from __future__ import annotations

from datetime import UTC, date, datetime
from decimal import Decimal

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

from app.api.deps import CurrentUserContext
from app.db.base import Base
from app.models.financial_record import ExpenseClaim, ExpenseClaimItem
from app.schemas.ocr import OcrRecognizeBatchRead, OcrRecognizeDocumentRead
from app.schemas.reimbursement import ExpenseClaimItemCreate, ExpenseClaimItemUpdate
from app.services.expense_claims import ExpenseClaimService
from app.services.ocr import OcrService


def build_claim(*, expense_type: str, location: str) -> ExpenseClaim:
    claim = ExpenseClaim(
        id="claim-1",
        claim_no="EXP-202605-001",
        employee_id="emp-1",
        employee_name="张三",
        department_id="dept-1",
        department_name="市场部",
        project_code=None,
        expense_type=expense_type,
        reason="费用报销",
        location=location,
        amount=Decimal("88.00"),
        currency="CNY",
        invoice_count=1,
        occurred_at=datetime(2026, 5, 13, tzinfo=UTC),
        submitted_at=None,
        status="draft",
        approval_stage="待提交",
        risk_flags_json=[],
    )
    claim.items = [
        ExpenseClaimItem(
            id="item-1",
            claim_id="claim-1",
            item_date=date(2026, 5, 13),
            item_type=expense_type,
            item_reason="费用报销",
            item_location=location,
            item_amount=Decimal("88.00"),
            invoice_id="invoice-1",
        )
    ]
    return claim


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


def test_validate_claim_for_submission_allows_office_claim_without_location() -> None:
    service = ExpenseClaimService.__new__(ExpenseClaimService)
    claim = build_claim(expense_type="office", location="待补充")

    issues = service._validate_claim_for_submission(claim)

    assert "业务地点未完善" not in issues
    assert not any("缺少地点" in item for item in issues)


def test_validate_claim_for_submission_still_requires_location_for_travel_claim() -> None:
    service = ExpenseClaimService.__new__(ExpenseClaimService)
    claim = build_claim(expense_type="travel", location="待补充")

    issues = service._validate_claim_for_submission(claim)

    assert "业务地点未完善" in issues
    assert any("缺少地点" in item for item in issues)


def test_resolve_expense_type_maps_office_supplies_review_value_to_office() -> None:
    expense_type = ExpenseClaimService._resolve_expense_type(
        [],
        context_json={
            "review_form_values": {
                "expense_type": "办公用品"
            }
        },
    )

    assert expense_type == "office"


def test_create_claim_item_adds_blank_draft_row_without_forcing_attachment() -> None:
    current_user = CurrentUserContext(
        username="emp-1",
        name="张三",
        role_codes=[],
        is_admin=False,
    )

    with build_session() as db:
        claim = build_claim(expense_type="office", location="深圳南山")
        db.add(claim)
        db.commit()

        service = ExpenseClaimService(db)
        updated = service.create_claim_item(
            claim_id=claim.id,
            payload=ExpenseClaimItemCreate(),
            current_user=current_user,
        )

        assert updated is not None
        assert len(updated.items) == 2
        assert updated.amount == Decimal("88.00")
        assert updated.invoice_count == 1

        new_item = next(item for item in updated.items if item.id != "item-1")
        assert new_item.item_type == "office"
        assert new_item.item_reason == ""
        assert new_item.item_location == ""
        assert new_item.item_amount == Decimal("0.00")
        assert new_item.invoice_id is None


def test_update_claim_item_reanalyzes_existing_attachment(monkeypatch, tmp_path) -> None:
    current_user = CurrentUserContext(
        username="emp-1",
        name="张三",
        role_codes=[],
        is_admin=False,
    )

    def fake_recognize(
        self,
        files: list[tuple[str, bytes, str | None]],
    ) -> OcrRecognizeBatchRead:
        return OcrRecognizeBatchRead(
            total_file_count=1,
            success_count=1,
            documents=[
                OcrRecognizeDocumentRead(
                    filename="office-note.png",
                    media_type="image/png",
                    text="办公用品发票 金额88元 2026-05-13",
                    summary="识别到办公用品发票，金额 88 元。",
                    avg_score=0.98,
                    line_count=1,
                    page_count=1,
                    warnings=[],
                )
            ],
        )

    monkeypatch.setattr(OcrService, "recognize_files", fake_recognize)
    monkeypatch.setattr(ExpenseClaimService, "_get_attachment_storage_root", lambda self: tmp_path)

    with build_session() as db:
        claim = build_claim(expense_type="office", location="深圳南山")
        claim.invoice_count = 0
        claim.items[0].invoice_id = None
        claim.items[0].item_reason = "办公用品采购"
        db.add(claim)
        db.commit()

        service = ExpenseClaimService(db)
        service.upload_claim_item_attachment(
            claim_id=claim.id,
            item_id=claim.items[0].id,
            filename="office-note.png",
            content=b"fake-image-bytes",
            media_type="image/png",
            current_user=current_user,
        )

        uploaded_meta = service.get_claim_item_attachment_meta(
            claim_id=claim.id,
            item_id=claim.items[0].id,
            current_user=current_user,
        )
        assert uploaded_meta is not None
        assert uploaded_meta["analysis"]["severity"] == "pass"

        updated = service.update_claim_item(
            claim_id=claim.id,
            item_id=claim.items[0].id,
            payload=ExpenseClaimItemUpdate(
                item_type="transport",
                item_reason="打车报销",
            ),
            current_user=current_user,
        )

        assert updated is not None
        assert any(flag.get("source") == "attachment_analysis" for flag in updated.risk_flags_json)

        refreshed_meta = service.get_claim_item_attachment_meta(
            claim_id=claim.id,
            item_id=claim.items[0].id,
            current_user=current_user,
        )
        assert refreshed_meta is not None
        assert refreshed_meta["analysis"]["severity"] == "medium"
        assert any("用途字段" in point for point in refreshed_meta["analysis"]["points"])


def test_delete_claim_item_removes_row_and_attachment_files(monkeypatch, tmp_path) -> None:
    current_user = CurrentUserContext(
        username="emp-1",
        name="张三",
        role_codes=[],
        is_admin=False,
    )

    def fake_recognize(
        self,
        files: list[tuple[str, bytes, str | None]],
    ) -> OcrRecognizeBatchRead:
        return OcrRecognizeBatchRead(
            total_file_count=1,
            success_count=1,
            documents=[
                OcrRecognizeDocumentRead(
                    filename="office-note.png",
                    media_type="image/png",
                    text="办公用品发票 金额88元 2026-05-13",
                    summary="识别到办公用品发票，金额 88 元。",
                    avg_score=0.98,
                    line_count=1,
                    page_count=1,
                    warnings=[],
                )
            ],
        )

    monkeypatch.setattr(OcrService, "recognize_files", fake_recognize)
    monkeypatch.setattr(ExpenseClaimService, "_get_attachment_storage_root", lambda self: tmp_path)

    with build_session() as db:
        claim = build_claim(expense_type="office", location="深圳南山")
        claim.invoice_count = 0
        claim.items[0].invoice_id = None
        claim.items[0].item_reason = "办公用品采购"
        db.add(claim)
        db.commit()

        service = ExpenseClaimService(db)
        upload_payload = service.upload_claim_item_attachment(
            claim_id=claim.id,
            item_id=claim.items[0].id,
            filename="office-note.png",
            content=b"fake-image-bytes",
            media_type="image/png",
            current_user=current_user,
        )

        assert upload_payload is not None
        attachment_root = tmp_path / claim.id / claim.items[0].id
        assert attachment_root.exists()

        delete_payload = service.delete_claim_item(
            claim_id=claim.id,
            item_id=claim.items[0].id,
            current_user=current_user,
        )

        assert delete_payload is not None
        assert delete_payload["claim_id"] == claim.id
        refreshed_claim = service.get_claim(claim.id, current_user)
        assert refreshed_claim is not None
        assert refreshed_claim.items == []
        assert refreshed_claim.amount == Decimal("0.00")
        assert refreshed_claim.invoice_count == 0
        assert not attachment_root.exists()