package online.undergroundapps.appstore;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.net.Uri;
import android.os.Environment;
import android.os.ParcelFileDescriptor;
import android.provider.OpenableColumns;

import java.io.File;
import java.io.FileNotFoundException;

public class ApkProvider extends ContentProvider {
    public static final String AUTHORITY = "online.undergroundapps.appstore.apkprovider";

    public static Uri uriFor(File file) {
        return new Uri.Builder()
                .scheme("content")
                .authority(AUTHORITY)
                .appendPath(file.getName())
                .build();
    }

    private File root() {
        File base = getContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS);
        File dir = new File(base, "underground-installers");
        if (!dir.exists()) dir.mkdirs();
        return dir;
    }

    private File resolve(Uri uri) throws FileNotFoundException {
        String name = uri.getLastPathSegment();
        if (name == null || name.contains("/") || name.contains("\\") || name.contains("..")) {
            throw new FileNotFoundException("Invalid file");
        }
        try {
            File base = root().getCanonicalFile();
            File target = new File(base, name).getCanonicalFile();
            if (!target.getPath().startsWith(base.getPath() + File.separator)) {
                throw new FileNotFoundException("Outside provider root");
            }
            if (!target.exists()) throw new FileNotFoundException(target.getName());
            return target;
        } catch (FileNotFoundException e) {
            throw e;
        } catch (Exception e) {
            throw new FileNotFoundException(e.getMessage());
        }
    }

    @Override public boolean onCreate() { return true; }

    @Override
    public String getType(Uri uri) {
        return "application/vnd.android.package-archive";
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        try {
            File f = resolve(uri);
            String[] cols = projection != null ? projection : new String[]{OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE};
            MatrixCursor c = new MatrixCursor(cols, 1);
            MatrixCursor.RowBuilder row = c.newRow();
            for (String col : cols) {
                if (OpenableColumns.DISPLAY_NAME.equals(col)) row.add(f.getName());
                else if (OpenableColumns.SIZE.equals(col)) row.add(f.length());
                else row.add(null);
            }
            return c;
        } catch (Exception e) {
            return null;
        }
    }

    @Override
    public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
        if (!"r".equals(mode)) throw new FileNotFoundException("Read only");
        return ParcelFileDescriptor.open(resolve(uri), ParcelFileDescriptor.MODE_READ_ONLY);
    }

    @Override public Uri insert(Uri uri, ContentValues values) { return null; }
    @Override public int delete(Uri uri, String selection, String[] selectionArgs) { return 0; }
    @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { return 0; }
}