from __future__ import annotations

from datetime import UTC, datetime
from decimal import Decimal

import pytest
from sqlalchemy import create_engine, select
from sqlalchemy.orm import Session, sessionmaker
from sqlalchemy.pool import StaticPool

from app.db.base import Base
from app.models.ai_learning import AIDecision, AIDecisionFeedback, WorkflowOutcome
from app.models.employee import Employee
from app.models.expense_case import BusinessEvent, ExpenseCaseLink
from app.models.financial_record import ExpenseClaim
from app.schemas.ontology import OntologyParseResult
from app.schemas.user_agent import UserAgentRequest
from app.services.expense_cases import ExpenseCaseService
from app.services.user_agent import UserAgentService


def build_session_factory() -> sessionmaker[Session]:
    engine = create_engine(
        "sqlite+pysqlite:///:memory:",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(bind=engine)
    return sessionmaker(bind=engine, autoflush=False, autocommit=False)


def build_request(
    *,
    run_id: str,
    tenant_id: str = "tenant-a",
    changed_fields: list[dict[str, str]] | None = None,
) -> UserAgentRequest:
    return UserAgentRequest(
        run_id=run_id,
        user_id="owner@example.com",
        message="保存申请草稿",
        ontology=OntologyParseResult(run_id=run_id),
        context_json={
            "session_type": "application",
            "tenant_id": tenant_id,
            "name": "张三",
            "employee_no": "E001",
            "department_name": "市场部",
            "application_preview": {
                "modelReviewStatus": "completed",
                "fields": {
                    "applicationType": "差旅费用申请",
                    "time": "2026-07-13 至 2026-07-14",
                    "location": "上海",
                    "reason": "客户现场差旅",
                    "amount": "880元",
                },
                "aiDecisionFeedback": {
                    "schemaVersion": 1,
                    "changedFields": changed_fields or [],
                },
            },
        },
    )


def build_facts(*, reason: str = "客户现场差旅") -> dict[str, str]:
    return {
        "application_type": "差旅费用申请",
        "time": "2026-07-13 至 2026-07-14",
        "location": "上海",
        "reason": reason,
        "amount": "880元",
    }


def test_ai_application_draft_update_writes_tenant_scoped_event() -> None:
    session_factory = build_session_factory()
    with session_factory() as db:
        owner = Employee(
            id="owner-1",
            employee_no="E001",
            name="张三",
            email="owner@example.com",
        )
        claim = ExpenseClaim(
            id="application-1",
            claim_no="AP-DRAFT-001",
            employee_id=owner.id,
            employee_name=owner.name,
            department_name="市场部",
            expense_type="travel_application",
            reason="原申请事由",
            location="北京",
            amount=Decimal("500.00"),
            currency="CNY",
            invoice_count=0,
            occurred_at=datetime(2026, 7, 10, tzinfo=UTC),
            submitted_at=None,
            status="returned",
            approval_stage="退回补充",
            risk_flags_json=[],
        )
        db.add_all([owner, claim])
        db.commit()

        service = UserAgentService(db)
        request = build_request(run_id="application-draft-update")
        updated = service._update_expense_application_record(
            request,
            build_facts(reason="更新后的申请事由"),
            claim,
            submit=False,
            learning_current_user=service._build_application_current_user(request),
        )

        assert updated.status == "draft"
        event = db.scalar(select(BusinessEvent).where(BusinessEvent.aggregate_id == claim.id))
        assert event is not None
        assert event.event_type == "claim_draft_updated"
        assert event.tenant_id == "tenant-a"
        assert event.actor_id == "owner@example.com"
        assert event.correlation_id == "application-draft-update"
        assert event.payload_json["previous_status"] == "returned"
        assert event.payload_json["next_status"] == "draft"
        link = db.scalar(select(ExpenseCaseLink).where(ExpenseCaseLink.resource_id == claim.id))
        assert link is not None
        assert link.tenant_id == "tenant-a"
        decision = db.scalar(select(AIDecision).where(AIDecision.expense_claim_id == claim.id))
        feedback = db.scalar(
            select(AIDecisionFeedback).where(AIDecisionFeedback.expense_claim_id == claim.id)
        )
        outcome = db.scalar(
            select(WorkflowOutcome).where(WorkflowOutcome.expense_claim_id == claim.id)
        )
        assert decision is not None
        assert decision.business_event_id == event.id
        assert feedback is not None
        assert feedback.feedback_type == "accepted"
        assert outcome is not None
        assert outcome.outcome_type == "draft_saved"


def test_untrusted_application_path_does_not_write_learning_ledger() -> None:
    session_factory = build_session_factory()
    with session_factory() as db:
        claim = UserAgentService(db)._create_expense_application_record(
            build_request(run_id="application-untrusted-path"),
            build_facts(),
            submit=False,
        )

        assert db.get(ExpenseClaim, claim.id) is not None
        assert db.scalar(
            select(BusinessEvent).where(BusinessEvent.aggregate_id == claim.id)
        ) is not None
        assert list(db.scalars(select(AIDecision)).all()) == []
        assert list(db.scalars(select(AIDecisionFeedback)).all()) == []
        assert list(db.scalars(select(WorkflowOutcome)).all()) == []


@pytest.mark.parametrize(
    "preview_patch",
    [
        {"modelReviewStatus": "template"},
        {"applicationEditMode": True},
    ],
)
def test_non_ai_or_detail_preview_is_not_recorded_as_ai_feedback(
    preview_patch: dict[str, object],
) -> None:
    session_factory = build_session_factory()
    with session_factory() as db:
        request = build_request(run_id="application-ineligible-preview")
        request.context_json["application_preview"].update(preview_patch)
        service = UserAgentService(db)
        claim = service._create_expense_application_record(
            request,
            build_facts(),
            submit=False,
            learning_current_user=service._build_application_current_user(request),
        )

        assert db.get(ExpenseClaim, claim.id) is not None
        assert list(db.scalars(select(AIDecision)).all()) == []
        assert list(db.scalars(select(AIDecisionFeedback)).all()) == []
        assert list(db.scalars(select(WorkflowOutcome)).all()) == []


def test_ai_application_draft_creation_rolls_back_when_event_write_fails(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    session_factory = build_session_factory()

    def fail_event(*_args, **_kwargs):
        raise RuntimeError("模拟草稿事件写入失败")

    monkeypatch.setattr(ExpenseCaseService, "record_claim_event", fail_event)
    with session_factory() as db:
        with pytest.raises(RuntimeError, match="模拟草稿事件写入失败"):
            UserAgentService(db)._create_expense_application_record(
                build_request(run_id="application-draft-rollback"),
                build_facts(),
                submit=False,
            )

        db.commit()
        assert list(db.scalars(select(ExpenseClaim)).all()) == []
        assert list(db.scalars(select(ExpenseCaseLink)).all()) == []
        assert list(db.scalars(select(BusinessEvent)).all()) == []


def test_ai_application_draft_update_rolls_back_when_event_write_fails(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    session_factory = build_session_factory()
    with session_factory() as db:
        owner = Employee(
            id="owner-1",
            employee_no="E001",
            name="张三",
            email="owner@example.com",
        )
        claim = ExpenseClaim(
            id="application-1",
            claim_no="AP-DRAFT-ROLLBACK-001",
            employee_id=owner.id,
            employee_name=owner.name,
            department_name="市场部",
            expense_type="travel_application",
            reason="原申请事由",
            location="北京",
            amount=Decimal("500.00"),
            currency="CNY",
            invoice_count=0,
            occurred_at=datetime(2026, 7, 10, tzinfo=UTC),
            submitted_at=None,
            status="returned",
            approval_stage="退回补充",
            risk_flags_json=[],
        )
        db.add_all([owner, claim])
        db.commit()

        def fail_event(*_args, **_kwargs):
            raise RuntimeError("模拟草稿事件写入失败")

        monkeypatch.setattr(ExpenseCaseService, "record_claim_event", fail_event)
        with pytest.raises(RuntimeError, match="模拟草稿事件写入失败"):
            UserAgentService(db)._update_expense_application_record(
                build_request(run_id="application-draft-update-rollback"),
                build_facts(reason="不应落库的新事由"),
                claim,
                submit=False,
            )

        db.commit()
        persisted = db.get(ExpenseClaim, claim.id)
        assert persisted is not None
        assert persisted.reason == "原申请事由"
        assert persisted.location == "北京"
        assert persisted.amount == Decimal("500.00")
        assert persisted.status == "returned"
        assert persisted.approval_stage == "退回补充"
        assert list(db.scalars(select(ExpenseCaseLink)).all()) == []
        assert list(db.scalars(select(BusinessEvent)).all()) == []


def test_ai_application_draft_update_deduplicates_identical_snapshot() -> None:
    session_factory = build_session_factory()
    with session_factory() as db:
        owner = Employee(
            id="owner-1",
            employee_no="E001",
            name="张三",
            email="owner@example.com",
        )
        claim = ExpenseClaim(
            id="application-1",
            claim_no="AP-DRAFT-IDEMPOTENT-001",
            employee_id=owner.id,
            employee_name=owner.name,
            department_name="市场部",
            expense_type="travel_application",
            reason="原申请事由",
            location="北京",
            amount=Decimal("500.00"),
            currency="CNY",
            invoice_count=0,
            occurred_at=datetime(2026, 7, 10, tzinfo=UTC),
            submitted_at=None,
            status="returned",
            approval_stage="退回补充",
            risk_flags_json=[],
        )
        db.add_all([owner, claim])
        db.commit()

        request = build_request(run_id="application-draft-idempotent")
        facts = build_facts(reason="同一份草稿")
        service = UserAgentService(db)
        learning_current_user = service._build_application_current_user(request)
        service._update_expense_application_record(
            request,
            facts,
            claim,
            submit=False,
            learning_current_user=learning_current_user,
        )
        service._update_expense_application_record(
            request,
            facts,
            claim,
            submit=False,
            learning_current_user=learning_current_user,
        )

        events = list(
            db.scalars(
                select(BusinessEvent).where(BusinessEvent.aggregate_id == claim.id)
            ).all()
        )
        assert len(events) == 1
        assert events[0].event_type == "claim_draft_updated"
        assert events[0].payload_json["previous_status"] == "returned"
        assert len(list(db.scalars(select(AIDecision)).all())) == 1
        assert len(list(db.scalars(select(AIDecisionFeedback)).all())) == 1
        assert len(list(db.scalars(select(WorkflowOutcome)).all())) == 1


def test_ai_application_draft_update_keeps_distinct_snapshots_in_same_run() -> None:
    session_factory = build_session_factory()
    with session_factory() as db:
        owner = Employee(
            id="owner-1",
            employee_no="E001",
            name="张三",
            email="owner@example.com",
        )
        claim = ExpenseClaim(
            id="application-1",
            claim_no="AP-DRAFT-VERSIONS-001",
            employee_id=owner.id,
            employee_name=owner.name,
            department_name="市场部",
            expense_type="travel_application",
            reason="原申请事由",
            location="北京",
            amount=Decimal("500.00"),
            currency="CNY",
            invoice_count=0,
            occurred_at=datetime(2026, 7, 10, tzinfo=UTC),
            submitted_at=None,
            status="returned",
            approval_stage="退回补充",
            risk_flags_json=[],
        )
        db.add_all([owner, claim])
        db.commit()

        request = build_request(run_id="application-draft-multi-version")
        service = UserAgentService(db)
        learning_current_user = service._build_application_current_user(request)
        service._update_expense_application_record(
            request,
            build_facts(reason="第一版草稿"),
            claim,
            submit=False,
            learning_current_user=learning_current_user,
        )
        service._update_expense_application_record(
            request,
            build_facts(reason="第二版草稿"),
            claim,
            submit=False,
            learning_current_user=learning_current_user,
        )

        events = list(
            db.scalars(
                select(BusinessEvent).where(BusinessEvent.aggregate_id == claim.id)
            ).all()
        )
        assert len(events) == 2
        assert {event.event_type for event in events} == {"claim_draft_updated"}
        assert len({event.idempotency_key for event in events}) == 2
        assert len(list(db.scalars(select(AIDecision)).all())) == 2


def test_ai_application_draft_records_explicit_field_correction() -> None:
    session_factory = build_session_factory()
    with session_factory() as db:
        owner = Employee(
            id="owner-1",
            employee_no="E001",
            name="张三",
            email="owner@example.com",
        )
        claim = ExpenseClaim(
            id="application-1",
            claim_no="AP-DRAFT-FEEDBACK-001",
            employee_id=owner.id,
            employee_name=owner.name,
            department_name="市场部",
            expense_type="travel_application",
            reason="原申请事由",
            location="北京",
            amount=Decimal("500.00"),
            currency="CNY",
            invoice_count=0,
            occurred_at=datetime(2026, 7, 10, tzinfo=UTC),
            submitted_at=None,
            status="returned",
            approval_stage="退回补充",
            risk_flags_json=[],
        )
        db.add_all([owner, claim])
        db.commit()

        service = UserAgentService(db)
        request = build_request(
            run_id="application-draft-feedback",
            changed_fields=[
                {
                    "fieldKey": "reason",
                    "suggestedValue": "客户拜访",
                    "finalValue": "客户端伪造值不会直接入账",
                }
            ],
        )
        service._update_expense_application_record(
            request,
            build_facts(reason="客户现场实施"),
            claim,
            submit=False,
            learning_current_user=service._build_application_current_user(request),
        )

        decision = db.scalar(select(AIDecision))
        feedback = db.scalar(select(AIDecisionFeedback))
        assert decision is not None
        assert decision.training_eligible is False
        assert decision.suggestion_json["field_keys"]
        assert decision.suggestion_json["value_fingerprint"].startswith("sha256:")
        assert feedback is not None
        assert feedback.feedback_type == "edited"
        assert feedback.verification_status == "client_observed"
        assert feedback.training_eligible is False
        assert feedback.changed_fields_json[0]["field_key"] == "reason"
        assert feedback.changed_fields_json[0]["suggested_value_fingerprint"].startswith(
            "sha256:"
        )
        assert "客户拜访" not in str(feedback.changed_fields_json)
        assert "客户现场实施" not in str(feedback.final_value_json)