true,
            notification_threshold: ErrorSeverity::Error,
        }
    }
}

impl fmt::Display for ErrorSeverity {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            ErrorSeverity::Info => write!(f, "INFO"),
            ErrorSeverity::Warning => write!(f, "WARNING"),
            ErrorSeverity::Error => write!(f, "ERROR"),
            ErrorSeverity::Critical => write!(f, "CRITICAL"),
            ErrorSeverity::Fatal => write!(f, "FATAL"),
        }
    }
}

impl fmt::Display for ErrorCategory {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            ErrorCategory::Configuration => write!(f, "Configuration"),
            ErrorCategory::Network => write!(f, "Network"),
            ErrorCategory::FileSystem => write!(f, "FileSystem"),
            ErrorCategory::Memory => write!(f, "Memory"),
            ErrorCategory::ModelLoading => write!(f, "ModelLoading"),
            ErrorCategory::AudioProcessing => write!(f, "AudioProcessing"),
            ErrorCategory::Synthesis => write!(f, "Synthesis"),
            ErrorCategory::Authentication => write!(f, "Authentication"),
            ErrorCategory::Permission => write!(f, "Permission"),
            ErrorCategory::ResourceExhaustion => write!(f, "ResourceExhaustion"),
            ErrorCategory::Dependency => write!(f, "Dependency"),
            ErrorCategory::Hardware => write!(f, "Hardware"),
            ErrorCategory::UserInput => write!(f, "UserInput"),
            ErrorCategory::Internal => write!(f, "Internal"),
            ErrorCategory::ExternalService => write!(f, "ExternalService"),
        }
    }
}

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

    #[tokio::test]
    async fn test_error_handler_creation() {
        let config = ErrorHandlerConfig::default();
        let handler = AdvancedErrorHandler::new(config);

        // Test basic creation
        assert!(handler.pattern_rules.len() > 0);
    }

    #[tokio::test]
    async fn test_error_handling() {
        let config = ErrorHandlerConfig::default();
        let handler = AdvancedErrorHandler::new(config);

        let error = AdvancedError {
            category: ErrorCategory::Network,
            severity: ErrorSeverity::Error,
            message: "Connection failed".to_string(),
            technical_details: "TCP connection timeout".to_string(),
            context: ErrorContext {
                operation: "test_operation".to_string(),
                user: None,
                session_id: None,
                request_id: None,
                component: "network_client".to_string(),
                function: Some("connect".to_string()),
                location: None,
                parameters: HashMap::new(),
                system_state: SystemState {
                    available_memory_bytes: 1000000,
                    cpu_usage_percent: 50.0,
                    active_operations: 1,
                    queue_depth: 0,
                    last_success_time: None,
                    uptime_seconds: 3600,
                },
                performance_metrics: None,
            },
            recovery_suggestions: vec![],
            related_errors: vec![],
            timestamp: SystemTime::now()
                .duration_since(SystemTime::UNIX_EPOCH)
                .unwrap()
                .as_secs(),
            error_id: "test_error_123".to_string(),
            recoverable: true,
            retry_info: Some(RetryInfo {
                attempt: 0,
                max_attempts: 3,
                retry_delay: Duration::from_secs(5),
                backoff_strategy: BackoffStrategy::Exponential,
                last_retry: None,
                success_history: vec![],
            }),
        };

        let result = handler.handle_error(error).await;

        assert!(result.handled);
        assert_eq!(result.error_id, "test_error_123");
    }

    #[test]
    fn test_error_severity_ordering() {
        assert!(ErrorSeverity::Fatal > ErrorSeverity::Critical);
        assert!(ErrorSeverity::Critical > ErrorSeverity::Error);
        assert!(ErrorSeverity::Error > ErrorSeverity::Warning);
        assert!(ErrorSeverity::Warning > ErrorSeverity::Info);
    }

    #[test]
    fn test_backoff_strategy() {
        let retry_info = RetryInfo {
            attempt: 2,
            max_attempts: 5,
            retry_delay: Duration::from_secs(10),
            backoff_strategy: BackoffStrategy::Exponential,
            last_retry: None,
            success_history: vec![false, false],
        };

        assert_eq!(retry_info.backoff_strategy, BackoffStrategy::Exponential);
        assert_eq!(retry_info.attempt, 2);
    }

    #[test]
    fn test_user_impact_assessment() {
        let config = ErrorHandlerConfig::default();
        let handler = AdvancedErrorHandler::new(config);

        let fatal_error = AdvancedError {
            severity: ErrorSeverity::Fatal,
            category: ErrorCategory::Internal,
            // ... other fields with default values for testing
            message: "Fatal error".to_string(),
            technical_details: "System crash".to_string(),
            context: ErrorContext {
                operation: "test".to_string(),
                user: None,
                session_id: None,
                request_id: None,
                component: "test".to_string(),
                function: None,
                location: None,
                parameters: HashMap::new(),
                system_state: SystemState {
                    available_memory_bytes: 0,
                    cpu_usage_percent: 0.0,
                    active_operations: 0,
                    queue_depth: 0,
                    last_success_time: None,
                    uptime_seconds: 0,
                },
                performance_metrics: None,
            },
            recovery_suggestions: vec![],
            related_errors: vec![],
            timestamp: 0,
            error_id: "test".to_string(),
            recoverable: false,
            retry_info: None,
        };

        let impact = handler.assess_user_impact(&fatal_error);
        assert_eq!(impact, UserImpact::Severe);
    }
}