#!/usr/bin/python2

import yaml


class ParsingError(ValueError):
    pass


class _EventGroup(object):

    def __init__(self, events):
        if not events:
            raise ValueError("no events in event group")
        self._events = events

    @property
    def all_events(self):
        return self._events

    @property
    def asserts(self):
        return [e for e in self._events if e.is_assert]

    @property
    def fails(self):
        return [e for e in self._events if e.etype == 'FAIL']

    @property
    def passes(self):
        return [e for e in self._events if e.etype == 'PASS']

    @property
    def events(self):
        return self._events

    @property
    def lints(self):
        lints = []
        for e in self._events:
            lints += e.lints
        return lints


class Event(object):

    is_assert = False

    def __str__(self):
        return str(self._rawdata)

    def __init__(self, rawdata):
        self._rawdata = rawdata
        self.origin = rawdata['origin']
        self.stamp = rawdata['stamp']
        self.hint = rawdata['hint']
        self.beids = [BeId(b) for b in rawdata['beids']]
        self.edata = rawdata['data']
        self.etype = rawdata['etype']
        self.phaseid = rawdata['phase']['id']
        self.phasename = rawdata['phase']['name']
        self.phasetype = rawdata['phase']['type']

    @staticmethod
    def from_data(data):
        etype = data['etype']
        if etype in ['PASS', 'FAIL']:
            cls = AssertEvent
        elif etype == 'SINFO':
            cls = StructureInfoEvent
        elif etype == 'TEST_ERROR':
            cls = TestErrorEvent
        elif etype == 'PROMISE':
            cls = PromiseEvent
        else:
            raise ParsingError("unknown event type: %s" % etype)
        return cls(data)

    @property
    def lints(self):
        return []


class StrayEvent(Event):
    pass


class TestErrorEvent(Event):

    def lints(self):
        return [Lint("test error", self._rawdata)]

class PromiseEvent(Event):
    pass


class StructureInfoEvent(Event):
    pass


class AssertEvent(Event):

    is_assert = True

    @property
    def lints(self):
        lints = []
        if self.phaseid == '0000000000-000000000':
            lints.append(Lint('assert outside phase', self))
        return lints


class BeId(object):

    def __init__(self, data):
        self._data = data


class Phase(_EventGroup):

    @property
    def name(self):
        return self.all_events[0].phasename

    @property
    def type(self):
        return self.all_events[0].phasetype


class EventLog(_EventGroup):
    """
    Session event log (all events from session)
    """

    @classmethod
    def from_data(cls, data):
        return cls([Event.from_data(e) for e in data])


class Lint(object):
    """
    Lint-like warning coming from log parsing (eg. unclosed phase)
    """

    def __init__(self, msg, data):
        self.msg = msg
        self._data = data


class Session(object):

    def __init__(self, doc):
        self._doc = doc
        self._format = doc['format']
        if not self._format.startswith('jat/0.'):
            raise ParsingError('unsupported log format: %s' % self._format)
        self.jat_version = doc['jat_version']
        self.start = doc['start']
        self.sessid = 'noid'
        self.finalized = doc.get('finalized', False)
        self.end = doc.get('end')
        self.lints = []
        self.eventlog = EventLog.from_data(doc['events'])
        self.lints += self.eventlog.lints
        self.phases, lints = self._es2ps(self.eventlog)
        self.lints += lints
        if not self.finalized:
            self.lints.append(Lint("session not finalized", self.sessid))

    class _PhaseBuff:

        def __init__(self):
            self.phaseid = None
            self.events = []

        def is_anon(self):
            return self.phaseid == '0000000000.000000000'

        def dump2phase(self):
            phase = Phase(self.events) 
            self.phaseid = None
            self.events = []
            return phase

        def match(self, event):
            if self.phaseid is None:
                return True
            else:
                return self.phaseid == event.phaseid

        def append(self, event):
            self.phaseid = event.phaseid
            self.events.append(event)

        def __nonzero__(self):
            return bool(self.events)

        def __bool__(self):
            return bool(self.events)

        def __len__(self):
            return len(self.events)

    @staticmethod
    def _es2ps(eventlog):

        def addlint(msg):
            lints.append(Lint(msg, event))

        phases = []
        lints = []
        this_phaseid = None
        pbuff = Session._PhaseBuff()
        for event in eventlog.all_events:
            if event.origin == 'jat__sinit':
                continue
            if event.origin == 'jat__sfinish':
                if pbuff:
                    phases.append(pbuff.dump2phase())
                    addlint('unfinished phase: %s' % pbuff.phaseid)
                continue
            if event.origin == 'jat__pend':
                #
                # Phase end
                #
                if pbuff:
                    phases.append(pbuff.dump2phase())
                else:
                    addlint('dangling phase end')
            elif event.origin == '__jat__pstart':
                #
                # Phase start
                #
                if pbuff:
                    phases.append(pbuff.dump2phase())
                    if not pbuff.is_anon():
                        addlint('phase starts before previous ends')
            elif pbuff:
                #
                # Second or later event
                #
                if not pbuff.match(event):
                    phases.append(pbuff.dump2phase())
                    addlint('phase mismatch: %s =! %s'\
                            % (event.phaseid, pbuff.phaseid))
                pbuff.append(event)
            else:
                #
                # First event
                #
                pbuff.append(event)
        return phases, lints


def load(fpath):
    with open(fpath) as ylog:
        sessions = [Session(doc) for doc in yaml.load_all(ylog)]
    return sessions