package funkin.util;

import haxe.zip.Entry;
import lime.utils.Bytes;
import lime.ui.FileDialog;
import openfl.net.FileFilter;
import haxe.io.Path;
import openfl.net.FileReference;
import openfl.events.Event;
import openfl.events.IOErrorEvent;
import haxe.ui.containers.dialogs.Dialog.DialogButton;
import haxe.ui.containers.dialogs.Dialogs;
import haxe.ui.containers.dialogs.Dialogs.SelectedFileInfo;
import haxe.ui.containers.dialogs.Dialogs.FileDialogExtensionInfo;

/**
 * Utilities for reading and writing files on various platforms.
 */
class FileUtil
{
  public static final FILE_FILTER_FNFC:FileFilter = new FileFilter("Friday Night Funkin' Chart (.fnfc)", "*.fnfc");
  public static final FILE_FILTER_ZIP:FileFilter = new FileFilter("ZIP Archive (.zip)", "*.zip");

  public static final FILE_EXTENSION_INFO_FNFC:FileDialogExtensionInfo =
    {
      extension: 'fnfc',
      label: 'Friday Night Funkin\' Chart',
    };
  public static final FILE_EXTENSION_INFO_ZIP:FileDialogExtensionInfo =
    {
      extension: 'zip',
      label: 'ZIP Archive',
    };

  /**
   * Browses for a single file, then calls `onSelect(fileInfo)` when a file is selected.
   * Powered by HaxeUI, so it works on all platforms.
   * File contents will be binary, not String.
   *
   * @param typeFilter
   * @param onSelect A callback that provides a `SelectedFileInfo` object when a file is selected.
   * @param onCancel A callback that is called when the user closes the dialog without selecting a file.
   */
  public static function browseForBinaryFile(dialogTitle:String, ?typeFilter:Array<FileDialogExtensionInfo>, ?onSelect:SelectedFileInfo->Void,
      ?onCancel:Void->Void)
  {
    var onComplete = function(button, selectedFiles) {
      if (button == DialogButton.OK && selectedFiles.length > 0)
      {
        onSelect(selectedFiles[0]);
      }
      else
      {
        onCancel();
      }
    };

    Dialogs.openFile(onComplete,
      {
        readContents: true,
        readAsBinary: true, // Binary
        multiple: false,
        extensions: typeFilter ?? [],
        title: dialogTitle,
      });
  }

  /**
   * Browses for a single file, then calls `onSelect(fileInfo)` when a file is selected.
   * Powered by HaxeUI, so it works on all platforms.
   * File contents will be a String, not binary.
   *
   * @param typeFilter
   * @param onSelect A callback that provides a `SelectedFileInfo` object when a file is selected.
   * @param onCancel A callback that is called when the user closes the dialog without selecting a file.
   */
  public static function browseForTextFile(dialogTitle:String, ?typeFilter:Array<FileDialogExtensionInfo>, ?onSelect:SelectedFileInfo->Void,
      ?onCancel:Void->Void)
  {
    var onComplete = function(button, selectedFiles) {
      if (button == DialogButton.OK && selectedFiles.length > 0)
      {
        onSelect(selectedFiles[0]);
      }
      else
      {
        onCancel();
      }
    };

    Dialogs.openFile(onComplete,
      {
        readContents: true,
        readAsBinary: false, // Text
        multiple: false,
        extensions: typeFilter ?? [],
        title: dialogTitle,
      });
  }

  /**
   * Browses for a directory, then calls `onSelect(path)` when a path chosen.
   * Note that on HTML5 this will immediately fail.
   *
   * @param typeFilter TODO What does this do?
   * @return Whether the file dialog was opened successfully.
   */
  public static function browseForDirectory(?typeFilter:Array<FileFilter>, ?onSelect:String->Void, ?onCancel:Void->Void, ?defaultPath:String,
      ?dialogTitle:String):Bool
  {
    #if desktop
    var filter:String = convertTypeFilter(typeFilter);
    var fileDialog:FileDialog = new FileDialog();
    if (onSelect != null) fileDialog.onSelect.add(onSelect);
    if (onCancel != null) fileDialog.onCancel.add(onCancel);
    fileDialog.browse(OPEN_DIRECTORY, filter, defaultPath, dialogTitle);
    return true;
    #elseif html5
    onCancel();
    return false;
    #else
    onCancel();
    return false;
    #end
  }

  /**
   * Browses for multiple file, then calls `onSelect(paths)` when a path chosen.
   * Note that on HTML5 this will immediately fail.
   *
   * @return Whether the file dialog was opened successfully.
   */
  public static function browseForMultipleFiles(?typeFilter:Array<FileFilter>, ?onSelect:Array<String>->Void, ?onCancel:Void->Void, ?defaultPath:String,
      ?dialogTitle:String):Bool
  {
    #if desktop
    var filter:String = convertTypeFilter(typeFilter);
    var fileDialog:FileDialog = new FileDialog();
    if (onSelect != null) fileDialog.onSelectMultiple.add(onSelect);
    if (onCancel != null) fileDialog.onCancel.add(onCancel);
    fileDialog.browse(OPEN_MULTIPLE, filter, defaultPath, dialogTitle);
    return true;
    #elseif html5
    onCancel();
    return false;
    #else
    onCancel();
    return false;
    #end
  }

  /**
   * Browses for a file location to save to, then calls `onSave(path)` when a path chosen.
   * Note that on HTML5 you can't do much with this, you should call `saveFile(resource:haxe.io.Bytes)` instead.
   *
   * @param typeFilter TODO What does this do?
   * @return Whether the file dialog was opened successfully.
   */
  public static function browseForSaveFile(?typeFilter:Array<FileFilter>, ?onSelect:String->Void, ?onCancel:Void->Void, ?defaultPath:String,
      ?dialogTitle:String):Bool
  {
    #if desktop
    var filter:String = convertTypeFilter(typeFilter);
    var fileDialog:FileDialog = new FileDialog();
    if (onSelect != null) fileDialog.onSelect.add(onSelect);
    if (onCancel != null) fileDialog.onCancel.add(onCancel);
    fileDialog.browse(SAVE, filter, defaultPath, dialogTitle);
    return true;
    #elseif html5
    onCancel();
    return false;
    #else
    onCancel();
    return false;
    #end
  }

  /**
   * Browses for a single file location, then writes the provided `haxe.io.Bytes` data and calls `onSave(path)` when done.
   * Works great on desktop and HTML5.
   *
   * @return Whether the file dialog was opened successfully.
   */
  public static function saveFile(data:Bytes, ?typeFilter:Array<FileFilter>, ?onSave:String->Void, ?onCancel:Void->Void, ?defaultFileName:String,
      ?dialogTitle:String):Bool
  {
    #if desktop
    var filter:String = convertTypeFilter(typeFilter);
    var fileDialog:FileDialog = new FileDialog();
    if (onSave != null) fileDialog.onSave.add(onSave);
    if (onCancel != null) fileDialog.onCancel.add(onCancel);
    fileDialog.save(data, filter, defaultFileName, dialogTitle);
    return true;
    #elseif html5
    var filter:String = defaultFileName != null ? Path.extension(defaultFileName) : null;
    var fileDialog:FileDialog = new FileDialog();
    if (onSave != null) fileDialog.onSave.add(onSave);
    if (onCancel != null) fileDialog.onCancel.add(onCancel);
    fileDialog.save(data, filter, defaultFileName, dialogTitle);
    return true;
    #else
    onCancel();
    return false;
    #end
  }

  /**
   * Prompts the user to save multiple files.
   * On desktop, this will prompt the user for a directory, then write all of the files to there.
   * On HTML5, this will zip the files up and prompt the user to save that.
   *
   * @param typeFilter TODO What does this do?
   * @return Whether the file dialog was opened successfully.
   */
  public static function saveMultipleFiles(resources:Array<Entry>, ?onSaveAll:Array<String>->Void, ?onCancel:Void->Void, ?defaultPath:String,
      force:Bool = false):Bool
  {
    #if desktop
    // Prompt the user for a directory, then write all of the files to there.
    var onSelectDir:String->Void = function(targetPath:String):Void {
      var paths:Array<String> = [];
      for (resource in resources)
      {
        var filePath = haxe.io.Path.join([targetPath, resource.fileName]);
        try
        {
          if (resource.data == null)
          {
            trace('WARNING: File $filePath has no data or content. Skipping.');
            continue;
          }
          else
          {
            writeBytesToPath(filePath, resource.data, force ? Force : Skip);
          }
        }
        catch (_)
        {
          throw 'Failed to write file (probably already exists): $filePath';
        }
        paths.push(filePath);
      }
      onSaveAll(paths);
    }
    trace('Browsing for directory to save individual files to...');
    #if mac
    defaultPath = null;
    #end
    browseForDirectory(null, onSelectDir, onCancel, defaultPath, 'Choose directory to save all files to...');
    return true;
    #elseif html5
    saveFilesAsZIP(resources, onSaveAll, onCancel, defaultPath, force);
    return true;
    #else
    onCancel();
    return false;
    #end
  }

  /**
   * Takes an array of file entries and prompts the user to save them as a ZIP file.
   */
  public static function saveFilesAsZIP(resources:Array<Entry>, ?onSave:Array<String>->Void, ?onCancel:Void->Void, ?defaultPath:String, force:Bool = false):Bool
  {
    // Create a ZIP file.
    var zipBytes:Bytes = createZIPFromEntries(resources);
    var onSave:String->Void = function(path:String) {
      trace('Saved ${resources.length} files to ZIP at "$path".');
      if (onSave != null) onSave([path]);
    };
    // Prompt the user to save the ZIP file.
    saveFile(zipBytes, [FILE_FILTER_ZIP], onSave, onCancel, defaultPath, 'Save files as ZIP...');
    return true;
  }

  /**
   * Takes an array of file entries and prompts the user to save them as a FNFC file.
   */
  public static function saveChartAsFNFC(resources:Array<Entry>, ?onSave:Array<String>->Void, ?onCancel:Void->Void, ?defaultPath:String,
      force:Bool = false):Bool
  {
    // Create a ZIP file.
    var zipBytes:Bytes = createZIPFromEntries(resources);
    var onSave:String->Void = function(path:String) {
      trace('Saved FNF file to "$path"');
      if (onSave != null) onSave([path]);
    };
    // Prompt the user to save the ZIP file.
    saveFile(zipBytes, [FILE_FILTER_FNFC], onSave, onCancel, defaultPath, 'Save chart as FNFC...');
    return true;
  }

  /**
   * Takes an array of file entries and forcibly writes a ZIP to the given path.
   * Only works on desktop, because HTML5 doesn't allow you to write files to arbitrary paths.
   * Use `saveFilesAsZIP` instead.
   * @param force Whether to force overwrite an existing file.
   */
  public static function saveFilesAsZIPToPath(resources:Array<Entry>, path:String, mode:FileWriteMode = Skip):Bool
  {
    #if desktop
    // Create a ZIP file.
    var zipBytes:Bytes = createZIPFromEntries(resources);
    // Write the ZIP.
    writeBytesToPath(path, zipBytes, mode);
    return true;
    #else
    return false;
    #end
  }

  /**
   * Read string file contents directly from a given path.
   * Only works on desktop.
   *
   * @param path The path to the file.
   * @return The file contents.
   */
  public static function readStringFromPath(path:String):String
  {
    #if sys
    return sys.io.File.getContent(path);
    #else
    trace('ERROR: readStringFromPath not implemented for this platform');
    return null;
    #end
  }

  /**
   * Read bytes file contents directly from a given path.
   * Only works on desktop.
   *
   * @param path The path to the file.
   * @return The file contents.
   */
  public static function readBytesFromPath(path:String):Bytes
  {
    #if sys
    if (!doesFileExist(path)) return null;
    return sys.io.File.getBytes(path);
    #else
    return null;
    #end
  }

  public static function doesFileExist(path:String):Bool
  {
    #if sys
    return sys.FileSystem.exists(path);
    #else
    return false;
    #end
  }

  /**
   * Browse for a file to read and execute a callback once we have a file reference.
   * Works great on HTML5 or desktop.
   *
   * @param	callback The function to call when the file is loaded.
   */
  public static function browseFileReference(callback:FileReference->Void)
  {
    var file = new FileReference();
    file.addEventListener(Event.SELECT, function(e) {
      var selectedFileRef:FileReference = e.target;
      trace('Selected file: ' + selectedFileRef.name);
      selectedFileRef.addEventListener(Event.COMPLETE, function(e) {
        var loadedFileRef:FileReference = e.target;
        trace('Loaded file: ' + loadedFileRef.name);
        callback(loadedFileRef);
      });
      selectedFileRef.load();
    });
    file.browse();
  }

  /**
   * Prompts the user to save a file to their computer.
   */
  public static function writeFileReference(path:String, data:String)
  {
    var file = new FileReference();
    file.addEventListener(Event.COMPLETE, function(e:Event) {
      trace('Successfully wrote file.');
    });
    file.addEventListener(Event.CANCEL, function(e:Event) {
      trace('Cancelled writing file.');
    });
    file.addEventListener(IOErrorEvent.IO_ERROR, function(e:IOErrorEvent) {
      trace('IO error writing file.');
    });
    file.save(data, path);
  }

  /**
   * Read JSON file contents directly from a given path.
   * Only works on desktop.
   *
   * @param path The path to the file.
   * @return The JSON data.
   */
  public static function readJSONFromPath(path:String):Dynamic
  {
    #if sys
    try
    {
      return SerializerUtil.fromJSON(sys.io.File.getContent(path));
    }
    catch (ex)
    {
      return null;
    }
    #else
    return null;
    #end
  }

  /**
   * Write string file contents directly to a given path.
   * Only works on desktop.
   *
   * @param path The path to the file.
   * @param data The string to write.
   * @param mode Whether to Force, Skip, or Ask to overwrite an existing file.
   */
  public static function writeStringToPath(path:String, data:String, mode:FileWriteMode = Skip):Void
  {
    #if sys
    createDirIfNotExists(Path.directory(path));
    switch (mode)
    {
      case Force:
        sys.io.File.saveContent(path, data);
      case Skip:
        if (!doesFileExist(path))
        {
          sys.io.File.saveContent(path, data);
        }
        else
        {
          // Do nothing.
          // throw 'File already exists: $path';
        }
      case Ask:
        if (doesFileExist(path))
        {
          // TODO: We don't have the technology to use native popups yet.
          throw 'File already exists: $path';
        }
        else
        {
          sys.io.File.saveContent(path, data);
        }
    }
    #else
    throw 'Direct file writing by path not supported on this platform.';
    #end
  }

  /**
   * Write byte file contents directly to a given path.
   * Only works on desktop.
   *
   * @param path The path to the file.
   * @param data The bytes to write.
   * @param mode Whether to Force, Skip, or Ask to overwrite an existing file.
   */
  public static function writeBytesToPath(path:String, data:Bytes, mode:FileWriteMode = Skip):Void
  {
    #if sys
    createDirIfNotExists(Path.directory(path));
    switch (mode)
    {
      case Force:
        sys.io.File.saveBytes(path, data);
      case Skip:
        if (!doesFileExist(path))
        {
          sys.io.File.saveBytes(path, data);
        }
        else
        {
          // Do nothing.
          // throw 'File already exists: $path';
        }
      case Ask:
        if (doesFileExist(path))
        {
          // TODO: We don't have the technology to use native popups yet.
          throw 'File already exists: $path';
        }
        else
        {
          sys.io.File.saveBytes(path, data);
        }
    }
    #else
    throw 'Direct file writing by path not supported on this platform.';
    #end
  }

  /**
   * Write string file contents directly to the end of a file at the given path.
   * Only works on desktop.
   *
   * @param path The path to the file.
   * @param data The string to append.
   */
  public static function appendStringToPath(path:String, data:String):Void
  {
    #if sys
    sys.io.File.append(path, false).writeString(data);
    #else
    throw 'Direct file writing by path not supported on this platform.';
    #end
  }

  /**
   * Create a directory if it doesn't already exist.
   * Only works on desktop.
   *
   * @param dir The path to the directory.
   */
  public static function createDirIfNotExists(dir:String):Void
  {
    #if sys
    if (!doesFileExist(dir))
    {
      sys.FileSystem.createDirectory(dir);
    }
    #end
  }

  static var tempDir:String = null;
  static final TEMP_ENV_VARS:Array<String> = ['TEMP', 'TMPDIR', 'TEMPDIR', 'TMP'];

  /**
   * Get the path to a temporary directory we can use for writing files.
   * Only works on desktop.
   *
   * @return The path to the temporary directory.
   */
  public static function getTempDir():String
  {
    if (tempDir != null) return tempDir;
    #if sys
    #if windows
    var path:String = null;
    for (envName in TEMP_ENV_VARS)
    {
      path = Sys.getEnv(envName);
      if (path == '') path = null;
      if (path != null) break;
    }
    tempDir = Path.join([path, 'funkin/']);
    return tempDir;
    #else
    tempDir = '/tmp/funkin/';
    return tempDir;
    #end
    #else
    return null;
    #end
  }

  /**
   * Create a Bytes object containing a ZIP file, containing the provided entries.
   *
   * @param entries The entries to add to the ZIP file.
   * @return The ZIP file as a Bytes object.
   */
  public static function createZIPFromEntries(entries:Array<Entry>):Bytes
  {
    var o:haxe.io.BytesOutput = new haxe.io.BytesOutput();
    var zipWriter:haxe.zip.Writer = new haxe.zip.Writer(o);
    zipWriter.write(entries.list());
    return o.getBytes();
  }

  public static function readZIPFromBytes(input:Bytes):Array<Entry>
  {
    trace('TEST: ' + input.length);
    trace(input.sub(0, 30).toHex());
    var bytesInput = new haxe.io.BytesInput(input);
    var zippedEntries = haxe.zip.Reader.readZip(bytesInput);
    var results:Array<Entry> = [];
    for (entry in zippedEntries)
    {
      if (entry.compressed)
      {
        entry.data = haxe.zip.Reader.unzip(entry);
      }
      results.push(entry);
    }
    return results;
  }

  public static function mapZIPEntriesByName(input:Array<Entry>):Map<String, Entry>
  {
    var results:Map<String, Entry> = [];
    for (entry in input)
    {
      results.set(entry.fileName, entry);
    }
    return results;
  }

  /**
   * Create a ZIP file entry from a file name and its string contents.
   *
   * @param name The name of the file. You can use slashes to create subdirectories.
   * @param content The string contents of the file.
   * @return The resulting entry.
   */
  public static function makeZIPEntry(name:String, content:String):Entry
  {
    var data:Bytes = haxe.io.Bytes.ofString(content, UTF8);
    return makeZIPEntryFromBytes(name, data);
  }

  /**
   * Create a ZIP file entry from a file name and its string contents.
   *
   * @param name The name of the file. You can use slashes to create subdirectories.
   * @param data The byte data of the file.
   * @return The resulting entry.
   */
  public static function makeZIPEntryFromBytes(name:String, data:haxe.io.Bytes):Entry
  {
    return {
      fileName: name,
      fileSize: data.length,
      data: data,
      dataSize: data.length,
      compressed: false,
      fileTime: Date.now(),
      crc32: null,
      extraFields: null,
    };
  }

  static function convertTypeFilter(typeFilter:Array<FileFilter>):String
  {
    var filter:String = null;
    if (typeFilter != null)
    {
      var filters:Array<String> = [];
      for (type in typeFilter)
      {
        filters.push(StringTools.replace(StringTools.replace(type.extension, '*.', ''), ';', ','));
      }
      filter = filters.join(';');
    }
    return filter;
  }
}

enum FileWriteMode
{
  /**
   * Forcibly overwrite the file if it already exists.
   */
  Force;

  /**
   * Ask the user if they want to overwrite the file if it already exists.
   */
  Ask;

  /**
   * Skip the file if it already exists.
   */
  Skip;
}