use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, VecDeque};
use std::path::PathBuf;
use std::sync::Arc;
use tokio::sync::RwLock;

/// Debug feature types
#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum DebugFeature {
    APITesting,
    PerformanceMonitoring,
    MemoryProfiling,
    NetworkInspector,
    EventLogger,
    StateInspector,
    LogViewer,
    CrashReporter,
    BenchmarkRunner,
    DiagnosticReport,
}

/// Debug log level
#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
pub enum LogLevel {
    Trace,
    Debug,
    Info,
    Warn,
    Error,
}

/// Debug log entry
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct LogEntry {
    pub timestamp: DateTime<Utc>,
    pub level: LogLevel,
    pub component: String,
    pub message: String,
    pub metadata: HashMap<String, serde_json::Value>,
}

/// Performance metric
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceMetric {
    pub name: String,
    pub value: f64,
    pub unit: String,
    pub timestamp: DateTime<Utc>,
    pub tags: HashMap<String, String>,
}

/// Memory snapshot
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MemorySnapshot {
    pub timestamp: DateTime<Utc>,
    pub heap_used_mb: f64,
    pub heap_total_mb: f64,
    pub external_mb: f64,
    pub process_rss_mb: f64,
    pub details: HashMap<String, f64>,
}

/// Network request log
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NetworkRequest {
    pub id: String,
    pub timestamp: DateTime<Utc>,
    pub method: String,
    pub url: String,
    pub status: Option<u16>,
    pub duration_ms: Option<u64>,
    pub request_headers: HashMap<String, String>,
    pub response_headers: HashMap<String, String>,
    pub request_body: Option<String>,
    pub response_body: Option<String>,
    pub error: Option<String>,
}

/// API test case
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct APITestCase {
    pub id: String,
    pub name: String,
    pub endpoint: String,
    pub method: String,
    pub headers: HashMap<String, String>,
    pub body: Option<serde_json::Value>,
    pub expected_status: u16,
    pub expected_body: Option<serde_json::Value>,
    pub timeout_ms: u64,
}

/// API test result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct APITestResult {
    pub test_id: String,
    pub success: bool,
    pub actual_status: Option<u16>,
    pub actual_body: Option<serde_json::Value>,
    pub duration_ms: u64,
    pub error: Option<String>,
    pub timestamp: DateTime<Utc>,
}

/// Benchmark configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BenchmarkConfig {
    pub name: String,
    pub iterations: u32,
    pub warmup_iterations: u32,
    pub timeout_ms: u64,
    pub collect_memory: bool,
    pub collect_cpu: bool,
}

/// Benchmark result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BenchmarkResult {
    pub name: String,
    pub iterations: u32,
    pub mean_ms: f64,
    pub median_ms: f64,
    pub min_ms: f64,
    pub max_ms: f64,
    pub std_dev_ms: f64,
    pub memory_usage_mb: Option<f64>,
    pub cpu_usage_percent: Option<f64>,
    pub timestamp: DateTime<Utc>,
}

/// Diagnostic report
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DiagnosticReport {
    pub timestamp: DateTime<Utc>,
    pub system_info: SystemInfo,
    pub app_info: AppInfo,
    pub performance_summary: PerformanceSummary,
    pub error_summary: ErrorSummary,
    pub recommendations: Vec<String>,
}

/// System information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SystemInfo {
    pub os: String,
    pub arch: String,
    pub cpu_count: usize,
    pub total_memory_mb: u64,
    pub available_memory_mb: u64,
    pub disk_space_mb: u64,
    pub node_version: Option<String>,
    pub rust_version: String,
}

/// Application information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AppInfo {
    pub version: String,
    pub build_date: String,
    pub uptime_seconds: u64,
    pub active_sessions: usize,
    pub total_requests: u64,
    pub error_count: u64,
}

/// Performance summary
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceSummary {
    pub avg_response_time_ms: f64,
    pub p95_response_time_ms: f64,
    pub p99_response_time_ms: f64,
    pub requests_per_second: f64,
    pub cpu_usage_percent: f64,
    pub memory_usage_mb: f64,
}

/// Error summary
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ErrorSummary {
    pub total_errors: u64,
    pub errors_by_type: HashMap<String, u64>,
    pub recent_errors: Vec<LogEntry>,
}

/// Debug settings
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DebugSettings {
    pub enabled: bool,
    pub log_level: LogLevel,
    pub max_log_entries: usize,
    pub enable_performance_monitoring: bool,
    pub enable_memory_profiling: bool,
    pub enable_network_inspector: bool,
    pub enable_crash_reporting: bool,
    pub log_to_file: bool,
    pub log_file_path: Option<PathBuf>,
    pub performance_sample_interval_ms: u64,
    pub memory_sample_interval_ms: u64,
}

impl Default for DebugSettings {
    fn default() -> Self {
        Self {
            enabled: cfg!(debug_assertions),
            log_level: LogLevel::Info,
            max_log_entries: 10000,
            enable_performance_monitoring: false,
            enable_memory_profiling: false,
            enable_network_inspector: false,
            enable_crash_reporting: true,
            log_to_file: false,
            log_file_path: None,
            performance_sample_interval_ms: 1000,
            memory_sample_interval_ms: 5000,
        }
    }
}

/// Debug features manager
pub struct DebugFeaturesManager {
    settings: Arc<RwLock<DebugSettings>>,
    logs: Arc<RwLock<VecDeque<LogEntry>>>,
    performance_metrics: Arc<RwLock<VecDeque<PerformanceMetric>>>,
    memory_snapshots: Arc<RwLock<VecDeque<MemorySnapshot>>>,
    network_requests: Arc<RwLock<HashMap<String, NetworkRequest>>>,
    api_test_results: Arc<RwLock<HashMap<String, Vec<APITestResult>>>>,
    benchmark_results: Arc<RwLock<Vec<BenchmarkResult>>>,
    notification_manager: Option<Arc<crate::notification_manager::NotificationManager>>,
}

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

impl DebugFeaturesManager {
    /// Create a new debug features manager
    pub fn new() -> Self {
        Self {
            settings: Arc::new(RwLock::new(DebugSettings::default())),
            logs: Arc::new(RwLock::new(VecDeque::new())),
            performance_metrics: Arc::new(RwLock::new(VecDeque::new())),
            memory_snapshots: Arc::new(RwLock::new(VecDeque::new())),
            network_requests: Arc::new(RwLock::new(HashMap::new())),
            api_test_results: Arc::new(RwLock::new(HashMap::new())),
            benchmark_results: Arc::new(RwLock::new(Vec::new())),
            notification_manager: None,
        }
    }

    /// Set the notification manager
    pub fn set_notification_manager(
        &mut self,
        notification_manager: Arc<crate::notification_manager::NotificationManager>,
    ) {
        self.notification_manager = Some(notification_manager);
    }

    /// Get debug settings
    pub async fn get_settings(&self) -> DebugSettings {
        self.settings.read().await.clone()
    }

    /// Update debug settings
    pub async fn update_settings(&self, settings: DebugSettings) {
        *self.settings.write().await = settings;
    }

    /// Log a message
    pub async fn log(
        &self,
        level: LogLevel,
        component: &str,
        message: &str,
        metadata: HashMap<String, serde_json::Value>,
    ) {
        let settings = self.settings.read().await;

        // Check if logging is enabled and level is appropriate
        if !settings.enabled || level < settings.log_level {
            return;
        }

        let entry = LogEntry {
            timestamp: Utc::now(),
            level,
            component: component.to_string(),
            message: message.to_string(),
            metadata,
        };

        // Add to in-memory log
        let mut logs = self.logs.write().await;
        logs.push_back(entry.clone());

        // Limit log size
        while logs.len() > settings.max_log_entries {
            logs.pop_front();
        }

        // Log to file if enabled
        if settings.log_to_file {
            if let Some(path) = &settings.log_file_path {
                let _ = self.write_log_to_file(&entry, path).await;
            }
        }
    }

    /// Record a performance metric
    pub async fn record_metric(
        &self,
        name: &str,
        value: f64,
        unit: &str,
        tags: HashMap<String, String>,
    ) {
        let settings = self.settings.read().await;

        if !settings.enabled || !settings.enable_performance_monitoring {
            return;
        }

        let metric = PerformanceMetric {
            name: name.to_string(),
            value,
            unit: unit.to_string(),
            timestamp: Utc::now(),
            tags,
        };

        let mut metrics = self.performance_metrics.write().await;
        metrics.push_back(metric);

        // Keep only last 1000 metrics
        while metrics.len() > 1000 {
            metrics.pop_front();
        }
    }

    /// Take a memory snapshot
    pub async fn take_memory_snapshot(&self) -> Result<MemorySnapshot, String> {
        let settings = self.settings.read().await;

        if !settings.enabled || !settings.enable_memory_profiling {
            return Err("Memory profiling is disabled".to_string());
        }

        // TODO: Implement actual memory profiling
        let snapshot = MemorySnapshot {
            timestamp: Utc::now(),
            heap_used_mb: 0.0,
            heap_total_mb: 0.0,
            external_mb: 0.0,
            process_rss_mb: 0.0,
            details: HashMap::new(),
        };

        let mut snapshots = self.memory_snapshots.write().await;
        snapshots.push_back(snapshot.clone());

        // Keep only last 100 snapshots
        while snapshots.len() > 100 {
            snapshots.pop_front();
        }

        Ok(snapshot)
    }

    /// Log a network request
    #[allow(dead_code)]
    pub async fn log_network_request(&self, request: NetworkRequest) {
        let settings = self.settings.read().await;

        if !settings.enabled || !settings.enable_network_inspector {
            return;
        }

        let mut requests = self.network_requests.write().await;
        requests.insert(request.id.clone(), request);

        // Keep only last 500 requests
        if requests.len() > 500 {
            // Remove oldest entries
            let mut ids: Vec<_> = requests.keys().cloned().collect();
            ids.sort();
            for id in ids.iter().take(requests.len() - 500) {
                requests.remove(id);
            }
        }
    }

    /// Run API tests
    pub async fn run_api_tests(&self, tests: Vec<APITestCase>) -> Vec<APITestResult> {
        let mut results = Vec::new();

        for test in tests {
            let result = self.run_single_api_test(&test).await;
            results.push(result.clone());

            // Store result
            let mut test_results = self.api_test_results.write().await;
            test_results
                .entry(test.id.clone())
                .or_insert_with(Vec::new)
                .push(result);
        }

        results
    }

    /// Run a single API test
    async fn run_single_api_test(&self, test: &APITestCase) -> APITestResult {
        let start = std::time::Instant::now();

        // TODO: Implement actual API testing
        let duration_ms = start.elapsed().as_millis() as u64;

        APITestResult {
            test_id: test.id.clone(),
            success: false,
            actual_status: None,
            actual_body: None,
            duration_ms,
            error: Some("API testing not yet implemented".to_string()),
            timestamp: Utc::now(),
        }
    }

    /// Run benchmarks
    pub async fn run_benchmarks(&self, configs: Vec<BenchmarkConfig>) -> Vec<BenchmarkResult> {
        let mut results = Vec::new();

        for config in configs {
            let result = self.run_single_benchmark(&config).await;
            results.push(result.clone());

            // Store result
            self.benchmark_results.write().await.push(result);
        }

        results
    }

    /// Run a single benchmark
    async fn run_single_benchmark(&self, config: &BenchmarkConfig) -> BenchmarkResult {
        // TODO: Implement actual benchmarking
        BenchmarkResult {
            name: config.name.clone(),
            iterations: config.iterations,
            mean_ms: 0.0,
            median_ms: 0.0,
            min_ms: 0.0,
            max_ms: 0.0,
            std_dev_ms: 0.0,
            memory_usage_mb: None,
            cpu_usage_percent: None,
            timestamp: Utc::now(),
        }
    }

    /// Generate diagnostic report
    pub async fn generate_diagnostic_report(&self) -> DiagnosticReport {
        let system_info = self.get_system_info().await;
        let app_info = self.get_app_info().await;
        let performance_summary = self.get_performance_summary().await;
        let error_summary = self.get_error_summary().await;
        let recommendations = self.generate_recommendations(
            &system_info,
            &app_info,
            &performance_summary,
            &error_summary,
        );

        DiagnosticReport {
            timestamp: Utc::now(),
            system_info,
            app_info,
            performance_summary,
            error_summary,
            recommendations,
        }
    }

    /// Get recent logs
    pub async fn get_logs(&self, limit: Option<usize>, level: Option<LogLevel>) -> Vec<LogEntry> {
        let logs = self.logs.read().await;
        let iter = logs.iter().rev();

        let filtered: Vec<_> = if let Some(min_level) = level {
            iter.filter(|log| log.level >= min_level).cloned().collect()
        } else {
            iter.cloned().collect()
        };

        match limit {
            Some(n) => filtered.into_iter().take(n).collect(),
            None => filtered,
        }
    }

    /// Get performance metrics
    pub async fn get_performance_metrics(&self, limit: Option<usize>) -> Vec<PerformanceMetric> {
        let metrics = self.performance_metrics.read().await;
        match limit {
            Some(n) => metrics.iter().rev().take(n).cloned().collect(),
            None => metrics.iter().cloned().collect(),
        }
    }

    /// Get memory snapshots
    pub async fn get_memory_snapshots(&self, limit: Option<usize>) -> Vec<MemorySnapshot> {
        let snapshots = self.memory_snapshots.read().await;
        match limit {
            Some(n) => snapshots.iter().rev().take(n).cloned().collect(),
            None => snapshots.iter().cloned().collect(),
        }
    }

    /// Get network requests
    pub async fn get_network_requests(&self, limit: Option<usize>) -> Vec<NetworkRequest> {
        let requests = self.network_requests.read().await;
        let mut sorted: Vec<_> = requests.values().cloned().collect();
        sorted.sort_by(|a, b| b.timestamp.cmp(&a.timestamp));

        match limit {
            Some(n) => sorted.into_iter().take(n).collect(),
            None => sorted,
        }
    }

    /// Clear all debug data
    pub async fn clear_all_data(&self) {
        self.logs.write().await.clear();
        self.performance_metrics.write().await.clear();
        self.memory_snapshots.write().await.clear();
        self.network_requests.write().await.clear();
        self.api_test_results.write().await.clear();
        self.benchmark_results.write().await.clear();
    }

    /// Enable/disable debug mode
    pub async fn set_debug_mode(&self, enabled: bool) {
        self.settings.write().await.enabled = enabled;

        if let Some(notification_manager) = &self.notification_manager {
            let message = if enabled {
                "Debug mode enabled"
            } else {
                "Debug mode disabled"
            };
            let _ = notification_manager
                .notify_success("Debug Mode", message)
                .await;
        }
    }

    // Helper methods
    async fn write_log_to_file(&self, entry: &LogEntry, path: &PathBuf) -> Result<(), String> {
        use tokio::io::AsyncWriteExt;

        let log_line = format!(
            "[{}] [{}] [{}] {}\n",
            entry.timestamp.format("%Y-%m-%d %H:%M:%S%.3f"),
            format!("{:?}", entry.level),
            entry.component,
            entry.message
        );

        let mut file = tokio::fs::OpenOptions::new()
            .create(true)
            .append(true)
            .open(path)
            .await
            .map_err(|e| e.to_string())?;

        file.write_all(log_line.as_bytes())
            .await
            .map_err(|e| e.to_string())?;

        Ok(())
    }

    async fn get_system_info(&self) -> SystemInfo {
        SystemInfo {
            os: std::env::consts::OS.to_string(),
            arch: std::env::consts::ARCH.to_string(),
            cpu_count: num_cpus::get(),
            total_memory_mb: 0, // TODO: Get actual memory
            available_memory_mb: 0,
            disk_space_mb: 0,
            node_version: None,
            rust_version: "1.70.0".to_string(), // TODO: Get actual rust version
        }
    }

    async fn get_app_info(&self) -> AppInfo {
        AppInfo {
            version: env!("CARGO_PKG_VERSION").to_string(),
            build_date: chrono::Utc::now().to_rfc3339(), // TODO: Get actual build date
            uptime_seconds: 0,                           // TODO: Track uptime
            active_sessions: 0,
            total_requests: 0,
            error_count: 0,
        }
    }

    async fn get_performance_summary(&self) -> PerformanceSummary {
        PerformanceSummary {
            avg_response_time_ms: 0.0,
            p95_response_time_ms: 0.0,
            p99_response_time_ms: 0.0,
            requests_per_second: 0.0,
            cpu_usage_percent: 0.0,
            memory_usage_mb: 0.0,
        }
    }

    async fn get_error_summary(&self) -> ErrorSummary {
        let logs = self.logs.read().await;
        let errors: Vec<_> = logs
            .iter()
            .filter(|log| log.level == LogLevel::Error)
            .cloned()
            .collect();

        let mut errors_by_type = HashMap::new();
        for error in &errors {
            let error_type = error
                .metadata
                .get("type")
                .and_then(|v| v.as_str())
                .unwrap_or("unknown")
                .to_string();
            *errors_by_type.entry(error_type).or_insert(0) += 1;
        }

        ErrorSummary {
            total_errors: errors.len() as u64,
            errors_by_type,
            recent_errors: errors.into_iter().rev().take(10).collect(),
        }
    }

    fn generate_recommendations(
        &self,
        system: &SystemInfo,
        _app: &AppInfo,
        perf: &PerformanceSummary,
        errors: &ErrorSummary,
    ) -> Vec<String> {
        let mut recommendations = Vec::new();

        if perf.cpu_usage_percent > 80.0 {
            recommendations.push(
                "High CPU usage detected. Consider optimizing performance-critical code."
                    .to_string(),
            );
        }

        if perf.memory_usage_mb > (system.total_memory_mb as f64 * 0.8) {
            recommendations.push("High memory usage detected. Check for memory leaks.".to_string());
        }

        if errors.total_errors > 100 {
            recommendations
                .push("High error rate detected. Review error logs for patterns.".to_string());
        }

        if perf.avg_response_time_ms > 1000.0 {
            recommendations.push(
                "Slow response times detected. Consider caching or query optimization.".to_string(),
            );
        }

        recommendations
    }
}

/// Debug statistics
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DebugStats {
    pub total_logs: usize,
    pub logs_by_level: HashMap<String, usize>,
    pub total_metrics: usize,
    pub total_snapshots: usize,
    pub total_requests: usize,
    pub total_test_results: usize,
    pub total_benchmarks: usize,
}

// Re-export num_cpus if needed
extern crate num_cpus;
