#!/usr/bin/env python3
"""Attach the files of a release folder (release-files.py) to the Gitea release of the tag.

    TOKEN=<job token> python3 .gitea/scripts/release-attach.py /tmp/release

Reads GITHUB_SERVER_URL, GITHUB_REPOSITORY and GITHUB_REF_NAME (the tag), as Gitea Actions sets
them. Creates the release when the tag has none, with the tag's CHANGELOG.md section as its text.
Uploads every file of the folder except README.md, and <repository>-<tag>.zip with the whole folder;
an asset of the same name from an earlier run of the tag is replaced. Used by
.gitea/workflows/release.yml.
"""
import io
import json
import os
import re
import sys
import urllib.error
import urllib.parse
import urllib.request
import uuid
import zipfile
from pathlib import Path

ROOT = Path(__file__).resolve().parents[2]
ZIP_TIME = (2020, 1, 1, 0, 0, 0)


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


def bundle(folder, top):
    """The whole folder as a zip under <top>/, with fixed timestamps."""
    buf = io.BytesIO()
    with zipfile.ZipFile(buf, "w", zipfile.ZIP_DEFLATED) as z:
        for p in sorted(folder.rglob("*")):
            if p.is_file():
                info = zipfile.ZipInfo(f"{top}/{p.relative_to(folder).as_posix()}", date_time=ZIP_TIME)
                info.compress_type = zipfile.ZIP_DEFLATED
                z.writestr(info, p.read_bytes())
    return buf.getvalue()


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=120) 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
        notes = changelog(tag)
        body = (f"{notes}\n\n" if notes else "") + "Gerbers, BOM, pick and place, PDFs and documentation: the files below."
        return self.call("POST", "/releases", json.dumps({"tag_name": tag, "name": tag, "body": 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():
    if len(sys.argv) != 2:
        sys.exit(__doc__)
    folder = Path(sys.argv[1])
    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)}")
    tag, repo = env["GITHUB_REF_NAME"], env["GITHUB_REPOSITORY"]
    files = [(p.name, p.read_bytes()) for p in sorted(folder.rglob("*")) if p.is_file() and p.name != "README.md"]
    top = f"{repo.split('/')[-1]}-{tag}"
    files.append((f"{top}.zip", bundle(folder, top)))
    names = [n for n, _ in files]
    if len(set(names)) != len(names):
        sys.exit(f"two files of the same name: {sorted(n for n in names if names.count(n) > 1)}")

    g = Gitea(env["GITHUB_SERVER_URL"], repo, env["TOKEN"])
    rel, created = g.release(tag)
    print(("created" if created else "found") + f" release {tag} (id {rel['id']})")
    old = {a["name"]: a["id"] for a in rel.get("assets") or []}
    for name, data in files:
        if name in old:
            g.call("DELETE", f"/releases/{rel['id']}/assets/{old[name]}")
        g.upload(rel, name, data)
        print(f"   {'replaced' if name in old else 'attached'} {name} ({len(data):,} bytes)")


if __name__ == "__main__":
    main()