from xml.etree import ElementTree
import logging

from component import Component, ComponentType
from lemma_features import get_lemma_features

class SyntacticStructure:
    def __init__(self):
        self.id = None
        self.lbs = None
        self.components = []

    @staticmethod
    def from_xml(xml):
        st = SyntacticStructure()
        st.id = xml.get('id')
        st.lbs = xml.get('LBS')

        assert len(list(xml)) == 1
        system = next(iter(xml))

        assert system.get('type') == 'JOS'
        components, dependencies, definitions = list(system)

        deps = [(dep.get('from'), dep.get('to'), dep.get('label'), dep.get('order'))
                for dep in dependencies]
        comps = {comp.get('cid'): dict(comp.items()) for comp in components}

        restrs, forms = {}, {}

        for comp in definitions:
            n = comp.get('cid')
            restrs[n] = None
            forms[n] = []

            for el in comp:
                if el.tag.startswith("restriction"):
                    assert restrs[n] is None
                    restrs[n] = el
                elif el.tag.startswith("representation"):
                    st.add_representation(n, el, forms)
                else:
                    raise NotImplementedError("Unknown definition: {} in structure {}"
                                              .format(el.tag, st.id))

        fake_root_component = Component({'cid': '#', 'type': 'other'})
        st.components = fake_root_component.find_next(deps, comps, restrs, forms)

        st.determine_core2w()
        return st

    def determine_core2w(self):
        ppb_components = []
        for c in self.components:
            if c.type != ComponentType.Core:
                continue

            ppb = 4
            for r in c.restrictions:
                ppb = min(r.ppb, ppb)

            ppb_components.append((c, ppb))

        ppb_components = sorted(ppb_components, key=lambda c: c[1])
        if len(ppb_components) > 2 and ppb_components[1][1] == ppb_components[2][1]:
            raise RuntimeError("Cannot determine 2 'jedrna polnopomenska beseda' for", self.id)

        for c, _ in ppb_components[:2]:
            c.type = ComponentType.Core2w

    def add_representation(self, n, rep_el, forms):
        assert rep_el.tag == "representation"
        to_add = []
        for el in rep_el:
            assert el.tag == "feature"
            if 'rendition' in el.attrib or 'selection' in el.attrib:
                to_add.append(el)
            else:
                logging.warning("Strange representation feature in structure {}. Skipping"
                                .format(self.id))
                continue
        forms[n].append(to_add)

    def get_component(self, idx):
        for c in self.components:
            if c.idx == idx:
                return c
        raise RuntimeError("Unknown component id: {}".format(idx))

    def match(self, word):
        matches = self.components[0].match(word)
        return [] if matches is None else matches


def build_structures(filename):
    max_num_components = -1
    with open(filename, 'r') as fp:
        et = ElementTree.XML(fp.read())

    structures = []
    for structure in et.iter('syntactic_structure'):
        to_append = SyntacticStructure.from_xml(structure)
        if to_append is None:
            continue

        structures.append(to_append)
        max_num_components = max(max_num_components, len(to_append.components))
    
    lemma_features = get_lemma_features(et)
    return structures, lemma_features, max_num_components