using System;
using System.Diagnostics;
using System.Linq;
using System.Text;
using WhiteMagic;
using WhiteMagic.Discovery;

namespace WhiteMagic.Examples;

/// <summary>
/// Example 2: Pattern Scanning
/// Demonstrates finding patterns in target process memory
/// </summary>
public class PatternScanning
{
    /// <summary>
    /// Target process for examples
    /// </summary>
    private static Process? TargetProcess()
    {
        var processes = Process.GetProcessesByName("notepad");
        if (processes.Length > 0)
            return processes[0];

        Console.WriteLine("No Notepad process found. Please launch Notepad first.");
        return null;
    }

    /// <summary>
    /// Example 2.1: Simple pattern scan
    /// </summary>
    public static void SimplePatternScan()
    {
        Console.WriteLine("=== Example 2.1: Simple Pattern Scan ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Define a pattern to search for
        // mov rax, [rip+disp] (common in x64)
        byte[] pattern = { 0x48, 0x8B, 0x05, 0x00, 0x00, 0x00, 0x00 };
        string mask = "xxx????"; // 'x' = exact match, '?' = wildcard

        Console.WriteLine($"Scanning for pattern in module: {process.MainModule.ModuleName}");
        Console.WriteLine($"Pattern bytes: {BitConverter.ToString(pattern)}");
        Console.WriteLine($"Mask: {mask}");

        IntPtr result = PatternScanner.FindInModule(
            magic.Memory,
            pattern,
            mask,
            process.MainModule
        );

        if (result != IntPtr.Zero)
        {
            Console.WriteLine($"✓ Pattern found at: 0x{result:X}");
        }
        else
        {
            Console.WriteLine("✗ Pattern not found");
        }
    }

    /// <summary>
    /// Example 2.2: Pattern scan with multiple results
    /// </summary>
    public static void MultiplePatternScans()
    {
        Console.WriteLine("\n=== Example 2.2: Multiple Pattern Scans ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Multiple patterns to scan
        byte[][] patterns =
        {
            new byte[] { 0x48, 0x8B, 0x05, 0x00, 0x00, 0x00, 0x00 }, // mov rax, [rip+disp]
            new byte[] { 0xE8, 0x00, 0x00, 0x00, 0x00 },             // call rel32
            new byte[] { 0xB8, 0x00, 0x00, 0x00, 0x00 }              // mov eax, imm32
        };

        string[] masks =
        {
            "xxx????",
            "x????",
            "x????"
        };

        string[] descriptions =
        {
            "mov rax, [rip+disp]",
            "call rel32",
            "mov eax, imm32"
        };

        Console.WriteLine($"Scanning for {patterns.Length} patterns in {process.MainModule.ModuleName}...");
        Console.WriteLine("─────────────────────────────────────────────────────────────────");

        for (int i = 0; i < patterns.Length; i++)
        {
            try
            {
                IntPtr result = PatternScanner.FindInModule(
                    magic.Memory,
                    patterns[i],
                    masks[i],
                    process.MainModule
                );

                Console.WriteLine($"{descriptions[i],-25} {(result != IntPtr.Zero ? $"✓ 0x{result:X}" : "✗ Not found")}");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"{descriptions[i],-25} ✗ Error: {ex.Message}");
            }
        }
    }

    /// <summary>
    /// Example 2.3: Pattern scanning in specific region
    /// </summary>
    public static void RegionSpecificScan()
    {
        Console.WriteLine("\n=== Example 2.3: Region-Specific Scan ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Scan specific region: .text section (first 64KB of main module)
        IntPtr startAddress = process.MainModule.BaseAddress;
        IntPtr endAddress = startAddress + 0x10000; // 64KB

        byte[] pattern = { 0x48, 0x8B };
        string mask = "xx"; // Exact match for first 2 bytes

        Console.WriteLine($"Scanning region: 0x{startAddress:X} - 0x{endAddress:X}");

        try
        {
            IntPtr result = PatternScanner.Find(
                magic.Memory,
                pattern,
                mask,
                startAddress,
                endAddress
            );

            if (result != IntPtr.Zero)
            {
                Console.WriteLine($"✓ Pattern found at: 0x{result:X}");
                Console.WriteLine($"  Offset from module base: 0x{(result - startAddress):X}");
            }
            else
            {
                Console.WriteLine("✗ Pattern not found in region");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"✗ Scan failed: {ex.Message}");
        }
    }

    /// <summary>
    /// Example 2.4: Finding a function signature
    /// </summary>
    public static void FindFunctionSignature()
    {
        Console.WriteLine("\n=== Example 2.4: Finding Function Signature ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Common function prologue patterns
        byte[][] prologues =
        {
            // x64 prologue: push rbp; mov rbp, rsp
            new byte[] { 0x55, 0x48, 0x89, 0xE5 },
            
            // x64 prologue: push rbp
            new byte[] { 0x55 },
            
            // x64 prologue: sub rsp, XX (stack allocation)
            new byte[] { 0x48, 0x83, 0xEC, 0x00 } // last byte varies
        };

        string[] prologueMasks =
        {
            "xxxx",    // Exact match
            "x",       // Exact match
            "xxx?"     // Last byte wildcard
        };

        Console.WriteLine($"Scanning for function prologues in {process.MainModule.ModuleName}...");
        Console.WriteLine("─────────────────────────────────────────────────────────────────");

        for (int i = 0; i < prologues.Length; i++)
        {
            try
            {
                IntPtr result = PatternScanner.FindInModule(
                    magic.Memory,
                    prologues[i],
                    prologueMasks[i],
                    process.MainModule
                );

                Console.WriteLine($"Prologue {i + 1}: {(result != IntPtr.Zero ? $"✓ Found at 0x{result:X}" : "✗ Not found")}");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Prologue {i + 1}: ✗ Error: {ex.Message}");
            }
        }
    }

    /// <summary>
    /// Example 2.5: Pattern scanning with caching
    /// </summary>
    public static void CachedPatternScan()
    {
        Console.WriteLine("\n=== Example 2.5: Cached Pattern Scanning ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Create cache
        var cache = new PatternScannerCache(magic.Memory);

        byte[] pattern = { 0x48, 0x8B, 0x05, 0x00, 0x00, 0x00, 0x00 };
        string mask = "xxx????";

        Console.WriteLine("Demonstrating cache performance...");

        // First scan (uncached - reads memory)
        Console.Write("  First scan (uncached): ");
        var watch = System.Diagnostics.Stopwatch.StartNew();
        IntPtr result1 = cache.FindInModuleCached(pattern, mask, process.MainModule);
        watch.Stop();
        Console.WriteLine($"{(result1 != IntPtr.Zero ? $"✓ 0x{result1:X}" : "✗ Not found")} ({watch.ElapsedMilliseconds}ms)");

        // Second scan (cached - no memory read)
        Console.Write("  Second scan (cached):   ");
        watch.Restart();
        IntPtr result2 = cache.FindInModuleCached(pattern, mask, process.MainModule);
        watch.Stop();
        Console.WriteLine($"{(result2 != IntPtr.Zero ? $"✓ 0x{result2:X}" : "✗ Not found")} ({watch.ElapsedMilliseconds}ms)");

        if (result1 == result2)
        {
            Console.WriteLine("  ✓ Results match and cache is working");
        }
    }

    /// <summary>
    /// Example 2.6: Pattern scanning with wildcard flexibility
    /// </summary>
    public static void FlexibleWildcardPatterns()
    {
        Console.WriteLine("\n=== Example 2.6: Flexible Wildcard Patterns ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Same pattern, different wildcard masks
        byte[] pattern = { 0x48, 0x8B, 0x05, 0x12, 0x34, 0x56, 0x78 };

        string[] masks =
        {
            "xxx????",      // Last 4 bytes wildcard
            "xxxx???",      // Last 3 bytes wildcard
            "xxxxxxx",      // Exact match
            "x?x?x?x"       // Alternating wildcard
        };

        Console.WriteLine($"Testing same pattern with different masks...");
        Console.WriteLine($"Pattern: {BitConverter.ToString(pattern)}");
        Console.WriteLine("─────────────────────────────────────────────────────────────────");

        for (int i = 0; i < masks.Length; i++)
        {
            try
            {
                IntPtr result = PatternScanner.FindInModule(
                    magic.Memory,
                    pattern,
                    masks[i],
                    process.MainModule
                );

                Console.WriteLine($"Mask \"{masks[i],-10}\" {(result != IntPtr.Zero ? $"✓ Found at 0x{result:X}" : "✗ Not found")}");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Mask \"{masks[i],-10}\" ✗ Error: {ex.Message}");
            }
        }
    }

    /// <summary>
    /// Example 2.7: Combining pattern scan with validation
    /// </summary>
    public static void SignatureBasedScanning()
    {
        Console.WriteLine("\n=== Example 2.7: Pattern-Based Function Scanning ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Find MessageBoxA pattern in user32.dll (if loaded)
        var user32Module = process.Modules.Cast<System.Diagnostics.ProcessModule>()
            .FirstOrDefault(m => m.ModuleName.Equals("user32.dll", StringComparison.OrdinalIgnoreCase));

        if (user32Module == null)
        {
            Console.WriteLine("✗ user32.dll not loaded in target process");
            return;
        }

        Console.WriteLine($"Scanning {user32Module.ModuleName} for function signatures...");

        // Try to find common export patterns
        byte[] testPattern = { 0x48, 0x8B };
        string mask = "xx";

        try
        {
            IntPtr result = PatternScanner.FindInModule(
                magic.Memory,
                testPattern,
                mask,
                user32Module
            );

            if (result != IntPtr.Zero)
            {
                Console.WriteLine($"✓ Found pattern at 0x{result:X}");
                Console.WriteLine($"  Module base: 0x{user32Module.BaseAddress:X}");
                Console.WriteLine($"  Offset: 0x{(result - user32Module.BaseAddress):X}");
            }
            else
            {
                Console.WriteLine("✗ Pattern not found");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"✗ Scan failed: {ex.Message}");
        }
    }

    /// <summary>
    /// Example 2.8: Pattern validation and error handling
    /// </summary>
    public static void PatternValidation()
    {
        Console.WriteLine("\n=== Example 2.8: Pattern Validation ===");

        var process = TargetProcess();
        if (process == null) return;
        if (process.MainModule == null) return;

        using var magic = Magic.Open(process);

        // Test various invalid/edge case patterns
        Console.WriteLine("Testing edge cases and validation...");

        // Empty pattern
        try
        {
            IntPtr result = PatternScanner.FindInModule(
                magic.Memory,
                Array.Empty<byte>(),
                null,
                process.MainModule
            );
            Console.WriteLine("✗ Empty pattern should throw exception");
        }
        catch (ArgumentException)
        {
            Console.WriteLine("✓ Empty pattern correctly rejected");
        }

        // Mismatched pattern and mask length
        try
        {
            IntPtr result = PatternScanner.FindInModule(
                magic.Memory,
                new byte[] { 0x48, 0x8B },
                "x", // Mask too short
                process.MainModule
            );
            Console.WriteLine("✗ Mismatched mask length should throw exception");
        }
        catch (ArgumentException)
        {
            Console.WriteLine("✓ Mismatched mask length correctly rejected");
        }

        // Invalid mask characters
        try
        {
            IntPtr result = PatternScanner.FindInModule(
                magic.Memory,
                new byte[] { 0x48, 0x8B },
                "ab", // Invalid mask characters
                process.MainModule
            );
            Console.WriteLine("✗ Invalid mask characters should throw exception");
        }
        catch (ArgumentException)
        {
            Console.WriteLine("✓ Invalid mask characters correctly rejected");
        }

        Console.WriteLine("✓ All validation tests passed");
    }

    /// <summary>
    /// Run all pattern scanning examples
    /// </summary>
    public static void RunAll()
    {
        Console.WriteLine("╔════════════════════════════════════════════════════════════╗");
        Console.WriteLine("║   WhiteMagic Example 2: Pattern Scanning                 ║");
        Console.WriteLine("╚════════════════════════════════════════════════════════════╝");

        SimplePatternScan();
        MultiplePatternScans();
        RegionSpecificScan();
        FindFunctionSignature();
        CachedPatternScan();
        FlexibleWildcardPatterns();
        SignatureBasedScanning();
        PatternValidation();

        Console.WriteLine("\n✓ All pattern scanning examples completed!");
    }
}