cc-ci/runner/harness/screenshot.py

"""Phase 3 — app screenshot capture (plan-phase3-results-ux.md §4.2, R4/U1).

Captures a real screenshot of the deployed app while it is up (before teardown), reusing the Phase-1
Playwright browser already in the harness — no new heavy dep. The PNG is embedded in the summary
card (R3) and the dashboard (R5).

Secret-safety (R7, the cardinal screenshot guardrail): the screenshot step must NEVER capture a page
that displays generated credentials (an install wizard showing the initial admin password, a secrets
page, etc.). The DEFAULT capture is the app's **landing page** (a login form shows fields, not the
password) — safe for every recipe. A recipe that needs a post-login view opts in via a recipe-meta
`SCREENSHOT` hook: a callable `screenshot(page, domain, meta) -> None` that drives Playwright to a
safe, credential-free view and is responsible for not landing on a secrets page. The harness never
auto-fills a wizard.

Robustness (R7, cosmetics never block): every entry point is best-effort — any failure (Playwright
missing, app slow, navigation error) is swallowed and returns None so the run/verdict is unaffected.
"""

from __future__ import annotations

import os

from . import browser as harness_browser

# Default viewport for the captured screenshot — a desktop-ish frame that crops well into the card.
VIEWPORT = {"width": 1280, "height": 800}
# Hard cap so a wedged app can never hang the run on the screenshot step (R7 / Phase-1 timeouts).
NAV_DEADLINE_S = 45


def screenshot_path(run_artifact_dir: str) -> str:
    """Canonical on-disk path for a run's app screenshot (pure)."""
    return os.path.join(run_artifact_dir, "screenshot.png")


def _load_screenshot_hook(recipe_meta: dict | None):
    """Return the recipe's optional SCREENSHOT hook (a callable) if it declared one, else None.
    The hook drives Playwright to a safe post-login view; default is the landing page."""
    if not recipe_meta:
        return None
    hook = recipe_meta.get("SCREENSHOT")
    return hook if callable(hook) else None


def capture(domain: str, out_path: str, *, recipe_meta: dict | None = None) -> str | None:
    """Capture a screenshot of the live app at https://<domain>/ into out_path.

    Default: navigate to the landing page and screenshot it (credential-free, safe for any recipe).
    If the recipe declared a SCREENSHOT hook in recipe_meta, run it instead (post-login / app-specific
    view, recipe-responsible for avoiding secret pages). Returns out_path on success, else None
    (best-effort — never raises into the run; cosmetics never block, R7)."""
    try:
        from playwright.sync_api import sync_playwright
    except ImportError:  # pragma: no cover — playwright is always present in cc-ci-run
        print("  screenshot: playwright unavailable — skipping (verdict unaffected)", flush=True)
        return None

    os.makedirs(os.path.dirname(out_path) or ".", exist_ok=True)
    url = f"https://{domain}/"
    hook = _load_screenshot_hook(recipe_meta)
    try:
        with sync_playwright() as p:
            browser = p.chromium.launch(args=["--no-sandbox"])
            try:
                context = browser.new_context(ignore_https_errors=True, viewport=VIEWPORT)
                page = context.new_page()
                if hook is not None:
                    # Recipe-specific safe view (post-login etc.). The hook owns navigation +
                    # the no-secret-page guarantee; it should call page.screenshot itself, but if
                    # it doesn't, we still snap the resulting page below.
                    hook(page, domain, recipe_meta)
                    if not os.path.exists(out_path):
                        page.screenshot(path=out_path, full_page=False)
                else:
                    # Default: landing page. Accept any rendered status (200 or an auth redirect to a
                    # login form) — both are credential-free and representative of "the app is up".
                    harness_browser.goto_with_retry(
                        page,
                        url,
                        accept_statuses=(200, 301, 302, 303, 401, 403),
                        deadline_seconds=NAV_DEADLINE_S,
                        wait_until="domcontentloaded",
                    )
                    page.screenshot(path=out_path, full_page=False)
            finally:
                browser.close()
        if os.path.exists(out_path) and os.path.getsize(out_path) > 0:
            print(f"  screenshot: captured {out_path}", flush=True)
            return out_path
        print("  screenshot: produced no file — skipping (verdict unaffected)", flush=True)
        return None
    except Exception as e:  # noqa: BLE001 — screenshot is cosmetic; never fail/hang a run (R7)
        print(f"  screenshot: capture failed (non-fatal, verdict unaffected): {e}", flush=True)
        return None