#!/usr/bin/env python3
import datetime
import hashlib
import hmac
import json
import pathlib
import re
import subprocess
import sys
import time
import urllib.error
import urllib.request

BASE = pathlib.Path("/srv/graphite")
AGENT_ENV = pathlib.Path("/etc/graphite/agent.env")
HUB = "graphite-hub"
LINE = re.compile(r"""^([A-Z_][A-Z0-9_]*)=(?:'([^']*)'|"((?:[^"\\]|\\.)*)"|(.*))$""")
ESCAPES = {"n": "\n", "r": "\r", "t": "\t"}


def settings(path):
    found = {}
    for line in path.read_text(encoding="utf-8").splitlines() if path.exists() else []:
        match = LINE.match(line)
        if match:
            single, double, plain = match.group(2, 3, 4)
            found[match[1]] = single if single is not None else re.sub(
                r"\\(.)", lambda escape: ESCAPES.get(escape[1], escape[1]), double
            ) if double is not None else plain.strip()
    return found


def docker(*args):
    return subprocess.run(["docker", *args], capture_output=True, text=True, timeout=30).stdout.strip()


def hub_address():
    container = docker(
        "ps", "-q",
        "--filter", f"label=com.docker.compose.project={HUB}",
        "--filter", "label=com.docker.compose.service=app",
    ).split("\n")[0]
    if not container:
        return None
    return docker("inspect", "-f", '{{with index .NetworkSettings.Networks "edge"}}{{.IPAddress}}{{end}}', container) or None


def health(host):
    started = time.monotonic()
    try:
        probe = urllib.request.Request(f"https://{host}/", headers={"User-Agent": "project-graphite-deploy-report"})
        with urllib.request.urlopen(probe, timeout=10) as response:
            status = response.status
    except urllib.error.HTTPError as error:
        status = error.code
    except (urllib.error.URLError, OSError):
        status = None
    return status, round((time.monotonic() - started) * 1000)


def main(name, started, exit_status):
    project = settings(BASE / name / "values")
    if "HOST" not in project:
        print(f"graphite-report: {name} has no host to report")
        return 0
    secret = settings(AGENT_ENV).get("DEPLOY_REPORT_SECRET")
    address = hub_address()
    if not secret or not address:
        print(f"graphite-report: nothing reported for {name}")
        return 0
    status, ms = health(project["HOST"])
    body = json.dumps({
        "project": name,
        "tag": project.get("IMAGE_TAG", "unknown"),
        "startedAt": started,
        "finishedAt": datetime.datetime.now(datetime.UTC).strftime("%Y-%m-%dT%H:%M:%SZ"),
        "ok": exit_status == "0",
        **({"healthStatus": status} if status is not None else {}),
        "healthMs": ms,
    }).encode()
    stamp = str(int(time.time()))
    request = urllib.request.Request(
        f"http://{address}:3000/internal/deploys",
        data=body,
        method="POST",
        headers={
            "Content-Type": "application/json",
            "X-Graphite-Timestamp": stamp,
            "X-Graphite-Signature": hmac.new(secret.encode(), stamp.encode() + b"." + body, hashlib.sha256).hexdigest(),
        },
    )
    with urllib.request.urlopen(request, timeout=10) as response:
        print(f"graphite-report: {name} reported to the hub ({response.status})")
    return 0


if __name__ == "__main__":
    sys.exit(main(*sys.argv[1:4]))