# -*- coding: utf-8 -*-
"""
    jandd.sphinxext.ip
    ~~~~~~~~~~~~~~~~~~

    The IP domain.

    :copyright: Copyright (c) 2016-2021 Jan Dittberner
    :license: GPLv3+, see COPYING file for details.
"""
__version__ = "0.5.0-dev"

from collections import defaultdict
from typing import Iterable, List, Optional, Tuple

from docutils import nodes
from ipcalc import IP, Network
from sphinx import addnodes
from sphinx.addnodes import desc_signature, pending_xref
from sphinx.builders import Builder
from sphinx.directives import ObjectDescription, T
from sphinx.domains import Domain, ObjType
from sphinx.environment import BuildEnvironment
from sphinx.errors import NoUri
from sphinx.locale import _
from sphinx.roles import XRefRole
from sphinx.util import logging
from sphinx.util.nodes import make_refnode

logger = logging.getLogger(__name__)


class ip_range(nodes.General, nodes.Element):
    pass


class IPRangeDirective(ObjectDescription):
    """A custom directive that describes an IP address range."""

    has_content = True
    required_arguments = 1
    title_prefix = None
    range_spec = None

    def get_title_prefix(self) -> str:
        if self.title_prefix is None:
            raise NotImplemented("subclasses must set title_prefix")
        return self.title_prefix

    def handle_signature(self, sig: str, signode: desc_signature) -> T:
        signode += addnodes.desc_name(text="{} {}".format(self.get_title_prefix(), sig))
        self.range_spec = sig
        return sig

    def transform_content(self, contentnode: addnodes.desc_content) -> None:
        ip_range_node = ip_range()
        ip_range_node["range_spec"] = self.range_spec
        contentnode += ip_range_node


class IPV4RangeDirective(IPRangeDirective):
    title_prefix = _("IPv4 range")

    def add_target_and_index(self, name: T, sig: str, signode: desc_signature) -> None:
        signode["ids"].append("ip4_range" + "-" + sig)
        ips = self.env.get_domain("ip")
        ips.add_ip4_range(sig)
        idx_text = "{}; {}".format(self.title_prefix, name)
        self.indexnode["entries"] = [
            ("single", idx_text, name, "", None),
        ]


class IPV6RangeDirective(IPRangeDirective):
    title_prefix = _("IPv6 range")

    def add_target_and_index(self, name: T, sig: str, signode: desc_signature) -> None:
        signode["ids"].append("ip6_range" + "-" + sig)
        ips = self.env.get_domain("ip")
        ips.add_ip6_range(sig)
        idx_text = "{}; {}".format(self.title_prefix, name)
        self.indexnode["entries"] = [
            ("single", idx_text, name, "", None),
        ]


class IPXRefRole(XRefRole):
    def __init__(self, index_type):
        self.index_type = index_type
        super().__init__()

    def process_link(
        self,
        env: BuildEnvironment,
        refnode: nodes.Element,
        has_explicit_title: bool,
        title: str,
        target: str,
    ) -> Tuple[str, str]:
        refnode.attributes.update(env.ref_context)

        ips = env.get_domain("ip")
        if refnode["reftype"] == "v4":
            ips.add_ip4_address_reference(target)
        elif refnode["reftype"] == "v6":
            ips.add_ip6_address_reference(target)
        elif refnode["reftype"] == "v4range":
            ips.add_ip4_range_reference(target)
        elif refnode["reftype"] == "v6range":
            ips.add_ip6_range_reference(target)

        return title, target

    def result_nodes(
        self,
        document: nodes.document,
        env: BuildEnvironment,
        node: nodes.Element,
        is_ref: bool,
    ) -> Tuple[List[nodes.Node], List[nodes.system_message]]:
        node_list, message = super().result_nodes(document, env, node, is_ref)

        ip = env.get_domain("ip")
        if self.reftype in ["v4", "v6"] and self.target not in ip.data["ips"]:
            return node_list, message
        if (
            self.reftype in ["v4range", "v6range"]
            and self.target not in ip.data["ranges"]
        ):
            return node_list, message

        index_node = addnodes.index()
        target_id = "index-{}".format(env.new_serialno("index"))
        target_node = nodes.target("", "", ids=[target_id])
        doc_title = next(d for d in document.traverse(nodes.title)).astext()

        node_text = node.astext()

        idx_text = "{}; {}".format(node_text, doc_title)
        idx_text_2 = "{}; {}".format(self.index_type, node.astext())
        index_node["entries"] = [
            ("single", idx_text, target_id, "", None),
            ("single", idx_text_2, target_id, "", None),
        ]

        node_list.insert(0, target_node)
        node_list.insert(0, index_node)
        return node_list, message


class IPDomain(Domain):
    """Custom domain for IP addresses and ranges."""

    name = "ip"
    label = "IP addresses and ranges."

    object_types = {
        "v4": ObjType(_("v4"), "v4", "obj"),
        "v6": ObjType(_("v6"), "v6", "obj"),
        "v4range": ObjType(_("v4range"), "v4range", "obj"),
        "v6range": ObjType(_("v6range"), "v6range", "obj"),
    }

    directives = {
        "v4range": IPV4RangeDirective,
        "v6range": IPV6RangeDirective,
    }

    roles = {
        "v4": IPXRefRole("IPv4 address"),
        "v6": IPXRefRole("IPv6 address"),
        "v4range": IPXRefRole("IPv4 range"),
        "v6range": IPXRefRole("IPv6 range"),
    }

    initial_data = {
        "range_nodes": [],
        "ip_refs": [],
        "range_refs": [],
        "ranges": defaultdict(list),
        "ips": defaultdict(list),
        "ip_dict": {},
    }

    def get_full_qualified_name(self, node: nodes.Element) -> Optional[str]:
        return "{}.{}".format("ip", node)

    def get_objects(self) -> Iterable[Tuple[str, str, str, str, str, int]]:
        for obj in self.data["range_nodes"]:
            yield obj

    def add_ip4_range(self, sig: desc_signature):
        logger.debug("add_ip4_range: %s", sig)
        self._add_ip_range("v4", sig)

    def add_ip6_range(self, sig: desc_signature):
        logger.debug("add_ip6_range: %s", sig)
        self._add_ip_range("v6", sig)

    def _add_ip_range(self, family: str, sig: desc_signature):
        name = "ip{}range.{}".format(family, sig)
        anchor = "ip-ip{}range-{}".format(family, sig)
        try:
            ip_range = Network(sig)
            self.data["range_nodes"].append(
                (name, family, sig, self.env.docname, anchor, 0)
            )
            self.data["ranges"][sig].append((ip_range, self.env.docname, anchor))
        except ValueError as e:
            logger.error("invalid ip range address '%s': %s", sig, e)

    def add_ip4_address_reference(self, ip_address: str):
        logger.debug("add_ip4_address_reference")
        self._add_ip_address_reference("v4", ip_address)

    def add_ip6_address_reference(self, ip_address: str):
        logger.debug("add_ip4_address_reference")
        self._add_ip_address_reference("v6", ip_address)

    def _add_ip_address_reference(self, family, sig):
        name = "ip{}.{}".format(family, sig)
        anchor = "ip-ip{}-{}".format(family, sig)
        try:
            ip = IP(sig)
            self.data["ip_refs"].append(
                (
                    name,
                    sig,
                    "IP{}".format(family),
                    str(ip),
                    self.env.docname,
                    anchor,
                    0,
                )
            )
            self.data["ips"][sig].append((ip, self.env.docname, anchor))
            self.data["ip_dict"][sig] = ip
        except ValueError as e:
            logger.error("invalid ip address '%s': %s", sig, e)

    def add_ip4_range_reference(self, ip_range: str):
        logger.debug("add_ip4_range_reference")
        self._add_ip_range_reference("v4", ip_range)

    def add_ip6_range_reference(self, ip_range: str):
        logger.debug("add_ip6_address_reference")
        self._add_ip_range_reference("v6", ip_range)

    def _add_ip_range_reference(self, family, sig):
        name = "iprange{}.{}".format(family, sig)
        anchor = "ip-iprange{}-{}".format(family, sig)
        try:
            ip_range = Network(sig)
            self.data["range_refs"].append(
                (
                    name,
                    sig,
                    "IP{} range".format(family),
                    str(ip_range),
                    self.env.docname,
                    anchor,
                    0,
                )
            )
        except ValueError as e:
            logger.error("invalid ip range '%s': %s", sig, e)

    def resolve_xref(
        self,
        env: BuildEnvironment,
        fromdocname: str,
        builder: Builder,
        typ: str,
        target: str,
        node: pending_xref,
        contnode: nodes.Element,
    ) -> Optional[nodes.Element]:
        match = []
        if typ in ("v4", "v6"):
            # reference to IP range
            if target not in self.data["ip_dict"]:
                # invalid ip address
                raise NoUri(target)
            match = [
                (docname, anchor)
                for ip_range, docname, anchor in [
                    r
                    for range_nodes in self.data["ranges"].values()
                    for r in range_nodes
                ]
                if self.data["ip_dict"][target] in ip_range
            ]
        elif typ in ("v4range", "v6range"):
            if target in self.data["ranges"]:
                match = [
                    (docname, anchor)
                    for ip_range, docname, anchor in [
                        range_nodes for range_nodes in self.data["ranges"][target]
                    ]
                ]
        if len(match) > 0:
            todocname = match[0][0]
            targ = match[0][1]

            return make_refnode(builder, fromdocname, todocname, targ, contnode, targ)
        else:
            logger.error("found no link target for %s", target)
        return None


def process_ip_nodes(app, doctree, fromdocname):
    env = app.builder.env
    ips = env.get_domain(IPDomain.name)

    header = (_("IP address"), _("Used by"))
    column_widths = (2, 5)

    for node in doctree.traverse(ip_range):
        content = []
        net = Network(node["range_spec"])
        addresses = defaultdict(list)
        for ip_address_sig, refs in ips.data["ips"].items():
            for ip_address, todocname, anchor in refs:
                if ip_address in net:
                    addresses[ip_address_sig].append((ip_address, todocname, anchor))
                    logger.debug(
                        "found %s in network %s on %s",
                        ip_address_sig,
                        net.to_compressed(),
                        todocname,
                    )
        if addresses:
            table = nodes.table()
            table.attributes["classes"].append("indextable")
            table.attributes["align"] = "left"

            tgroup = nodes.tgroup(cols=len(header))
            table += tgroup
            for column_width in column_widths:
                tgroup += nodes.colspec(colwidth=column_width)

            thead = nodes.thead()
            tgroup += thead
            thead += create_table_row([nodes.paragraph(text=label) for label in header])

            tbody = nodes.tbody()
            tgroup += tbody

            for ip_address_sig, ip_info in [(key, addresses[key]) for key in sorted(addresses, key=sort_by_ip)]:
                para = nodes.paragraph()
                para += nodes.literal("", ip_info[0][0].to_compressed())

                ref_node = nodes.paragraph()
                ref_uris = set()
                ref_nodes = []

                for item in ip_info:
                    ip_address, todocname, anchor = item

                    newnode = nodes.reference("", "", internal=True)
                    try:
                        newnode["refuri"] = app.builder.get_relative_uri(
                            fromdocname, todocname
                        )
                        if newnode["refuri"] in ref_uris:
                            continue
                        ref_uris.add(newnode["refuri"])
                    except NoUri:
                        pass
                    title = env.titles[todocname]
                    innernode = nodes.Text(title.astext())
                    newnode.append(innernode)
                    ref_nodes.append(newnode)
                for count in range(len(ref_nodes)):
                    ref_node.append(ref_nodes[count])
                    if count < len(ref_nodes) - 1:
                        ref_node.append(nodes.Text(", "))
                tbody += create_table_row([para, ref_node])
            content.append(table)
        else:
            para = nodes.paragraph(_("No IP addresses in this range"))
            content.append(para)

        node.replace_self(content)


def create_table_row(rowdata):
    row = nodes.row()
    for cell in rowdata:
        entry = nodes.entry()
        row += entry
        entry += cell
    return row


def sort_by_ip(item):
    return IP(item).ip


def setup(app):
    app.add_domain(IPDomain)
    app.connect("doctree-resolved", process_ip_nodes)
    return {
        "version": __version__,
        "env_version": 4,
        "parallel_read_safe": True,
        "parallel_write_safe": True,
    }