# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

from __future__ import absolute_import, unicode_literals

import os

import ldap
import paramiko


class LDAP(object):
    """Interface to an LDAP server."""

    def __init__(self, uri, username=None, password=None):
        self.c = ldap.initialize(uri)

        if username and password:
            self.c.simple_bind_s(username, password)

    def create_user(
        self,
        email,
        username,
        uid,
        fullname,
        key_filename=None,
        scm_level=None,
        hg_access=True,
        hg_enabled=True,
        bugzilla_email=None,
        groups=None,
    ):
        """Create a new user in LDAP.

        The user has an ``email`` address, a full ``name``, a
        ``username`` (for system accounts) and a numeric ``uid``.
        """

        if not bugzilla_email:
            bugzilla_email = email

        dn = "mail=%s,o=com,dc=mozilla" % email

        username = username.encode("utf-8")
        fullname = fullname.encode("utf-8")
        bugzilla_email = bugzilla_email.encode("utf-8")

        r = [
            (
                "objectClass",
                [
                    b"inetOrgPerson",
                    b"organizationalPerson",
                    b"person",
                    b"posixAccount",
                    b"bugzillaAccount",
                    b"top",
                ],
            ),
            ("cn", [fullname]),
            ("gidNumber", [b"100"]),
            ("homeDirectory", [b"/home/%s" % username]),
            ("sn", [fullname.split()[-1]]),
            ("uid", [username]),
            ("uidNumber", [str(uid).encode("utf-8")]),
            ("bugzillaEmail", [bugzilla_email]),
        ]

        if hg_access:
            r[0][1].append(b"hgAccount")
            value = b"TRUE" if hg_enabled else b"FALSE"
            r.extend(
                [
                    ("fakeHome", [b"/tmp"]),
                    ("hgAccountEnabled", [value]),
                    ("hgHome", [b"/tmp"]),
                    ("hgShell", [b"/bin/sh"]),
                ]
            )

        self.c.add_s(dn, r)

        res = {
            "dn": dn,
            "ldap_groups": set(),
        }

        if key_filename:
            pubkey_filename = "%s.pub" % key_filename
            if os.path.exists(key_filename):
                with open(pubkey_filename, "rb") as fh:
                    pubkey = fh.read()
            else:
                k = paramiko.rsakey.RSAKey.generate(2048)
                k.write_private_key_file(key_filename)
                pubkey = "%s %s %s" % (k.get_name(), k.get_base64(), email)
                pubkey = pubkey.encode("utf-8")
                with open(pubkey_filename, "wb") as fh:
                    fh.write(pubkey)

            self.add_ssh_key(email, pubkey)
            res["ssh_pubkey"] = pubkey
            res["ssh_key_filename"] = key_filename
            res["ssh_pubkey_filename"] = pubkey_filename

        if scm_level:
            if scm_level < 1 or scm_level > 4:
                raise ValueError(
                    "scm level must be between 1 and 3 (or 4 for "
                    "`scm_allow_direct_push`): %s" % scm_level
                )

            for level in range(1, scm_level + 1):
                if level == 4:
                    group = "scm_allow_direct_push"
                else:
                    group = "scm_level_%d" % level

                self.add_user_to_group(email, group)
                res["ldap_groups"].add(group)

        if groups:
            for group in groups:
                self.add_user_to_group(email, group)
                res["ldap_groups"].add(group)

        return res

    def delete_user(self, email):
        """Deletes the specified user from LDAP."""
        dn = "mail=%s,o=com,dc=mozilla" % email

        # Remove from posix groups.
        results = self.c.search_s(
            "ou=groups,dc=mozilla",
            ldap.SCOPE_SUBTREE,
            "(memberUid=%s)" % email,
            [b"cn"],
        )
        for result in results:
            self.c.modify_s(result[0], [(ldap.MOD_DELETE, b"memberUid", str(email))])

        # Remove from ldap groups.
        results = self.c.search_s(
            "ou=groups,dc=mozilla", ldap.SCOPE_SUBTREE, "(member=%s)" % dn, [b"cn"]
        )
        for result in results:
            self.c.modify_s(result[0], [(ldap.MOD_DELETE, b"member", str(dn))])

        # Delete the user entry.
        self.c.delete_s(dn)

    def create_vcs_sync_login(self, pubkey):
        dn = "uid=vcs-sync,ou=logins,dc=mozilla"

        r = [
            (
                "objectClass",
                [
                    b"account",
                    b"top",
                    b"uidObject",
                    b"hgAccount",
                    b"mailObject",
                    b"posixAccount",
                    b"ldapPublicKey",
                ],
            ),
            ("cn", [b"VCS Sync"]),
            ("fakeHome", [b"/tmp"]),
            ("gidNumber", [b"100"]),
            ("hgAccountEnabled", [b"TRUE"]),
            ("hgHome", [b"/tmp"]),
            ("hgShell", [b"/bin/sh"]),
            ("homeDirectory", [b"/home/vcs-sync"]),
            ("mail", [b"vcs-sync@mozilla.com"]),
            ("uidNumber", [b"1500"]),
            ("sshPublicKey", [pubkey.encode("utf-8")]),
        ]

        self.c.add_s(dn, r)

    def add_ssh_key(self, email, key):
        """Add an SSH key to a user in LDAP."""
        dn = "mail=%s,o=com,dc=mozilla" % email

        modlist = []

        try:
            existing = self.c.search_s(dn, ldap.SCOPE_BASE, attrlist=["objectClass"])[
                0
            ][1]
            if b"ldapPublicKey" not in existing["objectClass"]:
                modlist.append((ldap.MOD_ADD, "objectClass", b"ldapPublicKey"))
        except ldap.NO_SUCH_OBJECT:
            pass

        modlist.append((ldap.MOD_ADD, "sshPublicKey", key))

        self.c.modify_s(dn, modlist)

    def add_user_to_group(self, email, group):
        """Add a user to the specified LDAP group.

        The ``group`` is defined in terms of its ``cn`` under
        ``ou=groups,dc=mozilla`. e.g. ``scm_level_3``.
        """
        dn = "mail=%s,o=com,dc=mozilla" % email

        group_dn = "cn=%s,ou=groups,dc=mozilla" % group
        modlist = [(ldap.MOD_ADD, "memberUid", email.encode("utf-8"))]
        self.c.modify_s(group_dn, modlist)

        # MoCo LDAP has an active_* for each scm_level_* group, which we need
        # to emulate here.
        if group.startswith("scm_"):
            group_dn = "cn=active_%s,ou=groups,dc=mozilla" % group
            modlist = [(ldap.MOD_ADD, "member", dn.encode("utf-8"))]
            self.c.modify_s(group_dn, modlist)