#!/usr/bin/env python3
"""Attach files to the Gitea release of the current tag; create the release when missing.

    TOKEN=<job token> python3 .gitea/scripts/release-attach.py dist/*.zip dist/*.tar.gz

Reads GITHUB_SERVER_URL, GITHUB_REPOSITORY and GITHUB_REF_NAME (the tag), as Gitea Actions sets
them. A new release gets the tag's CHANGELOG.md section as its text. An asset of the same name
from an earlier run of the tag is replaced. Used by .gitea/workflows/release.yml.
"""
import json
import os
import re
import sys
import urllib.error
import urllib.parse
import urllib.request
import uuid
from pathlib import Path

ROOT = Path(__file__).resolve().parents[2]


def changelog(tag):
    path = ROOT / "CHANGELOG.md"
    if not path.exists():
        return ""
    text = path.read_text(encoding="utf-8")
    m = re.search(rf"^## {re.escape(tag)}\b.*?$(.*?)(?=^## |\Z)", text, re.M | re.S)
    return m.group(1).strip() if m else ""


class Gitea:
    def __init__(self, server, repo, token):
        self.api = f"{server.rstrip('/')}/api/v1/repos/{repo}"
        self.auth = {"Authorization": f"token {token}"}

    def call(self, method, path, body=None, ctype="application/json"):
        req = urllib.request.Request(
            self.api + path,
            data=body,
            method=method,
            headers={**self.auth, "Content-Type": ctype, "Accept": "application/json"},
        )
        with urllib.request.urlopen(req, timeout=300) as r:
            data = r.read()
        return json.loads(data) if data.strip() else None

    def release(self, tag):
        try:
            return self.call("GET", f"/releases/tags/{urllib.parse.quote(tag, safe='')}"), False
        except urllib.error.HTTPError as e:
            if e.code != 404:
                raise
        body = json.dumps({"tag_name": tag, "name": f"NFC tag writer {tag}", "body": changelog(tag)})
        return self.call("POST", "/releases", body.encode()), True

    def upload(self, rel, name, data):
        b = uuid.uuid4().hex
        head = (
            f'--{b}\r\nContent-Disposition: form-data; name="attachment"; filename="{name}"\r\n'
            "Content-Type: application/octet-stream\r\n\r\n"
        ).encode()
        body = head + data + f"\r\n--{b}--\r\n".encode()
        self.call(
            "POST",
            f"/releases/{rel['id']}/assets?name={urllib.parse.quote(name)}",
            body,
            f"multipart/form-data; boundary={b}",
        )


def main():
    paths = [Path(p) for p in sys.argv[1:]]
    if not paths:
        sys.exit(__doc__)
    env = {k: os.environ.get(k, "") for k in ("GITHUB_SERVER_URL", "GITHUB_REPOSITORY", "GITHUB_REF_NAME", "TOKEN")}
    missing = [k for k, v in env.items() if not v]
    if missing:
        sys.exit(f"missing environment: {', '.join(missing)}")
    g = Gitea(env["GITHUB_SERVER_URL"], env["GITHUB_REPOSITORY"], env["TOKEN"])
    rel, created = g.release(env["GITHUB_REF_NAME"])
    print(("created" if created else "found") + f" release {env['GITHUB_REF_NAME']} (id {rel['id']})")
    old = {a["name"]: a["id"] for a in rel.get("assets") or []}
    for p in paths:
        if p.name in old:
            g.call("DELETE", f"/releases/{rel['id']}/assets/{old[p.name]}")
        data = p.read_bytes()
        g.upload(rel, p.name, data)
        print(f"   {'replaced' if p.name in old else 'attached'} {p.name} ({len(data):,} bytes)")


if __name__ == "__main__":
    main()