import { describe, expect, it, vi } from "vitest";

import { collectCommitHistory, COMMIT_HISTORY_DAYS, COMMIT_HISTORY_TIME_ZONE, parseArgs, renderCsv, renderSvg, toBerlinDateKey } from "./commit-history.mjs";

const TIP = "dddddddddddddddddddddddddddddddddddddddd";

function fixtureHistory() {
  const rows = Array.from({ length: COMMIT_HISTORY_DAYS }, (_, index) => ({
    count: index === 57 ? 151 : index === 59 ? 75 : index % 9,
    date: new Date(Date.UTC(2026, 5, 3 + index, 12)).toISOString().slice(0, 10),
  }));
  return {
    days: COMMIT_HISTORY_DAYS,
    endDate: "2026-08-01",
    resolvedRef: TIP,
    rows,
    startDate: "2026-06-03",
    tipTimestamp: "2026-08-01T14:17:15+02:00",
  };
}

describe("commit-history", () => {
  it("defaults to a 60-day Berlin calendar window", () => {
    expect(parseArgs([])).toEqual({
      days: 60,
      label: "origin/main",
      outputDir: "docs/metrics",
      ref: "origin/main",
    });
    expect(COMMIT_HISTORY_TIME_ZONE).toBe("Europe/Berlin");
    expect(() => parseArgs(["--days", "0"])).toThrow("--days must be an integer between 1 and 365");
  });

  it("groups offsets by their Berlin calendar date", () => {
    expect(toBerlinDateKey("2026-07-31T23:30:00Z")).toBe("2026-08-01");
    expect(toBerlinDateKey("2026-10-25T00:30:00Z")).toBe("2026-10-25");
  });

  it("counts every reachable commit and preserves zero-commit days", () => {
    const calls = [];
    const runGit = vi.fn((args) => {
      calls.push(args);
      if (args[0] === "rev-parse") return `${TIP}\n`;
      if (args[0] === "show") return "2026-08-01T14:17:15+02:00\n";
      if (args[0] === "log") {
        return [
          `${TIP}\t2026-08-01T14:17:15+02:00`,
          `cccccccccccccccccccccccccccccccccccccccc\t2026-07-31T23:30:00Z`,
          `bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\t2026-07-30T18:00:00+02:00`,
          `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\t2026-07-01T10:00:00+02:00`,
        ].join("\n");
      }
      throw new Error(`Unexpected Git call: ${args.join(" ")}`);
    });

    const history = collectCommitHistory("HEAD", { days: 3, runGit });

    expect(history.rows).toEqual([
      { count: 1, date: "2026-07-30" },
      { count: 0, date: "2026-07-31" },
      { count: 2, date: "2026-08-01" },
    ]);
    const logCall = calls.find((args) => args[0] === "log");
    expect(logCall).not.toContain("--first-parent");
    expect(logCall).toContain(TIP);
  });

  it("renders deterministic CSV metadata and the approved SVG metrics", () => {
    const history = fixtureHistory();
    const csv = renderCsv(history, "origin/main");
    const svg = renderSvg(history, "origin/main");

    expect(renderCsv(history, "origin/main")).toBe(csv);
    expect(renderSvg(history, "origin/main")).toBe(svg);
    expect(csv).toContain("# window_days=60");
    expect(csv).toContain("# timezone=Europe/Berlin");
    expect(csv).toContain("2026-08-01,75");
    expect(svg).toContain("HiveGrid · Commit-Aktivität");
    expect(svg).toContain("Ø PRO TAG · 60 TAGE");
    expect(svg).toContain("PEAK · 30.07.");
    expect(svg).toContain(">151 Commits<");
    expect(svg).toContain(">75 Commits<");
    expect(svg).toContain("7-Tage-Durchschnitt");
  });
});