#!/usr/bin/env python3
"""LDAP client tool for ScadaLink test infrastructure."""

import argparse
import sys

from ldap3 import Server, Connection, NONE, SUBTREE, SIMPLE


DEFAULT_HOST = "localhost"
DEFAULT_PORT = 3893
DEFAULT_BASE_DN = "dc=scadalink,dc=local"
# GLAuth places users under ou=<PrimaryGroupName>,ou=users,dc=...
# The admin user (primarygroup SCADA-Admins) needs search capabilities in config.
DEFAULT_BIND_DN = "cn=admin,ou=SCADA-Admins,ou=users,dc=scadalink,dc=local"
DEFAULT_BIND_PASSWORD = "password"


def make_connection(args):
    """Create and return an authenticated LDAP connection."""
    server = Server(args.host, port=args.port, get_info=NONE)
    bind_dn = getattr(args, "bind_dn", DEFAULT_BIND_DN) or DEFAULT_BIND_DN
    bind_password = getattr(args, "bind_password", DEFAULT_BIND_PASSWORD) or DEFAULT_BIND_PASSWORD
    conn = Connection(server, user=bind_dn, password=bind_password, authentication=SIMPLE, auto_bind=True)
    return conn


def cmd_check(args):
    """Test LDAP connectivity and base DN search."""
    try:
        conn = make_connection(args)
        print(f"Connected to: {args.host}:{args.port}")
        print(f"Bind DN:      {DEFAULT_BIND_DN}")

        conn.search(DEFAULT_BASE_DN, "(objectClass=*)", search_scope=SUBTREE, attributes=["dn"])
        print(f"Base DN search ({DEFAULT_BASE_DN}): {len(conn.entries)} entries found")

        for entry in conn.entries:
            print(f"  {entry.entry_dn}")

        conn.unbind()
        print("\nLDAP server is healthy.")
    except Exception as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)


def cmd_bind(args):
    """Test user authentication via bind.

    GLAuth DN format: cn=<user>,ou=<PrimaryGroup>,ou=users,dc=scadalink,dc=local
    Since we don't know the user's primary group upfront, we search for the user first
    to discover the full DN, then rebind with that DN.
    """
    try:
        # First, use admin to find the user's actual DN
        admin_conn = make_connection(args)
        admin_conn.search(
            DEFAULT_BASE_DN,
            f"(cn={args.user})",
            search_scope=SUBTREE,
            attributes=["cn"],
        )

        if not admin_conn.entries:
            print(f"User not found: {args.user}", file=sys.stderr)
            sys.exit(1)

        # Find the user entry (skip group entries that also match cn)
        user_dn = None
        for entry in admin_conn.entries:
            dn = entry.entry_dn
            if dn.startswith(f"cn={args.user},"):
                user_dn = dn
                break

        admin_conn.unbind()

        if not user_dn:
            print(f"Could not resolve DN for user: {args.user}", file=sys.stderr)
            sys.exit(1)

        # Now bind with the discovered DN
        server = Server(args.host, port=args.port, get_info=NONE)
        conn = Connection(server, user=user_dn, password=args.password, authentication=SIMPLE, auto_bind=True)
        print(f"Bind successful: {user_dn}")
        conn.unbind()
    except Exception as e:
        print(f"Bind failed for {args.user}: {e}", file=sys.stderr)
        sys.exit(1)


def cmd_search(args):
    """Search with arbitrary LDAP filter."""
    try:
        conn = make_connection(args)
        base = args.base or DEFAULT_BASE_DN
        conn.search(base, args.filter, search_scope=SUBTREE, attributes=["*"])

        print(f"Filter: {args.filter}")
        print(f"Base:   {base}")
        print(f"Results: {len(conn.entries)}\n")

        for entry in conn.entries:
            print(f"DN: {entry.entry_dn}")
            for attr in entry.entry_attributes:
                print(f"  {attr}: {entry[attr].value}")
            print()

        conn.unbind()
    except Exception as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)


def cmd_users(args):
    """List all users with group memberships."""
    try:
        conn = make_connection(args)

        # Find all groups to map GIDs and memberships
        conn.search(DEFAULT_BASE_DN, "(objectClass=posixGroup)",
                     search_scope=SUBTREE, attributes=["cn", "gidNumber", "memberUid"])
        groups_by_gid = {}
        groups_with_members = {}
        for entry in conn.entries:
            gid = entry["gidNumber"].value if "gidNumber" in entry.entry_attributes else None
            cn = entry["cn"].value
            if gid:
                groups_by_gid[int(gid)] = cn
            member_uids = entry["memberUid"].value if "memberUid" in entry.entry_attributes else []
            if isinstance(member_uids, str):
                member_uids = [member_uids]
            groups_with_members[cn] = member_uids

        # Find all users
        conn.search(DEFAULT_BASE_DN, "(objectClass=posixAccount)",
                     search_scope=SUBTREE, attributes=["cn", "mail", "gidNumber"])

        print("Users:")
        print(f"{'Username':<20} {'Email':<35} {'Primary Group':<25} {'Additional Groups'}")
        print("-" * 110)

        for entry in conn.entries:
            cn = entry["cn"].value
            mail = entry["mail"].value if "mail" in entry.entry_attributes else ""
            gid = int(entry["gidNumber"].value) if "gidNumber" in entry.entry_attributes else None
            primary = groups_by_gid.get(gid, str(gid)) if gid else ""

            # Find additional groups via memberUid
            additional = []
            for group_name, members in groups_with_members.items():
                if cn in members and group_name != primary:
                    additional.append(group_name)

            print(f"{cn:<20} {mail:<35} {primary:<25} {', '.join(additional)}")

        conn.unbind()
    except Exception as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)


def cmd_groups(args):
    """List all groups with member counts."""
    try:
        conn = make_connection(args)
        conn.search(DEFAULT_BASE_DN, "(objectClass=posixGroup)",
                     search_scope=SUBTREE, attributes=["cn", "gidNumber", "memberUid", "description"])

        print("Groups:")
        print(f"{'Group':<25} {'GID':<10} {'Members'}")
        print("-" * 70)

        for entry in conn.entries:
            cn = entry["cn"].value
            gid = entry["gidNumber"].value if "gidNumber" in entry.entry_attributes else ""
            members = entry["memberUid"].value if "memberUid" in entry.entry_attributes else []
            if isinstance(members, str):
                members = [members]
            member_list = ", ".join(members) if members else "(none)"
            print(f"{cn:<25} {gid:<10} {member_list}")

        conn.unbind()
    except Exception as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)


def main():
    parser = argparse.ArgumentParser(description="LDAP client tool for ScadaLink test infrastructure")
    parser.add_argument("--host", default=DEFAULT_HOST, help=f"LDAP host (default: {DEFAULT_HOST})")
    parser.add_argument("--port", type=int, default=DEFAULT_PORT, help=f"LDAP port (default: {DEFAULT_PORT})")

    sub = parser.add_subparsers(dest="command", required=True)

    sub.add_parser("check", help="Test LDAP connectivity")

    bind_p = sub.add_parser("bind", help="Test user authentication")
    bind_p.add_argument("--user", required=True, help="Username (e.g. designer)")
    bind_p.add_argument("--password", default="password", help="Password (default: password)")

    search_p = sub.add_parser("search", help="Search with LDAP filter")
    search_p.add_argument("--bind-dn", default=DEFAULT_BIND_DN, help="Bind DN")
    search_p.add_argument("--bind-password", default=DEFAULT_BIND_PASSWORD, help="Bind password")
    search_p.add_argument("--filter", required=True, help="LDAP filter")
    search_p.add_argument("--base", help=f"Search base (default: {DEFAULT_BASE_DN})")

    users_p = sub.add_parser("users", help="List all users with group memberships")
    users_p.add_argument("--bind-dn", default=DEFAULT_BIND_DN, help="Bind DN")
    users_p.add_argument("--bind-password", default=DEFAULT_BIND_PASSWORD, help="Bind password")

    groups_p = sub.add_parser("groups", help="List all groups with members")
    groups_p.add_argument("--bind-dn", default=DEFAULT_BIND_DN, help="Bind DN")
    groups_p.add_argument("--bind-password", default=DEFAULT_BIND_PASSWORD, help="Bind password")

    args = parser.parse_args()

    commands = {
        "check": cmd_check,
        "bind": cmd_bind,
        "search": cmd_search,
        "users": cmd_users,
        "groups": cmd_groups,
    }

    commands[args.command](args)


if __name__ == "__main__":
    main()