dragDropInstaller.py

# ----------------------------------------------------------------------
# Installation script to install a module-based script or plug-in for
# Autodesk Maya.
# ----------------------------------------------------------------------

import maya.cmds as cmds
from maya.api import OpenMaya as om2

from datetime import datetime
import errno
import logging
import os
import shutil
import subprocess

logger = logging.getLogger(__name__)

INSTALL_ROOT = os.path.dirname(os.path.realpath(__file__))
MODULES_DIR = "modules"
MODULE_NAME = os.path.basename(INSTALL_ROOT)

HELP_FILE = os.path.join(INSTALL_ROOT, "installationGuide.html")
LOG_FILE = os.path.join(INSTALL_ROOT, "install.log")
LOGO_FILE = os.path.join(os.path.join(INSTALL_ROOT, "resources"), "{}.png".format(MODULE_NAME))

EULA_WIN = "EULAWin"
INSTALL_WIN = "installerWin"
INFO_TEXT = "installerInfoText"
MODULE_PATH_FIELD = "installerModulePathField"
CONTENT_PATH_FIELD = "installerContentPathField"
PROGRESS_LIST = "installProgressList"
INSTALL_BUTTON = "installInstallButton"
UNINSTALL_BUTTON = "installUninstallButton"
HELP_BUTTON = "installHelpButton"
MODULE_BUTTON = "installCreateModulesButton"

PREV_MOD_PATHS = "previousModulePaths"
PREV_CONTENT_PATHS = "previousContentPaths"
MOD_PATHS_VAR = "".join((MODULE_NAME, PREV_MOD_PATHS))
CONTENT_PATHS_VAR = "".join((MODULE_NAME, PREV_CONTENT_PATHS))


# ----------------------------------------------------------------------
# utilities
# ----------------------------------------------------------------------

def currentTimeLong():
    """Return the current time as a nice formatted string.

    :return: The current date and time.
    :rtype: str
    """
    return datetime.now().strftime("%Y-%m-%d %H:%M:%S")


def getMayaVersions():
    """Return the list of Maya versions which are included in the
    module within the plug-ins sub folder.

    :return: The ordered list of available Maya versions.
    :rtype: list(str)
    """
    path = getPluginsPath(MODULE_NAME)
    path = os.path.join(path, getPlatform())
    sortedItems = []
    try:
        sortedItems = sorted(os.listdir(path))
    except:
        pass
    return sortedItems


def getModuleNames():
    """Return the names of the modules to be installed.

    :return: The ordered list of module names.
    :rtype: list(str)
    """
    modulesFolder = os.path.join(INSTALL_ROOT, MODULES_DIR)
    files = os.listdir(modulesFolder)
    modules = []
    for f in files:
        if os.path.isdir(os.path.join(modulesFolder, f)):
            modules.append(f)
    return sorted(modules)


def getPlatform():
    """Return the string identifying the current platform.

    :return: The platform string.
    :rtype: str
    """
    platform = cmds.about(os=True)
    if platform == 'mac':
        platform = 'macOS'
    return platform


def getPlugins():
    """Return a list with all plug-ins contained in the installation.

    :return: A list with all platform specific plug-ins.
    :rtype: list(str)
    """
    plugins = []
    versions = getMayaVersions()
    if not len(versions):
        return []
    version = getMayaVersions()[-1]
    for searchModule in getModuleNames():
        if hasPlugins(searchModule):
            path = os.path.join(getPluginsPath(searchModule), getPlatform())
            path = os.path.join(path, version)
            plugins.extend(os.listdir(path))
    return list(set(plugins))


def getPluginsPath(name):
    """Return the path to the plug-ins folder of the given module to
    install.

    :param name: The name of the module.
    :type name: str

    :return: The path to the modules plug-ins folder
    :rtype: str
    """
    items = [INSTALL_ROOT, MODULES_DIR, name, "plug-ins"]
    path = ""
    for item in items:
        path = os.path.join(path, item)
    return path


def getUserPrefsPath():
    """Return the path of the current user preferences.

    :return: The path of the user preferences,
    :rtype: str
    """
    prefsPath = cmds.internalVar(userPrefDir=True)
    # The preferences path is returned with an ending slash. Therefore
    # it's necessary to walk up three levels.
    return os.path.abspath(os.path.join(prefsPath, "../.."))


def hasPlugins(name):
    """Return True, if the module contains plug-ins.

    :param name: The name of the module.
    :type name: str

    :return: True, if the module contains a plug-in folder.
    :rtype: bool
    """
    return os.path.isdir(getPluginsPath(name))


def helpExists():
    """Return True, if the help file is present.

    :return: True, if the help file exists.
    :rtype: bool
    """
    return os.path.exists(HELP_FILE)


def installExists():
    """Performs a check if the source files for the installation exist
    in the same folder as the installer script.

    :return: True, if the source file path exists.
    :rtype: bool
    """
    if not os.path.isdir(os.path.join(INSTALL_ROOT, MODULES_DIR)):
        message = "The source files for the installation cannot be found. " \
                  "Make sure that all files have been unzipped and that the " \
                  "modules folder is in the same folder as the drag and drop " \
                  "installer python file.\n\n"
        om2.MGlobal.displayError(message)
        return False
    return True


def logInfo(message=""):
    """Write the given message to the log file.

    :param message: The message to display.
    :type message: str
    """
    if not len(message):
        message = " "
    lines = message if isinstance(message, list) else [message]
    for i in range(len(lines)):
        lines[i] = "{} : {}".format(currentTimeLong(), lines[i])
    message = "\n".join(lines)

    try:
        with open(LOG_FILE, "a") as logObj:
            logObj.write("{}\n".format(message))
    except Exception as exception:
        om2.MGlobal.displayError("Unable to write log file {}".format(LOG_FILE))
        print(str(exception))


def unloadPlugins():
    """Unload any plug-ins which are about to be installed.

    :return: True, if the plug-ins have been unloaded.
    :rtype: bool
    """
    loaded = False
    active = []
    for item in getPlugins():
        if cmds.pluginInfo(item, query=True, loaded=True):
            message = "Found loaded plug-in: {}".format(item)
            logInfo(message)
            addProgress(message)
            loaded = True
            active.append(item)

    if loaded:
        message = "One or more plug-ins which are about to be installed are currently loaded. " \
                  "To unload the plug-ins and continue with the installation the undo queue must be reset. " \
                  "Do you want to continue?"
        result = cmds.confirmDialog(title="Plug-ins loaded",
                                    message=message,
                                    button=("Continue", "Cancel"))
        if result == "Continue":
            cmds.flushUndo()
            for item in active:
                try:
                    cmds.unloadPlugin(item)
                    message = "Unloaded plug-in: {}".format(item)
                    logInfo(message)
                    addProgress(message)
                except Exception as exception:
                    message = "Unable to unload plug-in: {}".format(item)
                    logInfo(message)
                    addProgress(message)
                    return False
        else:
            return False

    return True


# ----------------------------------------------------------------------
# file operations
# ----------------------------------------------------------------------

def copyDir(source, destination):
    """Copy the folder at the given path to the given location.

    :param source: The full path of the folder to copy.
    :type source: str
    :param destination: The full path to copy the folder to.
    :type destination: str

    :return: True, if copying was successful.
    :rtype: bool
    """
    try:
        shutil.copytree(str(source), str(destination))
        logInfo("Copying: {} to: {}".format(source, destination))
    except shutil.Error as error:
        message = "Error copying: {} to: {}".format(source, destination)
        logInfo(message)
        logInfo(str(error))
        om2.MGlobal.displayError(message)
        return False
    return True


def removeDir(path):
    """Delete the folder at the given path.

    :param path: The full path of the folder to delete.
    :type path: str

    :return: True, if deleting was successful.
    :rtype: bool
    """
    try:
        shutil.rmtree(str(path))
        logInfo("Removed: {}".format(path))
    except shutil.Error as error:
        message = "Error deleting folder: {}".format(path)
        logInfo(message)
        logInfo(str(error))
        om2.MGlobal.displayError(message)
        return False
    return True


def removeFile(fileName):
    """Delete the file at the given path.

    :param fileName: The full path of the file to delete.
    :type fileName: str

    :return: True, if deleting was successful.
    :rtype: bool
    """
    try:
        os.remove(fileName)
        logInfo("Deleting: {}".format(fileName))
    except OSError:
        message = "Error deleting file: {}".format(fileName)
        logInfo(message)
        om2.MGlobal.displayError(message)
        return False
    return True


def makeDirectory(path):
    """Try to create the directory. If it already exists ignore the
    error but with any other error the result is set to false.

    Important: Only the directory is tested and created. Files are not
    supported.

    :param path: The directory to create and test.
    :type path: str

    :return: True, if the directory has been created or exists. False,
             if the path cannot be accessed.
    :rtype: bool
    """
    try:
        os.makedirs(path)
    except OSError as exception:
        if exception.errno != errno.EEXIST:
            return False
    return True


# ----------------------------------------------------------------------
# file i/o
# ----------------------------------------------------------------------

def read(filePath):
    """Return the content of the given text file as a list. Return an
    empty list if the file doesn't exist.

    :param filePath: The file path of the file to read.
    :type filePath: str

    :return: The file content as a list.
    :rtype: list(str)
    """
    content = []

    if os.path.exists(filePath):
        try:
            with open(filePath, "r") as fileObj:
                return list(line.rstrip() for line in fileObj)
        except OSError:
            pass
    return content


def write(filePath, data, mode):
    """Export the given data to the given text file.

    :param filePath: The file path of the file to write.
    :type filePath: str
    :param data: The data to write.
    :type data: str
    :param mode: The write mode.
    :type mode: str

    :return: True, if writing was successful.
    :rtype: bool
    """
    try:
        with open(filePath, mode) as fileObj:
            fileObj.write(data)
        return True
    except OSError:
        message = "Error writing: {}".format(filePath)
        logInfo(message)
    return False


# ----------------------------------------------------------------------
# checking previous installations
# ----------------------------------------------------------------------

def getExistingInstallationPaths():
    """Go through all known module paths and search for existing
    modules and their contents.
    Because older installations are located within their specific Maya
    version folder and newer installations are located on the top level
    of the Maya preferences all locations need to be checked.
    Also, because it's possible that files have been manually moved.

    Returns a tuple with:
        modules: Module files which match the modules to be installed.
        contents: Paths of the contents of the modules. These are the
                  paths which are stored in the module files.
        currentPaths: The paths which relate to the main module to be
                       installed. The first path in the list is used to
                       serve as a suggestion for the new installation.
        currentModules: The paths of the module files of the currently
                         installed main module.

    :return: A tuple with lists of paths of the currently found
             installations.
    :rtype: tuple(list(str), list(str), list(str), list(str))
    """
    # Get the list of modules paths of the current Maya session.
    modulePaths = os.environ["MAYA_MODULE_PATH"]
    # In case of Windows the path separator is different from macOS and
    # Linux.
    separator = ":"
    if getPlatform() == "win64":
        separator = ";"
    modules = []
    contents = []
    currentPaths = []
    currentModules = []
    # For every registered path, check if it exists because some paths
    # may be registered but don't exist by default.
    for modulePath in modulePaths.split(separator):
        if os.path.exists(modulePath):
            # Go through every .mod file in the current path and see if
            # it matches the ones to be installed.
            for modFile in os.listdir(modulePath):
                for searchModule in getModuleNames():
                    # In case the module is found get the contents of
                    # the module file and store the contained paths.
                    if modFile == ".".join((searchModule, "mod")):
                        filePath = os.path.join(modulePath, modFile)
                        contentPaths = getModuleContentPaths(filePath, searchModule)

                        modules.append(os.path.join(modulePath, modFile))
                        contents.extend(contentPaths)

                        # If the current module matches the main module
                        # store the paths separately to serve as a
                        # suggestion for the new installation.
                        if modFile == ".".join((MODULE_NAME, "mod")):
                            currentPaths.extend(contentPaths)
                            currentModules.append(filePath)

    # Remove any duplicate paths.
    modules = list(set(modules))
    contents = list(set(contents))

    return modules, contents, currentPaths, currentModules


def getModuleContentPaths(filePath, module):
    """Return a list of paths which are contained in the given module
    file.

    :param filePath: The path of the module file to read.
    :type filePath: str
    :param module: The name of the module to find.
    :type module: str

    :return: The list of contained paths.
    :rtype: list(str)
    """
    content = read(filePath)
    paths = []
    for line in content:
        if " {} ".format(module) in line:
            filePath = line.split(" ")[-1]
            if os.path.exists(filePath):
                paths.append(filePath)
    return paths


# ----------------------------------------------------------------------
# installation
# ----------------------------------------------------------------------

def prepareInstallation(*args):
    """Gather all information about previously installed modules and
    the location of the user preferences. Populate the path fields with
    these pre-defined paths.
    """
    # Build and show the installer window.
    showUI()

    # Make sure that all plug-ins are unloaded.
    if not unloadPlugins():
        message = "Error: Unable to perform the installation with loaded plug-ins."
        logInfo(message)
        addProgress(message)
        installationFailed()
        return

    # Get the path from installed modules.
    modules, contents, mainPaths, mainModules = getExistingInstallationPaths()

    contentPath = ""
    modulePath = ""
    if len(mainPaths):
        info = "Using the previous installation path to install the module{}.".format(multiSuffix())
        if len(mainPaths):
            contentPath = os.path.dirname(mainPaths[0])
        if len(mainModules):
            modulePath = os.path.dirname(mainModules[0])
    else:
        info = "Using the default user preferences path to install the module{}.".format(multiSuffix())
        contentPath = modulePath = os.path.join(getUserPrefsPath(), MODULES_DIR)

    cmds.text(INFO_TEXT,
              edit=True,
              label=info)
    cmds.textFieldGrp(CONTENT_PATH_FIELD,
                      edit=True,
                      text=contentPath)
    cmds.textFieldGrp(MODULE_PATH_FIELD,
                      edit=True,
                      text=modulePath)

    # Store the paths in optionVars to access these when the
    # installation is performed.
    if len(modules):
        cmds.optionVar(stringValue=(MOD_PATHS_VAR, ",".join(modules)))
        logInfo("Found existing modules:")
        for i in modules:
            logInfo("\t{}".format(i))

    if len(contents):
        cmds.optionVar(stringValue=(CONTENT_PATHS_VAR, ",".join(contents)))
        logInfo("Found existing module contents:")
        for i in contents:
            logInfo("\t{}".format(i))

    logInfo("Setting automatic paths:")
    logInfo(info)
    logInfo(contentPath)
    logInfo(modulePath)


def performUninstall(*args):
    """Remove any existing installation paths which have been found.
    """
    modules = []
    contents = []
    # Get the previously found paths for the modules and their contents.
    if cmds.optionVar(exists=MOD_PATHS_VAR):
        modules = cmds.optionVar(query=MOD_PATHS_VAR).split(",")
        cmds.optionVar(remove=MOD_PATHS_VAR)
    if cmds.optionVar(exists=CONTENT_PATHS_VAR):
        contents = cmds.optionVar(query=CONTENT_PATHS_VAR).split(",")
        cmds.optionVar(remove=CONTENT_PATHS_VAR)

    # Delete the existing modules.
    if len(modules):
        message = "Deleting previously installed modules."
        logInfo(message)
        addProgress(message)
        for item in modules:
            if not removeFile(item):
                installationFailed()
                addProgress("Error: Deleting: {}".format(item))
                return
            addProgress("Deleting: {}".format(item))
    elif len(args):
        message = "No previously installed modules found."
        logInfo(message)
        addProgress(message)

    # Delete the existing module contents.
    if len(contents):
        message = "Deleting previously installed module contents."
        logInfo(message)
        addProgress(message)
        for item in contents:
            if not removeDir(item):
                installationFailed()
                addProgress("Error: Deleting: {}".format(item))
                return
            addProgress("Deleting: {}".format(item))
    elif len(args):
        message = "No previously installed modules contents found."
        logInfo(message)
        addProgress(message)

    # If the method hasn't been called from the UI but from performing
    # the uninstallation return to finish it.
    if not len(args):
        return

    message = "Uninstall completed."
    logInfo(message)
    addProgress(message)


def performInstallation(*args):
    """Perform the installation.
    """
    # Remove the previous installation.
    performUninstall()

    # Get the path where the module contents should be installed.
    contentPath = cmds.textFieldGrp(CONTENT_PATH_FIELD,
                                    query=True,
                                    text=True)

    # Copy the modules to the given location.
    message = "Installing files to: {}".format(contentPath)
    logInfo(message)
    addProgress(message)

    if not copyModuleContents(contentPath):
        installationFailed()
        return

    # Create the module files.
    performBuildModuleFiles()

    # Finish the installation.
    message = "Installation complete."
    logInfo(message)
    addProgress(message)

    finish()


def performBuildModuleFiles(*args):
    """Write the module files to the defined folder.
    """
    # Get the path where the module contents are located.
    contentPath = cmds.textFieldGrp(CONTENT_PATH_FIELD,
                                    query=True,
                                    text=True)
    # Get the path where the module files should be saved.
    modulePath = cmds.textFieldGrp(MODULE_PATH_FIELD,
                                   query=True,
                                   text=True)

    message = "Creating module file{} in: {}".format(multiSuffix(), modulePath)
    logInfo(message)
    addProgress(message)

    if not writeModuleFiles(modulePath, contentPath):
        installationFailed()
        return

    # If the method hasn't been called from the UI but from performing
    # the installation return to finish it.
    if not len(args):
        return

    message = "Module file{} created.".format(multiSuffix())
    logInfo(message)
    addProgress(message)


def copyModuleContents(destination):
    """Copy the module folders from the installation source to the
    given destination path.

    :param destination: The path where to copy the module folders to.
    :type destination: str

    :return: True, if copying was successful.
    :rtype: bool
    """
    for module in getModuleNames():
        source = os.path.join(os.path.join(INSTALL_ROOT, MODULES_DIR), module)
        contentPath = os.path.join(destination, module)

        # In case the destination module path exists but hasn't been
        # detected yet because the module file has been missing delete
        # the folder.
        if os.path.exists(contentPath):
            removeDir(contentPath)

        if not copyDir(source, contentPath):
            addProgress("Error: Installing {} to: {}".format(module, contentPath))
            return False
        addProgress("Installing {} to: {}".format(module, contentPath))

        # In case of Linux flatten the icons folder because currently
        # nested icon folders aren't respected with the recursive option
        # of the module file.
        # If an error occurs during flattening it doesn't interrupt the
        # installation. This is on purpose as changing the folder
        # structure might produce errors. This is currently being
        # monitored and subject to change once verified that it's
        # stable.
        if getPlatform() == "linux64":
            flattenFolder(os.path.join(contentPath, "icons"))
    return True


# ----------------------------------------------------------------------
# ui
# ----------------------------------------------------------------------

def showEULA():
    """Build and show the EULA window.
    """
    deleteExistingWindow(EULA_WIN)

    cmds.window(EULA_WIN,
                title="End User License Agreement",
                sizeable=False)

    layout = cmds.rowColumnLayout()

    fileObj = open(os.path.join(INSTALL_ROOT, "LICENSE"), "rb")
    fileString = fileObj.read()
    fileObj.close()

    showLogo()

    cmds.scrollField(text=fileString,
                     font="plainLabelFont",
                     width=550,
                     height=300,
                     editable=False,
                     wordWrap=True)

    cmds.separator(style="none", height=10)
    cmds.rowLayout(numberOfColumns=2)
    cmds.button(label="Agree",
                width=100,
                height=30,
                command=prepareInstallation)
    cmds.button(label="Decline",
                width=100,
                height=30,
                command=dismissEULA)
    cmds.setParent(layout)
    cmds.showWindow(EULA_WIN)


def dismissEULA(*args):
    """Close the EULA window when cancelled.
    """
    logInfo("EULA declined")
    logInfo("Installation cancelled")
    cmds.deleteUI(EULA_WIN)


def showUI():
    """Build and show the main installer window.
    """
    deleteExistingWindow(EULA_WIN)
    deleteExistingWindow(INSTALL_WIN)

    cmds.window(INSTALL_WIN,
                title="Install {}".format(MODULE_NAME),
                width=550,
                sizeable=False,
                resizeToFitChildren=True)

    layout = cmds.rowColumnLayout()

    showLogo()

    # ------------------------------------------------------------------
    # paths
    # ------------------------------------------------------------------

    cmds.frameLayout(label="Paths",
                     width=550,
                     collapsable=False,
                     collapse=False,
                     marginWidth=5,
                     marginHeight=5)
    cmds.columnLayout(columnAlign="left",
                      adjustableColumn=True)
    cmds.separator(style="none", height=5)
    cmds.text(INFO_TEXT,
              label="",
              align="center")
    cmds.separator(style="none", height=15)
    cmds.textFieldButtonGrp(CONTENT_PATH_FIELD,
                            label="Install Path",
                            buttonLabel="Select",
                            columnAttach3=("left", "both", "right"),
                            columnWidth3=(80, 405, 55),
                            columnOffset3=(5, 0, 5),
                            buttonCommand=selectContentPath)
    addFieldComment("The path where all files of the module{} will be installed.".format(multiSuffix()))
    cmds.separator(style="none", height=5)
    cmds.textFieldButtonGrp(MODULE_PATH_FIELD,
                            label="Module Path",
                            buttonLabel="Select",
                            columnAttach3=("left", "both", "right"),
                            columnWidth3=(80, 405, 55),
                            columnOffset3=(5, 0, 5),
                            buttonCommand=selectModulePath)
    addFieldComment("The path where the {}.mod file{} will be saved.".format(MODULE_NAME, multiSuffix()))
    cmds.setParent(layout)

    cmds.separator(style="none", height=10)

    # ------------------------------------------------------------------
    # progress
    # ------------------------------------------------------------------

    cmds.frameLayout(label="Progress",
                     width=550,
                     collapsable=False,
                     collapse=False,
                     marginWidth=5,
                     marginHeight=5)
    cmds.columnLayout(columnAlign="left")
    cmds.textScrollList(PROGRESS_LIST,
                        width=537,
                        height=120)
    cmds.setParent(layout)

    cmds.separator(style="none", height=10)

    # ------------------------------------------------------------------
    # buttons
    # ------------------------------------------------------------------

    form = cmds.formLayout(width=550)
    cmds.button(INSTALL_BUTTON,
                label="Install",
                width=150,
                height=30,
                command=performInstallation)
    cmds.button(UNINSTALL_BUTTON,
                label="Uninstall",
                width=150,
                height=30,
                command=performUninstall)
    cmds.button(HELP_BUTTON,
                label="Help",
                width=60,
                height=30,
                command=openHelp,
                enable=helpExists())
    cmds.button(MODULE_BUTTON,
                label="Create .mod file{} only".format(multiSuffix()),
                width=150,
                height=30,
                command=performBuildModuleFiles)
    cmds.formLayout(form,
                    edit=True,
                    attachForm=[(INSTALL_BUTTON, "left", 0),
                                (INSTALL_BUTTON, "bottom", 0),
                                (UNINSTALL_BUTTON, "bottom", 0),
                                (MODULE_BUTTON, "bottom", 0),
                                (HELP_BUTTON, "right", 0),
                                (HELP_BUTTON, "bottom", 0)],
                    attachControl=[(UNINSTALL_BUTTON, "left", 5, INSTALL_BUTTON),
                                   (MODULE_BUTTON, "left", 5, UNINSTALL_BUTTON)],
                    attachNone=[(HELP_BUTTON, "left")])
    cmds.setParent(layout)

    cmds.showWindow(INSTALL_WIN)


def deleteExistingWindow(name):
    """Delete the given window if it exists along with it's preferences.

    :param name: The name of the window.
    :type name: str
    """
    if cmds.window(name, exists=True):
        cmds.deleteUI(name)
    if cmds.windowPref(name, query=True, exists=True):
        cmds.windowPref(name, remove=True)


def showLogo():
    """Build the window section which contains the logo if it exists.
    """
    if not os.path.exists(LOGO_FILE):
        return

    cmds.image(image=LOGO_FILE)


def addFieldComment(text):
    """Build the elements for adding an italic comment line below the
    path fields.

    :param text: The information string.
    :type text: str
    """
    cmds.rowLayout(numberOfColumns=2)
    cmds.separator(style="none", width=85)
    cmds.text(label=text, font="obliqueLabelFont")
    cmds.setParent("..")


def addProgress(message):
    """Add the given message string to the progress scroll list.

    :param message: The message to add to the list.
    :type message: str
    """
    cmds.textScrollList(PROGRESS_LIST,
                        edit=True,
                        append=message)


def openHelp(*args):
    """Open the installation help document.
    """
    if not helpExists():
        return

    currentOS = getPlatform()

    if currentOS == "win64":
        os.startfile(HELP_FILE)
    else:
        cmd = "open" if currentOS == "macOS" else "xdg-open"
        subprocess.call([cmd, HELP_FILE])


def multiSuffix():
    """Return 's' to rename from 'file' to 'files' in case there is more
    than one module to install.
    """
    if len(getModuleNames()) > 1:
        return "s"
    return ""


# ----------------------------------------------------------------------
# path selection
# ----------------------------------------------------------------------

def selectContentPath():
    """Get a user defined path for the module content and display it in
    the path field.
    """
    filePath = cmds.textFieldGrp(CONTENT_PATH_FIELD,
                                 query=True,
                                 text=True)
    filePath = selectCustomPath(filePath)[0]
    cmds.textFieldGrp(CONTENT_PATH_FIELD,
                      edit=True,
                      text=filePath)


def selectModulePath():
    """Get a user defined path for the module file and display it in
    the path field.
    """
    filePath = cmds.textFieldGrp(MODULE_PATH_FIELD,
                                 query=True,
                                 text=True)
    filePath = selectCustomPath(filePath)[0]
    cmds.textFieldGrp(MODULE_PATH_FIELD,
                      edit=True,
                      text=filePath)


def selectCustomPath(filePath):
    """Open a file dialog starting at the given path and return the
    chosen path.

    :param filePath: The path to start the dialog with.
    :type filePath: str

    :return: The selected path from the dialog.
    :rtype: str
    """
    return cmds.fileDialog2(caption="Select Path",
                            startingDirectory=filePath,
                            fileMode=3,
                            okCaption="Select")


# ----------------------------------------------------------------------
# module files
# ----------------------------------------------------------------------

def writeModuleFiles(destination, contentPath):
    """Write a module file for each module which is included in the
    installation.

    :param destination: The path where to write the module file to.
    :type destination: str
    :param contentPath: The path of the module contents.
    :type contentPath: str

    :return: True, if writing was successful.
    :rtype: bool
    """
    for module in getModuleNames():
        if not createModuleFile(destination, module, contentPath):
            return False
    return True


def createModuleFile(modulePath, module, contentPath):
    """Generate the content of the module file for the given module and
    write it to the given path.

    :param modulePath: The path where to write the module file to.
    :type modulePath: str
    :param module: The name of the module.
    :type module: str
    :param contentPath: The path of the module contents.
    :type contentPath: str

    :return: True, if writing was successful.
    :rtype: bool
    """
    fileName = "{}.mod".format(os.path.join(modulePath, module))

    recursiveIcons = True
    if getPlatform() == "linux64":
        recursiveIcons = False

    lines = ""
    if hasPlugins(module):
        for version in getMayaVersions():
            lines += "+ MAYAVERSION:{} {} any {}/{}\n".format(version, module, contentPath, module)
            lines += buildContentSubpath(module, "plug-ins", version, getPlatform())
            lines += buildContentSubpath(module, "icons", recursive=recursiveIcons)
            lines += buildContentSubpath(module, "scripts", recursive=True)
            lines += "\n"
    else:
        lines += "+ {} any {}/{}\n".format(module, contentPath, module)
        lines += buildContentSubpath(module, "icons", recursive=recursiveIcons)
        lines += buildContentSubpath(module, "scripts", recursive=True)
        lines += "\n"

    if not write(fileName, lines, "w"):
        addProgress("Error: Writing module file: {}".format(fileName))
        return False

    message = "Writing module file: {}".format(fileName)
    logInfo(message)
    addProgress(message)

    return True


def buildContentSubpath(module, data, version="", platform="", recursive=False):
    """Generate the line for the module which points to the given data
    content at a relative path.

    :param module: The name of the module.
    :type module: str
    :param data: The name of the data content.
    :type data: str
    :param version: The Maya version string.
    :type version: str
    :param platform: The platform string.
    :type platform: str
    :param recursive: True, if the path should be defined as recursive.
    :type recursive: bool

    :return: The line for the relative content of the module.
    :rtype: str
    """
    nested = ""
    if recursive:
        nested = "[r] "

    line = ""
    subdir = os.path.join(os.path.join(os.path.join(INSTALL_ROOT, MODULES_DIR), module), data)
    if os.path.exists(subdir):
        subPath = data
        if len(platform):
            subPath = "/".join((subPath, platform))
        if len(version):
            subPath = "/".join((subPath, version))
        line = "{}{}: {}\n".format(nested, data, subPath)
    return line


def flattenFolder(basePath):
    """Remove the sub folders from the given base path and place their
    contents at the top level.
    Currently necessary for installations on Linux where the recursive
    path option doesn't work for icons.

    :param basePath: The path of the folder which should be flattened.
    :type basePath: str

    :return: True, if flattening was successful.
    :rtype: bool
    """
    result = True
    for folder in os.listdir(basePath):
        folderPath = os.path.join(basePath, folder)
        if os.path.isdir(folderPath):
            for item in os.listdir(folderPath):
                if not item.startswith("."):
                    try:
                        shutil.move(os.path.join(folderPath, item), basePath)
                    except OSError:
                        result = False
            if not removeDir(folderPath):
                result = False

    if not result:
        message = "An error occurred while flattening the folder: {}".format(basePath)
        logInfo(message)
        addProgress(message)

    return result


# ----------------------------------------------------------------------
# finishing
# ----------------------------------------------------------------------

def disableButtons():
    """Disable the installation buttons when they are not required
    anymore.
    """
    cmds.button(INSTALL_BUTTON,
                edit=True,
                label="Close",
                command="cmds.deleteUI('{}')".format(INSTALL_WIN))
    cmds.button(UNINSTALL_BUTTON,
                edit=True,
                enable=False)
    cmds.button(MODULE_BUTTON,
                edit=True,
                enable=False)


def finish():
    """Finish the installation by cleaning up and displaying a
    confirmation window to restart Maya.
    """
    disableButtons()

    result = cmds.confirmDialog(title="Installation successful",
                                message="You need to restart Maya for changes to take affect.",
                                button=("Close", "Quit Maya"))
    if result == "Quit Maya":
        cmds.quit(force=True)


def installationFailed():
    """Finish the installation upon failure. Cleanup and displaying the
    error.
    """
    disableButtons()

    logInfo("Installation cancelled because an error has occurred.")
    om2.MGlobal.displayError("Installation failed. See install.log for details.")
    cmds.confirmDialog(title="Installation failed",
                       message="The installation has been cancelled because of an error.\nSee install.log for details.",
                       button="Close")


# ----------------------------------------------------------------------
# method which gets executed upon drag and drop
# ----------------------------------------------------------------------

def onMayaDroppedPythonFile(*args, **kwargs):
    """Main function that runs when dragging the file into Maya.
    Installation is performed by copying the module to the user
    preferences and creating a module file.
    """
    # Don't continue if the installation files are missing.
    if not installExists():
        return

    logInfo("Begin installation")

    # If a license file exists display the EULA window. Otherwise
    # continue to the installation window.
    if os.path.exists(os.path.join(INSTALL_ROOT, "LICENSE")):
        logInfo("Show EULA")
        showEULA()
    else:
        prepareInstallation()


# ----------------------------------------------------------------------
# License
#
# Copyright (c) 2021 Ingo Clemens, brave rabbit
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
# Author: Ingo Clemens    www.braverabbit.com
# ----------------------------------------------------------------------