import json
import os
import sys
import threading
import time
from dataclasses import replace
from http.server import BaseHTTPRequestHandler, HTTPServer
from pathlib import Path

import pytest

from src.release_engine import (
    CommandResult,
    EngineConfig,
    GiteaClient,
    Issue,
    ReleaseEngine,
    RunState,
    ShellRunner,
    StateStore,
    _parse_args,
    branch_name,
    select_issue,
)


def test_shell_runner_treats_metacharacters_as_literal_arguments(tmp_path):
    output = tmp_path / "argument.txt"
    injected = tmp_path / "injected.txt"
    payload = f"release title; touch {injected}"

    result = ShellRunner().run(
        [
            sys.executable,
            "-c",
            "from pathlib import Path; import sys; Path(sys.argv[1]).write_text(sys.argv[2])",
            str(output),
            payload,
        ],
        tmp_path,
    )

    assert result.returncode == 0
    assert output.read_text() == payload
    assert not injected.exists()


def test_shell_runner_uses_only_the_explicit_environment(tmp_path, monkeypatch):
    output = tmp_path / "environment.json"
    monkeypatch.setenv("GITEA_TOKEN", "write-capable-secret")
    monkeypatch.setenv("UNRELATED_SECRET", "also-secret")

    result = ShellRunner().run(
        [
            sys.executable,
            "-c",
            "import json, os, sys; json.dump(dict(os.environ), open(sys.argv[1], 'w'))",
            str(output),
        ],
        tmp_path,
        {"PATH": os.environ["PATH"], "EXPECTED_VALUE": "available"},
    )

    environment = json.loads(output.read_text())
    assert result.returncode == 0
    assert environment["EXPECTED_VALUE"] == "available"
    assert "GITEA_TOKEN" not in environment
    assert "UNRELATED_SECRET" not in environment


def test_shell_runner_times_out_and_terminates_spawned_children(tmp_path):
    marker = tmp_path / "child-survived.txt"
    child = (
        "import time; from pathlib import Path; "
        f"time.sleep(0.3); Path({str(marker)!r}).write_text('survived')"
    )
    parent = (
        "import subprocess, sys, time; "
        f"subprocess.Popen([sys.executable, '-c', {child!r}]); "
        "time.sleep(10)"
    )

    started = time.monotonic()
    result = ShellRunner().run(
        [sys.executable, "-c", parent],
        tmp_path,
        timeout_seconds=0.05,
        termination_grace_seconds=0.05,
    )
    elapsed = time.monotonic() - started
    time.sleep(0.35)

    assert result.timed_out is True
    assert elapsed < 0.5
    assert not marker.exists()


def test_stale_token_error_explains_how_to_restore_cron_authentication():
    class UnauthorizedHandler(BaseHTTPRequestHandler):
        def do_GET(self):
            self.send_response(401)
            self.end_headers()
            self.wfile.write(b'{"message":"user does not exist [uid: 0, name: ]"}')

        def log_message(self, format, *args):
            pass

    server = HTTPServer(("127.0.0.1", 0), UnauthorizedHandler)
    thread = threading.Thread(target=server.handle_request)
    thread.start()
    try:
        client = GiteaClient(f"http://127.0.0.1:{server.server_port}", "stale-token")
        with pytest.raises(RuntimeError, match="refresh the cron GITEA_TOKEN"):
            client.list_open_issues("stackchain/stackchain-dashboard")
    finally:
        thread.join(timeout=2)
        server.server_close()


class FakeClient:
    def __init__(self, issues, verified_assignee="timmy", existing_pr=None):
        self.issues = issues
        self.verified_assignee = verified_assignee
        self.existing_pr = existing_pr
        self.claimed = []
        self.created_prs = []

    def list_open_issues(self, repo):
        return self.issues

    def claim_issue(self, repo, number, assignee):
        self.claimed.append((repo, number, assignee))

    def get_issue(self, repo, number):
        issue = next(i for i in self.issues if i.number == number)
        return Issue(**{**issue.__dict__, "assignee": self.verified_assignee})

    def find_open_pr(self, repo, head):
        return self.existing_pr

    def create_pr(self, repo, head, base, title, body):
        self.created_prs.append((repo, head, base, title, body))
        return {"number": 44, "html_url": "https://forge/pr/44"}


class FakeRunner:
    def __init__(self, results):
        self.results = list(results)
        self.commands = []
        self.environments = []
        self.options = []

    def run(self, command, cwd, env=None, **options):
        self.commands.append(command)
        self.environments.append(env)
        self.options.append(options)
        return self.results.pop(0)


@pytest.fixture
def issues():
    return [
        Issue(2, "P2 task", "body", "open", ["P2"], None),
        Issue(3, "Owned P0", "body", "open", ["P0"], "other"),
        Issue(4, "Unowned P0", "body", "open", ["P0"], None),
    ]


def config(tmp_path):
    return EngineConfig(
        repo="stackchain/stackchain-dashboard",
        agent="timmy",
        repo_path=tmp_path,
        state_path=tmp_path / "state.json",
        agent_command="agent --issue-from-env",
        test_command="pytest -q",
    )


def test_selection_prioritizes_p0_and_skips_other_assignees(issues):
    assert select_issue(issues, agent="timmy").number == 4


def test_explicit_issue_must_be_eligible(issues):
    with pytest.raises(ValueError, match="assigned to other"):
        select_issue(issues, agent="timmy", issue_number=3)


def test_branch_name_is_reproducible_and_bounded():
    assert branch_name("Timmy", Issue(14, "Autonomous Issue-to-Release Engine!", "", "open", [], None)) == "timmy/14-autonomous-issue-to-release-engine"


def test_claim_verification_blocks_execution(tmp_path):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue], verified_assignee="other")
    runner = FakeRunner([])
    engine = ReleaseEngine(config(tmp_path), client, runner)

    with pytest.raises(RuntimeError, match="claim verification failed"):
        engine.execute(issue_number=14)

    assert runner.commands == []


def test_empty_agent_command_fails_before_claim(tmp_path):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue])
    cfg = EngineConfig(
        repo="stackchain/stackchain-dashboard",
        agent="timmy",
        repo_path=tmp_path,
        state_path=tmp_path / "state.json",
        agent_command="  ",
        test_command="pytest -q",
    )

    with pytest.raises(ValueError, match="invalid agent command: command is empty"):
        ReleaseEngine(cfg, client, FakeRunner([])).execute(issue_number=14)

    assert client.claimed == []


@pytest.mark.parametrize(
    ("field", "value"),
    [
        ("agent_timeout_seconds", 0),
        ("test_timeout_seconds", -1),
        ("termination_grace_seconds", 0),
    ],
)
def test_non_positive_command_deadlines_fail_before_claim(tmp_path, field, value):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue])
    cfg = replace(config(tmp_path), **{field: value})

    with pytest.raises(ValueError, match=field.replace("_", " ")):
        ReleaseEngine(cfg, client, FakeRunner([])).execute(issue_number=14)

    assert client.claimed == []


@pytest.mark.parametrize("name", ["GITEA_TOKEN", "RELEASE_REPO", "bad-name", "1START"])
def test_invalid_agent_environment_allowlist_fails_before_claim(tmp_path, name):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue])
    cfg = replace(config(tmp_path), agent_env_vars=(name,))

    with pytest.raises(ValueError, match="invalid agent environment variable"):
        ReleaseEngine(cfg, client, FakeRunner([])).execute(issue_number=14)

    assert client.claimed == []


def test_command_deadlines_are_configurable_from_cli(monkeypatch):
    monkeypatch.setattr(sys, "argv", [
        "release-engine",
        "--repo", "stackchain/stackchain-dashboard",
        "--agent-timeout", "120",
        "--test-timeout", "45.5",
        "--termination-grace", "2",
        "--agent-env", "CODEX_HOME",
        "--agent-env", "HTTPS_PROXY",
    ])

    args = _parse_args()

    assert args.agent_timeout == 120
    assert args.test_timeout == 45.5
    assert args.termination_grace == 2
    assert args.agent_env == ["CODEX_HOME", "HTTPS_PROXY"]


def test_agent_failure_blocks_tests_and_pr(tmp_path):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue])
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(1, "", "agent failed"),
    ])
    engine = ReleaseEngine(config(tmp_path), client, runner)

    with pytest.raises(RuntimeError, match="coding agent failed"):
        engine.execute(issue_number=14)

    assert runner.commands == [
        ["git", "checkout", "-B", "timmy/14-engine"],
        ["agent", "--issue-from-env"],
    ]
    assert client.created_prs == []


def test_agent_timeout_records_terminal_state_and_blocks_tests(tmp_path):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue])
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(-9, "partial output", "stalled", timed_out=True),
    ])
    cfg = config(tmp_path)

    with pytest.raises(RuntimeError, match="coding agent timed out"):
        ReleaseEngine(cfg, client, runner).execute(issue_number=14)

    state = StateStore(cfg.state_path).load()
    assert state is not None
    assert state.status == "agent_timed_out"
    assert "partial output" in state.evidence
    assert runner.commands == [
        ["git", "checkout", "-B", "timmy/14-engine"],
        ["agent", "--issue-from-env"],
    ]
    assert runner.options[1] == {
        "timeout_seconds": cfg.agent_timeout_seconds,
        "termination_grace_seconds": cfg.termination_grace_seconds,
    }
    assert client.created_prs == []


def test_issue_content_reaches_agent_only_through_environment(tmp_path):
    title = "$(touch /tmp/title-injected); `id`"
    body = "line one\n&& touch /tmp/body-injected > stolen"
    issue = Issue(14, title, body, "open", [], None)
    client = FakeClient([issue])
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(1, "", "agent stopped"),
    ])
    cfg = EngineConfig(
        repo="stackchain/stackchain-dashboard",
        agent="timmy",
        repo_path=tmp_path,
        state_path=tmp_path / "state.json",
        agent_command="agent --work",
        test_command="pytest -q",
    )

    with pytest.raises(RuntimeError, match="coding agent failed"):
        ReleaseEngine(cfg, client, runner).execute(issue_number=14)

    assert runner.commands == [
        ["git", "checkout", "-B", "timmy/14-touch-tmp-title-injected-id"],
        ["agent", "--work"],
    ]
    assert runner.environments[1]["RELEASE_ISSUE_TITLE"] == title
    assert runner.environments[1]["RELEASE_ISSUE_BODY"] == body


def test_release_stages_receive_least_privilege_environments(tmp_path, monkeypatch):
    monkeypatch.setenv("GITEA_TOKEN", "write-capable-secret")
    monkeypatch.setenv("UNRELATED_SECRET", "also-secret")
    monkeypatch.setenv("CODEX_HOME", "/approved/codex")
    issue = Issue(14, "Engine MVP", "sensitive body", "open", [], None)
    client = FakeClient([issue])
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "implemented", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, "8 passed", ""),
        CommandResult(0, "", ""),
    ])
    cfg = replace(config(tmp_path), agent_env_vars=("CODEX_HOME",))

    ReleaseEngine(cfg, client, runner).execute(issue_number=14)

    for environment in runner.environments:
        assert environment is not None
        assert "PATH" in environment
        assert "GITEA_TOKEN" not in environment
        assert "UNRELATED_SECRET" not in environment
    agent_environment = runner.environments[1]
    assert agent_environment["CODEX_HOME"] == "/approved/codex"
    assert agent_environment["RELEASE_ISSUE_NUMBER"] == "14"
    assert agent_environment["RELEASE_ISSUE_TITLE"] == issue.title
    assert agent_environment["RELEASE_ISSUE_BODY"] == issue.body
    assert agent_environment["RELEASE_REPO"] == cfg.repo
    assert agent_environment["RELEASE_BRANCH"] == "timmy/14-engine-mvp"
    assert not any(
        name.startswith("RELEASE_")
        for name in runner.environments[3]
    )


def test_failed_tests_block_push_and_pr(tmp_path):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue])
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "changed", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(1, "1 failed", ""),
    ])
    engine = ReleaseEngine(config(tmp_path), client, runner)

    with pytest.raises(RuntimeError, match="tests failed"):
        engine.execute(issue_number=14)

    assert not any(command[:2] == ["git", "push"] for command in runner.commands)
    assert client.created_prs == []


def test_test_timeout_records_terminal_state_and_blocks_push(tmp_path):
    issue = Issue(14, "Engine", "body", "open", [], None)
    client = FakeClient([issue])
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "implemented", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(-15, "3 passed before stall", "", timed_out=True),
    ])
    cfg = config(tmp_path)

    with pytest.raises(RuntimeError, match="tests timed out"):
        ReleaseEngine(cfg, client, runner).execute(issue_number=14)

    state = StateStore(cfg.state_path).load()
    assert state is not None
    assert state.status == "tests_timed_out"
    assert "3 passed before stall" in state.evidence
    assert runner.options[3] == {
        "timeout_seconds": cfg.test_timeout_seconds,
        "termination_grace_seconds": cfg.termination_grace_seconds,
    }
    assert not any(command[:2] == ["git", "push"] for command in runner.commands)
    assert client.created_prs == []


def test_passing_run_pushes_and_opens_linked_pr(tmp_path):
    issue = Issue(14, "Engine MVP", "body", "open", ["P1"], None)
    client = FakeClient([issue])
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "implemented", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, "8 passed", ""),
        CommandResult(0, "", ""),
    ])
    engine = ReleaseEngine(config(tmp_path), client, runner)

    result = engine.execute(issue_number=14)

    assert result["pr_number"] == 44
    assert runner.commands[-1] == ["git", "push", "-u", "origin", "timmy/14-engine-mvp"]
    assert len(client.created_prs) == 1
    body = client.created_prs[0][4]
    assert "Closes #14" in body
    assert "pytest -q" in body
    assert "8 passed" in body


def test_dry_run_does_not_claim_or_execute(tmp_path):
    issue = Issue(14, "Engine MVP", "body", "open", [], None)
    client = FakeClient([issue])
    runner = FakeRunner([])
    engine = ReleaseEngine(config(tmp_path), client, runner)

    result = engine.execute(issue_number=14, dry_run=True)

    assert result["dry_run"] is True
    assert result["issue"] == 14
    assert client.claimed == []
    assert runner.commands == []


def test_existing_pr_is_reused_without_agent_execution(tmp_path):
    issue = Issue(14, "Engine MVP", "body", "open", [], "timmy")
    client = FakeClient([issue], existing_pr={"number": 9, "html_url": "https://forge/pr/9"})
    runner = FakeRunner([])
    engine = ReleaseEngine(config(tmp_path), client, runner)

    result = engine.execute(issue_number=14)

    assert result["pr_number"] == 9
    assert runner.commands == []
    assert client.created_prs == []


def test_state_store_round_trip_is_atomic(tmp_path):
    store = StateStore(tmp_path / "state.json")
    expected = RunState(issue=14, branch="timmy/14-engine", status="tests_passed", evidence="8 passed")
    store.save(expected)
    assert store.load() == expected
    assert not (tmp_path / "state.json.tmp").exists()


def test_restart_from_agent_complete_skips_claim_and_coding(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], "timmy")
    client = FakeClient([issue])
    cfg = config(tmp_path)
    branch = "timmy/331-resume-releases"
    cfg.state_path.write_text(json.dumps({
        "schema_version": 1,
        "repo": cfg.repo,
        "issue": issue.number,
        "branch": branch,
        "status": "agent_complete",
        "evidence": "",
        "pr_number": None,
        "pr_url": "",
        "head_sha": "abc123",
    }))
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, "", ""),
        CommandResult(0, "8 passed", ""),
        CommandResult(0, "", ""),
    ])

    result = ReleaseEngine(cfg, client, runner).execute(issue_number=331)

    assert result["tests"] == "passed"
    assert client.claimed == []
    assert ["agent", "--issue-from-env"] not in runner.commands
    assert runner.commands[:3] == [
        ["git", "checkout", branch],
        ["git", "rev-parse", "HEAD"],
        ["git", "status", "--porcelain"],
    ]


def test_restart_from_tests_passed_skips_claim_coding_and_tests(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], "timmy")
    client = FakeClient([issue])
    cfg = config(tmp_path)
    branch = "timmy/331-resume-releases"
    StateStore(cfg.state_path).save(RunState(
        issue=issue.number,
        branch=branch,
        status="tests_passed",
        evidence="604 passed",
        repo=cfg.repo,
        head_sha="abc123",
    ))
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, "", ""),
        CommandResult(0, "", ""),
    ])

    result = ReleaseEngine(cfg, client, runner).execute(issue_number=331)

    assert result["tests"] == "passed"
    assert client.claimed == []
    assert ["agent", "--issue-from-env"] not in runner.commands
    assert ["pytest", "-q"] not in runner.commands
    assert runner.commands == [
        ["git", "checkout", branch],
        ["git", "rev-parse", "HEAD"],
        ["git", "status", "--porcelain"],
        ["git", "push", "-u", "origin", branch],
    ]


def test_restart_from_pushed_verifies_remote_and_only_opens_pr(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], "timmy")
    client = FakeClient([issue])
    cfg = config(tmp_path)
    branch = "timmy/331-resume-releases"
    StateStore(cfg.state_path).save(RunState(
        issue=issue.number,
        branch=branch,
        status="pushed",
        evidence="604 passed",
        repo=cfg.repo,
        head_sha="abc123",
    ))
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, "", ""),
        CommandResult(0, f"abc123\trefs/heads/{branch}\n", ""),
    ])

    result = ReleaseEngine(cfg, client, runner).execute(issue_number=331)

    assert result["pr_number"] == 44
    assert client.claimed == []
    assert len(client.created_prs) == 1
    assert runner.commands == [
        ["git", "checkout", branch],
        ["git", "rev-parse", "HEAD"],
        ["git", "status", "--porcelain"],
        ["git", "ls-remote", "--heads", "origin", branch],
    ]


def test_fresh_run_persists_repository_and_commit_identity(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], None)
    client = FakeClient([issue])
    cfg = config(tmp_path)
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "implemented", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, "604 passed", ""),
        CommandResult(0, "", ""),
    ])

    ReleaseEngine(cfg, client, runner).execute(issue_number=331)

    state = StateStore(cfg.state_path).load()
    assert state is not None
    assert state.status == "pr_opened"
    assert state.schema_version == 1
    assert state.repo == cfg.repo
    assert state.head_sha == "abc123"
    assert ["git", "rev-parse", "HEAD"] in runner.commands


def test_resume_fails_closed_when_checkpoint_worktree_is_dirty(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], "timmy")
    client = FakeClient([issue])
    cfg = config(tmp_path)
    branch = "timmy/331-resume-releases"
    StateStore(cfg.state_path).save(RunState(
        issue=issue.number,
        branch=branch,
        status="tests_passed",
        evidence="604 passed",
        repo=cfg.repo,
        head_sha="abc123",
    ))
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, " M src/release_engine.py\n", ""),
        CommandResult(0, "", ""),
    ])

    with pytest.raises(RuntimeError, match="worktree is not clean"):
        ReleaseEngine(cfg, client, runner).execute(issue_number=331)

    assert not any(command[:2] == ["git", "push"] for command in runner.commands)
    assert client.created_prs == []


def test_resume_fails_closed_when_checkpoint_targets_another_repository(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], "timmy")
    client = FakeClient([issue])
    cfg = config(tmp_path)
    StateStore(cfg.state_path).save(RunState(
        issue=issue.number,
        branch="timmy/331-resume-releases",
        status="tests_passed",
        repo="other/repository",
        head_sha="abc123",
    ))

    with pytest.raises(RuntimeError, match="checkpoint does not match"):
        ReleaseEngine(cfg, client, FakeRunner([])).execute(issue_number=331)

    assert client.created_prs == []


def test_resume_fails_closed_when_local_commit_changed(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], "timmy")
    client = FakeClient([issue])
    cfg = config(tmp_path)
    StateStore(cfg.state_path).save(RunState(
        issue=issue.number,
        branch="timmy/331-resume-releases",
        status="tests_passed",
        repo=cfg.repo,
        head_sha="abc123",
    ))
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "different-sha\n", ""),
    ])

    with pytest.raises(RuntimeError, match="commit does not match the local branch"):
        ReleaseEngine(cfg, client, runner).execute(issue_number=331)

    assert client.created_prs == []


def test_resume_fails_closed_when_remote_commit_changed(tmp_path):
    issue = Issue(331, "Resume releases", "body", "open", [], "timmy")
    client = FakeClient([issue])
    cfg = config(tmp_path)
    branch = "timmy/331-resume-releases"
    StateStore(cfg.state_path).save(RunState(
        issue=issue.number,
        branch=branch,
        status="pushed",
        evidence="604 passed",
        repo=cfg.repo,
        head_sha="abc123",
    ))
    runner = FakeRunner([
        CommandResult(0, "", ""),
        CommandResult(0, "abc123\n", ""),
        CommandResult(0, "", ""),
        CommandResult(0, f"different-sha\trefs/heads/{branch}\n", ""),
    ])

    with pytest.raises(RuntimeError, match="commit does not match the remote branch"):
        ReleaseEngine(cfg, client, runner).execute(issue_number=331)

    assert client.created_prs == []