import copy

import pytest
from conftest import golden_entries, golden_manifest

from target_revenue import fold, hashing, validation


def test_golden_entries_are_individually_conformant():
    for entry in golden_entries():
        validation.validate_ledger_entry(entry)


def test_golden_entries_currency_matches_phase():
    errors = validation.check_currency_consistency(golden_manifest(), golden_entries())
    assert errors == []


def test_currency_mismatch_is_detected():
    manifest = golden_manifest()
    entries = copy.deepcopy(golden_entries())
    entries[0]["currency"] = "EUR"
    errors = validation.check_currency_consistency(manifest, entries)
    assert len(errors) == 1
    assert "EUR" in errors[0]


def test_golden_hash_chain_is_valid():
    hashing.verify_chain(golden_entries())


def test_tampered_entry_breaks_hash_chain():
    entries = copy.deepcopy(golden_entries())
    entries[2]["amount"] = 999999  # tamper after the chain was computed
    with pytest.raises(ValueError, match="hash chain broken"):
        hashing.verify_chain(entries)


def test_reordered_entries_break_hash_chain():
    entries = copy.deepcopy(golden_entries())
    entries[1], entries[2] = entries[2], entries[1]
    with pytest.raises(ValueError, match="hash chain broken"):
        hashing.verify_chain(entries)


def test_fold_matches_concept_section_23_first_checkpoint():
    """spec/TargetRevenueLicenseConcept.md §23: after the first four entries,
    Development Credit $37,000, Remission Credit $18,000, Outstanding $45,000."""
    manifest = golden_manifest()
    first_four = golden_entries()[:4]
    result = fold.fold_outstanding_target(
        manifest["phase"]["initial_target"]["amount"], first_four
    )
    assert result.development_credit == 37000
    assert result.remission_credit == 18000
    assert result.outstanding_target == 45000
    assert not result.is_converted


def test_fold_reaches_zero_and_converts():
    """spec/TargetRevenueLicenseConcept.md §23: full six-entry sequence
    reaches Outstanding Target = 0 (Development Credit $67,000 + Remission
    Credit $33,000 = Initial Target $100,000)."""
    manifest = golden_manifest()
    result = fold.fold_phase(manifest, golden_entries())
    assert result.development_credit == 67000
    assert result.remission_credit == 33000
    assert result.outstanding_target == 0
    assert result.is_converted


def test_credit_reversal_reduces_development_credit():
    entries = [
        {
            "id": "trsl:entry:t0001",
            "phase": "trsl:phase:t",
            "type": "development-credit",
            "amount": 5000,
            "currency": "USD",
            "recognized_at": "2026-01-01T00:00:00Z",
            "extension": {"id": "trsl:extension:development-license", "version": "1.0"},
            "evidence_reference": "confidential:evidence:t0001",
            "previous_entry_hash": "GENESIS",
        },
    ]
    entries.append(
        {
            "id": "trsl:entry:t0002",
            "phase": "trsl:phase:t",
            "type": "credit-reversal",
            "amount": 5000,
            "currency": "USD",
            "recognized_at": "2026-01-02T00:00:00Z",
            "evidence_reference": "confidential:evidence:t0002-refund",
            "previous_entry_hash": hashing.entry_hash(entries[0]),
            "reverses": "trsl:entry:t0001",
        }
    )
    result = fold.fold_outstanding_target(100000, entries)
    assert result.development_credit == 0
    assert result.outstanding_target == 100000


def test_remission_correction_can_reduce_over_remission():
    entries = [
        {
            "id": "trsl:entry:t0001",
            "phase": "trsl:phase:t",
            "type": "remission-credit",
            "amount": 20000,
            "currency": "USD",
            "recognized_at": "2026-01-01T00:00:00Z",
            "extension": {"id": "trsl:policy:linear-longstop-v0", "version": "1.0"},
            "evidence_reference": "confidential:evidence:t0001",
            "previous_entry_hash": "GENESIS",
        },
    ]
    entries.append(
        {
            "id": "trsl:entry:t0002",
            "phase": "trsl:phase:t",
            "type": "remission-correction",
            "amount": -5000,
            "currency": "USD",
            "recognized_at": "2026-01-02T00:00:00Z",
            "evidence_reference": "confidential:evidence:t0002-correction",
            "previous_entry_hash": hashing.entry_hash(entries[0]),
            "reverses": "trsl:entry:t0001",
        }
    )
    result = fold.fold_outstanding_target(100000, entries)
    assert result.remission_credit == 15000
    assert result.outstanding_target == 85000