"""Regression tests for the read-only Settings → Extensions diagnostics panel."""
from pathlib import Path
import re


ROOT = Path(__file__).parent.parent
INDEX_HTML = (ROOT / "static" / "index.html").read_text(encoding="utf-8")
PANELS_JS = (ROOT / "static" / "panels.js").read_text(encoding="utf-8")
STYLE_CSS = (ROOT / "static" / "style.css").read_text(encoding="utf-8")
I18N_JS = (ROOT / "static" / "i18n.js").read_text(encoding="utf-8")
DOCS_EXTENSIONS = (ROOT / "docs" / "EXTENSIONS.md").read_text(encoding="utf-8")


def _function_block(name: str, *, extra: int = 2200) -> str:
    start = PANELS_JS.find(f"function {name}")
    assert start >= 0, f"{name} not found"
    return PANELS_JS[start:start + extra]


def _between(start_marker: str, end_marker: str) -> str:
    start = PANELS_JS.find(start_marker)
    assert start >= 0, f"{start_marker} not found"
    end = PANELS_JS.find(end_marker, start)
    assert end >= 0, f"{end_marker} not found after {start_marker}"
    return PANELS_JS[start:end]


def _locale_count() -> int:
    return len(re.findall(r"^  (?:[A-Za-z_][A-Za-z0-9_]*|'[^']+'):\s*\{", I18N_JS, re.MULTILINE))


def _locale_blocks() -> dict[str, str]:
    matches = list(re.finditer(r"^  ((?:[A-Za-z_][A-Za-z0-9_]*|'[^']+')):\s*\{", I18N_JS, re.MULTILINE))
    blocks = {}
    for idx, match in enumerate(matches):
        end = matches[idx + 1].start() if idx + 1 < len(matches) else len(I18N_JS)
        blocks[match.group(1)] = I18N_JS[match.start():end]
    return blocks


def _contains_post_method(block: str) -> bool:
    """Return True when a JS block contains a method: 'POST' style mutation."""
    return bool(re.search(r"\bmethod\s*:\s*([\"'`])POST\1", block))


def test_settings_sidebar_has_extensions_section_and_pane():
    assert 'data-settings-section="extensions"' in INDEX_HTML
    assert "switchSettingsSection('extensions')" in INDEX_HTML
    assert 'id="settingsPaneExtensions"' in INDEX_HTML
    assert 'id="extensionsDiagnostics"' in INDEX_HTML
    assert 'id="extensionsCopyDiagnosticsBtn"' in INDEX_HTML
    assert 'data-i18n="settings_tab_extensions"' in INDEX_HTML


def test_extensions_panel_is_read_only_and_warns_about_trust_model():
    pane_start = INDEX_HTML.index('id="settingsPaneExtensions"')
    pane_end = INDEX_HTML.index('id="settingsPaneSystem"', pane_start)
    pane = INDEX_HTML[pane_start:pane_end]

    assert "Read-only diagnostics" in pane
    assert "Extensions run in the WebUI browser origin" in pane
    assert "Only load trusted local extension directories" in pane
    assert "copyExtensionsDiagnostics()" in pane
    assert "saveSettings(" not in pane
    assert "api('/api/settings'" not in pane
    assert "type=\"checkbox\"" not in pane
    assert "toggle" not in pane.lower()
    assert "install" not in pane.lower()
    assert "marketplace" not in pane.lower()


def test_switch_settings_section_supports_extensions_lazy_load():
    switch_block = _function_block("switchSettingsSection", extra=2300)

    assert "name==='extensions'" in switch_block
    assert "plugins:'Plugins',extensions:'Extensions'" in switch_block
    assert "'plugins','extensions','system'" in switch_block.replace("\n", "")
    assert "if(section==='extensions') loadExtensionsPanel();" in switch_block


def test_settings_search_knows_extensions_pane():
    build_block = _function_block("_buildSettingsIndex", extra=2600)
    filter_block = _function_block("filterSettings", extra=1700)
    resolve_block = _function_block("_resolveSettingsField", extra=1400)

    assert "loadExtensionsPanel()" in build_block
    assert "settingsPaneExtensions: 'extensions'" in build_block
    assert "extensions: t('settings_tab_extensions') || 'Extensions'" in filter_block
    assert "extensions: 'settingsPaneExtensions'" in resolve_block


def test_extensions_panel_fetches_status_endpoint_only():
    load_block = _function_block("loadExtensionsPanel", extra=900)

    assert "api('/api/extensions/status')" in load_block
    assert "api('/api/settings'" not in load_block
    assert not _contains_post_method(load_block)
    assert "extensions-error" in load_block


def test_extensions_panel_renders_sanitized_status_payload():
    render_block = _between("function _renderExtensionsPanel", "async function loadExtensionsPanel")
    warning_block = _function_block("_extensionWarningList", extra=900)
    asset_block = _function_block("_extensionAssetList", extra=500)

    assert "extension_dir_configured" in render_block
    assert "extension_dir_valid" in render_block
    assert "manifest.status" in render_block
    assert "manifest.entry_count" in render_block
    assert "manifest.script_count" in render_block
    assert "manifest.stylesheet_count" in render_block
    assert "script_urls" in render_block
    assert "stylesheet_urls" in render_block
    assert "data&&data.warnings" in render_block
    assert "esc(url)" in asset_block
    assert "esc(manifest.status||'unknown')" in render_block
    assert "esc((item&&item.code)||'unknown_warning')" in warning_block
    assert "esc((item&&item.source)||'unknown')" in warning_block
    assert "Rejected" not in render_block  # rejected values must never be rendered directly


def test_copy_extensions_diagnostics_copies_current_sanitized_payload():
    copy_block = _between("function copyExtensionsDiagnostics", "// ── Plugins panel")

    assert "JSON.stringify(_extensionsStatusData,null,2)" in copy_block
    assert "navigator.clipboard.writeText(text)" in copy_block
    assert "api('/api/settings'" not in copy_block
    assert "api('/api/extensions'" not in copy_block
    assert not _contains_post_method(copy_block)


def test_extensions_styles_are_scoped_to_extensions_panel():
    assert ".extensions-diagnostics" in STYLE_CSS
    assert ".extensions-trust-note" in STYLE_CSS
    assert ".extension-summary-grid" in STYLE_CSS
    assert ".extension-warning-list" in STYLE_CSS
    assert ".extension-url-list" in STYLE_CSS


def test_extensions_tab_i18n_key_exists_for_all_locales():
    blocks = _locale_blocks()

    assert len(blocks) == _locale_count()
    missing = [name for name, block in blocks.items() if "settings_tab_extensions" not in block]
    assert not missing, f"Locale(s) missing settings_tab_extensions: {missing}"


def test_extensions_docs_mentions_settings_panel_without_mutation_claims():
    diagnostics_section = DOCS_EXTENSIONS[DOCS_EXTENSIONS.index("## Diagnostics"):]

    assert "Settings → Extensions" in diagnostics_section
    assert "enable, disable, install, or mutate extensions" in diagnostics_section
    assert "`/api/extensions/status`" in diagnostics_section
    assert "do **not** return" in diagnostics_section