from ansible.module_utils._text import to_native

import re

ENTRY_RE = re.compile(r'^\s*(?P<domain>\S+)(\s+(?P<ttl>\d+))?(\s+(?P<class>[a-zA-Z]+))?\s+(?P<type>[a-zA-Z]+)\s+(?P<data>\S(.*\S)?)\s*$')

def dns_entry_interpeter(entry):
    if isinstance(entry, dict):
        return entry
    m = ENTRY_RE.match(entry)
    if not m:
        raise Exception("Entry not in expected format: %s" % to_native(entry))
    ret = {}
    for key, val in m.groupdict().items():
        if val is not None:
            if key in ["ttl"]:
                ret[key] = int(val)
            else:
                ret[key] = val
    return ret

def dns_entry_equal(a, b):
    return a.get("domain", "@") == b.get("domain", "@") and a.get("ttl", -1) == b.get("ttl", -1) and a.get("class", "IN") == b.get("class", "IN") and a["type"] == b["type"]

def dns_entries_combiner(entries):
    ret = []
    for a in entries:
        found = False
        for b in ret:
            if dns_entry_equal(a, b):
                found = True
                if not isinstance(b["data"], list):
                    b["data"] = [b["data"]]
                if isinstance(a["data"], list):
                    b["data"] += a["data"]
                else:
                    b["data"].append(a["data"])
                break
        if not found:
            ret.append(a)
    return ret

def dns_entries_interpreter(entries):
    if isinstance(entries, str):
        entries = [e for e in entries.splitlines() if e]
    return dns_entries_combiner(map(dns_entry_interpeter, entries))

class FilterModule(object):
    def filters(self):
        return {
            'dns_entry_interpreter': dns_entry_interpeter,
            'dns_entries_combiner': dns_entries_combiner,
            'dns_entries_interpreter': dns_entries_interpreter,
        }