from copy import deepcopy
from datetime import datetime, timedelta, timezone

import pytest

from app.domain.domain_errors import DomainError
from app.domain.schemas.operational_task import TaskSafeChart
from app.services.time_comparison_chart import validate_time_comparison_chart


def comparison_chart(start="2026-07-16T05:00:00+08:00", interval=15):
    times = [datetime.fromisoformat(start) + timedelta(minutes=index * interval) for index in range(13)]
    return {"title": "七天同期对比", "chart_type": "time_comparison",
            "x_data": [at.strftime("%H:%M") for at in times], "series": [
                {"name": "当前", "type": "line", "data": [25.] * 13,
                 "sample_times": [at.isoformat() for at in times]},
                *[{"name": f"前{day}天", "type": "scatter", "data": [None] * 10 + [26.] * 3,
                   "sample_times": [None] * 10 + [(at - timedelta(days=day)).isoformat() for at in times[10:]]}
                  for day in range(1, 8)],
            ]}


@pytest.mark.parametrize("start,interval", [
    ("2026-07-16T05:00:00+08:00", 15),
    ("2026-07-16T23:00:00+08:00", 15),
    ("2026-07-16T05:00:00+08:00", 5),
])
def test_same_time_comparison_preserves_seven_sparse_days_and_sampling_intervals(start, interval):
    chart = comparison_chart(start, interval)
    # A missing current observation is still a real empty slot.
    chart["series"][0]["data"][11] = None
    chart["series"][0]["sample_times"][11] = None
    # UTC and local-offset spellings refer to the same real historical instant.
    chart["series"][1]["sample_times"][12] = (
        datetime.fromisoformat(chart["series"][1]["sample_times"][12])
        .astimezone(timezone.utc).isoformat().replace("+00:00", "Z")
    )
    before = deepcopy(chart)
    validate_time_comparison_chart(TaskSafeChart.model_validate(chart).model_dump(mode="json"))
    assert chart == before


@pytest.mark.parametrize("defect", [
    "appended_history", "duplicate_slots", "wrong_slot", "missing_times", "missing_point_time",
    "mixed_dates", "same_day", "future_day", "bar_series", "only_line", "no_current_observations",
])
def test_special_comparison_rejects_misleading_projections(defect):
    chart = comparison_chart()
    history = chart["series"][1]
    if defect == "appended_history":
        chart["x_data"] = [f"07-16 {slot}" for slot in chart["x_data"]] + ["07-15 07:30", "07-15 07:45", "07-15 08:00"]
        for series in chart["series"]:
            series["data"] += [None] * 3
            series["sample_times"] += [None] * 3
    elif defect == "duplicate_slots":
        chart["x_data"][11] = chart["x_data"][10]
    elif defect == "wrong_slot":
        history["sample_times"][10] = "2026-07-15T07:45:00+08:00"
    elif defect == "missing_times":
        del history["sample_times"]
    elif defect == "missing_point_time":
        history["sample_times"][10] = None
    elif defect == "mixed_dates":
        history["sample_times"][10] = "2026-07-14T07:30:00+08:00"
    elif defect in {"same_day", "future_day"}:
        day = 16 if defect == "same_day" else 17
        history["sample_times"] = [at.replace("07-15", f"07-{day}") if at else None for at in history["sample_times"]]
    elif defect == "bar_series":
        history["type"] = "bar"
    elif defect == "only_line":
        chart["series"] = chart["series"][:1]
    elif defect == "no_current_observations":
        chart["series"][0]["data"] = chart["series"][0]["sample_times"] = [None] * 13
    with pytest.raises(DomainError) as error:
        validate_time_comparison_chart(TaskSafeChart.model_validate(chart).model_dump(mode="json"))
    assert error.value.code == "TIME_COMPARISON_INVALID"


def test_ordinary_charts_skip_comparison_validation_and_old_mixed_charts_remain_readable():
    chart = {"title": "普通趋势", "chart_type": "line", "x_data": ["07-16 08:00"],
             "series": [{"name": "当前", "data": [25.]}]}
    validate_time_comparison_chart(chart)
    chart["chart_type"] = "bar"
    validate_time_comparison_chart(chart)
    chart["chart_type"] = "line"
    chart["series"].append({"name": "旧版散点", "type": "scatter", "data": [26.]})
    assert TaskSafeChart.model_validate(chart).model_dump(mode="json") == chart
    with pytest.raises(DomainError, match="time_comparison"):
        validate_time_comparison_chart(chart)


@pytest.mark.parametrize("labels,times", [
    (["07:45"], ["9999-12-31T23:45:00Z"]),
    (["08:00"], ["0001-01-01T00:00:00+23:59"]),
    (["23:45", "00:15"], [None, "0001-01-01T00:15:00+08:00"]),
])
def test_calendar_range_overflow_returns_a_domain_rejection(labels, times):
    chart = {"title": "日期边界", "chart_type": "time_comparison", "x_data": labels, "series": [
        {"name": "当前", "type": "line", "data": [1. if at else None for at in times], "sample_times": times},
        {"name": "历史缺测", "type": "scatter", "data": [None] * len(labels), "sample_times": [None] * len(labels)},
    ]}
    with pytest.raises(DomainError, match="日期范围") as error:
        validate_time_comparison_chart(TaskSafeChart.model_validate(chart).model_dump(mode="json"))
    assert error.value.code == "TIME_COMPARISON_INVALID"
    assert error.value.status == 422