use crate::{GhostError, MemoryRegion, ProcessInfo};
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::time::SystemTime;

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DynamicYaraEngine {
    rules: Vec<YaraRule>,
    sources: Vec<YaraRuleSource>,
    scan_cache: HashMap<String, CachedScanResult>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct YaraRule {
    pub name: String,
    pub content: String,
    pub source: String,
    pub threat_level: ThreatLevel,
    pub last_updated: SystemTime,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct YaraRuleSource {
    pub name: String,
    pub url: String,
    pub enabled: bool,
    pub rule_count: usize,
    pub last_update: SystemTime,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct YaraScanResult {
    pub matches: Vec<RuleMatch>,
    pub scan_time_ms: u64,
    pub bytes_scanned: u64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RuleMatch {
    pub rule_name: String,
    pub threat_level: ThreatLevel,
    pub offset: u64,
    pub length: u32,
    pub metadata: HashMap<String, String>,
}

#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
pub enum ThreatLevel {
    Info = 1,
    Low = 2,
    Medium = 3,
    High = 4,
    Critical = 5,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct CachedScanResult {
    result: YaraScanResult,
    timestamp: SystemTime,
}

impl DynamicYaraEngine {
    pub fn new(config_path: Option<&str>) -> Result<Self, GhostError> {
        let sources = vec![
            YaraRuleSource {
                name: "Malware Bazaar".to_string(),
                url: "https://bazaar.abuse.ch/browse/".to_string(),
                enabled: true,
                rule_count: 0,
                last_update: SystemTime::now(),
            },
            YaraRuleSource {
                name: "VX-Underground".to_string(),
                url: "https://vx-underground.org/yara".to_string(),
                enabled: true,
                rule_count: 0,
                last_update: SystemTime::now(),
            },
        ];

        Ok(DynamicYaraEngine {
            rules: Vec::new(),
            sources,
            scan_cache: HashMap::new(),
        })
    }

    pub async fn update_rules(&mut self) -> Result<usize, GhostError> {
        let mut updated_count = 0;

        for source in &mut self.sources {
            if !source.enabled {
                continue;
            }

            // Simulate rule download
            let new_rules = vec![YaraRule {
                name: format!("generic_malware_{}", updated_count + 1),
                content: "rule generic_malware { condition: true }".to_string(),
                source: source.name.clone(),
                threat_level: ThreatLevel::Medium,
                last_updated: SystemTime::now(),
            }];

            self.rules.extend(new_rules);
            source.rule_count = self.rules.len();
            source.last_update = SystemTime::now();
            updated_count += 1;
        }

        Ok(updated_count)
    }

    pub async fn scan_process(
        &self,
        process: &ProcessInfo,
        memory_regions: &[MemoryRegion],
    ) -> Result<YaraScanResult, GhostError> {
        let start_time = SystemTime::now();
        let mut matches = Vec::new();
        let mut bytes_scanned = 0;

        // Simulate YARA scanning
        for (i, region) in memory_regions.iter().enumerate() {
            bytes_scanned += region.size;

            // Simulate finding suspicious patterns
            if region.protection.is_executable() && region.protection.is_writable() {
                matches.push(RuleMatch {
                    rule_name: "suspicious_rwx_memory".to_string(),
                    threat_level: ThreatLevel::High,
                    offset: region.base_address as u64,
                    length: 1024,
                    metadata: HashMap::new(),
                });
            }
        }

        let scan_time_ms = start_time.elapsed().unwrap_or_default().as_millis() as u64;

        Ok(YaraScanResult {
            matches,
            scan_time_ms,
            bytes_scanned: bytes_scanned as u64,
        })
    }

    pub fn get_rule_count(&self) -> usize {
        self.rules.len()
    }

    pub fn get_sources(&self) -> &[YaraRuleSource] {
        &self.sources
    }
}