#!/usr/bin/env python3
"""Shared utilities for GitLab npm registry scripts."""

import json
import os
import ssl
import time
from dataclasses import dataclass, field
from pathlib import Path
from typing import Callable, Optional, TypeVar
from urllib.error import HTTPError, URLError
from urllib.parse import quote
from urllib.request import Request, urlopen

T = TypeVar("T")


class Color:
    """ANSI color codes for terminal output."""
    RED = "\033[0;31m"
    GREEN = "\033[0;32m"
    YELLOW = "\033[1;33m"
    BLUE = "\033[0;34m"
    CYAN = "\033[0;36m"
    BOLD = "\033[1m"
    DIM = "\033[2m"
    NC = "\033[0m"


GITLAB_NPM_REGISTRY = "https://gitlab.com/api/v4/packages/npm"
GITLAB_API_BASE = "https://gitlab.com/api/v4"
DEFAULT_SCOPE = "@transquinnftw"


class RateLimiter:
    """Rate limiter with exponential backoff for API calls."""

    def __init__(
        self,
        min_interval: float = 0.5,
        max_retries: int = 5,
        base_backoff: float = 2.0,
        max_backoff: float = 60.0,
    ):
        self.min_interval = min_interval
        self.max_retries = max_retries
        self.base_backoff = base_backoff
        self.max_backoff = max_backoff
        self._last_request_time: float = 0

    def _wait_for_interval(self) -> None:
        """Ensure minimum interval between requests."""
        elapsed = time.time() - self._last_request_time
        if elapsed < self.min_interval:
            time.sleep(self.min_interval - elapsed)

    def _get_backoff_time(self, attempt: int) -> float:
        """Calculate backoff time with exponential increase."""
        backoff = self.base_backoff ** attempt
        return min(backoff, self.max_backoff)

    def execute(
        self,
        func: Callable[[], T],
        retry_on: tuple[type[Exception], ...] = (HTTPError,),
        retry_codes: tuple[int, ...] = (401, 429, 500, 502, 503, 504),
    ) -> T:
        """Execute function with rate limiting and retry logic."""
        last_error: Optional[Exception] = None

        for attempt in range(self.max_retries):
            self._wait_for_interval()

            try:
                result = func()
                self._last_request_time = time.time()
                return result
            except retry_on as e:
                last_error = e
                should_retry = False

                if isinstance(e, HTTPError) and e.code in retry_codes:
                    should_retry = True
                elif not isinstance(e, HTTPError):
                    should_retry = True

                if should_retry and attempt < self.max_retries - 1:
                    backoff = self._get_backoff_time(attempt)
                    code = getattr(e, "code", "N/A")
                    print(
                        f"{Color.DIM}  Rate limited (HTTP {code}), "
                        f"retrying in {backoff:.1f}s (attempt {attempt + 1}/{self.max_retries})...{Color.NC}"
                    )
                    time.sleep(backoff)
                    self._last_request_time = time.time()
                else:
                    raise

        if last_error:
            raise last_error
        raise RuntimeError("Rate limiter exhausted without result")


# Global rate limiter instance
_rate_limiter = RateLimiter()


def get_rate_limiter() -> RateLimiter:
    """Get the global rate limiter instance."""
    return _rate_limiter


def set_rate_limiter(limiter: RateLimiter) -> None:
    """Set a custom rate limiter."""
    global _rate_limiter
    _rate_limiter = limiter


@dataclass
class Package:
    """Represents an npm package in the workspace."""
    name: str
    version: str
    path: Path
    is_private: bool
    has_publish_config: bool
    registry: Optional[str] = None
    dependencies: dict = field(default_factory=dict)
    dev_dependencies: dict = field(default_factory=dict)

    @property
    def can_publish(self) -> bool:
        return not self.is_private and self.has_publish_config

    @property
    def scoped_name(self) -> str:
        """Return URL-encoded package name for API queries."""
        return quote(self.name, safe="")

    @property
    def short_name(self) -> str:
        """Return name without scope."""
        if "/" in self.name:
            return self.name.split("/", 1)[1]
        return self.name


@dataclass
class RegistryPackageInfo:
    """Package metadata from GitLab npm registry."""
    name: str
    latest_version: Optional[str]
    all_versions: list[str]
    dist_tags: dict[str, str]
    exists: bool
    error: Optional[str] = None


@dataclass
class LinkReference:
    """A link: or file:// reference in package.json."""
    package_json_path: Path
    dependency_name: str
    current_value: str
    dep_type: str  # dependencies, devDependencies, peerDependencies


class GitLabApiClient:
    """Client for GitLab REST API with rate limiting."""

    def __init__(self, token: Optional[str] = None):
        self.token = token or os.environ.get("GITLAB_TOKEN") or os.environ.get("GITLAB_PAT")
        self.ctx = ssl.create_default_context()
        self.rate_limiter = get_rate_limiter()

    def _request(
        self,
        url: str,
        method: str = "GET",
        data: Optional[dict] = None,
    ) -> Optional[dict]:
        """Make an API request with rate limiting."""
        headers = {
            "Accept": "application/json",
            "Content-Type": "application/json",
        }
        if self.token:
            headers["PRIVATE-TOKEN"] = self.token

        body = json.dumps(data).encode() if data else None
        req = Request(url, headers=headers, data=body, method=method)

        def do_request() -> Optional[dict]:
            with urlopen(req, timeout=30, context=self.ctx) as resp:
                content = resp.read().decode()
                return json.loads(content) if content else {}

        try:
            return self.rate_limiter.execute(do_request)
        except HTTPError as e:
            if e.code == 404:
                return None
            raise
        except (URLError, json.JSONDecodeError):
            return None

    def create_project(
        self,
        name: str,
        visibility: str = "private",
        description: Optional[str] = None,
    ) -> Optional[dict]:
        """Create a new GitLab project."""
        data = {"name": name, "visibility": visibility}
        if description:
            data["description"] = description
        return self._request(f"{GITLAB_API_BASE}/projects", method="POST", data=data)

    def delete_project(self, project_path: str) -> bool:
        """Delete a GitLab project. Returns True if successful."""
        encoded_path = quote(project_path, safe="")
        try:
            result = self._request(
                f"{GITLAB_API_BASE}/projects/{encoded_path}",
                method="DELETE",
            )
            return result is not None
        except HTTPError:
            return False

    def get_project(self, project_path: str) -> Optional[dict]:
        """Get project info by path (e.g., 'TransQuinnFTW/ui')."""
        encoded_path = quote(project_path, safe="")
        return self._request(f"{GITLAB_API_BASE}/projects/{encoded_path}")

    def unarchive_project(self, project_path: str) -> bool:
        """Unarchive a project."""
        encoded_path = quote(project_path, safe="")
        try:
            result = self._request(
                f"{GITLAB_API_BASE}/projects/{encoded_path}/unarchive",
                method="POST",
            )
            return result is not None
        except HTTPError:
            return False

    def restore_project(self, project_path: str) -> bool:
        """Restore a project scheduled for deletion."""
        encoded_path = quote(project_path, safe="")
        try:
            result = self._request(
                f"{GITLAB_API_BASE}/projects/{encoded_path}/restore",
                method="POST",
            )
            return result is not None
        except HTTPError:
            return False


class GitLabNpmClient:
    """Client for GitLab npm registry API."""

    def __init__(self, token: Optional[str] = None):
        self.token = token or os.environ.get("GITLAB_NPM_TOKEN")
        self.ctx = ssl.create_default_context()
        self.rate_limiter = get_rate_limiter()

    def _fetch(self, url: str) -> Optional[dict]:
        """Fetch JSON from URL with optional auth and rate limiting."""
        headers = {"Accept": "application/json"}
        if self.token:
            headers["Authorization"] = f"Bearer {self.token}"

        req = Request(url, headers=headers)

        def do_fetch() -> Optional[dict]:
            with urlopen(req, timeout=15, context=self.ctx) as resp:
                return json.loads(resp.read().decode())

        try:
            return self.rate_limiter.execute(do_fetch)
        except HTTPError as e:
            if e.code == 404:
                return None
            raise
        except (URLError, json.JSONDecodeError):
            return None

    def get_package_info(self, name: str) -> RegistryPackageInfo:
        """Get package metadata from GitLab npm registry."""
        encoded = quote(name, safe="")
        url = f"{GITLAB_NPM_REGISTRY}/{encoded}"

        try:
            data = self._fetch(url)
        except Exception as e:
            return RegistryPackageInfo(
                name=name,
                latest_version=None,
                all_versions=[],
                dist_tags={},
                exists=False,
                error=str(e),
            )

        if not data:
            return RegistryPackageInfo(
                name=name,
                latest_version=None,
                all_versions=[],
                dist_tags={},
                exists=False,
            )

        versions = list(data.get("versions", {}).keys())
        dist_tags = data.get("dist-tags", {})
        latest = dist_tags.get("latest")

        return RegistryPackageInfo(
            name=name,
            latest_version=latest,
            all_versions=versions,
            dist_tags=dist_tags,
            exists=True,
        )

    def get_latest_version(self, name: str) -> Optional[str]:
        """Get latest published version of a package."""
        info = self.get_package_info(name)
        return info.latest_version if info.exists else None


def load_package(pkg_path: Path) -> Optional[Package]:
    """Load package info from package.json."""
    try:
        with open(pkg_path) as f:
            data = json.load(f)
    except (json.JSONDecodeError, IOError):
        return None

    name = data.get("name", "")
    if not name or name.endswith("/root"):
        return None

    publish_config = data.get("publishConfig", {})
    registry = None
    for key, value in publish_config.items():
        if "registry" in key.lower():
            registry = value
            break

    return Package(
        name=name,
        version=data.get("version", "0.0.0"),
        path=pkg_path.parent,
        is_private=data.get("private", False),
        has_publish_config=bool(publish_config),
        registry=registry,
        dependencies=data.get("dependencies", {}),
        dev_dependencies=data.get("devDependencies", {}),
    )


def find_packages(base_path: Path) -> list[Package]:
    """Find all packages in the workspace."""
    packages = []

    # Check for pnpm workspace
    workspace_yaml = base_path / "pnpm-workspace.yaml"
    if workspace_yaml.exists():
        packages = find_workspace_packages(base_path)
    else:
        # Single package
        root_pkg = base_path / "package.json"
        if root_pkg.exists():
            pkg = load_package(root_pkg)
            if pkg:
                packages.append(pkg)

    return packages


def find_workspace_packages(base_path: Path) -> list[Package]:
    """Find all packages in a pnpm workspace."""
    packages = []

    for pkg_json in base_path.rglob("package.json"):
        if "node_modules" in str(pkg_json):
            continue
        if pkg_json.parent == base_path:
            continue

        pkg = load_package(pkg_json)
        if pkg:
            packages.append(pkg)

    return sorted(packages, key=lambda p: p.name)


def find_link_references(base_path: Path, scope: str = DEFAULT_SCOPE) -> list[LinkReference]:
    """Find all link: and file:// references to scoped packages."""
    refs = []

    for pkg_json in base_path.rglob("package.json"):
        if "node_modules" in str(pkg_json):
            continue

        try:
            with open(pkg_json) as f:
                data = json.load(f)
        except (json.JSONDecodeError, IOError):
            continue

        for dep_type in ["dependencies", "devDependencies", "peerDependencies"]:
            deps = data.get(dep_type, {})
            for name, value in deps.items():
                if not name.startswith(scope):
                    continue
                if value.startswith(("link:", "file:")):
                    refs.append(LinkReference(
                        package_json_path=pkg_json,
                        dependency_name=name,
                        current_value=value,
                        dep_type=dep_type,
                    ))

    return refs


def get_dependency_tiers(packages: list[Package], scope: str = DEFAULT_SCOPE) -> list[list[Package]]:
    """Sort packages into dependency tiers for ordered publishing.

    Tier 0: Packages with no internal dependencies
    Tier 1: Packages depending only on Tier 0
    Tier 2: Packages depending on Tier 1
    etc.
    """
    package_names = {p.name for p in packages}
    remaining = list(packages)
    tiers = []
    resolved = set()

    while remaining:
        tier = []
        for pkg in remaining:
            # Get all internal dependencies
            all_deps = {**pkg.dependencies, **pkg.dev_dependencies}
            internal_deps = {d for d in all_deps if d.startswith(scope) and d in package_names}

            # Check if all internal deps are already resolved
            if internal_deps.issubset(resolved):
                tier.append(pkg)

        if not tier:
            # Circular dependency or error - add all remaining
            tier = remaining
            remaining = []
        else:
            for pkg in tier:
                remaining.remove(pkg)
                resolved.add(pkg.name)

        tiers.append(tier)

    return tiers


def check_token() -> bool:
    """Verify GITLAB_NPM_TOKEN is set."""
    token = os.environ.get("GITLAB_NPM_TOKEN")
    if not token:
        print(f"{Color.RED}Error: GITLAB_NPM_TOKEN environment variable not set{Color.NC}")
        print(f"{Color.DIM}Set it with: export GITLAB_NPM_TOKEN=glpat-...{Color.NC}")
        return False
    return True


def get_npmrc_registry_lines(scope: str = DEFAULT_SCOPE, token_env: str = "GITLAB_NPM_TOKEN") -> str:
    """Generate .npmrc registry configuration lines."""
    return f"""{scope}:registry={GITLAB_NPM_REGISTRY}/
//gitlab.com/api/v4/packages/npm/:_authToken=${{{token_env}}}
"""


def print_header(title: str, width: int = 80) -> None:
    """Print a formatted header."""
    print(f"{Color.BOLD}{'═' * width}{Color.NC}")
    print(f"{Color.BOLD}  {title}{Color.NC}")
    print(f"{Color.BOLD}{'═' * width}{Color.NC}")
    print()