feat: improve CLI interface

README.md

@@ -1 +1,127 @@
-# MotionExtract
+# MotionExtract
+
+A command-line tool to split Google Motion Photos into separate photo and video files.
+
+## What are Motion Photos?
+
+Motion Photos (on Google Pixel phones) store a short video clip inside a JPG file. This tool extracts them into separate files.
+
+## Usage
+
+### Process a folder
+
+```bash
+# Windows
+MotionExtract "C:\Users\YourName\Pictures\MotionPhotos"
+
+# Linux/macOS
+./MotionExtract "/home/user/Pictures/MotionPhotos"
+```
+
+### Specify output directory
+
+```bash
+# Use --output or -o to specify where to save extracted files
+MotionExtract "C:\Photos" --output "D:\Extracted"
+
+# Short form
+MotionExtract "C:\Photos" -o "D:\Extracted"
+
+# Without --output, files are saved to <source-directory>/output (default)
+```
+
+### Interactive mode
+
+```bash
+# Run without arguments to be prompted for a directory
+MotionExtract
+```
+
+### Get help
+
+```bash
+MotionExtract --help
+# or
+MotionExtract -h
+```
+
+### Check version
+
+```bash
+MotionExtract --version
+# or
+MotionExtract -v
+```
+
+### Output
+
+Files are saved to an `output` subdirectory:
+
+- `<filename>_photo.jpg` - The still photo
+- `<filename>_video.mp4` - The video clip
+
+**Example:**
+
+```text
+Input:  C:\Photos\PXL_20220613_003727701.MP.jpg
+Output: C:\Photos\output\PXL_20220613_003727701.MP_photo.jpg
+        C:\Photos\output\PXL_20220613_003727701.MP_video.mp4
+```
+
+### Sample Output
+
+```text
+Scanning for files in: C:\Photos
+Found 15 file(s)
+Output directory: C:\Photos\output
+
+[1/15] IMG_1234.bmp... ⚠ Skipped (not JPG)
+[2/15] PXL_20220613_003727701.MP.jpg... ✓
+[3/15] PXL_20220614_120000123.MP.jpg... ✓
+...
+
+Summary:
+  Total processed: 15
+  Extracted: 12
+  Skipped: 3
+```
+
+### Exit Codes
+
+- `0` - Success (all files processed without errors)
+- `1` - Errors occurred during processing
+
+## Requirements
+
+- .NET 8.0 SDK or runtime
+
+## Installation
+
+```bash
+# Build
+dotnet build -c Release
+
+# Executable will be in: src/MotionExtract/bin/Release/net8.0/
+```
+
+## Developer Commands
+
+```bash
+# Run tests
+dotnet test
+
+# Run application
+dotnet run --project src/MotionExtract -- "C:\path\to\photos"
+
+# Format code
+dotnet format
+
+# Clean
+dotnet clean
+```
+
+## How It Works
+
+Searches for the MP4 `ftyp` signature and JPG end marker (`FF D9`) to split the embedded files.
+
+Based on [this solution](https://android.stackexchange.com/a/203898).

src/MotionExtract/IPhotoVideo.cs

@@ -4,4 +4,5 @@ public interface IPhotoVideo
 {
     void Extract();
     void Save(string outputDir);
+    bool HasValidData();
 }

src/MotionExtract/MotionExtract.csproj

@@ -6,6 +6,7 @@
     <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <Version>1.0.0</Version>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.ILLink.Tasks" Version="8.0.20" />

src/MotionExtract/MotionPhoto.cs

@@ -10,6 +10,9 @@ public class MotionPhoto(FileInfo baseFile) : IPhotoVideo
 
     public void Save(string outputDir)
     {
+        // Ensure output directory exists
+        Directory.CreateDirectory(outputDir);
+
         var baseFileName = Path.GetFileNameWithoutExtension(_baseFile.FullName);
 
         var jpgFileName = $"{baseFileName}_photo.jpg";
@@ -21,8 +24,6 @@ public void Save(string outputDir)
 
     public void Extract()
     {
-        Console.WriteLine($"Processing: {_baseFile.FullName}, size: {_baseFile.Length} bytes");
-
         var data = File.ReadAllBytes(_baseFile.FullName);
 
         // Look for the position of the "ftyp" in the data to detect MP4 start
@@ -42,17 +43,14 @@ public void Extract()
                 JpgData = [.. data.Take(jpgEndPos)];
                 Mp4Data = [.. data.Skip(mp4StartPos)];
             }
-            else
-            {
-                Console.WriteLine("SKIPPING - File appears to contain an MP4 but no valid JPG EOI segment could be found.");
-            }
-        }
-        else
-        {
-            Console.WriteLine("SKIPPING - File does not appear to be a Google motion photo.");
         }
     }
 
+    public bool HasValidData()
+    {
+        return JpgData.Length > 0 && Mp4Data.Length > 0;
+    }
+
     /// <summary>
     /// Find the position of the "ftyp" pattern in the byte array
     /// </summary>