# Copyright 2026 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Contains helper utilities for hf CLI extensions."""

import errno
import json
import os
import re
import shutil
import subprocess
try:
    import venv
except ImportError:
    pass
from dataclasses import asdict, dataclass
from datetime import datetime, timezone
from pathlib import Path
from typing import Annotated, Literal

import typer

from huggingface_hub.errors import CLIError, CLIExtensionInstallError, ConfirmationError
from huggingface_hub.utils import get_session, logging

from ._cli_utils import typer_factory
from ._output import out


DEFAULT_EXTENSION_OWNER = "huggingface"
EXTENSIONS_ROOT = Path("~/.local/share/hf/extensions")
MANIFEST_FILENAME = "manifest.json"
EXTENSIONS_HELP = (
    "Manage hf CLI extensions.\n\n"
    "Security Warning: extensions are third-party executables or Python packages. "
    "Install only from sources you trust."
)
extensions_cli = typer_factory(help=EXTENSIONS_HELP)
_EXTENSIONS_DEFAULT_BRANCH = "main"  # Fallback when the GitHub API is unreachable.
_EXTENSIONS_GITHUB_TOPIC = "hf-extension"
_EXTENSIONS_DOWNLOAD_TIMEOUT = 10
_EXTENSIONS_PIP_INSTALL_TIMEOUT = 300

logger = logging.get_logger(__name__)


@dataclass
class ExtensionManifest:
    owner: str
    repo: str
    repo_id: str
    short_name: str
    executable_name: str
    executable_path: str
    type: Literal["binary", "python"]
    installed_at: datetime
    source: str
    description: str | None = None

    @classmethod
    def load(cls, path: Path) -> "ExtensionManifest":
        manifest_path = path / MANIFEST_FILENAME
        if not manifest_path.is_file():
            raise CLIError(f"Manifest file not found at {manifest_path}. Your extension may be corrupted.")
        data = json.loads(manifest_path.read_text())
        data["installed_at"] = datetime.fromisoformat(data["installed_at"])
        return ExtensionManifest(**data)

    def save(self, path: Path) -> None:
        manifest_path = path / MANIFEST_FILENAME
        manifest_path.parent.mkdir(parents=True, exist_ok=True)
        data = asdict(self)
        data["installed_at"] = self.installed_at.isoformat()
        manifest_path.write_text(json.dumps(data, indent=2, sort_keys=True))


@extensions_cli.command(
    "install",
    examples=[
        "hf extensions install hf-claude",
        "hf extensions install hanouticelina/hf-claude",
        "hf extensions install alvarobartt/hf-mem",
    ],
)
def extension_install(
    ctx: typer.Context,
    repo_id: Annotated[
        str,
        typer.Argument(help="GitHub extension repository in `[OWNER/]hf-<name>` format."),
    ],
    force: Annotated[bool, typer.Option("--force", help="Overwrite if already installed.")] = False,
) -> None:
    """Install an extension from a public GitHub repository.

    Security warning: this installs a third-party executable or Python package.
    Install only from sources you trust.
    """
    owner, repo_name, short_name = _normalize_repo_id(repo_id)
    root_ctx = ctx.find_root()
    reserved_commands = set(getattr(root_ctx.command, "commands", {}).keys())
    if short_name in reserved_commands:
        raise CLIError(
            f"Cannot install extension '{short_name}' because it conflicts with an existing `hf {short_name}` command."
        )

    extension_dir = _get_extension_dir(short_name)
    extension_exists = extension_dir.exists()
    if extension_exists and not force:
        raise CLIError(f"Extension '{short_name}' is already installed. Use --force to overwrite.")

    branch, description = _resolve_github_repo_info(owner=owner, repo_name=repo_name)

    if extension_exists:
        shutil.rmtree(extension_dir)

    manifest = _install_extension_from_github(
        owner=owner,
        repo_name=repo_name,
        short_name=short_name,
        extension_dir=extension_dir,
        branch=branch,
        description=description,
    )
    ext_type = manifest.type.capitalize()
    print(f"{ext_type} extension installed successfully from {owner}/{repo_name}.")
    print(f"Run it with: hf {short_name}")


@extensions_cli.command(
    "exec",
    context_settings={"allow_extra_args": True, "allow_interspersed_args": False, "ignore_unknown_options": True},
    examples=[
        "hf extensions exec claude -- --help",
        "hf extensions exec claude --model zai-org/GLM-5",
    ],
)
def extension_exec(
    ctx: typer.Context,
    name: Annotated[
        str,
        typer.Argument(help="Extension name (with or without `hf-` prefix)."),
    ],
) -> None:
    """Execute an installed extension."""
    short_name = _normalize_extension_name(name)
    executable_path = _resolve_installed_executable_path(short_name)

    if not executable_path.is_file():
        raise CLIError(f"Extension '{short_name}' is not installed.")

    exit_code = _execute_extension_binary(executable_path=executable_path, args=list(ctx.args))
    raise typer.Exit(code=exit_code)


@extensions_cli.command("list | ls", examples=["hf extensions list"])
def extension_list() -> None:
    """List installed extension commands."""
    rows = [
        {
            "command": f"hf {manifest.short_name}",
            "source": str(manifest.repo_id),
            "type": str(manifest.type),
            "installed": manifest.installed_at.strftime("%Y-%m-%d"),
            "description": manifest.description,
        }
        for manifest in _list_installed_extensions()
    ]
    out.table(rows, id_key="command")


@extensions_cli.command("search", examples=["hf extensions search"])
def extension_search() -> None:
    """Search extensions available on GitHub (tagged with 'hf-extension' topic)."""
    response = get_session().get(
        "https://api.github.com/search/repositories",
        params={"q": f"topic:{_EXTENSIONS_GITHUB_TOPIC}", "sort": "stars", "order": "desc", "per_page": 100},
        follow_redirects=True,
        timeout=_EXTENSIONS_DOWNLOAD_TIMEOUT,
    )
    response.raise_for_status()
    data = response.json()

    installed = {m.short_name for m in _list_installed_extensions()}

    rows = []
    for repo in data.get("items", []):
        repo_name = repo["name"]
        short_name = repo_name[3:] if repo_name.startswith("hf-") else repo_name
        rows.append(
            {
                "name": short_name,
                "repo": repo["full_name"],
                "stars": repo.get("stargazers_count", 0),
                "description": repo.get("description") or "",
                "installed": "yes" if short_name in installed else "",
            }
        )

    out.table(rows, id_key="repo", alignments={"stars": "right"})


@extensions_cli.command("remove | rm", examples=["hf extensions remove claude"])
def extension_remove(
    name: Annotated[
        str,
        typer.Argument(help="Extension name to remove (with or without `hf-` prefix)."),
    ],
) -> None:
    """Remove an installed extension."""
    short_name = _normalize_extension_name(name)
    extension_dir = _get_extension_dir(short_name)

    if not extension_dir.is_dir():
        raise CLIError(f"Extension '{short_name}' is not installed.")

    shutil.rmtree(extension_dir)
    print(f"Removed extension '{short_name}'.")


### HELPER FUNCTIONS


def _list_installed_extensions() -> list[ExtensionManifest]:
    """Return manifests for all validly-installed extensions, sorted by directory name."""
    root_dir = EXTENSIONS_ROOT.expanduser()
    if not root_dir.is_dir():
        return []
    manifests = []
    for extension_dir in sorted(root_dir.iterdir()):
        if not extension_dir.is_dir() or not extension_dir.name.startswith("hf-"):
            continue
        try:
            manifests.append(ExtensionManifest.load(extension_dir))
        except Exception as e:
            logger.debug(f"Failed to load manifest for extension '{extension_dir.name}': {e}")
            continue
    return manifests


def list_installed_extensions_for_help() -> list[tuple[str, str]]:
    entries = []
    for manifest in _list_installed_extensions():
        tag = f"[extension {manifest.repo_id}]"
        help_text = f"{manifest.description} {tag}" if manifest.description is not None else tag
        entries.append((manifest.short_name, help_text))
    return entries


def dispatch_unknown_top_level_extension(args: list[str], known_commands: set[str]) -> int | None:
    if not args:
        return None

    command_name = args[0]
    if command_name.startswith("-"):
        return None
    all_known = {a.strip() for cmd in known_commands for a in cmd.split("|")}
    if command_name in all_known:
        return None

    short_name = command_name[3:] if command_name.startswith("hf-") else command_name
    if not short_name:
        return None

    executable_path: Path | None = None
    try:
        executable_path = _resolve_installed_executable_path(short_name)
    except Exception:
        executable_path = _auto_install_official_extension(short_name)

    if executable_path is None or not executable_path.is_file():
        return None

    return _execute_extension_binary(executable_path=executable_path, args=list(args[1:]))


def _auto_install_official_extension(short_name: str) -> Path | None:
    """Try to auto-install huggingface/hf-<name>. Returns executable path or None."""
    owner, repo_name = DEFAULT_EXTENSION_OWNER, f"hf-{short_name}"
    try:
        extension_dir = _get_extension_dir(short_name)
    except Exception:
        return None
    if extension_dir.exists():
        return None
    try:
        response = get_session().get(
            f"https://api.github.com/repos/{owner}/{repo_name}",
            follow_redirects=True,
            timeout=_EXTENSIONS_DOWNLOAD_TIMEOUT,
        )
        if response.status_code == 404:
            return None
        response.raise_for_status()
        branch = response.json()["default_branch"]
    except Exception:
        return None
    try:
        out.confirm(f"'{short_name}' is an official Hugging Face extension ({owner}/{repo_name}). Install it?")
    except ConfirmationError:
        return None
    try:
        manifest = _install_extension_from_github(
            owner=owner, repo_name=repo_name, short_name=short_name, extension_dir=extension_dir, branch=branch
        )
        return Path(manifest.executable_path).expanduser()
    except Exception:
        shutil.rmtree(extension_dir, ignore_errors=True)
        return None


def _install_extension_from_github(
    *,
    owner: str,
    repo_name: str,
    short_name: str,
    extension_dir: Path,
    branch: str,
    description: str | None = None,
) -> ExtensionManifest:
    """Fetch, install (binary or Python), and save manifest for a GitHub extension."""
    try:
        binary = _fetch_remote_binary(owner=owner, repo_name=repo_name, branch=branch, short_name=short_name)
    except Exception:
        binary = None
    if binary is not None:
        manifest = _install_binary_extension(
            owner=owner, repo_name=repo_name, short_name=short_name, extension_dir=extension_dir, binary=binary
        )
    else:
        manifest = _install_python_extension(
            owner=owner, repo_name=repo_name, short_name=short_name, extension_dir=extension_dir, branch=branch
        )
    manifest.description = _try_fetch_remote_description(
        owner=owner, repo_name=repo_name, branch=branch, candidate_description=description
    )
    manifest.save(extension_dir)
    return manifest


def _fetch_remote_binary(owner: str, repo_name: str, branch: str, short_name: str) -> bytes:
    executable_name = _get_executable_name(short_name)
    raw_url = f"https://raw.githubusercontent.com/{owner}/{repo_name}/refs/heads/{branch}/{executable_name}"
    response = get_session().get(raw_url, follow_redirects=True, timeout=_EXTENSIONS_DOWNLOAD_TIMEOUT)
    response.raise_for_status()
    return response.content


def _install_binary_extension(
    *, owner: str, repo_name: str, short_name: str, extension_dir: Path, binary: bytes
) -> ExtensionManifest:
    # Save extension binary
    executable_name = _get_executable_name(short_name)
    extension_dir.mkdir(parents=True, exist_ok=False)
    executable_path = extension_dir / executable_name
    executable_path.write_bytes(binary)

    # Make it executable
    if os.name != "nt":
        os.chmod(executable_path, 0o755)

    # Create manifest
    return ExtensionManifest(
        owner=owner,
        repo=repo_name,
        repo_id=f"{owner}/{repo_name}",
        short_name=short_name,
        executable_name=executable_name,
        executable_path=str(executable_path),
        type="binary",
        installed_at=datetime.now(timezone.utc),
        source=f"https://github.com/{owner}/{repo_name}",
    )


def _install_python_extension(
    *, owner: str, repo_name: str, short_name: str, extension_dir: Path, branch: str
) -> ExtensionManifest:
    source_url = f"https://github.com/{owner}/{repo_name}/archive/refs/heads/{branch}.zip"
    venv_dir = extension_dir / "venv"
    installed = False

    status = out.status()
    try:
        status.update(f"Creating virtual environment in {venv_dir}")
        if extension_dir.exists():
            shutil.rmtree(extension_dir, ignore_errors=True)
        extension_dir.mkdir(parents=True, exist_ok=False)

        uv_path = shutil.which("uv")
        venv_python = _get_venv_python_path(venv_dir)
        if uv_path:
            subprocess.run([uv_path, "venv", str(venv_dir)], check=True)
            status.done(f"Virtual environment created in {venv_dir}")

            status.update(f"Installing package from {source_url}")
            subprocess.run(
                [uv_path, "pip", "install", "--python", str(venv_python), source_url],
                check=True,
                timeout=_EXTENSIONS_PIP_INSTALL_TIMEOUT,
            )
        else:
            venv.EnvBuilder(with_pip=True).create(str(venv_dir))
            status.done(f"Virtual environment created in {venv_dir}")

            status.update(f"Installing package from {source_url}")
            subprocess.run(
                [
                    str(venv_python),
                    "-m",
                    "pip",
                    "install",
                    "--disable-pip-version-check",
                    "--no-input",
                    source_url,
                ],
                check=True,
                timeout=_EXTENSIONS_PIP_INSTALL_TIMEOUT,
            )
        status.done(f"Package installed from {source_url}")

        executable_name = _get_executable_name(short_name)
        venv_executable = _get_venv_extension_executable_path(venv_dir, short_name)
        if not venv_executable.is_file():
            raise CLIError(
                f"Installed package from '{owner}/{repo_name}' does not expose the required console script "
                f"'{executable_name}'."
            )

        manifest = ExtensionManifest(
            owner=owner,
            repo=repo_name,
            repo_id=f"{owner}/{repo_name}",
            short_name=short_name,
            executable_name=executable_name,
            executable_path=str(venv_executable.resolve()),
            type="python",
            installed_at=datetime.now(timezone.utc),
            source=f"https://github.com/{owner}/{repo_name}",
        )
        installed = True
        return manifest
    except CLIError:
        raise
    except subprocess.TimeoutExpired as e:
        raise CLIExtensionInstallError(
            f"Pip install timed out after {_EXTENSIONS_PIP_INSTALL_TIMEOUT}s for '{owner}/{repo_name}'. "
            "See pip output above for details."
        ) from e
    except subprocess.CalledProcessError as e:
        raise CLIExtensionInstallError(
            f"Failed to install pip package from '{owner}/{repo_name}' (exit code {e.returncode}). "
            "See pip output above for details."
        ) from e
    except Exception as e:
        raise CLIExtensionInstallError(f"Failed to set up pip extension from '{owner}/{repo_name}': {e}") from e
    finally:
        if not installed:
            shutil.rmtree(extension_dir, ignore_errors=True)


def _try_fetch_remote_description(
    owner: str, repo_name: str, branch: str, candidate_description: str | None
) -> str | None:
    """Try to fetch project description either from:
    - manifest.json
    - pyproject.toml

    Only best effort, no error handling.
    """
    # from manifest.json
    try:
        response = get_session().get(
            f"https://raw.githubusercontent.com/{owner}/{repo_name}/refs/heads/{branch}/{MANIFEST_FILENAME}",
            follow_redirects=True,
        )
        response.raise_for_status()
        data = response.json()
        description = data.get("description")
        if isinstance(description, str):
            return description
    except Exception:
        pass

    # from pyproject.toml
    try:
        response = get_session().get(
            f"https://raw.githubusercontent.com/{owner}/{repo_name}/refs/heads/{branch}/pyproject.toml",
            follow_redirects=True,
        )
        response.raise_for_status()

        # Weak parser but ok for "best effort"
        for line in response.text.splitlines():
            line = line.strip()
            if line.startswith("description"):
                _, _, value = line.partition("=")
                return value.strip().strip("\"'")
    except Exception:
        pass

    # fallback to value fetched from GH API directly
    return candidate_description


def _get_extensions_root() -> Path:
    root_dir = EXTENSIONS_ROOT.expanduser()
    root_dir.mkdir(parents=True, exist_ok=True)
    return root_dir


def _get_extension_dir(short_name: str) -> Path:
    safe_name = _validate_extension_short_name(short_name, original_input=short_name)
    root = _get_extensions_root().resolve()
    target = (root / f"hf-{safe_name}").resolve()
    if root not in target.parents:
        raise CLIError(f"Invalid extension name '{short_name}'.")
    return target


def _resolve_github_repo_info(owner: str, repo_name: str) -> tuple[str, str | None]:
    try:
        response = get_session().get(
            f"https://api.github.com/repos/{owner}/{repo_name}",
            follow_redirects=True,
            timeout=_EXTENSIONS_DOWNLOAD_TIMEOUT,
        )
        response.raise_for_status()
        data = response.json()
        return data["default_branch"], data.get("description")
    except Exception:
        return _EXTENSIONS_DEFAULT_BRANCH, None


def _get_executable_name(short_name: str) -> str:
    name = f"hf-{short_name}"
    if os.name == "nt":
        name += ".exe"
    return name


def _resolve_installed_executable_path(short_name: str) -> Path:
    extension_dir = _get_extension_dir(short_name)
    manifest = ExtensionManifest.load(extension_dir)
    return Path(manifest.executable_path).expanduser()


def _get_venv_python_path(venv_dir: Path) -> Path:
    if os.name == "nt":
        return venv_dir / "Scripts" / "python.exe"
    return venv_dir / "bin" / "python"


def _get_venv_extension_executable_path(venv_dir: Path, short_name: str) -> Path:
    executable_name = _get_executable_name(short_name)
    if os.name == "nt":
        return venv_dir / "Scripts" / executable_name
    return venv_dir / "bin" / executable_name


_ALLOWED_EXTENSION_NAME = re.compile(r"^[A-Za-z0-9][A-Za-z0-9._-]*$")


def _validate_extension_short_name(short_name: str, *, original_input: str) -> str:
    name = short_name.strip()
    if not name:
        raise CLIError("Extension name cannot be empty.")
    if any(sep in name for sep in ("/", "\\")):
        raise CLIError(f"Invalid extension name '{original_input}'.")
    if ".." in name or ":" in name:
        raise CLIError(f"Invalid extension name '{original_input}'.")
    if not _ALLOWED_EXTENSION_NAME.fullmatch(name):
        raise CLIError(
            f"Invalid extension name '{original_input}'. Allowed characters: letters, digits, '.', '_' and '-'."
        )
    return name


def _normalize_repo_id(repo_id: str) -> tuple[str, str, str]:
    if "://" in repo_id:
        raise CLIError("Only GitHub repositories in `[OWNER/]hf-<name>` format are supported.")

    parts = repo_id.split("/")
    if len(parts) == 1:
        owner = DEFAULT_EXTENSION_OWNER
        repo_name = parts[0]
    elif len(parts) == 2 and all(parts):
        owner, repo_name = parts
    else:
        raise CLIError(f"Expected `[OWNER/]REPO` format, got '{repo_id}'.")

    if not repo_name.startswith("hf-"):
        raise CLIError(f"Extension repository name must start with 'hf-', got '{repo_name}'.")

    short_name = repo_name[3:]
    if not short_name:
        raise CLIError("Invalid extension repository name 'hf-'.")
    _validate_extension_short_name(short_name, original_input=repo_id)

    return owner, repo_name, short_name


def _normalize_extension_name(name: str) -> str:
    candidate = name.strip()
    if not candidate:
        raise CLIError("Extension name cannot be empty.")
    normalized = candidate[3:] if candidate.startswith("hf-") else candidate
    return _validate_extension_short_name(normalized, original_input=name)


def _execute_extension_binary(executable_path: Path, args: list[str]) -> int:
    try:
        return subprocess.call([str(executable_path)] + args)
    except OSError as e:
        if os.name == "nt" or e.errno != errno.ENOEXEC:
            raise
        return subprocess.call(["sh", str(executable_path)] + args)