/**
 * @file Tests for syncDefaultProjects — the incremental, mtime-fingerprinted
 * sync of ~/.claude/projects that backs the background session-sync poll
 * (server/index.js startSessionSync). Verifies that a project added after the
 * one-time backfill is discovered, that an unchanged sweep does no work, and
 * that a grown session is reported as an update (not a new session).
 *
 * Runs in its own process (node --test isolates files), so pointing CLAUDE_HOME
 * and DASHBOARD_DB_PATH at temp locations before requiring the modules gives a
 * clean, isolated projects dir + database without touching the real ones.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { describe, it, before, after } = require("node:test");
const assert = require("node:assert/strict");
const path = require("path");
const fs = require("fs");
const os = require("os");

const TMP_HOME = fs.mkdtempSync(path.join(os.tmpdir(), "agenthub-sync-home-"));
process.env.CLAUDE_HOME = TMP_HOME;
process.env.DASHBOARD_DB_PATH = path.join(TMP_HOME, "dashboard.db");
process.env.DASHBOARD_DATA_DIR = path.join(TMP_HOME, "data");

const PROJECTS_DIR = path.join(TMP_HOME, "projects");
fs.mkdirSync(PROJECTS_DIR, { recursive: true });

const dbModule = require("../db");
const { syncDefaultProjects } = require("../../scripts/import-history");

const SESSION_NEW = "11111111-aaaa-4aaa-8aaa-111111111111";

function fixtureLines(sessionId, cwd, extra = []) {
  return [
    {
      type: "user",
      cwd,
      sessionId,
      timestamp: "2026-04-18T12:00:00.000Z",
      message: { content: "hi" },
    },
    {
      type: "assistant",
      cwd,
      sessionId,
      timestamp: "2026-04-18T12:00:00.000Z",
      message: {
        model: "claude-opus-4-8",
        content: [{ type: "text", text: "ok" }],
        usage: { input_tokens: 10, output_tokens: 5 },
      },
    },
    ...extra,
  ];
}

function writeSession(projName, sessionId, lines) {
  const projDir = path.join(PROJECTS_DIR, projName);
  fs.mkdirSync(projDir, { recursive: true });
  const file = path.join(projDir, `${sessionId}.jsonl`);
  fs.writeFileSync(file, lines.map((o) => JSON.stringify(o)).join("\n") + "\n");
  return file;
}

after(() => {
  if (dbModule.db) dbModule.db.close();
  fs.rmSync(TMP_HOME, { recursive: true, force: true });
});

describe("syncDefaultProjects", () => {
  const mtimeCache = new Map();

  it("discovers a newly added project and reports it as a new session", async () => {
    writeSession("-work", SESSION_NEW, fixtureLines(SESSION_NEW, "/work"));

    const { changed } = await syncDefaultProjects(dbModule, { mtimeCache });

    const hit = changed.find((c) => c.sessionId === SESSION_NEW);
    assert.ok(hit, "the new session should be reported");
    assert.equal(hit.isNew, true, "a session not yet in the DB is new");
    assert.ok(dbModule.stmts.getSession.get(SESSION_NEW), "session should be imported into the DB");
  });

  it("does no work on a second sweep when nothing changed", async () => {
    const { changed } = await syncDefaultProjects(dbModule, { mtimeCache });
    assert.equal(changed.length, 0, "an unchanged sweep reports no sessions");
  });

  it("reports a grown session as an update, not a new session", async () => {
    const file = writeSession(
      "-work",
      SESSION_NEW,
      fixtureLines(SESSION_NEW, "/work", [
        {
          type: "assistant",
          cwd: "/work",
          sessionId: SESSION_NEW,
          timestamp: "2026-04-18T12:05:00.000Z",
          message: {
            model: "claude-opus-4-8",
            content: [{ type: "text", text: "more" }],
            usage: { input_tokens: 7, output_tokens: 3 },
          },
        },
      ])
    );
    // Force a clearly-later mtime so the sweep treats the file as changed.
    const future = Date.now() / 1000 + 60;
    fs.utimesSync(file, future, future);

    const { changed } = await syncDefaultProjects(dbModule, { mtimeCache });

    const hit = changed.find((c) => c.sessionId === SESSION_NEW);
    assert.ok(hit, "the grown session should be reported");
    assert.equal(hit.isNew, false, "an already-imported session counts as an update");
  });

  it("never throws when the projects dir is empty of sessions", async () => {
    const emptyCache = new Map();
    const emptyProj = path.join(PROJECTS_DIR, "-empty");
    fs.mkdirSync(emptyProj, { recursive: true });
    const { changed } = await syncDefaultProjects(dbModule, { mtimeCache: emptyCache });
    // -empty contributes nothing; the pre-existing -work session is brand new to
    // this fresh cache, so it is reported once — but the empty dir must not error.
    assert.ok(Array.isArray(changed));
  });

  it("skips re-parsing an already-imported, unchanged session even on a cold cache", async () => {
    // Models the immediate sweep after every server restart: mtimeCache is
    // empty, but the DB already holds these sessions. An unchanged file must NOT
    // be re-parsed/re-reported (the cold-restart fast path), so a large history
    // doesn't re-parse every transcript on boot.
    const SESSION_STABLE = "22222222-bbbb-4bbb-8bbb-222222222222";
    writeSession("-stable", SESSION_STABLE, fixtureLines(SESSION_STABLE, "/stable"));

    // First sweep (cold cache) imports it.
    const first = await syncDefaultProjects(dbModule, { mtimeCache: new Map() });
    assert.ok(
      first.changed.find((c) => c.sessionId === SESSION_STABLE && c.isNew),
      "first sweep imports the new session"
    );

    // Second sweep with a FRESH (cold) cache: the file is unchanged and the row
    // exists, so the gate skips it — nothing reported for SESSION_STABLE.
    const second = await syncDefaultProjects(dbModule, { mtimeCache: new Map() });
    assert.equal(
      second.changed.find((c) => c.sessionId === SESSION_STABLE),
      undefined,
      "an unchanged, already-imported session is skipped on a cold cache"
    );
  });
});

describe("syncDefaultProjects — sessions hooks are feeding", () => {
  const SNAP_DIR = path.join(process.env.DASHBOARD_DATA_DIR, "transcripts");
  const more = (sessionId, cwd, ts) => ({
    type: "assistant",
    cwd,
    sessionId,
    timestamp: ts,
    message: {
      model: "claude-opus-4-8",
      content: [{ type: "text", text: "later" }],
      usage: { input_tokens: 3, output_tokens: 2 },
    },
  });
  const bumpMtime = (file) => {
    const future = Date.now() / 1000 + 120;
    fs.utimesSync(file, future, future);
  };
  const ageSession = (id) =>
    dbModule.db
      .prepare("UPDATE sessions SET updated_at = ? WHERE id = ?")
      .run(new Date(Date.now() - 10 * 60_000).toISOString(), id);

  it("defers a live hook-fed imported session, then catches it up once quiet", async () => {
    const ID = "33333333-cccc-4ccc-8ccc-333333333333";
    const cache = new Map();
    const file = writeSession("-live", ID, fixtureLines(ID, "/live"));
    await syncDefaultProjects(dbModule, { mtimeCache: cache });
    assert.ok(dbModule.stmts.getSession.get(ID), "imported first");

    // A hook arrives: its event is the newest, and it touches the session.
    dbModule.stmts.insertEvent.run(ID, `${ID}-main`, "PreToolUse", "Bash", "hook", "{}");
    dbModule.stmts.touchSession.run(ID);
    writeSession(
      "-live",
      ID,
      fixtureLines(ID, "/live", [more(ID, "/live", "2026-04-18T12:09:00.000Z")])
    );
    bumpMtime(file);

    const live = await syncDefaultProjects(dbModule, { mtimeCache: cache });
    assert.equal(
      live.changed.find((c) => c.sessionId === ID),
      undefined,
      "deferred while live"
    );
    assert.equal(cache.get(file), -1, "kept in the cache so the watcher ignores its appends");

    ageSession(ID); // the hooks went quiet
    const quiet = await syncDefaultProjects(dbModule, { mtimeCache: cache });
    assert.ok(
      quiet.changed.find((c) => c.sessionId === ID && !c.isNew),
      "caught up once quiet"
    );
    assert.notEqual(cache.get(file), -1);
  });

  it("never re-parses a hook-created session, only refreshes its snapshot once quiet", async () => {
    const ID = "44444444-dddd-4ddd-8ddd-444444444444";
    dbModule.stmts.insertSession.run(ID, "hooked", "active", "/hooked", null, null);
    dbModule.stmts.insertEvent.run(ID, null, "SessionStart", null, "hook", "{}");
    const file = writeSession("-hooked", ID, fixtureLines(ID, "/hooked"));
    bumpMtime(file);
    const snap = path.join(SNAP_DIR, `${ID}.jsonl`);
    const cache = new Map();

    await syncDefaultProjects(dbModule, { mtimeCache: cache });
    assert.equal(fs.existsSync(snap), false, "no snapshot copy while hooks are live");

    ageSession(ID);
    const before = dbModule.db.prepare("SELECT COUNT(*) AS n FROM events WHERE session_id = ?");
    const n0 = before.get(ID).n;
    const r = await syncDefaultProjects(dbModule, { mtimeCache: cache });
    assert.equal(
      r.changed.find((c) => c.sessionId === ID),
      undefined,
      "nothing imported"
    );
    assert.equal(before.get(ID).n, n0, "no events written for a hook-created session");
    assert.equal(fs.existsSync(snap), true, "snapshot taken once quiet");
  });
});