/**
 * @file tmux.test.js
 * @description Unit tests for the tmux command wrapper. Injects a fake exec
 * implementation so the suite never shells out to a real `tmux` binary (CI
 * has none installed).
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */
const { describe, it, beforeEach } = require("node:test");
const assert = require("node:assert/strict");
const tmux = require("../lib/tmux");

describe("tmux wrapper", () => {
  beforeEach(() => {
    tmux.__reset();
  });

  it("hasSession returns true when execFileSync exits 0", () => {
    tmux.__setExecImpl(() => "");
    assert.equal(tmux.hasSession("agenthub-lane-1"), true);
  });

  it("hasSession returns false when execFileSync throws", () => {
    tmux.__setExecImpl(() => {
      const e = new Error("no such session");
      e.status = 1;
      throw e;
    });
    assert.equal(tmux.hasSession("agenthub-lane-1"), false);
  });

  it("liveSessions answers every live name with ONE list-sessions call", () => {
    const calls = [];
    tmux.__setExecImpl((args) => {
      calls.push(args[0]);
      return "agenthub-lane-1\nagenthub-lane-12\nmain\n";
    });
    assert.deepEqual([...tmux.liveSessions()], ["agenthub-lane-1", "agenthub-lane-12", "main"]);
    assert.deepEqual(calls, ["list-sessions"]);
  });

  it("reads psmux's list-sessions, which ignores -F, as bare names (Windows)", () => {
    // psmux prints its default line whatever `-F` asks for; read as names,
    // every pane looked dead and the heal beat closed its run within seconds.
    tmux.__setExecImpl((args) =>
      args[0] === "list-sessions"
        ? "agenthub-lane-2-5: 1 windows (created Sat Oct 10 11:44:39 2026)\r\n" +
          "agenthub-lane-2: 1 windows (created Sat Oct 10 10:43:16 2026)\r\n"
        : ""
    );
    assert.deepEqual([...tmux.liveSessions()], ["agenthub-lane-2-5", "agenthub-lane-2"]);
    assert.deepEqual(tmux.listSessions("agenthub-lane-"), ["agenthub-lane-2-5", "agenthub-lane-2"]);
  });

  it("liveSessions is empty when tmux answers that no server runs (or is not installed)", () => {
    tmux.__setExecImpl(() => {
      throw Object.assign(new Error("no server running"), { status: 1 });
    });
    assert.equal(tmux.liveSessions().size, 0);
    tmux.__setExecImpl(() => {
      throw Object.assign(new Error("spawn tmux ENOENT"), { code: "ENOENT" });
    });
    assert.equal(tmux.liveSessions().size, 0);
  });

  it("liveSessions is null when tmux could not be asked — not 'every pane is gone'", () => {
    // Out of memory/processes: the panes are fine, the question failed.
    tmux.__setExecImpl(() => {
      throw Object.assign(new Error("spawnSync tmux EAGAIN"), { code: "EAGAIN" });
    });
    assert.equal(tmux.liveSessions(), null);
  });

  describe(
    "the tmux server outlives the dashboard (Linux)",
    { skip: process.platform !== "linux" },
    () => {
      // Fake tmux: no server until a new-session, then every call succeeds.
      const fake =
        (calls, { running = false } = {}) =>
        (args) => {
          calls.push(["tmux", ...args].join(" "));
          if (args[0] === "display-message" && !running)
            throw Object.assign(new Error("no server"), { status: 1 });
          if (args[0] === "has-session" && !running)
            throw Object.assign(new Error("no session"), { status: 1 });
          return args[0] === "display-message" ? "4242\n" : "";
        };

      it("starts the FIRST session in its own systemd scope, not the dashboard's cgroup", () => {
        const calls = [];
        tmux.__setExecImpl(fake(calls));
        tmux.__setScopeImpl((args) => calls.push(["systemd-run", "tmux", ...args].join(" ")));
        tmux.newSession({ name: "agenthub-lane-1", cwd: "/w", argv: ["claude"], env: {} });
        assert.ok(
          calls.includes("systemd-run tmux new-session -d -s agenthub-lane-1 -c /w -- claude")
        );
        assert.ok(!calls.some((c) => c.startsWith("tmux new-session")));
      });

      it("adds a session to a running server directly", () => {
        const calls = [];
        tmux.__setExecImpl(fake(calls, { running: true }));
        tmux.__setScopeImpl(() => assert.fail("a running server needs no scope"));
        tmux.newSession({ name: "agenthub-lane-1", cwd: "/w", argv: ["claude"], env: {} });
        assert.ok(calls.includes("tmux new-session -d -s agenthub-lane-1 -c /w -- claude"));
      });

      it("starts it plainly when no systemd user manager answers", () => {
        const calls = [];
        tmux.__setExecImpl(fake(calls));
        tmux.__setScopeImpl(() => {
          throw Object.assign(new Error("Failed to connect to bus"), { status: 1 });
        });
        tmux.newSession({ name: "agenthub-lane-1", cwd: "/w", argv: ["claude"], env: {} });
        assert.ok(calls.includes("tmux new-session -d -s agenthub-lane-1 -c /w -- claude"));
      });
    }
  );

  it("newSession names a command that exited at once instead of tmux's set-option error", () => {
    tmux.__setExecImpl((args) => {
      if (args[0] === "new-session") return "";
      throw Object.assign(new Error("Command failed: tmux " + args.join(" ")), { status: 1 });
    });
    assert.throws(
      () =>
        tmux.newSession({ name: "agenthub-lane-4", cwd: "/tmp/repo", argv: ["claude", "-p", "x"] }),
      (err) =>
        err.code === "EPANEEXITED" && /exited as soon as it started: claude$/.test(err.message)
    );
  });

  it("newSession with no argv leaves tmux its default shell (no trailing --)", () => {
    const calls = [];
    tmux.__setExecImpl((args) => {
      calls.push(args);
      return "";
    });
    tmux.newSession({ name: "agenthub-lane-1", cwd: "C:\\repo", argv: [] });
    assert.deepEqual(calls[0], ["new-session", "-d", "-s", "agenthub-lane-1", "-c", "C:\\repo"]);
  });

  it("names sessions bare on psmux, which has no `=name` targets, and keeps `=` on tmux", () => {
    // psmux (the WinGet `tmux` on Windows) answers "no server running on
    // session '=agenthub-lane-1'" for a session that is alive, so every
    // `=` target read a live pane as gone.
    const fake = (supportsExact) => {
      const calls = [];
      tmux.__setExecImpl(
        (args) => {
          calls.push(args);
          if (args[0] === "list-sessions") return "agenthub-lane-1\n";
          const t = args[args.indexOf("-t") + 1];
          if (t && t.startsWith("=") && !supportsExact) throw new Error("no server running");
          return "";
        },
        { exact: null }
      );
      return calls;
    };

    let calls = fake(false);
    assert.equal(tmux.hasSession("agenthub-lane-1"), true);
    tmux.enableMouse("agenthub-lane-1");
    assert.ok(calls.some((c) => c[0] === "set-option" && c[2] === "agenthub-lane-1"));
    assert.ok(!calls.some((c) => c[0] === "set-option" && c[2].startsWith("=")));

    calls = fake(true);
    tmux.enableMouse("agenthub-lane-1");
    assert.ok(calls.some((c) => c[0] === "set-option" && c[2] === "=agenthub-lane-1:"));
    // tmux chains the four options into two spawns; psmux above got four.
    const sets = calls.filter((c) => c[0] === "set-option");
    assert.equal(sets.length, 2);
    assert.deepEqual(sets[0], [
      "set-option",
      "-t",
      "=agenthub-lane-1:",
      "mouse",
      "on",
      ";",
      "set-option",
      "-t",
      "=agenthub-lane-1:",
      "status",
      "off",
    ]);
  });

  it("newSession builds the correct argv", () => {
    const calls = [];
    tmux.__setExecImpl((args) => {
      calls.push(args);
      return "";
    });
    tmux.newSession({
      name: "agenthub-lane-1",
      cwd: "/tmp/repo",
      argv: ["claude", "--model", "opus"],
    });
    assert.deepEqual(calls[0], [
      "new-session",
      "-d",
      "-s",
      "agenthub-lane-1",
      "-c",
      "/tmp/repo",
      "--",
      "claude",
      "--model",
      "opus",
    ]);
    // One tmux call per `;`-chained group: the options every tmux knows, then
    // the 3.7+ scrollbar pair (allowed to fail on its own).
    assert.deepEqual(calls[1], [
      ...["set-option", "-t", "=agenthub-lane-1:", "mouse", "on", ";"],
      ...["set-option", "-t", "=agenthub-lane-1:", "status", "off"],
    ]);
    assert.deepEqual(calls[2], [
      ...["set-option", "-t", "=agenthub-lane-1:", "pane-scrollbars", "on", ";"],
      ...["set-option", "-t", "=agenthub-lane-1:", "pane-scrollbars-style"],
      "fg=brightwhite,bg=black,width=1,pad=0",
    ]);
    assert.equal(calls.length, 3);
  });

  it("newSession still succeeds on a tmux older than 3.7 (no pane-scrollbars)", () => {
    tmux.__setExecImpl((args) => {
      if (args.includes("pane-scrollbars")) throw new Error("invalid option: pane-scrollbars");
      return "";
    });
    assert.doesNotThrow(() =>
      tmux.newSession({ name: "agenthub-lane-1", cwd: "/tmp/repo", argv: ["claude"] })
    );
  });

  it("sendText types the literal string and presses Enter, with no quoting", () => {
    const calls = [];
    tmux.__setExecImpl((args) => {
      calls.push(args);
      return "";
    });
    tmux.sendText("agenthub-lane-1", 'Reminder: run "agenthub stage implement"');
    assert.deepEqual(calls[0], [
      "send-keys",
      "-t",
      "=agenthub-lane-1:",
      "-l",
      'Reminder: run "agenthub stage implement"',
    ]);
    assert.deepEqual(calls[1], ["send-keys", "-t", "=agenthub-lane-1:", "Enter"]);
  });

  it("targets a session exactly, so lane 1 never resolves to lane 12 by prefix", () => {
    const calls = [];
    tmux.__setExecImpl((args) => {
      calls.push(args);
      return "";
    });
    tmux.hasSession("agenthub-lane-1");
    tmux.killSession("agenthub-lane-1");
    assert.deepEqual(calls, [
      ["has-session", "-t", "=agenthub-lane-1"],
      ["kill-session", "-t", "=agenthub-lane-1"],
    ]);
  });

  it("killSession never throws when the session is already gone", () => {
    tmux.__setExecImpl(() => {
      const e = new Error("no such session");
      e.status = 1;
      throw e;
    });
    assert.doesNotThrow(() => tmux.killSession("agenthub-lane-1"));
  });

  it("listSessions filters by prefix and ignores unrelated sessions", () => {
    tmux.__setExecImpl(() => "agenthub-lane-1\nagenthub-lane-2\nsome-other-session\n");
    assert.deepEqual(tmux.listSessions("agenthub-lane-"), ["agenthub-lane-1", "agenthub-lane-2"]);
  });

  it("shares one list-sessions answer for a second, until this process creates or kills one", () => {
    const calls = [];
    let names = "agenthub-lane-1\n";
    tmux.__setExecImpl((args) => {
      calls.push(args[0]);
      return args[0] === "list-sessions" ? names : "";
    });
    assert.deepEqual(tmux.listSessions("agenthub-lane-"), ["agenthub-lane-1"]);
    assert.deepEqual([...tmux.liveSessions()], ["agenthub-lane-1"]);
    assert.equal(calls.filter((c) => c === "list-sessions").length, 1);
    tmux.killSession("agenthub-lane-1");
    names = "";
    assert.deepEqual(tmux.listSessions("agenthub-lane-"), []);
    assert.equal(calls.filter((c) => c === "list-sessions").length, 2);
  });

  it("listSessions returns [] when tmux has no sessions at all (exit 1)", () => {
    tmux.__setExecImpl(() => {
      const e = new Error("no server running");
      e.status = 1;
      throw e;
    });
    assert.deepEqual(tmux.listSessions("agenthub-lane-"), []);
  });

  it("isTmuxAvailable reflects whether the binary resolves on PATH", () => {
    tmux.__setExecImpl(() => "tmux 3.4");
    assert.equal(tmux.isTmuxAvailable(), true);
    tmux.__setExecImpl(() => {
      throw new Error("ENOENT");
    });
    assert.equal(tmux.isTmuxAvailable(), false);
  });
});