from vulture import Vulture

from prospector.encoding import CouldNotHandleEncoding, read_py_file
from prospector.message import Location, Message, make_tool_error_message
from prospector.tools.base import ToolBase


class ProspectorVulture(Vulture):
    def __init__(self, found_files):
        Vulture.__init__(self, verbose=False)
        self._files = found_files
        self._internal_messages = []
        self.file = None
        self.filename = None

    def scavenge(self, _=None, __=None):
        # The argument is a list of paths, but we don't care
        # about that as we use the found_files object. The
        # argument is here to explicitly acknowledge that we
        # are overriding the Vulture.scavenge method.
        for module in self._files.python_modules:
            try:
                module_string = read_py_file(module)
            except CouldNotHandleEncoding as err:
                self._internal_messages.append(
                    make_tool_error_message(
                        module,
                        "vulture",
                        "V000",
                        message=f"Could not handle the encoding of this file: {err.encoding}",
                    )
                )
                continue
            self.file = module
            self.filename = module
            try:
                self.scan(module_string, filename=module)
            except TypeError:
                self.scan(module_string)

    def get_messages(self):
        all_items = (
            ("unused-function", "Unused function %s", self.unused_funcs),
            ("unused-property", "Unused property %s", self.unused_props),
            ("unused-variable", "Unused variable %s", self.unused_vars),
            ("unused-attribute", "Unused attribute %s", self.unused_attrs),
        )

        vulture_messages = []
        for code, template, items in all_items:
            for item in items:
                try:
                    filename = item.file
                except AttributeError:
                    filename = item.filename
                if hasattr(item, "lineno"):
                    lineno = item.lineno  # for older versions of vulture
                else:
                    lineno = item.first_lineno
                loc = Location(filename, None, None, lineno, -1)
                message_text = template % item
                message = Message("vulture", code, loc, message_text)
                vulture_messages.append(message)

        return self._internal_messages + vulture_messages


class VultureTool(ToolBase):
    def __init__(self):
        ToolBase.__init__(self)
        self._vulture = None
        self.ignore_codes = ()

    def configure(self, prospector_config, found_files):
        self.ignore_codes = prospector_config.get_disabled_messages("vulture")

    def run(self, found_files):
        vulture = ProspectorVulture(found_files)
        vulture.scavenge()
        return [message for message in vulture.get_messages() if message.code not in self.ignore_codes]