import { describe, expect, it } from "bun:test";
import { historyChart, queryHistoryChart } from "../../src/product/history-chart.js";
describe("history chart", () => {
  it("keeps returned units, drops null samples and never manufactures missing history", () => {
    expect(() => historyChart({ series: [] }, "J1")).toThrow("NO_HISTORY_DATA");
    const chart = historyChart({ series: [{ element_id: "J1", metric: "pressure", source: "scada_raw", source_unit: "m", points: [{ time: "t1", value: null }, { time: "t2", value: 20 }] }] }, "J1");
    expect(chart.title).toContain("(m)");
    expect(chart.x_data).toEqual(["t2"]);
    expect(chart.series[0].data).toEqual([20]);
  });
});

const series = { element_id: "J1", metric: "pressure", source: "raw", source_unit: "m", device_id: "D1" };
it("continues past a null first page to use real later samples", async () => {
  const pages: number[][] = [];
  const chart = await queryHistoryChart("J1", async (limit, offset) => {
    pages.push([limit, offset]);
    return { content: [], structuredContent: { page: { limit, offset, has_more: offset === 0 }, truncated: offset === 0,
      data: { series: [{ ...series, points: offset === 0 ? Array.from({ length: limit }, (_, i) => ({ time: String(i), value: null })) : [{ time: "500", value: 25 }] }] } } };
  });
  expect(pages).toEqual([[500, 0], [500, 500]]);
  expect(chart.series[0].data).toEqual([25]);
});

it("stops within a fixed budget and distinguishes unread history from absent history", async () => {
  let calls = 0;
  await expect(queryHistoryChart("J1", async (limit, offset) => {
    calls++;
    return { content: [], structuredContent: { page: { limit, offset, has_more: true }, data: { series: [{ ...series, points: [{ time: String(offset), value: null }] }] } } };
  })).rejects.toThrow("仍有未读取数据");
  expect(calls).toBe(2);
});

it("shrinks oversized pages without skipping data or retrying unrelated failures", async () => {
  const calls: number[][] = [];
  const chart = await queryHistoryChart("J1", async (limit, offset) => {
    calls.push([limit, offset]);
    if (limit > 125) return { isError: true, content: [], structuredContent: { error: { code: "RESULT_TOO_LARGE" } } };
    return { content: [], structuredContent: { page: { limit, offset, has_more: offset === 0 }, data: {
      series: [{ ...series, points: [{ time: String(offset), value: offset === 0 ? null : 25 }] }],
    } } };
  });
  expect(calls).toEqual([[500, 0], [250, 0], [125, 0], [125, 125]]);
  expect(chart.series[0].data).toEqual([25]);
  let failures = 0;
  await expect(queryHistoryChart("J1", async () => {
    failures++;
    return { isError: true, content: [], structuredContent: { error: { code: "ACCESS_DENIED" } } };
  })).rejects.toThrow("历史查询暂不可用");
  expect(failures).toBe(1);
});

it("bounds displayed values and identifies a partial query", async () => {
  let calls = 0;
  const chart = await queryHistoryChart("J1", async (limit, offset) => {
    calls++;
    return { content: [], structuredContent: { page: { limit, offset, has_more: true },
      data: { series: [{ ...series, points: Array.from({ length: 100 }, (_, i) => ({ time: String(i), value: i })) }] } } };
  });
  expect(calls).toBe(1);
  expect(chart.series[0].data).toHaveLength(100);
  expect(chart.title).toContain("未覆盖完整时间窗");
});