#!/usr/bin/env python3
"""Guarded deploy for the shared Supabase edge-function volume.

Several independent projects deploy into one edge-runtime volume. Before this
gate existed they rsynced whole trees into it, so whoever deployed last silently
overwrote any function name they happened to share. That is how the miniapp's
telegram-auth disappeared on 2026-06-28 and stayed broken for a month.

This is the only supported way to write into the volume. It refuses to touch a
directory the calling project does not own, and it refuses names that are not in
the registry at all, so a new collision cannot be introduced by accident.

  supabase-deploy-functions --project <name> --src <dir> [--restart] [--dry-run]

Exit codes: 0 ok, 1 refused (nothing written), 2 usage/internal error.
"""

import argparse
import fcntl
import json
import os
import shutil
import subprocess
import sys
import tempfile
import time
from datetime import datetime, timezone

REGISTRY = "/opt/supabase-self-hosted/functions-registry.json"
VOLUME = "/opt/supabase-self-hosted/docker/volumes/functions"
LOG = "/var/log/supabase-function-deploys.log"
LOCK = "/var/lock/supabase-function-deploy.lock"
CONTAINER = "supabase-edge-functions"
COMPOSE_DIR = "/opt/supabase-self-hosted/docker"


def fail(msg, code=1):
    print("ERROR: " + msg, file=sys.stderr)
    sys.exit(code)


def load_registry():
    try:
        with open(REGISTRY) as fh:
            data = json.load(fh)
    except FileNotFoundError:
        fail("registry not found at " + REGISTRY, 2)
    except json.JSONDecodeError as exc:
        fail("registry is not valid JSON: %s" % exc, 2)

    projects = data.get("projects")
    if not isinstance(projects, dict):
        fail("registry has no 'projects' object", 2)

    owner_of = {}
    for project, names in projects.items():
        for name in names:
            if name in owner_of:
                fail("registry is inconsistent: '%s' is claimed by both '%s' and '%s'"
                     % (name, owner_of[name], project), 2)
            owner_of[name] = project
    return projects, owner_of


def container_running():
    out = subprocess.run(
        ["docker", "inspect", "-f", "{{.State.Running}}", CONTAINER],
        capture_output=True, text=True,
    )
    return out.returncode == 0 and out.stdout.strip() == "true"


def restart_runtime():
    """Recreate the edge runtime, tolerating a racing restart.

    `docker compose up --force-recreate` fails with "No such container" when
    something else recreated the container between compose reading state and
    acting on it — a hand-run restart, or another project's deploy. The deploy
    itself already succeeded at that point, so failing the whole run over it
    reports a false failure. Retry, then fall back to checking whether the
    runtime is actually up.
    """
    for attempt in (1, 2, 3):
        r = subprocess.run(
            ["docker", "compose", "up", "-d", "--force-recreate", "functions"],
            cwd=COMPOSE_DIR, capture_output=True, text=True,
        )
        if r.returncode == 0:
            print("Edge runtime recreated.")
            return
        print("restart attempt %d failed: %s" % (attempt, r.stderr.strip()[:200]), file=sys.stderr)
        time.sleep(3)

    # Compose kept failing. If the runtime is up it is serving the files we just
    # wrote, so the deploy stands; say so rather than reporting a false failure.
    if container_running():
        print("WARNING: could not recreate the runtime, but %s is running and "
              "serving the deployed files." % CONTAINER, file=sys.stderr)
        log_line("%s RESTART-DEGRADED container=%s" % (
            datetime.now(timezone.utc).isoformat(timespec="seconds"), CONTAINER))
        return
    fail("restart failed and %s is not running" % CONTAINER, 2)


def log_line(text):
    try:
        with open(LOG, "a") as fh:
            fh.write(text + "\n")
    except OSError:
        pass  # logging must never block a deploy


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--project", required=True)
    ap.add_argument("--src", required=True, help="staging dir holding one subdir per function")
    ap.add_argument("--restart", action="store_true", help="recreate the edge runtime afterwards")
    ap.add_argument("--dry-run", action="store_true")
    args = ap.parse_args()

    projects, owner_of = load_registry()
    if args.project not in projects:
        fail("unknown project '%s'. Known: %s" % (args.project, ", ".join(sorted(projects))), 2)
    owned = set(projects[args.project])

    if not os.path.isdir(args.src):
        fail("source dir not found: " + args.src, 2)

    incoming = sorted(
        d for d in os.listdir(args.src)
        if os.path.isdir(os.path.join(args.src, d)) and not d.startswith("__")
    )
    if not incoming:
        fail("no function directories found under " + args.src, 2)

    # Validate everything before writing anything: a partial deploy is worse
    # than a refused one.
    foreign, unknown = [], []
    for name in incoming:
        if name in owned:
            continue
        if name in owner_of:
            foreign.append((name, owner_of[name]))
        else:
            unknown.append(name)

    if foreign or unknown:
        print("Refusing to deploy — nothing was written.\n", file=sys.stderr)
        for name, owner in foreign:
            print("  '%s' belongs to '%s', not '%s'" % (name, owner, args.project), file=sys.stderr)
        for name in unknown:
            print("  '%s' is not in the registry. Add it to %s under an owner first."
                  % (name, REGISTRY), file=sys.stderr)
        print("\nRegistry: " + REGISTRY, file=sys.stderr)
        log_line("%s REFUSED project=%s foreign=%s unknown=%s" % (
            datetime.now(timezone.utc).isoformat(timespec="seconds"),
            args.project, [n for n, _ in foreign], unknown))
        sys.exit(1)

    if args.dry_run:
        print("dry-run OK — %s may deploy: %s" % (args.project, ", ".join(incoming)))
        return

    # Two projects deploy into this volume and both restart the same runtime, so
    # serialise from here on. Without it a second deploy can recreate the
    # container while the first is mid-restart, which is exactly what turned a
    # successful deploy into a failed job on 2026-07-30.
    lock_fd = os.open(LOCK, os.O_CREAT | os.O_RDWR, 0o644)
    try:
        fcntl.flock(lock_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
    except BlockingIOError:
        print("another deploy is in progress, waiting for it to finish...")
        fcntl.flock(lock_fd, fcntl.LOCK_EX)

    os.makedirs(VOLUME, exist_ok=True)
    for name in incoming:
        src = os.path.join(args.src, name)
        dst = os.path.join(VOLUME, name)
        # Stage beside the target, then swap, so a reader never sees a half-written function.
        staged = tempfile.mkdtemp(prefix=".deploy-%s-" % name, dir=VOLUME)
        try:
            tree = os.path.join(staged, name)
            shutil.copytree(src, tree)
            old = dst + ".old"
            if os.path.exists(old):
                shutil.rmtree(old)
            if os.path.exists(dst):
                os.rename(dst, old)
            os.rename(tree, dst)
            if os.path.exists(old):
                shutil.rmtree(old)
        finally:
            shutil.rmtree(staged, ignore_errors=True)

    stamp = datetime.now(timezone.utc).isoformat(timespec="seconds")
    log_line("%s DEPLOYED project=%s functions=%s" % (stamp, args.project, ",".join(incoming)))
    print("Deployed %d function(s) for %s: %s" % (len(incoming), args.project, ", ".join(incoming)))

    if args.restart:
        restart_runtime()


if __name__ == "__main__":
    main()