"""Files and folders in a project are represented as resource objects.

Files and folders are access through `Resource` objects. `Resource` has
two subclasses: `File` and `Folder`. What we care about is that
refactorings and `rope.base.change.Change`s use resources.

There are two options to create a `Resource` for a path in a project.
Note that in these examples `path` is the path to a file or folder
relative to the project's root. A project's root folder is represented
by an empty string.

  1) Use the `rope.base.Project.get_resource()` method. E.g.:

       myresource = myproject.get_resource(path)


  2) Use the `rope.base.libutils` module. `libutils` has a function
     named `path_to_resource()`. It takes a project and a path:

       from rope.base import libutils

       myresource = libutils.path_to_resource(myproject, path)

Once we have a `Resource`, we can retrieve information from it, like
getting the path relative to the project's root (via `path`), reading
from and writing to the resource, moving the resource, etc.
"""

import os
import re
import warnings

from rope.base import change
from rope.base import exceptions
from rope.base import fscommands
from pathlib import Path


class Resource:
    """Represents files and folders in a project"""

    def __init__(self, project, path):
        self.project = project
        self._path = path

    def __repr__(self):
        return '<{}.{} "{}" at {}>'.format(
            self.__class__.__module__,
            self.__class__.__name__,
            self.path,
            hex(id(self)),
        )

    def move(self, new_location):
        """Move resource to `new_location`"""
        self._perform_change(
            change.MoveResource(self, new_location),
            "Moving <{}> to <{}>".format(self.path, new_location),
        )

    def remove(self):
        """Remove resource from the project"""
        self._perform_change(change.RemoveResource(self), "Removing <%s>" % self.path)

    def is_folder(self):
        """Return true if the resource is a folder"""

    def create(self):
        """Create this resource"""

    def exists(self):
        return os.path.exists(self.real_path)

    @property
    def parent(self):
        parent = "/".join(self.path.split("/")[0:-1])
        return self.project.get_folder(parent)

    @property
    def path(self):
        """Return the path of this resource relative to the project root

        The path is the list of parent directories separated by '/' followed
        by the resource name.
        """
        return self._path

    @property
    def name(self):
        """Return the name of this resource"""
        return self.path.split("/")[-1]

    @property
    def real_path(self):
        """Return the file system path of this resource"""
        return self.project._get_resource_path(self.path)

    @property
    def pathlib(self):
        """Return the file as a pathlib path."""
        return Path(self.real_path)

    def __eq__(self, obj):
        return self.__class__ == obj.__class__ and self.path == obj.path

    def __ne__(self, obj):
        return not self.__eq__(obj)

    def __hash__(self):
        return hash(self.path)

    def _perform_change(self, change_, description):
        changes = change.ChangeSet(description)
        changes.add_change(change_)
        self.project.do(changes)


class File(Resource):
    """Represents a file"""

    def __init__(self, project, name):
        self.newlines = None
        super().__init__(project, name)

    def read(self):
        data = self.read_bytes()
        try:
            content, self.newlines = fscommands.file_data_to_unicode(data)
            return content
        except UnicodeDecodeError as e:
            raise exceptions.ModuleDecodeError(self.path, e.reason)

    def read_bytes(self):
        if not hasattr(self.project.fscommands, "read"):
            warnings.warn(
                "FileSystemCommands should implement read() method",
                DeprecationWarning,
                stacklevel=2,
            )
            with open(self.real_path, "rb") as handle:
                return handle.read()
        return self.project.fscommands.read(self.real_path)

    def write(self, contents):
        try:
            if contents == self.read():
                return
        except OSError:
            pass
        self._perform_change(
            change.ChangeContents(self, contents), "Writing file <%s>" % self.path
        )

    def is_folder(self):
        return False

    def create(self):
        self.parent.create_file(self.name)


class Folder(Resource):
    """Represents a folder"""

    def __init__(self, project, name):
        super().__init__(project, name)

    def is_folder(self):
        return True

    def get_children(self):
        """Return the children of this folder"""
        try:
            children = os.listdir(self.real_path)
        except OSError:
            return []
        result = []
        for name in children:
            try:
                child = self.get_child(name)
            except exceptions.ResourceNotFoundError:
                continue
            if not self.project.is_ignored(child):
                result.append(self.get_child(name))
        return result

    def create_file(self, file_name):
        self._perform_change(
            change.CreateFile(self, file_name),
            "Creating file <%s>" % self._get_child_path(file_name),
        )
        return self.get_child(file_name)

    def create_folder(self, folder_name):
        self._perform_change(
            change.CreateFolder(self, folder_name),
            "Creating folder <%s>" % self._get_child_path(folder_name),
        )
        return self.get_child(folder_name)

    def _get_child_path(self, name):
        if self.path:
            return self.path + "/" + name
        else:
            return name

    def get_child(self, name):
        return self.project.get_resource(self._get_child_path(name))

    def has_child(self, name):
        try:
            self.get_child(name)
            return True
        except exceptions.ResourceNotFoundError:
            return False

    def get_files(self):
        return [
            resource for resource in self.get_children() if not resource.is_folder()
        ]

    def get_folders(self):
        return [resource for resource in self.get_children() if resource.is_folder()]

    def contains(self, resource):
        if self == resource:
            return False
        return self.path == "" or resource.path.startswith(self.path + "/")

    def create(self):
        self.parent.create_folder(self.name)


class _ResourceMatcher:
    def __init__(self):
        self.patterns = []
        self._compiled_patterns = []

    def set_patterns(self, patterns):
        """Specify which resources to match

        `patterns` is a `list` of `str` that can contain ``*`` and
        ``?`` signs for matching resource names.

        """
        self._compiled_patterns = None
        self.patterns = patterns

    def _add_pattern(self, pattern):
        re_pattern = (
            pattern.replace(".", "\\.")
            .replace("*", "[^/]*")
            .replace("?", "[^/]")
            .replace("//", "/(.*/)?")
        )
        re_pattern = "^(.*/)?" + re_pattern + "(/.*)?$"
        self.compiled_patterns.append(re.compile(re_pattern))

    def does_match(self, resource):
        for pattern in self.compiled_patterns:
            if pattern.match(resource.path):
                return True
        path = os.path.join(resource.project.address, *resource.path.split("/"))
        return os.path.islink(path)

    @property
    def compiled_patterns(self):
        if self._compiled_patterns is None:
            self._compiled_patterns = []
            for pattern in self.patterns:
                self._add_pattern(pattern)
        return self._compiled_patterns
