import pytest

from central.app.dry_run_planner import (
    build_field_proposals,
    execute,
    mva_evidence,
    split_by_eligibility,
)


def _decision(**overrides):
    base = {
        "status": "EXACT_NCM",
        "cest_status": "NO_CEST_MAPPING_FOUND",
        "ipi_status": "NO_TIPI_MAPPING_FOUND",
        "ba_st_mva_status": "NO_MVA_MAPPING_FOUND",
        "classification": {
            "ncm": "07069000",
            "cest": [],
            "ipi": None,
            "ba_st_mva": None,
            "ba_st_mva_candidates": [],
        },
        "dataset_versions": {"ncm": "n1", "cest": "c1", "tipi_ipi": "t1", "ba_st_mva": "m1"},
        "engine_version": "0.1.0",
        "decision_version": "mvp",
        "request_fingerprint": "fp",
    }
    base.update(overrides)
    return base


def test_ipi_resolved_numeric_current_unknown():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "3.25", "rate_numeric": 3.25, "rate_kind": "NUMERIC", "ex": None}})
    proposals = build_field_proposals("000026", decision, {})
    ipi = next(p for p in proposals if p["field"] == "IPI")
    assert ipi["status"] == "CURRENT_UNKNOWN"
    assert ipi["write_eligible"] is False
    assert ipi["proposed_value"] == 3.25


def test_ipi_resolved_numeric_same_value():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "3.25", "rate_numeric": 3.25, "rate_kind": "NUMERIC", "ex": None}})
    proposals = build_field_proposals("000026", decision, {"ipi": 3.25, "ex_tipi": None})
    ipi = next(p for p in proposals if p["field"] == "IPI")
    assert ipi["status"] == "SAME_VALUE"
    assert ipi["write_eligible"] is False


def test_ipi_resolved_numeric_change_required():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "3.25", "rate_numeric": 3.25, "rate_kind": "NUMERIC", "ex": None}})
    proposals = build_field_proposals("000026", decision, {"ipi": None, "ex_tipi": None})
    ipi = next(p for p in proposals if p["field"] == "IPI")
    assert ipi["status"] == "CHANGE_REQUIRED"
    assert ipi["write_eligible"] is True
    assert ipi["proposed_value"] == 3.25


def test_ipi_non_numeric_marker_never_proposes_a_write():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "NT", "rate_numeric": None, "rate_kind": "NON_NUMERIC", "rate_classification": "NT_OR_NON_TAXED", "ex": None}})
    proposals = build_field_proposals("000004", decision, {"ipi": None, "ex_tipi": None})
    ipi = next(p for p in proposals if p["field"] == "IPI")
    assert ipi["status"] == "NON_NUMERIC_IPI_STATUS"
    assert ipi["proposed_value"] is None
    assert ipi["write_eligible"] is False
    assert ipi["reason_code"] == "TIPI_RATE_NT_OR_NON_TAXED"


def test_ipi_resolved_without_concrete_rate_still_produces_a_row():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": None, "rate_numeric": None, "rate_kind": "BLANK", "rate_classification": "SOURCE_BLANK", "ex": None}})
    proposals = build_field_proposals("000018", decision, {"ipi": 5, "ex_tipi": None})
    ipi = next(p for p in proposals if p["field"] == "IPI")
    assert ipi["status"] == "SOURCE_BLANK"
    assert ipi["proposed_value"] is None
    assert ipi["write_eligible"] is False
    assert ipi["reason_code"] == "TIPI_RATE_SOURCE_BLANK"


def test_no_ex_tipi_row_when_no_ex_candidates():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "3.25", "rate_numeric": 3.25, "rate_kind": "NUMERIC", "ex": None}, "ipi_candidates": []})
    proposals = build_field_proposals("000026", decision, {"ipi": None, "ex_tipi": None})
    assert all(p["field"] != "EX_TIPI" for p in proposals)


def test_ex_tipi_concrete_single_candidate_change_required():
    decision = _decision(
        ipi_status="IPI_CANDIDATES",
        classification={**_decision()["classification"], "ipi": None, "ipi_candidates": [{"ncm": "07069000", "ex": "01", "description": "specific", "rate": "5"}]},
    )
    proposals = build_field_proposals("000004", decision, {"ex_tipi": None})
    ex = next(p for p in proposals if p["field"] == "EX_TIPI")
    assert ex["status"] == "CHANGE_REQUIRED"
    assert ex["proposed_value"] == "01"
    assert ex["write_eligible"] is True


def test_ex_tipi_multiple_candidates_is_candidate_not_eligible():
    decision = _decision(
        ipi_status="IPI_CANDIDATES",
        classification={**_decision()["classification"], "ipi": None, "ipi_candidates": [
            {"ncm": "07069000", "ex": "01", "description": "a", "rate": "5"},
            {"ncm": "07069000", "ex": "02", "description": "b", "rate": "7"},
        ]},
    )
    proposals = build_field_proposals("000004", decision, {"ex_tipi": None})
    ex = next(p for p in proposals if p["field"] == "EX_TIPI")
    assert ex["status"] == "CANDIDATE"
    assert ex["proposed_value"] is None
    assert ex["write_eligible"] is False


def test_cest_confirmed_change_required():
    decision = _decision(cest_status="CEST_CONFIRMED", classification={**_decision()["classification"], "cest": ["17.087.02"]})
    proposals = build_field_proposals("000018", decision, {"cest": ""})
    cest = next(p for p in proposals if p["field"] == "CEST")
    assert cest["status"] == "CHANGE_REQUIRED"
    assert cest["write_eligible"] is True
    assert cest["proposed_value"] == "17.087.02"


def test_cest_candidates_not_eligible():
    decision = _decision(cest_status="CEST_CANDIDATES")
    proposals = build_field_proposals("000024", decision, {"cest": ""})
    cest = next(p for p in proposals if p["field"] == "CEST")
    assert cest["status"] == "CANDIDATE"
    assert cest["proposed_value"] is None
    assert cest["write_eligible"] is False


def test_cest_description_mismatch_not_eligible():
    decision = _decision(cest_status="CEST_DESCRIPTION_MISMATCH")
    proposals = build_field_proposals("000018", decision, {"cest": ""})
    cest = next(p for p in proposals if p["field"] == "CEST")
    assert cest["status"] == "UNRESOLVED"
    assert cest["reason_code"] == "CEST_DESCRIPTION_SCORE_BELOW_THRESHOLD"
    assert cest["write_eligible"] is False


def test_legacy_ncm_review_no_invented_successor():
    decision = _decision(status="LEGACY_NCM", classification={**_decision()["classification"], "ncm": "02071400"})
    proposals = build_field_proposals("000016", decision, {"ipi": "3.25", "cest": ""})
    assert len(proposals) == 1
    row = proposals[0]
    assert row["field"] == "CLASSIFICACAO_FISCAL"
    assert row["status"] == "LEGACY_NCM_REVIEW"
    assert row["proposed_value"] is None
    assert row["write_eligible"] is False


def test_mva_never_produces_a_write_proposal():
    decision = _decision(ba_st_mva_status="MVA_CANDIDATES", classification={**_decision()["classification"], "ba_st_mva_candidates": [{"item": "1"}]})
    proposals = build_field_proposals("000024", decision, {"cest": ""})
    assert all(p["field"] != "BA_ST_MVA" for p in proposals)
    evidence = mva_evidence("000024", decision)
    assert evidence["status"] == "MVA_CANDIDATES"
    assert evidence["candidates"]


def test_split_by_eligibility():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "3.25", "rate_numeric": 3.25, "rate_kind": "NUMERIC", "ex": None}})
    proposals = build_field_proposals("000026", decision, {})
    split = split_by_eligibility(proposals)
    assert split["blocked"] == proposals
    assert split["eligible"] == []


def test_execute_refuses_non_eligible_proposal():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "3.25", "rate_numeric": 3.25, "rate_kind": "NUMERIC", "ex": None}})
    proposals = build_field_proposals("000026", decision, {})
    with pytest.raises(PermissionError):
        execute(proposals)


def test_execute_never_writes_even_when_eligible():
    decision = _decision(ipi_status="IPI_RESOLVED", classification={**_decision()["classification"], "ipi": {"rate": "3.25", "rate_numeric": 3.25, "rate_kind": "NUMERIC", "ex": None}})
    proposals = build_field_proposals("000026", decision, {"ipi": "0"})
    eligible_only = split_by_eligibility(proposals)["eligible"]
    assert eligible_only
    with pytest.raises(NotImplementedError):
        execute(eligible_only)