import { describe, test } from "node:test";
import assert from "node:assert/strict";
import { mkdtempSync, rmSync, writeFileSync, existsSync, readFileSync } from "node:fs";
import { join } from "node:path";
import { tmpdir, homedir } from "node:os";

import {
  REGISTER_SCHEMA_VERSION,
  completeEdition,
  defaultRegisterPath,
  elapsedDays,
  emptyRegister,
  listEditions,
  loadRegister,
  saveRegister,
  upsertEdition,
} from "../src/register.js";
import type { EditionRegister } from "../src/types.js";

const tmp = () => mkdtempSync(join(tmpdir(), "editions-register-"));

const T0 = "2026-07-20T08:00:00.000Z";
const T1 = "2026-07-21T08:00:00.000Z";
const T2 = "2026-07-24T20:00:00.000Z";

function seed(): EditionRegister {
  return upsertEdition(
    emptyRegister(),
    {
      series: "seres",
      editionId: "05",
      title: "Da pipelinen brøt sammen",
      path: "/series/seres",
      currentPhase: "research",
      nextAction: "Step 2.5 — skeleton",
    },
    T0,
  ).register;
}

describe("register — store shape", () => {
  test("emptyRegister carries the schema version and no rows", () => {
    const reg = emptyRegister();
    assert.equal(reg.schemaVersion, REGISTER_SCHEMA_VERSION);
    assert.deepEqual(reg.editions, []);
  });

  test("a missing register file loads as an empty one — the first edition is not an error", () => {
    const dir = tmp();
    try {
      const reg = loadRegister(join(dir, "nope", "register.json"));
      assert.equal(reg.schemaVersion, REGISTER_SCHEMA_VERSION);
      assert.deepEqual(reg.editions, []);
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  });

  test("save creates the parent directory and round-trips the rows", () => {
    const dir = tmp();
    try {
      const path = join(dir, "editions", "register.json");
      saveRegister(path, seed());
      assert.ok(existsSync(path), "saveRegister must create the parent dir");
      assert.ok(readFileSync(path, "utf8").endsWith("\n"), "file must end with a newline");
      const back = loadRegister(path);
      assert.equal(back.editions.length, 1);
      assert.equal(back.editions[0].editionId, "05");
      assert.equal(back.editions[0].startedAt, T0);
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  });

  test("a malformed register degrades to empty rows instead of throwing", () => {
    const dir = tmp();
    try {
      const path = join(dir, "register.json");
      writeFileSync(path, JSON.stringify({ schemaVersion: 1, editions: "not-an-array" }), "utf8");
      assert.deepEqual(loadRegister(path).editions, []);
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  });
});

describe("register — upsert", () => {
  test("a new edition is created as active, with startedAt == updatedAt", () => {
    const { register, row, created } = upsertEdition(
      emptyRegister(),
      { series: "seres", editionId: "05", title: "T", path: "/p", currentPhase: "load-context" },
      T0,
    );
    assert.equal(created, true);
    assert.equal(register.editions.length, 1);
    assert.equal(row.status, "active");
    assert.equal(row.startedAt, T0);
    assert.equal(row.updatedAt, T0);
    assert.equal(row.completedAt, null);
  });

  test("the same (series, editionId) is updated in place — never duplicated", () => {
    const { register, row, created } = upsertEdition(
      seed(),
      { series: "seres", editionId: "05", title: "T", path: "/p", currentPhase: "skeleton-pitch" },
      T1,
    );
    assert.equal(created, false);
    assert.equal(register.editions.length, 1);
    assert.equal(row.currentPhase, "skeleton-pitch");
    assert.equal(row.startedAt, T0, "startedAt is the lead-time anchor — it must survive every update");
    assert.equal(row.updatedAt, T1);
  });

  test("omitted nextAction/slot/title are PRESERVED, not blanked", () => {
    const withSlot = upsertEdition(
      seed(),
      { series: "seres", editionId: "05", path: "/p", currentPhase: "draft", slot: "2026-07-28 08:30" },
      T1,
    ).register;
    const { row } = upsertEdition(
      withSlot,
      { series: "seres", editionId: "05", path: "/p", currentPhase: "consistency-quality" },
      T2,
    );
    assert.equal(row.slot, "2026-07-28 08:30");
    assert.equal(row.nextAction, "Step 2.5 — skeleton");
    assert.equal(row.title, "Da pipelinen brøt sammen");
  });

  test("supplied nextAction/slot overwrite the previous values", () => {
    const { row } = upsertEdition(
      seed(),
      {
        series: "seres",
        editionId: "05",
        path: "/p",
        currentPhase: "draft",
        nextAction: "Step 4 — consistency",
        slot: "2026-07-28 08:30",
      },
      T1,
    );
    assert.equal(row.nextAction, "Step 4 — consistency");
    assert.equal(row.slot, "2026-07-28 08:30");
  });

  test("two editions of the same series are two rows", () => {
    const { register } = upsertEdition(
      seed(),
      { series: "seres", editionId: "06", title: "Neste", path: "/series/seres", currentPhase: "load-context" },
      T1,
    );
    assert.equal(register.editions.length, 2);
  });

  test("the same edition number in a different series is a different row", () => {
    const { register } = upsertEdition(
      seed(),
      { series: "annen", editionId: "05", title: "Annen 05", path: "/series/annen", currentPhase: "load-context" },
      T1,
    );
    assert.equal(register.editions.length, 2);
    assert.equal(register.editions[1].series, "annen");
  });

  test("re-upserting a completed edition reactivates it — a pivot re-opens the row it already has", () => {
    const done = completeEdition(seed(), { series: "seres", editionId: "05" }, T1).register;
    const { register, row } = upsertEdition(
      done,
      { series: "seres", editionId: "05", path: "/p", currentPhase: "factcheck-sweep" },
      T2,
    );
    assert.equal(register.editions.length, 1);
    assert.equal(row.status, "active");
    assert.equal(row.completedAt, null);
    assert.equal(row.startedAt, T0);
  });
});

describe("register — complete", () => {
  test("complete stamps completedAt and flips the status", () => {
    const { register, row } = completeEdition(seed(), { series: "seres", editionId: "05" }, T1);
    assert.equal(row?.status, "complete");
    assert.equal(row?.completedAt, T1);
    assert.equal(register.editions[0].updatedAt, T1);
  });

  test("completing twice keeps the FIRST completedAt — lead time must not drift on a re-run", () => {
    const once = completeEdition(seed(), { series: "seres", editionId: "05" }, T1).register;
    const { row } = completeEdition(once, { series: "seres", editionId: "05" }, T2);
    assert.equal(row?.completedAt, T1);
  });

  test("completing an unknown edition returns null and leaves the register untouched", () => {
    const reg = seed();
    const { register, row } = completeEdition(reg, { series: "seres", editionId: "99" }, T1);
    assert.equal(row, null);
    assert.equal(register.editions[0].status, "active");
  });
});

describe("register — list", () => {
  function twoActiveOneDone(): EditionRegister {
    let reg = seed();
    reg = upsertEdition(
      reg,
      { series: "annen", editionId: "02", title: "A", path: "/p", currentPhase: "draft" },
      T1,
    ).register;
    reg = upsertEdition(
      reg,
      { series: "seres", editionId: "04", title: "Eldre", path: "/p", currentPhase: "scheduling" },
      T1,
    ).register;
    return completeEdition(reg, { series: "seres", editionId: "04" }, T2).register;
  }

  test("list shows only the editions in flight by default", () => {
    const rows = listEditions(twoActiveOneDone());
    assert.equal(rows.length, 2);
    assert.ok(rows.every((r) => r.status === "active"));
  });

  test("includeComplete lists the whole history", () => {
    assert.equal(listEditions(twoActiveOneDone(), { includeComplete: true }).length, 3);
  });

  test("ordering is deterministic — active first, then series, then edition id", () => {
    const rows = listEditions(twoActiveOneDone(), { includeComplete: true });
    assert.deepEqual(
      rows.map((r) => `${r.status}:${r.series}/${r.editionId}`),
      ["active:annen/02", "active:seres/05", "complete:seres/04"],
    );
  });
});

describe("register — lead time", () => {
  test("elapsedDays measures the span between two ISO stamps", () => {
    assert.equal(elapsedDays(T0, T1), 1);
    assert.equal(elapsedDays(T0, T0), 0);
  });

  test("elapsedDays keeps sub-day precision — a two-editions-a-week cadence is measured in hours", () => {
    assert.equal(elapsedDays("2026-07-20T00:00:00.000Z", "2026-07-20T12:00:00.000Z"), 0.5);
  });

  test("an unparseable stamp yields null rather than NaN", () => {
    assert.equal(elapsedDays("ikke-en-dato", T1), null);
  });
});

describe("register — default path (M0 data-path convention)", () => {
  test("LINKEDIN_STUDIO_DATA relocates the register", () => {
    const prev = process.env.LINKEDIN_STUDIO_DATA;
    process.env.LINKEDIN_STUDIO_DATA = "/scratch/data";
    try {
      assert.equal(defaultRegisterPath(), join("/scratch/data", "editions", "register.json"));
    } finally {
      if (prev === undefined) delete process.env.LINKEDIN_STUDIO_DATA;
      else process.env.LINKEDIN_STUDIO_DATA = prev;
    }
  });

  test("without the env-var it falls back to the per-user data dir", () => {
    const prev = process.env.LINKEDIN_STUDIO_DATA;
    delete process.env.LINKEDIN_STUDIO_DATA;
    try {
      assert.equal(
        defaultRegisterPath(),
        join(homedir(), ".claude", "linkedin-studio", "editions", "register.json"),
      );
    } finally {
      if (prev !== undefined) process.env.LINKEDIN_STUDIO_DATA = prev;
    }
  });
});
