#!/usr/bin/env python
"""Launch the ows-analytics app for an endpoint_diff capture.

Same Flask app as ``make dev``, with three deliberate differences that make it
safe to drive programmatically and to compare two git checkouts:

* ``use_reloader=False`` -- single OS process, so it can be killed cleanly
  between ``git checkout``s (the debug reloader spawns a child watcher).
* ``debug=False``        -- deterministic error pages; an unhandled 500 returns
  the same plain body on both builds instead of the Werkzeug debugger HTML.
* ``REDIS_HOST`` forced empty -- ``analytics.connectors.redis`` then falls back
  to ``fakeredis``, an in-process cache that lives and dies with this process.
  Each capture therefore starts cold and no cached value can leak from one
  build's run into another's.

``application`` is imported *after* the environment is set and the repo root is
on ``sys.path``, so it always loads the currently checked-out code.

The repo root is normally derived from this file's location. ``run.sh`` /
``resample.sh`` stage a copy of this script into ``_out/`` so it survives a
``git checkout`` of a before-ref that predates this directory, and point the
copy back at the repo with ``ENDPOINT_DIFF_ROOT`` -- which takes precedence.
"""
import os
import subprocess
import sys

ROOT = os.environ.get("ENDPOINT_DIFF_ROOT") or os.path.abspath(
    os.path.join(os.path.dirname(__file__), "..", "..", "..")
)
os.chdir(ROOT)
sys.path.insert(0, ROOT)

# Force fakeredis. analytics.config calls load_dotenv(override=False), which
# will not override a variable that is already present in the environment.
os.environ["REDIS_HOST"] = ""
os.environ.setdefault("Environment", "dev")

HOST = os.environ.get("ENDPOINT_DIFF_HOST", "127.0.0.1")
PORT = int(os.environ.get("ENDPOINT_DIFF_PORT", "5000"))

from application import app  # noqa: E402  (env + sys.path must be set first)

if __name__ == "__main__":
    try:
        rev = subprocess.check_output(
            ["git", "rev-parse", "--short", "HEAD"], text=True, cwd=ROOT
        ).strip()
    except Exception:
        rev = "?"
    print(
        f"[endpoint_diff serve] git={rev} http://{HOST}:{PORT} "
        f"debug=off reloader=off fakeredis",
        flush=True,
    )
    app.run(host=HOST, port=PORT, debug=False, use_reloader=False, threaded=True)