"""Sync the public release repo and publish a GitHub Release.

``python build/run.py release github`` runs, in order:

1. certified-wheels gate (a passing ``release preflight`` report must exist and
   every wheel must still hash to what it recorded)
2. refuse if the version is already tagged or already has a GitHub Release
3. sync the open-source subset of this checkout into ``orisys-sdk-release``
   (``tools/sync_downstreams.py`` + the manifest's ``checks``)
4. stage ``SDK/<version>/*.whl`` into ``orisys-sdk-release/release/<version>/``
5. commit, tag ``v<version>``, push branch + tag
6. create the GitHub Release with the wheels attached, then verify the assets

Nothing mutates anything unless ``--apply`` is passed: the default is a dry run
that prints every command it would run.
"""

from __future__ import annotations

import json
import shutil
import subprocess
import sys
from dataclasses import dataclass, field
from pathlib import Path

_BUILD_ROOT = Path(__file__).resolve().parents[1]
if str(_BUILD_ROOT) not in sys.path:
    sys.path.insert(0, str(_BUILD_ROOT))

from common.paths import REPO_ROOT  # noqa: E402
from release.publish import GateResult, PublishGateError, load_gate  # noqa: E402

MANIFEST_PATH = REPO_ROOT / "tools" / "downstream_sync_manifest.json"
SYNC_TOOL = REPO_ROOT / "tools" / "sync_downstreams.py"
RELEASE_TARGET = "orisys-sdk-release"


@dataclass
class Options:
    version: str
    apply: bool = False
    notes_file: Path | None = None
    attach_preflight: bool = False
    allow_dirty_release: bool = False
    skip_fetch: bool = False
    skip_checks: bool = False
    skip_release_upload: bool = False


@dataclass
class CommandStep:
    description: str
    argv: list[str]
    cwd: Path | None = None


@dataclass
class Plan:
    release_repo: Path
    branch: str
    tag: str
    assets: list[Path] = field(default_factory=list)
    steps: list[CommandStep] = field(default_factory=list)


def manifest_entry() -> dict:
    """The manifest entry for the public release repo."""
    payload = json.loads(MANIFEST_PATH.read_text(encoding="utf-8"))
    for item in payload.get("downstreams", []):
        if item.get("name") == RELEASE_TARGET:
            return item
    raise PublishGateError(f"{MANIFEST_PATH} has no downstream named {RELEASE_TARGET!r}")


def release_repo_path() -> Path:
    return (REPO_ROOT / manifest_entry()["path"]).resolve()


def _git(repo: Path, *args: str, check: bool = True) -> str:
    completed = subprocess.run(
        ["git", "-C", str(repo), *args],
        capture_output=True,
        text=True,
        check=False,
    )
    if check and completed.returncode != 0:
        raise PublishGateError(
            f"git {' '.join(args)} failed in {repo}:\n{completed.stderr.strip()}"
        )
    return (completed.stdout or "").strip()


def build_release_notes(version: str, wheels: list[Path], git_commit: str | None) -> str:
    lines = [
        f"orisys {version}",
        "",
        "Wheels (Python 3.10 / 3.11 / 3.12, Windows x64 and Linux x86_64):",
    ]
    lines.extend(f"- `{wheel.name}`" for wheel in wheels)
    lines.append("")
    if git_commit:
        lines.append(
            f"Built from `{git_commit[:12]}` and certified by `release preflight`."
        )
    return "\n".join(lines) + "\n"


def build_github_steps(
    *,
    version: str,
    branch: str,
    tag: str,
    assets: list[Path],
    notes_file: Path | None,
    title: str | None = None,
) -> list[CommandStep]:
    """The mutating commands, as pure data so they can be asserted in tests."""
    release_argv = [
        "gh",
        "release",
        "create",
        tag,
        "--verify-tag",
        "--title",
        title or f"v{version}",
        "--latest",
    ]
    if notes_file is not None:
        release_argv += ["--notes-file", str(notes_file)]
    release_argv += [str(asset) for asset in assets]

    return [
        CommandStep("create tag", ["git", "tag", tag]),
        CommandStep("push branch", ["git", "push", "origin", branch]),
        CommandStep("push tag", ["git", "push", "origin", tag]),
        CommandStep("create GitHub Release with assets", release_argv),
    ]


def _check_gh() -> list[str]:
    """Problems that would stop the release step, reported before any mutation."""
    problems: list[str] = []
    if shutil.which("gh") is None:
        problems.append(
            "the `gh` CLI is not on PATH. Install it (`winget install --id GitHub.cli`) "
            "and authenticate (`gh auth login`), or use --skip-release-upload"
        )
        return problems
    completed = subprocess.run(
        ["gh", "auth", "status"], capture_output=True, text=True, check=False
    )
    if completed.returncode != 0:
        problems.append("`gh auth status` failed; run `gh auth login` first")
    return problems


def _existing_release_tags(repo: Path, version: str) -> list[str]:
    wanted = {version, f"v{version}"}
    tags = set(_git(repo, "tag", "--list").splitlines())
    return sorted(wanted & tags)


def _release_exists(tag: str) -> bool:
    completed = subprocess.run(
        ["gh", "release", "view", tag, "--json", "tagName"],
        capture_output=True,
        text=True,
        check=False,
    )
    return completed.returncode == 0


def _sync(*, run_checks: bool) -> None:
    """Copy the public subset into the release repo and run its checks."""
    python = sys.executable
    for command in (
        [python, str(SYNC_TOOL), "apply", "--target", RELEASE_TARGET],
        *(
            [[python, str(SYNC_TOOL), "run-checks", "--target", RELEASE_TARGET]]
            if run_checks
            else []
        ),
    ):
        completed = subprocess.run(command, cwd=REPO_ROOT, check=False)
        if completed.returncode != 0:
            raise PublishGateError(
                f"`{' '.join(command[1:])}` failed with exit {completed.returncode}"
            )


def _stage_wheels(wheels: list[Path], asset_dir: Path) -> None:
    asset_dir.mkdir(parents=True, exist_ok=True)
    for wheel in wheels:
        shutil.copy2(wheel, asset_dir / wheel.name)


def publish(options: Options) -> int:
    version = options.version
    mode = "APPLY" if options.apply else "DRY RUN"
    print(f"=== release github: orisys {version} ({mode}) ===")

    # --- 1. gate -------------------------------------------------------
    try:
        gate: GateResult = load_gate(REPO_ROOT, version)
    except PublishGateError as exc:
        print(f"[FAIL] {exc}")
        return 1
    print(f"[ok  ] preflight report: {gate.report_path}")
    print(f"       certified commit: {gate.git_commit}")
    for wheel in gate.wheels:
        print(f"       [ok] {wheel.name} sha256={wheel.sha256[:12]} {wheel.size} bytes")
    for warning in gate.warnings:
        print(f"[warn] {warning}")

    # --- 2. target repo ------------------------------------------------
    try:
        repo = release_repo_path()
    except PublishGateError as exc:
        print(f"[FAIL] {exc}")
        return 1
    if not (repo / ".git").exists():
        print(f"[FAIL] {repo} is not a git repository")
        return 1

    try:
        if not options.skip_fetch:
            _git(repo, "fetch", "--tags", "--quiet")
            print(f"[ok  ] git fetch --tags in {repo}")
        branch = _git(repo, "rev-parse", "--abbrev-ref", "HEAD")
        dirty = _git(repo, "status", "--porcelain")
    except PublishGateError as exc:
        print(f"[FAIL] {exc}")
        return 1

    if dirty and not options.allow_dirty_release:
        preview = "\n".join(dirty.splitlines()[:10])
        print(
            f"[FAIL] {repo} has uncommitted changes; commit or stash them first "
            f"(or pass --allow-dirty-release):\n{preview}"
        )
        return 1
    print(f"[ok  ] release repo: {repo} ({branch}) clean={not dirty}")

    tag = f"v{version}"
    existing = _existing_release_tags(repo, version)
    if existing:
        print(
            f"[FAIL] tag(s) {existing} already exist in {repo}; "
            f"{version} looks already released"
        )
        return 1
    if shutil.which("gh") and _release_exists(tag):
        print(f"[FAIL] GitHub Release {tag} already exists")
        return 1
    print(f"[ok  ] no existing tag or release for {tag}")

    # A dry run is a preview of what would happen, so missing tooling is a warning
    # there and a hard stop only when we are about to mutate something.
    if options.skip_release_upload:
        print("[warn] --skip-release-upload: the GitHub Release will be left to you")
    else:
        gh_problems = _check_gh()
        if gh_problems:
            for problem in gh_problems:
                print(f"[{'FAIL' if options.apply else 'warn'}] {problem}")
            if options.apply:
                return 1
        else:
            print("[ok  ] gh CLI is installed and authenticated")

    # --- 3. plan the mutating steps ------------------------------------
    wheels = [REPO_ROOT / "SDK" / version / record.name for record in gate.wheels]
    missing = [str(wheel) for wheel in wheels if not wheel.is_file()]
    if missing:
        print(f"[FAIL] wheels missing from disk: {missing}")
        return 1

    asset_dir = repo / "release" / version
    assets = [asset_dir / wheel.name for wheel in wheels]
    notes_file = options.notes_file
    steps = build_github_steps(
        version=version, branch=branch, tag=tag, assets=assets, notes_file=notes_file
    )

    print()
    print(f"[plan] sync {len(manifest_entry().get('sync', []))} entry(ies) into {repo}")
    print(f"[plan] stage {len(wheels)} wheel(s) into {asset_dir}")
    print(f"[plan] commit {repo} and tag {tag}")
    for step in steps:
        manual = options.skip_release_upload and step.description.startswith(
            "create GitHub Release"
        )
        prefix = "[plan] (left manual)" if manual else "[plan]"
        print(f"{prefix} {step.description}: {' '.join(step.argv)}")
    print()

    if not options.apply:
        print("dry run: nothing was changed. Re-run with --apply to execute.")
        return 0

    # --- 4. execute ----------------------------------------------------
    try:
        commit_before = _git(repo, "rev-parse", "HEAD")
        _sync(run_checks=not options.skip_checks)
        _stage_wheels(wheels, asset_dir)

        if options.attach_preflight:
            shutil.copy2(gate.report_path, asset_dir / f"{version}-preflight.json")

        _git(repo, "add", "-A")
        pending = _git(repo, "status", "--porcelain")
        if pending:
            _git(repo, "commit", "-m", f"release {version}")
            print(f"[ok  ] committed {len(pending.splitlines())} change(s) in {repo}")
        else:
            print("[ok  ] nothing new to commit in the release repo")

        _git(repo, "tag", tag)
        _git(repo, "push", "origin", branch)
        _git(repo, "push", "origin", tag)
        print(f"[ok  ] pushed {branch} and {tag}")
    except PublishGateError as exc:
        print(f"[FAIL] {exc}")
        return 1

    release_argv = next(
        step.argv for step in steps if step.description.startswith("create GitHub Release")
    )

    if options.skip_release_upload:
        print()
        print("[todo] publish the release yourself:")
        print("       " + " ".join(release_argv))
        print()
        print("=== release github: repo synced and tagged; release upload left manual ===")
        return 0

    completed = subprocess.run(release_argv, check=False)
    if completed.returncode != 0:
        print(f"[FAIL] gh release create exited {completed.returncode}")
        return 1
    print(f"[ok  ] GitHub Release {tag} created")

    # --- 5. verify the published assets --------------------------------
    completed = subprocess.run(
        ["gh", "release", "view", tag, "--json", "assets,tagName"],
        capture_output=True,
        text=True,
        check=False,
    )
    if completed.returncode != 0:
        print("[FAIL] could not read back the release to verify assets")
        return 1
    payload = json.loads(completed.stdout or "{}")
    published = {asset["name"] for asset in payload.get("assets", [])}
    expected = {asset.name for asset in assets}
    if options.attach_preflight:
        expected.add(f"{version}-preflight.json")
    if published != expected:
        print(
            f"[FAIL] release asset mismatch:\n  expected {sorted(expected)}\n"
            f"  published {sorted(published)}"
        )
        return 1
    print(f"[ok  ] verified {len(published)} asset(s) on the release")
    print()
    print(f"=== release github PASSED (commit {commit_before[:12]} -> {_git(repo, 'rev-parse', 'HEAD')[:12]}) ===")
    return 0