#!/usr/bin/env python3
"""Create a Forgejo release for the current tag and attach a binary asset.

Invoked by .forgejo/workflows/release.yml after the single-file executable
is built. Uses only the stdlib (urllib) so it runs in the bare CI Python
with no extra dependencies.

Environment:
    FORGEJO_TOKEN   API token with contents:write (the workflow's GITHUB_TOKEN)
    FORGEJO_API     base API URL, e.g. https://build.diganthrope.com/api/v1
    REPO            owner/name, e.g. pch/zubble
    TAG             release tag, e.g. v0.1.0
    GITHUB_WORKSPACE  checkout root (for git log). Defaults to cwd.

Usage:
    python scripts/make_release.py <asset_path>
"""
import json
import os
import subprocess
import sys
import urllib.error
import urllib.request
from pathlib import Path


def _notes(repo_root: str, tag: str) -> str:
    """Release notes = commit subjects since the previous tag (or full log)."""
    prev = _previous_tag(repo_root, tag)
    if prev:
        rng = f"{prev}..{tag}"
        header = f"### Changes since {prev}\n\n"
    else:
        rng = tag
        header = "### Changes\n\n"
    try:
        out = subprocess.run(
            ["git", "log", "--pretty=format:- %s", rng],
            cwd=repo_root, capture_output=True, text=True, check=True,
        ).stdout.strip()
    except Exception:
        return header.strip()
    return header + out


def _previous_tag(repo_root: str, tag: str) -> str | None:
    try:
        out = subprocess.run(
            ["git", "tag", "--sort=-v:refname", "--list", "v*"],
            cwd=repo_root, capture_output=True, text=True, check=True,
        ).stdout.split()
    except Exception:
        return None
    # tags strictly before this one, newest first
    if tag in out:
        out = out[out.index(tag) + 1:]
    return out[0] if out else None


def _api(method, path, token, api_base, body=None, multipart=None):
    url = f"{api_base}/{path.lstrip('/')}"
    headers = {"Authorization": f"token {token}"}
    data = None
    if body is not None:
        data = json.dumps(body).encode()
        headers["Content-Type"] = "application/json"
    elif multipart is not None:
        data, boundary = multipart
        headers["Content-Type"] = f"multipart/form-data; boundary={boundary}"
    req = urllib.request.Request(url, data=data, method=method, headers=headers)
    try:
        with urllib.request.urlopen(req) as r:
            raw = r.read()
            return r.status, json.loads(raw) if raw else {}
    except urllib.error.HTTPError as e:
        return e.code, e.read().decode(errors="replace")


def _upload_asset(release_id, asset_path, token, api_base, repo):
    """Upload one file as a release attachment (multipart form-data)."""
    boundary = "----zubble-release-boundary"
    path = Path(asset_path)
    fields = {"name": path.name}
    parts = []
    for k, v in fields.items():
        parts.append(f"--{boundary}\r\n"
                     f'Content-Disposition: form-data; name="{k}"\r\n\r\n'
                     f"{v}\r\n")
    body = "".join(parts).encode()
    body += (f"--{boundary}\r\n"
             'Content-Disposition: form-data; name="attachment"; '
             f'filename="{path.name}"\r\n'
             "Content-Type: application/octet-stream\r\n\r\n").encode()
    body += path.read_bytes()
    body += f"\r\n--{boundary}--\r\n".encode()
    status, resp = _api(
        "POST",
        f"repos/{repo}/releases/{release_id}/assets",
        token, api_base, multipart=(body, boundary),
    )
    if status not in (200, 201):
        print(f"asset upload failed ({status}): {resp}", file=sys.stderr)
        sys.exit(1)
    print(f"  attached {path.name} ({path.stat().st_size} bytes)")


def main():
    if len(sys.argv) != 2:
        print("usage: make_release.py <asset_path>", file=sys.stderr)
        sys.exit(2)
    asset = sys.argv[1]
    token = os.environ["FORGEJO_TOKEN"]
    api = os.environ["FORGEJO_API"]
    repo = os.environ["REPO"]
    tag = os.environ["TAG"]
    root = os.environ.get("GITHUB_WORKSPACE", os.getcwd())

    notes = _notes(root, tag)
    status, resp = _api(
        "POST", f"repos/{repo}/releases", token, api,
        body={"tag_name": tag, "name": tag, "body": notes,
              "draft": False, "prerelease": False},
    )
    if status == 409:
        # Release already exists for this tag — fetch it.
        status, resp = _api(
            "GET", f"repos/{repo}/releases/tags/{tag}", token, api,
        )
        if status != 200:
            print(f"release exists but fetch failed ({status}): {resp}",
                  file=sys.stderr)
            sys.exit(1)
    elif status not in (200, 201):
        print(f"release create failed ({status}): {resp}", file=sys.stderr)
        sys.exit(1)
    else:
        print(f"created release {tag}")

    release_id = resp["id"]
    print(f"  release id: {release_id}")
    _upload_asset(release_id, asset, token, api, repo)
    print(f"release {tag} published with {Path(asset).name}")


if __name__ == "__main__":
    main()