US05-01: Validate Credentials and Upload Readiness (#71)

photo_pipeline/integrations/immich_go.py

@@ -0,0 +1,107 @@
+"""immich-go adapter: binary discovery, version, and redacted command preview.
+
+Upload is the only stage that needs credentials, so this module is also the single
+place that knows an API key exists. It never returns, logs, or renders the secret:
+:func:`build_command` produces the real argument list for the uploader, and
+:func:`redact` produces the copy that is safe for the API, the browser, and the
+activity log. Both come from the same builder so the preview can never drift from
+the command that would actually run.
+
+Server reachability uses ``/api/server/ping`` through stdlib ``urllib`` — the app
+has no HTTP client dependency and this is one request.
+"""
+
+from __future__ import annotations
+
+import json
+import shutil
+import subprocess
+import urllib.error
+import urllib.request
+from pathlib import Path
+
+REDACTED = "***"
+PING_PATH = "/api/server/ping"
+PING_TIMEOUT_SECONDS = 5.0
+
+
+def find_binary(binary: str = "immich-go") -> str | None:
+    """Absolute path of the uploader, or ``None`` when it is not installed."""
+    return shutil.which(binary)
+
+
+def version(binary: str = "immich-go") -> str | None:
+    """Reported uploader version, or ``None`` when it is missing or unusable.
+
+    The version is persisted with every batch (concept §8) because immich-go's
+    flags and report text change between releases.
+    """
+    path = find_binary(binary)
+    if path is None:
+        return None
+    try:
+        result = subprocess.run([path, "--version"], capture_output=True, text=True, timeout=30)
+    except (OSError, subprocess.SubprocessError):
+        return None
+    output = (result.stdout or result.stderr or "").strip()
+    return output.splitlines()[0].strip() if output else None
+
+
+def ping(server_url: str, *, timeout: float = PING_TIMEOUT_SECONDS) -> tuple[bool, str | None]:
+    """``(reachable, detail)`` for the configured Immich server.
+
+    A reachable Immich answers ``{"res": "pong"}``. Anything else — wrong host, no
+    Immich, HTTP error — is a blocker with a short human detail. The detail never
+    carries the URL's credentials because the key travels in a header, not the URL.
+    """
+    if not server_url:
+        return False, "no server URL configured"
+    url = server_url.rstrip("/") + PING_PATH
+    try:
+        with urllib.request.urlopen(url, timeout=timeout) as response:  # noqa: S310
+            payload = json.loads(response.read().decode("utf-8") or "{}")
+    except (urllib.error.URLError, OSError, ValueError, TimeoutError) as error:
+        return False, f"{type(error).__name__}: {error}"
+    if payload.get("res") == "pong":
+        return True, None
+    return False, "server did not answer with pong"
+
+
+def build_command(
+    *,
+    binary: str,
+    server_url: str,
+    api_key: str,
+    album_name: str,
+    folder: Path | str,
+) -> list[str]:
+    """The exact upload invocation for one folder-as-album batch."""
+    return [
+        binary,
+        "upload",
+        "from-folder",
+        f"--server={server_url}",
+        f"--api-key={api_key}",
+        f"--album-name={album_name}",
+        str(folder),
+    ]
+
+
+def redact(command: list[str]) -> list[str]:
+    """The same command with every secret-bearing argument masked."""
+    return [f"--api-key={REDACTED}" if arg.startswith("--api-key=") else arg for arg in command]
+
+
+def preview_command(
+    *, binary: str, server_url: str, album_name: str, folder: Path | str
+) -> list[str]:
+    """Redacted preview built without ever handling the real key."""
+    return redact(
+        build_command(
+            binary=binary,
+            server_url=server_url,
+            api_key=REDACTED,
+            album_name=album_name,
+            folder=folder,
+        )
+    )