import json
import subprocess
import sys
import time

from tdprm.queue import gpuq


def write_job(tmp, name, body):
    p = tmp / f"{name}.sh"
    p.write_text("#!/usr/bin/env bash\n" + body + "\n")
    return str(p)


def test_queue_runs_dependencies_files_failures_and_pairs(tmp_path):
    marker = tmp_path / "ckpt" / "READY"
    seen = tmp_path / "seen.txt"
    jobs = [
        {"id": "a", "gpus": 1, "priority": 0, "deps": [],
         "script": write_job(tmp_path, "a", f"echo a:$CUDA_VISIBLE_DEVICES >> {seen}; mkdir -p {marker.parent}; "
                                            f"touch {marker}")},
        {"id": "b", "gpus": 2, "priority": 1, "deps": ["a"],
         "script": write_job(tmp_path, "b", f"echo b:$CUDA_VISIBLE_DEVICES >> {seen}")},
        {"id": "c", "gpus": 1, "priority": 2, "deps": [f"file:{marker}"],
         "script": write_job(tmp_path, "c", f"echo c:$TDPRM_GPU0 >> {seen}")},
        {"id": "d", "gpus": 0, "priority": 0, "deps": [], "script": write_job(tmp_path, "d", "exit 3")},
        {"id": "e", "gpus": 1, "priority": 0, "deps": ["d"], "script": write_job(tmp_path, "e", "echo never")},
    ]
    plan = tmp_path / "plan.json"
    plan.write_text(json.dumps({"jobs": jobs, "reservations": []}))
    proc = subprocess.run([sys.executable, "-m", "tdprm.queue.gpuq", "run", "--plan", str(plan), "--gpus", "0,1",
                           "--poll", "0.2", "--max-retries", "0", "--max-used-mib", str(10**9)],
                          capture_output=True, text=True, timeout=60)
    assert proc.returncode == 0, proc.stderr
    state = json.loads((tmp_path / "plan.state.json").read_text())
    assert [state[j]["status"] for j in "abcde"] == ["done", "done", "done", "failed", "blocked"]
    lines = seen.read_text().split()
    assert "b:0,1" in lines and any(x.startswith("a:") for x in lines) and any(x.startswith("c:") for x in lines)


def test_queue_auto_retries_a_failed_job_and_unblocks_dependents(tmp_path):
    flag = tmp_path / "failed_once"
    jobs = [{"id": "flaky", "gpus": 0, "priority": 0, "deps": [],
             "script": write_job(tmp_path, "flaky", f"if [ -f {flag} ]; then exit 0; fi; touch {flag}; exit 1")},
            {"id": "after", "gpus": 0, "priority": 1, "deps": ["flaky"], "script": write_job(tmp_path, "after", "exit 0")}]
    plan = tmp_path / "plan.json"
    plan.write_text(json.dumps({"jobs": jobs, "reservations": []}))
    proc = subprocess.run([sys.executable, "-m", "tdprm.queue.gpuq", "run", "--plan", str(plan), "--gpus", "0",
                           "--poll", "0.2", "--max-retries", "1", "--retry-after", "0"],
                          capture_output=True, text=True, timeout=60)
    assert proc.returncode == 0, proc.stderr
    state = json.loads((tmp_path / "plan.state.json").read_text())
    assert state["flaky"]["status"] == "done" and state["flaky"]["attempts"] == 1
    assert state["after"]["status"] == "done"


def test_simulate_respects_reservations(tmp_path, capsys):
    jobs = [{"id": "jev", "gpus": 1, "priority": 5, "deps": ["prep"], "est_hours": 2.0, "script": "x"},
            {"id": "prep", "gpus": 0, "priority": 0, "deps": [], "est_hours": 0.5, "script": "x"},
            {"id": "t1", "gpus": 1, "priority": 10, "deps": [], "est_hours": 3.0, "script": "x"},
            {"id": "t2", "gpus": 1, "priority": 10, "deps": [], "est_hours": 3.0, "script": "x"}]
    plan = tmp_path / "plan.json"
    plan.write_text(json.dumps({"jobs": jobs, "reservations": [{"gpus": [1], "jobs": ["jev"]}]}))

    class A:
        pass
    args = A()
    args.plan, args.gpus, args.all, args.backfill_max_hours = str(plan), "0,1", True, 0.5
    gpuq.simulate(args)
    out = capsys.readouterr().out
    # t1 takes GPU 0, GPU 1 is held for "jev" (starts at 0.5h), t2 waits until a GPU frees up.
    assert "gpus=[1]      jev" in out and "0.00h ->   3.00h  gpus=[0]      t1" in out
    assert "2.50h ->   5.50h" in out


def test_after_dependency_waits_for_any_final_outcome(tmp_path):
    """`after:X` runs once X is finished for good (here: failed with no retries left), unlike a plain dep."""
    seen = tmp_path / "seen.txt"
    jobs = [{"id": "x", "gpus": 0, "priority": 0, "deps": [], "script": write_job(tmp_path, "x", "exit 1")},
            {"id": "y", "gpus": 0, "priority": 1, "deps": ["after:x"],
             "script": write_job(tmp_path, "y", f"echo y >> {seen}")},
            {"id": "z", "gpus": 0, "priority": 1, "deps": ["x"], "script": write_job(tmp_path, "z", "exit 0")}]
    plan = tmp_path / "plan.json"
    plan.write_text(json.dumps({"jobs": jobs, "reservations": []}))
    proc = subprocess.run([sys.executable, "-m", "tdprm.queue.gpuq", "run", "--plan", str(plan), "--gpus", "0",
                           "--poll", "0.2", "--max-retries", "0"], capture_output=True, text=True, timeout=60)
    assert proc.returncode == 0, proc.stderr
    state = json.loads((tmp_path / "plan.state.json").read_text())
    assert [state[j]["status"] for j in "xyz"] == ["failed", "done", "blocked"] and seen.read_text() == "y\n"