"""Author: Sandeep Belgavi. Evidence-backed offline regression discovery."""
from dataclasses import dataclass
import json


@dataclass(frozen=True)
class Evidence:
    ref: str
    revision: str
    outcome: str
    complete: bool
    redacted: bool


@dataclass(frozen=True)
class Session:
    session_id: str
    revision: str
    claim: str
    evidence_ref: str


class Observer:
    """Sequential synthetic store; no model, production mutation or network."""
    def __init__(self, evidence):
        self.evidence = dict(evidence)
        self.seen, self.findings, self.fixtures = {}, {}, {}
        self.finding_evidence = {}
        self.unknown = self.duplicates = self.conflicts = 0

    def inspect(self, session):
        key = (session.session_id, session.revision)
        if key in self.seen:
            if self.seen[key] == session:
                self.duplicates += 1
                return 'duplicate'
            self.conflicts += 1
            return 'conflict'
        self.seen[key] = session
        evidence = self.evidence.get(session.evidence_ref)
        if (evidence is None or evidence.ref != session.evidence_ref or
                evidence.revision != session.revision or not evidence.complete or
                evidence.outcome not in ('completed', 'pending', 'failed')):
            self.unknown += 1
            return 'unknown'
        if session.claim == 'completed' and evidence.outcome != 'completed':
            self.findings[key] = session
            self.finding_evidence[key] = evidence
            return 'finding'
        return 'no_finding'

    def promote_fixture(self, key, approved=False):
        if not approved:
            raise PermissionError('Independent review required')
        session = self.findings[key]
        evidence = self.finding_evidence[key]
        if not evidence.redacted:
            raise PermissionError('Redaction required for fixture export')
        self.fixtures[key] = (session, evidence)
        return 'fixture_created'


def main():
    evidence = {'e1': Evidence('e1', 'v1', 'pending', True, True)}
    observer = Observer(evidence)
    bad = Session('s1', 'v1', 'completed', 'e1')
    observer.inspect(bad)
    observer.inspect(bad)
    observer.inspect(Session('s2', 'v1', 'completed', 'missing'))
    observer.promote_fixture(('s1', 'v1'), approved=True)
    print(json.dumps(dict(findings=len(observer.findings), unknown=observer.unknown, duplicates=observer.duplicates, fixtures=len(observer.fixtures), deployed_actions=0), sort_keys=True))


if __name__ == '__main__': main()