"""Provenance-stamp tests (method-spec §9).

The stamp is authoritative data, not display metadata: at least one citation,
the producing model/role, token usage, and ``validator_decision`` — which mirrors
the DETERMINISTIC VALIDATOR only, stamped from the validator's outcome BEFORE any
checker override, so the two falsifiers are never conflated.
"""

from __future__ import annotations

from typing import Any

import pytest
from pydantic import ValidationError

from portfolio_optimiser_claude.ir import SavingsProposal
from portfolio_optimiser_claude.provenance import (
    Citation,
    Provenance,
    stamp_validator_decision,
)
from portfolio_optimiser_claude.validator import Rejection, validate_proposal

CITATION: dict[str, Any] = {
    "file": "tiltak-led-retrofit.md",
    "span": "200 lysrorarmaturer (90 W -> 40 W)",
    "snippet": "LED-retrofit av 200 lysrorarmaturer (90 W -> 40 W) i kontorlokaler",
}


def proposal_claiming(claimed: float) -> SavingsProposal:
    return SavingsProposal(
        project_id="P1",
        measure="test measure",
        affected_items=[{"code": "EL", "quantity": 1000, "unit_cost": 1.0}],
        claimed_saving_nok=claimed,
    )


class TestValidatorDecisionMirror:
    """§9: validator_decision mirrors ONLY the deterministic validator."""

    def test_validated_outcome_stamps_validated(self) -> None:
        outcome = validate_proposal(proposal_claiming(200))
        assert stamp_validator_decision(outcome) == "validated"

    def test_rejection_stamps_rejected(self) -> None:
        outcome = validate_proposal(proposal_claiming(500))
        assert isinstance(outcome, Rejection)
        assert stamp_validator_decision(outcome) == "rejected"


class TestStampShape:
    """§9: at least one citation; decisions use the validator vocabulary; real usage."""

    def build(self, **overrides: Any) -> Provenance:
        kwargs: dict[str, Any] = {
            "citations": [CITATION],
            "role": "proposer",
            "validator_decision": "validated",
            "tokens_used": 0,
        }
        kwargs.update(overrides)
        return Provenance(**kwargs)

    def test_valid_stamp_constructs(self) -> None:
        stamp = self.build()
        assert stamp.citations[0] == Citation(**CITATION)
        assert stamp.role == "proposer"

    def test_zero_citations_rejected(self) -> None:
        # A run whose context yields no citable content MUST fail fast (§9).
        with pytest.raises(ValidationError):
            self.build(citations=[])

    def test_model_falls_back_to_neutral_unknown(self) -> None:
        # Never a fabricated model name — the fallback is the neutral 'unknown' (§9).
        assert self.build().model == "unknown"

    def test_checker_vocabulary_rejected(self) -> None:
        # 'approved' is checker/expert vocabulary (§4) — validator_decision speaks
        # the validator's language only: validated | rejected.
        with pytest.raises(ValidationError):
            self.build(validator_decision="approved")

    def test_negative_token_usage_rejected(self) -> None:
        with pytest.raises(ValidationError):
            self.build(tokens_used=-1)