win-auto-utils 0.1.1

//! Diagnostic Tools for DLL Injection

use std::ffi::c_void;

use windows::{
    Win32::{
        Foundation::CloseHandle,
        System::{
            Diagnostics::Debug::WriteProcessMemory,
            LibraryLoader::GetModuleHandleA,
            Memory::{VirtualAllocEx, VirtualFreeEx, MEM_RELEASE, PAGE_READWRITE},
        },
    },
};

use super::helpers::open_process_full;
use super::DllInjectorError;

/// Diagnostic report for DLL injection feasibility
#[derive(Debug)]
pub struct DiagnosticReport {
    /// Target process ID
    pub pid: u32,
    /// Can the process be opened with PROCESS_ALL_ACCESS?
    pub process_accessible: bool,
    /// Is kernel32.dll loaded in the target?
    pub kernel32_loaded: bool,
    /// Can we allocate memory in the target process?
    pub memory_allocatable: bool,
    /// Can we write to allocated memory in the target?
    pub memory_writable: bool,
}

impl DiagnosticReport {
    /// Check if injection is likely to succeed
    pub fn is_injection_feasible(&self) -> bool {
        self.process_accessible 
            && self.kernel32_loaded 
            && self.memory_allocatable 
            && self.memory_writable
    }

    /// Get human-readable summary
    pub fn summary(&self) -> String {
        let mut lines = Vec::new();
        lines.push(format!("🔍 Injection Diagnostic Report for PID {}:", self.pid));
        lines.push(String::from("─────────────────────────────────────────"));
        
        lines.push(format!(
            "Process Accessible:      {}",
            if self.process_accessible { "✅ Yes" } else { "❌ No" }
        ));
        
        lines.push(format!(
            "kernel32.dll Loaded:     {}",
            if self.kernel32_loaded { "✅ Yes" } else { "❌ No" }
        ));
        
        lines.push(format!(
            "Memory Allocatable:      {}",
            if self.memory_allocatable { "✅ Yes" } else { "❌ No" }
        ));
        
        lines.push(format!(
            "Memory Writable:         {}",
            if self.memory_writable { "✅ Yes" } else { "❌ No" }
        ));
        
        lines.push(String::from("─────────────────────────────────────────"));
        
        if self.is_injection_feasible() {
            lines.push(String::from("✅ Injection should succeed!"));
        } else {
            lines.push(String::from("❌ Injection will likely fail. Issues:"));
            
            if !self.process_accessible {
                lines.push(String::from("   • Cannot open process - Run as Administrator"));
            }
            if !self.kernel32_loaded {
                lines.push(String::from("   • kernel32.dll not found - Process may be protected"));
            }
            if !self.memory_allocatable {
                lines.push(String::from("   • Cannot allocate memory - Insufficient permissions"));
            }
            if !self.memory_writable {
                lines.push(String::from("   • Cannot write memory - Anti-injection protection?"));
            }
        }
        
        lines.join("\n")
    }
}

/// Perform diagnostic checks before attempting DLL injection
///
/// # Arguments
/// - `pid`: Target process ID to diagnose
///
/// # Returns
/// - `Ok(DiagnosticReport)` with detailed feasibility information
/// - `Err(DllInjectorError)` on critical failure
///
/// # Example
/// ```no_run
/// use win_auto_utils::dll_injector::diagnose_injection;
///
/// fn main() -> Result<(), Box<dyn std::error::Error>> {
///     let report = diagnose_injection(12345)?;
///     println!("{}", report.summary());
///
///     if report.is_injection_feasible() {
///         println!("Safe to proceed with injection");
///     }
///     Ok(())
/// }
/// ```

pub fn diagnose_injection(pid: u32) -> Result<DiagnosticReport, DllInjectorError> {
    let mut report = DiagnosticReport {
        pid,
        process_accessible: false,
        kernel32_loaded: false,
        memory_allocatable: false,
        memory_writable: false,
    };

    // Check 1: Can we open the process?
    match open_process_full(pid) {
        Ok(handle) => {
            report.process_accessible = true;

            unsafe {
                // Check 2: Is kernel32.dll accessible?
                if GetModuleHandleA(windows::core::PCSTR::from_raw("kernel32.dll\0".as_ptr())).is_ok() {
                    report.kernel32_loaded = true;
                }

                // Check 3: Can we allocate and write memory?
                let test_size = 64;
                let test_addr = VirtualAllocEx(handle, None, test_size, windows::Win32::System::Memory::MEM_COMMIT, PAGE_READWRITE);
                
                if !test_addr.is_null() {
                    report.memory_allocatable = true;

                    // Try writing
                    let test_data: u32 = 0xDEADBEEF;
                    let mut bytes_written = 0;
                    let write_ok = WriteProcessMemory(
                        handle,
                        test_addr,
                        &test_data as *const u32 as *const c_void,
                        4,
                        Some(&mut bytes_written),
                    ).is_ok();
                    
                    report.memory_writable = write_ok && bytes_written == 4;
                    
                    // Cleanup
                    let _ = VirtualFreeEx(handle, test_addr, 0, MEM_RELEASE);
                }

                let _ = CloseHandle(handle);
            }
        }
        Err(_) => {
            report.process_accessible = false;
        }
    }
    
    Ok(report)
}