import io
import json

import reversion
from reversion.models import Version

from dal import autocomplete
from django import forms
from django.conf import settings
from django.core.management import call_command
from peeringdb_server.models import (
    REFTAG_MAP,
    COMMANDLINE_TOOLS,
    CommandLineTool,
    InternetExchange,
    Facility,
    IXLan,
)

from peeringdb_server import maintenance


def _(m):
    return m


TOOL_MAP = {}


def register_tool(cls):
    TOOL_MAP[cls.tool] = cls


def get_tool(tool_id, form):
    """
    Arguments:
        tool_id (str): tool_id as it exists in COMMANDLINE_TOOLS
        form (django.forms.Form): form instance
    Returns:
        CommandLineToolWrapper instance
    """
    t = TOOL_MAP.get(tool_id)
    t = t(form)
    return t


def get_tool_from_data(data):
    """
    Arguments:
        data (dict): dict containing form data, at the very least
            needs to have a "tool" key containing the tool_id
    Returns:
        CommandLineToolWrapper instance
    """
    tool_id = data.get("tool")
    t = TOOL_MAP.get(tool_id)
    form = t.Form(data)
    form.is_valid()
    t = t(form)
    return t


class EmptyId:
    id = 0


class CommandLineToolWrapper:

    tool = None
    queue = 0
    maintenance = False

    class Form(forms.Form):
        pass

    def __init__(self, form):
        self.status = 0
        self.result = None
        self.args = []
        self.kwargs = {}
        self.form_instance = form
        self.set_arguments(form.cleaned_data)

    @property
    def name(self):
        return dict(COMMANDLINE_TOOLS).get(self.tool)

    @property
    def form(self):
        return self.Form()

    @property
    def description(self):
        return self.tool

    @property
    def pretty_result(self):
        if not self.result:
            return ""
        r = []
        for line in self.result.split("\n"):
            if line.find("[error]") > -1:
                r.append(f'<div class="error">{line}</div>')
            elif line.find("[warning]") > -1:
                r.append(f'<div class="warning">{line}</div>')
            else:
                r.append(f'<div class="info">{line}</div>')
        return "\n".join(r)

    def set_arguments(self, form_data):
        pass

    def validate(self):
        pass

    def _run(self, user, commit=False):
        r = io.StringIO()

        if self.maintenance and commit:
            maintenance.on()

        try:
            self.validate()
            if commit:
                call_command(
                    self.tool, *self.args, commit=True, stdout=r, **self.kwargs
                )
            else:
                call_command(self.tool, *self.args, stdout=r, **self.kwargs)
            self.result = r.getvalue()
        except Exception as inst:
            self.result = f"[error] {inst}"
            self.status = 1
        finally:
            if self.maintenance and commit:
                maintenance.off()

        if commit:
            CommandLineTool.objects.create(
                user=user,
                tool=self.tool,
                description=self.description,
                status="done",
                arguments=json.dumps({"args": self.args, "kwargs": self.kwargs}),
                result=self.result,
            )
        return self.result

    def run(self, user, commit=False):
        if self.queue and commit:

            if (
                CommandLineTool.objects.filter(tool=self.tool)
                .exclude(status="done")
                .count()
                >= self.queue
            ):
                self.result = "[error] {}".format(
                    _(
                        "This command is already waiting / running - please wait for it to finish before executing it again"
                    )
                )
                return self.result

            CommandLineTool.objects.create(
                user=user,
                tool=self.tool,
                description=self.description,
                status="waiting",
                arguments=json.dumps({"args": self.args, "kwargs": self.kwargs}),
                result="",
            )

            self.result = "[warn] {}".format(
                _(
                    "This command takes a while to complete and will be queued and ran in the "
                    "background. No output log can be provided at this point in time. You may "
                    "review once the command has finished."
                )
            )
            return self.result
        else:
            with reversion.create_revision():
                return self._run(user, commit=commit)


# TOOL: RENUMBER LAN


@register_tool
class ToolRenumberLans(CommandLineToolWrapper):
    """
    This tools runs the pdb_renumber_lans command to
    Renumber IP Spaces in an Exchange
    """

    tool = "pdb_renumber_lans"

    class Form(forms.Form):
        exchange = forms.ModelChoiceField(
            queryset=InternetExchange.handleref.undeleted().order_by("name"),
            widget=autocomplete.ModelSelect2(url="/autocomplete/ix/json"),
        )
        old_prefix = forms.CharField(
            help_text=_(
                "Old prefix - renumber all netixlans that fall into this prefix"
            )
        )
        new_prefix = forms.CharField(
            help_text=_(
                "New prefix - needs to be the same protocol and length as old prefix"
            )
        )

    @property
    def description(self):
        """ Provide a human readable description of the command that was run """
        try:
            return "{}: {} to {}".format(
                InternetExchange.objects.get(id=self.args[0]),
                self.args[1],
                self.args[2],
            )
        except:
            # if a version of this command was run before, we still need to able
            # to display a somewhat useful discription, so fall back to this basic
            # display
            return f"(Legacy) {self.args}"

    def set_arguments(self, form_data):
        self.args = [
            form_data.get("exchange", EmptyId()).id,
            form_data.get("old_prefix"),
            form_data.get("new_prefix"),
        ]


@register_tool
class ToolMergeFacilities(CommandLineToolWrapper):
    """
    This tool runs the pdb_fac_merge command to
    merge two facilities
    """

    tool = "pdb_fac_merge"

    class Form(forms.Form):
        other = forms.ModelChoiceField(
            queryset=Facility.handleref.undeleted().order_by("name"),
            widget=autocomplete.ModelSelect2(url="/autocomplete/fac/json"),
            help_text=_("Merge this facility - it will be deleted"),
        )

        target = forms.ModelChoiceField(
            queryset=Facility.handleref.undeleted().order_by("name"),
            widget=autocomplete.ModelSelect2(url="/autocomplete/fac/json"),
            help_text=_("Target facility"),
        )

    @property
    def description(self):
        """ Provide a human readable description of the command that was run """
        return "{} into {}".format(
            Facility.objects.get(id=self.kwargs["ids"]),
            Facility.objects.get(id=self.kwargs["target"]),
        )

    def set_arguments(self, form_data):
        self.kwargs = {
            "ids": str(form_data.get("other", EmptyId()).id),
            "target": str(form_data.get("target", EmptyId()).id),
        }


@register_tool
class ToolMergeFacilitiesUndo(CommandLineToolWrapper):
    """
    This tool runs the pdb_fac_merge_undo command to
    undo a facility merge
    """

    tool = "pdb_fac_merge_undo"

    class Form(forms.Form):
        merge = forms.ModelChoiceField(
            queryset=CommandLineTool.objects.filter(tool="pdb_fac_merge").order_by(
                "-created"
            ),
            widget=autocomplete.ModelSelect2(
                url="/autocomplete/admin/clt-history/pdb_fac_merge/"
            ),
            help_text=_("Undo this merge"),
        )

    @property
    def description(self):
        """ Provide a human readable description of the command that was run """

        # in order to make a useful description we need to collect the arguments
        # from the merge command that was undone
        kwargs = json.loads(
            CommandLineTool.objects.get(id=self.kwargs["clt"]).arguments
        ).get("kwargs")
        return "Undo: {} into {}".format(
            Facility.objects.get(id=kwargs["ids"]),
            Facility.objects.get(id=kwargs["target"]),
        )

    def set_arguments(self, form_data):
        self.kwargs = {"clt": form_data.get("merge", EmptyId()).id}


@register_tool
class ToolReset(CommandLineToolWrapper):
    tool = "pdb_wipe"
    queue = 1
    maintenance = True

    class Form(forms.Form):
        keep_users = forms.BooleanField(
            required=False,
            help_text=_(
                "Don't delete users. Note that superuser accounts are always kept - regardless of this setting."
            ),
        )
        load_data = forms.BooleanField(
            required=False, initial=True, help_text=_("Load data from peeringdb API")
        )
        load_data_url = forms.CharField(
            required=False, initial="https://www.peeringdb.com/api"
        )

    @property
    def description(self):
        return "Reset environment"

    def set_arguments(self, form_data):
        self.kwargs = form_data


@register_tool
class ToolUndelete(CommandLineToolWrapper):
    """
    Allows restoration of an object object and it's child objects
    """

    tool = "pdb_undelete"

    # These are the reftags that are currently supported by this
    # tool.
    supported_reftags = ["ixlan", "fac"]

    class Form(forms.Form):
        version = forms.ModelChoiceField(
            queryset=Version.objects.all().order_by("-revision_id"),
            widget=autocomplete.ModelSelect2(url="/autocomplete/admin/deletedversions"),
            help_text=_("Restore this object - search by [reftag] [id]"),
        )

    @property
    def description(self):
        return "{reftag} {id}".format(**self.kwargs)

    def set_arguments(self, form_data):
        version = form_data.get("version")
        if not version:
            return
        reftag = version.content_type.model_class().HandleRef.tag
        self.kwargs = {
            "reftag": reftag,
            "id": version.object_id,
            "version_id": version.id,
        }

    def validate(self):
        if self.kwargs.get("reftag") not in self.supported_reftags:
            raise ValueError(
                _(
                    "Only {} type objects may be restored "
                    "through this interface at this point"
                ).format(",".join(self.supported_reftags))
            )

        obj = REFTAG_MAP[self.kwargs.get("reftag")].objects.get(
            id=self.kwargs.get("id")
        )
        if obj.status != "deleted":
            raise ValueError(f"{obj} is not currently marked as deleted")


@register_tool
class ToolIXFIXPMemberImport(CommandLineToolWrapper):
    """
    Allows resets for various parts of the ix-f member data import protocol.
    And import ix-f member data for a single Ixlan at a time.
    """

    tool = "pdb_ixf_ixp_member_import"
    queue = 1

    class Form(forms.Form):
        ix = forms.ModelChoiceField(
            queryset=InternetExchange.objects.all(),
            widget=autocomplete.ModelSelect2(url="/autocomplete/ix/json"),
            help_text=_(
                "Select an Internet Exchange to perform an ix-f memberdata import"
            ),
        )

        if settings.RELEASE_ENV != "prod":

            # reset toggles are not available on production
            # environment

            reset = forms.BooleanField(
                required=False, initial=False, help_text=_("Reset all")
            )
            reset_hints = forms.BooleanField(
                required=False, initial=False, help_text=_("Reset hints")
            )
            reset_dismisses = forms.BooleanField(
                required=False, initial=False, help_text=_("Reset dismisses")
            )
            reset_email = forms.BooleanField(
                required=False, initial=False, help_text=_("Reset email")
            )
            reset_tickets = forms.BooleanField(
                required=False, initial=False, help_text=_("Reset tickets")
            )

    @property
    def description(self):
        return "IX-F Member Import Tool"

    def set_arguments(self, form_data):
        for key in [
            "reset",
            "reset_hints",
            "reset_dismisses",
            "reset_email",
            "reset_tickets",
        ]:
            self.kwargs[key] = form_data.get(key, False)

        if form_data.get("ix"):
            self.kwargs["ixlan"] = [form_data.get("ix").id]