"""Tests for _web_ui_build_needed — staleness check for the web UI dist.

Critical invariant: the Vite build outputs to hermes_cli/web_dist/
(vite.config.ts: outDir: "../hermes_cli/web_dist"), NOT web/dist/.
The sentinel must be checked in the correct output directory or the
freshness check is a no-op and the OOM rebuild always runs.
"""

import os
import time
from pathlib import Path
from unittest.mock import patch

import pytest

from hermes_cli.main import _web_ui_build_needed, _build_web_ui, _run_npm_install_deterministic


def _touch(path: Path, offset: float = 0.0) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.touch()
    if offset:
        t = time.time() + offset
        os.utime(path, (t, t))


def _make_web_dir(tmp_path: Path) -> tuple[Path, Path]:
    """Return (web_dir, dist_dir) matching real repo layout."""
    web_dir = tmp_path / "web"
    web_dir.mkdir()
    (web_dir / "package.json").touch()
    dist_dir = tmp_path / "hermes_cli" / "web_dist"
    return web_dir, dist_dir


class TestWebUIBuildNeeded:

    def test_returns_true_when_dist_missing(self, tmp_path):
        web_dir, _ = _make_web_dir(tmp_path)
        assert _web_ui_build_needed(web_dir) is True

    def test_returns_false_when_vite_manifest_fresh(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        _touch(web_dir / "src" / "App.tsx", offset=-10)
        _touch(dist_dir / ".vite" / "manifest.json")
        assert _web_ui_build_needed(web_dir) is False

    def test_returns_true_when_source_newer_than_manifest(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        _touch(dist_dir / ".vite" / "manifest.json", offset=-10)
        _touch(web_dir / "src" / "App.tsx")
        assert _web_ui_build_needed(web_dir) is True

    def test_falls_back_to_index_html_when_manifest_missing(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        _touch(web_dir / "src" / "main.ts", offset=-10)
        _touch(dist_dir / "index.html")
        assert _web_ui_build_needed(web_dir) is False

    def test_web_dist_dir_not_web_dist_subdir(self, tmp_path):
        """Regression: sentinel must be in hermes_cli/web_dist/, NOT web/dist/."""
        web_dir, dist_dir = _make_web_dir(tmp_path)
        _touch(web_dir / "src" / "App.tsx", offset=-10)
        # Place manifest in wrong location (web/dist/) — should NOT count as fresh
        wrong_dist = web_dir / "dist" / ".vite" / "manifest.json"
        _touch(wrong_dist)
        # Correct location is empty → still needs build
        assert _web_ui_build_needed(web_dir) is True

    def test_returns_true_when_package_lock_newer_than_dist(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        _touch(dist_dir / ".vite" / "manifest.json", offset=-10)
        _touch(web_dir / "package-lock.json")
        assert _web_ui_build_needed(web_dir) is True

    def test_returns_true_when_vite_config_newer_than_dist(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        _touch(dist_dir / ".vite" / "manifest.json", offset=-10)
        _touch(web_dir / "vite.config.ts")
        assert _web_ui_build_needed(web_dir) is True

    def test_ignores_node_modules(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        # package.json older than manifest; only node_modules file is newer
        _touch(web_dir / "package.json", offset=-20)
        _touch(dist_dir / ".vite" / "manifest.json", offset=-10)
        _touch(web_dir / "node_modules" / "react" / "index.js")
        assert _web_ui_build_needed(web_dir) is False

    def test_ignores_dist_subdir_under_web(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        # package.json older than manifest; only web/dist file is newer
        _touch(web_dir / "package.json", offset=-20)
        _touch(dist_dir / ".vite" / "manifest.json", offset=-10)
        _touch(web_dir / "dist" / "assets" / "index.js")
        assert _web_ui_build_needed(web_dir) is False


class TestBuildWebUISkipsWhenFresh:

    def test_skips_npm_when_dist_is_fresh(self, tmp_path):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        _touch(dist_dir / ".vite" / "manifest.json")

        with patch("hermes_cli.main.shutil.which", return_value="/usr/bin/npm"), \
             patch("hermes_cli.main.subprocess.run") as mock_run:
            result = _build_web_ui(web_dir)

        assert result is True
        mock_run.assert_not_called()

    def test_runs_npm_when_dist_missing(self, tmp_path):
        web_dir, _ = _make_web_dir(tmp_path)

        mock_cp = __import__("subprocess").CompletedProcess([], 0, stdout=b"", stderr=b"")
        with patch("hermes_cli.main.shutil.which", return_value="/usr/bin/npm"), \
             patch("hermes_cli.main.subprocess.run", return_value=mock_cp) as mock_run:
            result = _build_web_ui(web_dir)

        assert result is True
        assert mock_run.call_count == 2  # npm install + npm run build

    def test_npm_install_uses_utf8_replace_output_decoding(self, tmp_path):
        web_dir, _ = _make_web_dir(tmp_path)
        (web_dir / "package-lock.json").write_text("{}", encoding="utf-8")

        mock_cp = __import__("subprocess").CompletedProcess([], 0, stdout="", stderr="")
        with patch("hermes_cli.main.subprocess.run", return_value=mock_cp) as mock_run:
            result = _run_npm_install_deterministic("/usr/bin/npm", web_dir)

        assert result.returncode == 0
        _, kwargs = mock_run.call_args
        assert kwargs["text"] is True
        assert kwargs["encoding"] == "utf-8"
        assert kwargs["errors"] == "replace"

    def test_web_build_uses_utf8_replace_output_decoding(self, tmp_path):
        web_dir, _ = _make_web_dir(tmp_path)

        mock_cp = __import__("subprocess").CompletedProcess([], 0, stdout="", stderr="")
        with patch("hermes_cli.main.shutil.which", return_value="/usr/bin/npm"), \
             patch("hermes_cli.main.subprocess.run", side_effect=[mock_cp, mock_cp]) as mock_run:
            result = _build_web_ui(web_dir)

        assert result is True
        _, build_kwargs = mock_run.call_args_list[1]
        assert build_kwargs["text"] is True
        assert build_kwargs["encoding"] == "utf-8"
        assert build_kwargs["errors"] == "replace"


class TestBuildWebUIRetryAndStaleFallback:
    """Coverage for the retry + stale-dist fallback added in #23824 / issue #23817."""

    def test_retries_build_once_on_failure(self, tmp_path):
        web_dir, _ = _make_web_dir(tmp_path)
        Subprocess = __import__("subprocess")
        # install: success; build attempt 1: fail; build attempt 2: success
        install_ok = Subprocess.CompletedProcess([], 0, stdout="", stderr="")
        build_fail = Subprocess.CompletedProcess([], 1, stdout="", stderr="EPERM")
        build_ok = Subprocess.CompletedProcess([], 0, stdout="", stderr="")
        with patch("hermes_cli.main.shutil.which", return_value="/usr/bin/npm"), \
             patch("hermes_cli.main._time.sleep") as mock_sleep, \
             patch("hermes_cli.main.subprocess.run",
                   side_effect=[install_ok, build_fail, build_ok]) as mock_run:
            result = _build_web_ui(web_dir)

        assert result is True
        assert mock_run.call_count == 3  # install + build + retry
        mock_sleep.assert_called_once_with(3)

    def test_falls_back_to_stale_dist_when_retry_also_fails(self, tmp_path, capsys):
        web_dir, dist_dir = _make_web_dir(tmp_path)
        # Stale dist exists but is older than source
        _touch(dist_dir / "index.html", offset=-100)
        _touch(web_dir / "src" / "App.tsx")  # newer source -> build_needed=True

        Subprocess = __import__("subprocess")
        install_ok = Subprocess.CompletedProcess([], 0, stdout="", stderr="")
        build_fail = Subprocess.CompletedProcess([], 1, stdout="", stderr="vite ENOMEM")
        with patch("hermes_cli.main.shutil.which", return_value="/usr/bin/npm"), \
             patch("hermes_cli.main._time.sleep"), \
             patch("hermes_cli.main.subprocess.run",
                   side_effect=[install_ok, build_fail, build_fail]):
            result = _build_web_ui(web_dir, fatal=True)

        # MUST return True (serve stale) — issue #23817 — even with fatal=True,
        # because cmd_dashboard passes fatal=True and is the primary caller.
        assert result is True
        out = capsys.readouterr().out
        assert "serving stale dist as fallback" in out
        assert "vite ENOMEM" in out  # stderr surfaced to user

    def test_hard_fails_when_no_dist_to_fall_back_to(self, tmp_path, capsys):
        web_dir, _ = _make_web_dir(tmp_path)

        Subprocess = __import__("subprocess")
        install_ok = Subprocess.CompletedProcess([], 0, stdout="", stderr="")
        build_fail = Subprocess.CompletedProcess([], 1, stdout="", stderr="vite ENOMEM")
        with patch("hermes_cli.main.shutil.which", return_value="/usr/bin/npm"), \
             patch("hermes_cli.main._time.sleep"), \
             patch("hermes_cli.main.subprocess.run",
                   side_effect=[install_ok, build_fail, build_fail]):
            result = _build_web_ui(web_dir, fatal=True)

        assert result is False
        out = capsys.readouterr().out
        assert "Web UI build failed" in out
        assert "vite ENOMEM" in out
        assert "Run manually" in out