from __future__ import annotations

import csv
import json
from decimal import Decimal
from io import StringIO
from uuid import uuid4

from app.models.ltv_history import LtvHistoryRepository
from app.services.ltv_history import LtvHistoryService


def test_ltv_history_repository_persists_structured_workspace_snapshots(tmp_path) -> None:
    workspace_id = str(uuid4())
    service = LtvHistoryService(repository=LtvHistoryRepository(base_path=tmp_path / "workspaces"))

    service.record_workspace_snapshot(
        workspace_id,
        {
            "ltv_ratio": Decimal("0.74"),
            "margin_call_ltv": Decimal("0.80"),
            "loan_amount": Decimal("222000"),
            "gold_value": Decimal("300000"),
            "spot_price": Decimal("4041.9"),
            "quote_source": "yfinance",
            "quote_updated_at": "2026-03-20T00:00:00+00:00",
        },
    )

    payload = json.loads((tmp_path / "workspaces" / workspace_id / "ltv_history.json").read_text())

    assert payload[0]["ltv_ratio"] == {"value": "0.74", "unit": "ratio"}
    assert payload[0]["margin_threshold"] == {"value": "0.80", "unit": "ratio"}
    assert payload[0]["spot_price"] == {"value": "4041.9", "currency": "USD", "per_weight_unit": "ozt"}
    assert payload[0]["loan_amount"] == {"value": "222000", "currency": "USD"}
    assert payload[0]["collateral_value"] == {"value": "300000", "currency": "USD"}


def test_ltv_history_service_replaces_same_day_snapshot_and_builds_range_models(tmp_path) -> None:
    workspace_id = str(uuid4())
    service = LtvHistoryService(repository=LtvHistoryRepository(base_path=tmp_path / "workspaces"))

    service.record_workspace_snapshot(
        workspace_id,
        {
            "ltv_ratio": Decimal("0.70"),
            "margin_call_ltv": Decimal("0.80"),
            "loan_amount": Decimal("210000"),
            "gold_value": Decimal("300000"),
            "spot_price": Decimal("4100"),
            "quote_source": "seed",
            "quote_updated_at": "2026-01-01T00:00:00+00:00",
        },
    )
    service.record_workspace_snapshot(
        workspace_id,
        {
            "ltv_ratio": Decimal("0.75"),
            "margin_call_ltv": Decimal("0.80"),
            "loan_amount": Decimal("225000"),
            "gold_value": Decimal("300000"),
            "spot_price": Decimal("4000"),
            "quote_source": "seed",
            "quote_updated_at": "2026-03-15T00:00:00+00:00",
        },
    )
    service.record_workspace_snapshot(
        workspace_id,
        {
            "ltv_ratio": Decimal("0.76"),
            "margin_call_ltv": Decimal("0.80"),
            "loan_amount": Decimal("228000"),
            "gold_value": Decimal("300000"),
            "spot_price": Decimal("3990"),
            "quote_source": "seed",
            "quote_updated_at": "2026-03-15T12:00:00+00:00",
        },
    )
    snapshots = service.record_workspace_snapshot(
        workspace_id,
        {
            "ltv_ratio": Decimal("0.78"),
            "margin_call_ltv": Decimal("0.80"),
            "loan_amount": Decimal("234000"),
            "gold_value": Decimal("300000"),
            "spot_price": Decimal("3950"),
            "quote_source": "seed",
            "quote_updated_at": "2026-03-20T00:00:00+00:00",
        },
    )

    assert [snapshot.snapshot_date for snapshot in snapshots] == ["2026-01-01", "2026-03-15", "2026-03-20"]
    assert str(snapshots[1].ltv_ratio) == "0.76"

    chart_7 = service.chart_model(snapshots, days=7, current_margin_threshold=Decimal("0.80"))
    chart_30 = service.chart_model(snapshots, days=30, current_margin_threshold=Decimal("0.80"))
    chart_90 = service.chart_model(snapshots, days=90, current_margin_threshold=Decimal("0.80"))

    assert chart_7.title == "7 Day"
    assert chart_7.labels == ("2026-03-15", "2026-03-20")
    assert chart_7.ltv_values == (76.0, 78.0)
    assert chart_7.threshold_values == (80.0, 80.0)
    assert chart_30.labels == ("2026-03-15", "2026-03-20")
    assert chart_30.threshold_values == (80.0, 80.0)
    assert chart_90.labels == ("2026-01-01", "2026-03-15", "2026-03-20")


def test_ltv_history_repository_rejects_invalid_numeric_and_date_payloads(tmp_path) -> None:
    workspace_id = str(uuid4())
    repo = LtvHistoryRepository(base_path=tmp_path / "workspaces")
    history_path = tmp_path / "workspaces" / workspace_id / "ltv_history.json"
    history_path.parent.mkdir(parents=True, exist_ok=True)
    history_path.write_text(
        json.dumps(
            [
                {
                    "snapshot_date": "not-a-date",
                    "captured_at": "2026-03-20T00:00:00+00:00",
                    "ltv_ratio": {"value": "bad", "unit": "ratio"},
                    "margin_threshold": {"value": "0.80", "unit": "ratio"},
                    "loan_amount": {"value": "234000", "currency": "USD"},
                    "collateral_value": {"value": "300000", "currency": "USD"},
                    "spot_price": {"value": "3950", "currency": "USD", "per_weight_unit": "ozt"},
                    "source": "seed",
                }
            ]
        )
    )

    from app.models.ltv_history import LtvHistoryLoadError

    try:
        repo.load(workspace_id)
    except LtvHistoryLoadError as exc:
        assert "invalid" in str(exc)
    else:
        raise AssertionError("Expected invalid LTV history payload to raise LtvHistoryLoadError")


def test_ltv_history_service_exports_csv(tmp_path) -> None:
    workspace_id = str(uuid4())
    service = LtvHistoryService(repository=LtvHistoryRepository(base_path=tmp_path / "workspaces"))

    snapshots = service.record_workspace_snapshot(
        workspace_id,
        {
            "ltv_ratio": Decimal("0.78"),
            "margin_call_ltv": Decimal("0.80"),
            "loan_amount": Decimal("234000"),
            "gold_value": Decimal("300000"),
            "spot_price": Decimal("3950"),
            "quote_source": "seed",
            "quote_updated_at": "2026-03-20T00:00:00+00:00",
        },
    )

    csv_content = service.export_csv(snapshots)
    rows = list(csv.DictReader(StringIO(csv_content)))

    assert rows == [
        {
            "snapshot_date": "2026-03-20",
            "captured_at": "2026-03-20T00:00:00+00:00",
            "ltv_ratio_pct": "78.0",
            "margin_threshold_pct": "80.0",
            "loan_amount_usd": "234000",
            "collateral_value_usd": "300000",
            "spot_price_usd_per_ozt": "3950",
            "source": "seed",
        }
    ]