"""Shared utilities for cmdlets and funacts.

This module provides common utility functions for working with hashes, tags,
relationship data, and other frequently-needed operations.
"""

from __future__ import annotations

import json
import sys
import inspect
from collections.abc import Iterable as IterableABC

from helper.logger import log
from pathlib import Path
from typing import Any, Dict, Iterable, List, Optional, Sequence, Set
from dataclasses import dataclass, field
import models


@dataclass
class CmdletArg:
	"""Represents a single cmdlet argument with optional enum choices."""
	name: str
	"""Argument name, e.g., '-path' or 'location'"""
	type: str = "string"
	"""Argument type: 'string', 'int', 'flag', 'enum', etc."""
	required: bool = False
	"""Whether this argument is required"""
	description: str = ""
	"""Human-readable description of the argument"""
	choices: List[str] = field(default_factory=list)
	"""Optional list of valid choices for enum/autocomplete, e.g., ['hydrus', 'local', '0x0.st']"""
	alias: str = ""
	"""Optional alias for the argument name, e.g., 'loc' for 'location'"""
	handler: Optional[Any] = None
	"""Optional handler function/callable for processing this argument's value"""
	variadic: bool = False
	"""Whether this argument accepts multiple values (consumes remaining positional args)"""
	
	def to_dict(self) -> Dict[str, Any]:
		"""Convert to dict for backward compatibility."""
		d = {
			"name": self.name,
			"type": self.type,
			"required": self.required,
			"description": self.description,
			"variadic": self.variadic,
		}
		if self.choices:
			d["choices"] = self.choices
		if self.alias:
			d["alias"] = self.alias
		return d
	
	def resolve(self, value: Any) -> Any:
		"""Resolve/process the argument value using the handler if available.
		
		Args:
			value: The raw argument value to process
			
		Returns:
			Processed value from handler, or original value if no handler
			
		Example:
			# For STORAGE arg with a handler
			storage_path = SharedArgs.STORAGE.resolve('local')  # Returns Path.home() / "Videos"
		"""
		if self.handler is not None and callable(self.handler):
			return self.handler(value)
		return value
	
	def to_flags(self) -> tuple[str, ...]:
		"""Generate all flag variants (short and long form) for this argument.
		
		Returns a tuple of all valid flag forms for this argument, including:
		- Long form with double dash: --name
		- Single dash multi-char form: -name (for convenience)
		- Short form with single dash: -alias (if alias exists)
		
		For flags, also generates negation forms:
		- --no-name, -name (negation of multi-char form)
		- --no-name, -nalias (negation with alias)
		
		Returns:
			Tuple of flag strings, e.g., ('--archive', '-archive', '-arch')
			or for flags: ('--archive', '-archive', '-arch', '--no-archive', '-narch')
			
		Example:
			archive_flags = SharedArgs.ARCHIVE.to_flags()
			# Returns: ('--archive', '-archive', '-arch', '--no-archive', '-narch')
			
			storage_flags = SharedArgs.STORAGE.to_flags()
			# Returns: ('--storage', '-storage', '-s')
		"""
		flags = [f'--{self.name}', f'-{self.name}']  # Both double-dash and single-dash variants
		
		# Add short form if alias exists
		if self.alias:
			flags.append(f'-{self.alias}')
		
		# Add negation forms for flag type
		if self.type == 'flag':
			flags.append(f'--no-{self.name}')
			flags.append(f'-no{self.name}')  # Single-dash negation variant
			if self.alias:
				flags.append(f'-n{self.alias}')
		
		return tuple(flags)


# ============================================================================
# SHARED ARGUMENTS - Reusable argument definitions across cmdlets
# ============================================================================

class SharedArgs:
	"""Registry of shared CmdletArg definitions used across multiple cmdlets.
	
	This class provides a centralized location for common arguments so they're
	defined once and used consistently everywhere. Reduces duplication and ensures
	all cmdlets handle the same arguments identically.
	
	Example:
		CMDLET = Cmdlet(
			name="my-cmdlet",
			summary="Does something",
			usage="my-cmdlet",
			args=[
				SharedArgs.HASH,          # Use predefined shared arg
				SharedArgs.LOCATION,      # Use another shared arg
				CmdletArg(...),           # Mix with custom args
			]
		)
	"""
	
	# File/Hash arguments
	HASH = CmdletArg(
		"hash",
		type="string",
		description="Override the Hydrus file hash (SHA256) to target instead of the selected result."
	)
	
	LOCATION = CmdletArg(
		"location",
		type="enum",
		choices=["hydrus", "0x0", "local"],
		required=True,
		description="Destination location"
	)
	
	DELETE_FLAG = CmdletArg(
		"delete",
		type="flag",
		description="Delete the file and its .tags after successful operation."
	)
	
	# Metadata arguments
	ARTIST = CmdletArg(
		"artist",
		type="string",
		description="Filter by artist name (case-insensitive, partial match)."
	)
	
	ALBUM = CmdletArg(
		"album",
		type="string",
		description="Filter by album name (case-insensitive, partial match)."
	)
	
	TRACK = CmdletArg(
		"track",
		type="string",
		description="Filter by track title (case-insensitive, partial match)."
	)
	
	# Library/Search arguments
	LIBRARY = CmdletArg(
		"library",
		type="string",
		choices=["hydrus", "local", "soulseek", "libgen", "debrid", "ftp"],
		description="Search library or source location."
	)
	
	TIMEOUT = CmdletArg(
		"timeout",
		type="integer",
		description="Search or operation timeout in seconds."
	)
	
	LIMIT = CmdletArg(
		"limit",
		type="integer",
		description="Maximum number of results to return."
	)
	
	# Path/File arguments
	PATH = CmdletArg(
		"path",
		type="string",
		description="File or directory path."
	)
	
	OUTPUT = CmdletArg(
		"output",
		type="string",
		description="Output file path."
	)
	
	STORAGE = CmdletArg(
		"storage",
		type="enum",
		choices=["hydrus", "local", "debrid", "ftp"],
		required=False,
		description="Storage location or destination for saving/uploading files.",
		alias="s",
		handler=lambda val: SharedArgs.resolve_storage(val) if val else None
	)
	
	# Generic arguments
	QUERY = CmdletArg(
		"query",
		type="string",
		description="Search query string."
	)
	
	REASON = CmdletArg(
		"reason",
	 type="string",
	 description="Reason or explanation for the operation."
	)
	
	ARCHIVE = CmdletArg(
		"archive",
		type="flag",
		description="Archive the URL to Wayback Machine, Archive.today, and Archive.ph (requires URL argument in cmdlet).",
		alias="arch"
	)
	
	@staticmethod
	def resolve_storage(storage_value: Optional[str], default: Optional[Path] = None) -> Path:
		"""Resolve a storage location name to a filesystem Path.
		
		Maps storage identifiers (hydrus, local, debrid, ftp) to their actual
		filesystem paths. This is the single source of truth for storage location resolution.
		Note: 0x0.st is now accessed via file providers (-provider 0x0), not storage.
		
		Args:
			storage_value: One of 'hydrus', 'local', 'debrid', 'ftp', or None
			default: Path to return if storage_value is None (defaults to Videos)
			
		Returns:
			Resolved Path object for the storage location
			
		Raises:
			ValueError: If storage_value is not a recognized storage type
			
		Example:
			# In a cmdlet:
			storage_path = SharedArgs.resolve_storage(parsed.storage)
			
			# With defaults:
			path = SharedArgs.resolve_storage(None)  # Returns home/Videos
			path = SharedArgs.resolve_storage('local')  # Returns home/Videos
			path = SharedArgs.resolve_storage('hydrus')  # Returns home/.hydrus/client_files
		"""
		storage_map = {
			'local': Path.home() / "Videos",
			'hydrus': Path.home() / ".hydrus" / "client_files",
			'debrid': Path.home() / "Debrid",
			'ftp': Path.home() / "FTP",
		}
		
		if storage_value is None:
			return default or (Path.home() / "Videos")
		
		storage_lower = storage_value.lower()
		if storage_lower not in storage_map:
			raise ValueError(
				f"Unknown storage location '{storage_value}'. "
				f"Must be one of: {', '.join(storage_map.keys())}"
			)
		
		return storage_map[storage_lower]
	
	@classmethod
	def get(cls, name: str) -> Optional[CmdletArg]:
		"""Get a shared argument by name.
		
		Args:
			name: Uppercase name like 'HASH', 'LOCATION', etc.
			
		Returns:
			CmdletArg if found, None otherwise
			
		Example:
			arg = SharedArgs.get('HASH')  # Returns SharedArgs.HASH
		"""
		try:
			return getattr(cls, name.upper())
		except AttributeError:
			return None


@dataclass
class Cmdlet:
	"""Represents a cmdlet with metadata and arguments.
	
	Example:
		cmd = Cmdlet(
			name="add-file",
			summary="Upload a media file",
			usage="add-file <location>",
			aliases=["add-file-alias"],
			args=[
				CmdletArg("location", required=True, description="Destination location"),
				CmdletArg("-delete", type="flag", description="Delete after upload"),
			],
			details=[
				"- This is a detail line",
				"- Another detail",
			]
		)
		
		# Access properties
		log(cmd.name)  # "add-file"
		log(cmd.summary)  # "Upload a media file"
		log(cmd.args[0].name)  # "location"
		
		# Convert to dict for JSON serialization
		log(json.dumps(cmd.to_dict()))
	"""
	name: str
	"""Cmdlet name, e.g., 'add-file'"""
	summary: str
	"""One-line summary of the cmdlet"""
	usage: str
	"""Usage string, e.g., 'add-file <location> [-delete]'"""
	aliases: List[str] = field(default_factory=list)
	"""List of aliases for this cmdlet, e.g., ['add', 'add-f']"""
	args: List[CmdletArg] = field(default_factory=list)
	"""List of arguments accepted by this cmdlet"""
	details: List[str] = field(default_factory=list)
	"""Detailed explanation lines (for help text)"""
	exec: Optional[Any] = field(default=None)
	"""The execution function: func(result, args, config) -> int"""
	
	def __post_init__(self) -> None:
		"""Auto-discover _run function if exec not explicitly provided.
		
		If exec is None, looks for a _run function in the module where
		this Cmdlet was instantiated and uses it automatically.
		"""
		if self.exec is None:
			# Walk up the call stack to find _run in the calling module
			frame = inspect.currentframe()
			try:
				# Walk up frames until we find one with _run in globals
				while frame:
					if '_run' in frame.f_globals:
						self.exec = frame.f_globals['_run']
						break
					frame = frame.f_back
			finally:
				del frame  # Avoid reference cycles
	
	def to_dict(self) -> Dict[str, Any]:
		"""Convert to dict for backward compatibility with existing code.
		
		Returns a dict matching the old CMDLET format so existing code
		that expects a dict will still work.
		"""
		# Format command for display: "cmd: name alias: alias1, alias2"
		cmd_display = f"cmd: {self.name}"
		if self.aliases:
			aliases_str = ", ".join(self.aliases)
			cmd_display += f" alias: {aliases_str}"
		
		return {
			"name": self.name,
			"summary": self.summary,
			"usage": self.usage,
			"cmd": cmd_display,  # Display-friendly command name with aliases on one line
			"aliases": self.aliases,
			"args": [arg.to_dict() for arg in self.args],
			"details": self.details,
		}
	
	def __getitem__(self, key: str) -> Any:
		"""Dict-like access for backward compatibility.
		
		Allows code like: cmdlet["name"] or cmdlet["args"]
		"""
		d = self.to_dict()
		return d.get(key)
	
	def get(self, key: str, default: Any = None) -> Any:
		"""Dict-like get() method for backward compatibility."""
		d = self.to_dict()
		return d.get(key, default)
	
	def get_flags(self, arg_name: str) -> set[str]:
		"""Generate -name and --name flag variants for an argument.
		
		Args:
			arg_name: The argument name (e.g., 'library', 'tag', 'size')
		
		Returns:
			Set containing both single-dash and double-dash variants
			(e.g., {'-library', '--library'})
		
		Example:
			if low in cmdlet.get_flags('library'):
				# handle library flag
		"""
		return {f"-{arg_name}", f"--{arg_name}"}
	
	def build_flag_registry(self) -> Dict[str, set[str]]:
		"""Build a registry of all flag variants for this cmdlet's arguments.
		
		Automatically generates all -name and --name variants for each argument.
		Useful for parsing command-line arguments without hardcoding flags.
		
		Returns:
			Dict mapping argument names to their flag sets
			(e.g., {'library': {'-library', '--library'}, 'tag': {'-tag', '--tag'}})
		
		Example:
			flags = cmdlet.build_flag_registry()
			
			if low in flags.get('library', set()):
				# handle library
			elif low in flags.get('tag', set()):
				# handle tag
		"""
		return {arg.name: self.get_flags(arg.name) for arg in self.args}


# Tag groups cache (loaded from JSON config file)
_TAG_GROUPS_CACHE: Optional[Dict[str, List[str]]] = None
_TAG_GROUPS_MTIME: Optional[float] = None

# Path to tag groups configuration (set by caller or lazily discovered)
TAG_GROUPS_PATH: Optional[Path] = None


def set_tag_groups_path(path: Path) -> None:
	"""Set the path to the tag groups JSON file."""
	global TAG_GROUPS_PATH
	TAG_GROUPS_PATH = path


def parse_cmdlet_args(args: Sequence[str], cmdlet_spec: Dict[str, Any] | Cmdlet) -> Dict[str, Any]:
	"""Parse command-line arguments based on cmdlet specification.
	
	Extracts argument values from command-line tokens using the argument names
	and types defined in the cmdlet metadata. Automatically supports single-dash
	and double-dash variants of flag names. Arguments without dashes in definition
	are treated as positional arguments.
	
	Args:
		args: Command-line arguments (e.g., ["-path", "/home/file.txt", "-foo", "bar"])
		cmdlet_spec: Cmdlet metadata dict with "args" key containing list of arg specs,
		             or a Cmdlet object. Each arg spec should have at least "name" key.
		             Argument names can be defined with or without prefixes.
		             
	Returns:
		Dict mapping canonical arg names to their parsed values. If an arg is not 
		provided, it will not be in the dict. Lookup will normalize prefixes.
		
	Example:
		cmdlet = {
			"args": [
				{"name": "path", "type": "string"},  # Positional - matches bare value or -path/--path
				{"name": "count", "type": "int"}     # Positional - matches bare value or -count/--count
			]
		}
		result = parse_cmdlet_args(["value1", "-count", "5"], cmdlet)
		# result = {"path": "value1", "count": "5"}
	"""
	result: Dict[str, Any] = {}
	
	# Handle both dict and Cmdlet objects
	if isinstance(cmdlet_spec, Cmdlet):
		cmdlet_spec = cmdlet_spec.to_dict()
	
	# Build arg specs tracking which are positional vs flagged
	arg_specs: List[Dict[str, Any]] = cmdlet_spec.get("args", [])
	positional_args: List[Dict[str, Any]] = []  # args without prefix in definition
	flagged_args: List[Dict[str, Any]] = []  # args with prefix in definition
	
	arg_spec_map: Dict[str, str] = {}  # prefix variant -> canonical name (without prefix)
	
	for spec in arg_specs:
		name = spec.get("name")
		if not name:
			continue
		
		name_str = str(name)
		canonical_name = name_str.lstrip("-")
		
		# Determine if this is positional (no dashes in original definition)
		if "-" not in name_str:
			positional_args.append(spec)
		else:
			flagged_args.append(spec)
		
		# Register all prefix variants for flagged lookup
		arg_spec_map[canonical_name.lower()] = canonical_name  # bare name
		arg_spec_map[f"-{canonical_name}".lower()] = canonical_name  # single dash
		arg_spec_map[f"--{canonical_name}".lower()] = canonical_name  # double dash
	
	# Parse arguments
	i = 0
	positional_index = 0  # Track which positional arg we're on
	
	while i < len(args):
		token = str(args[i])
		token_lower = token.lower()
		
		# Check if this token is a known flagged argument
		if token_lower in arg_spec_map:
			canonical_name = arg_spec_map[token_lower]
			spec = next((s for s in arg_specs if str(s.get("name", "")).lstrip("-").lower() == canonical_name.lower()), None)
			
			# Check if it's a flag type (which doesn't consume next value, just marks presence)
			is_flag = spec and spec.get("type") == "flag"
			
			if is_flag:
				# For flags, just mark presence without consuming next token
				result[canonical_name] = True
				i += 1
			else:
				# For non-flags, consume next token as the value
				if i + 1 < len(args) and not str(args[i + 1]).startswith("-"):
					value = args[i + 1]
					
					# Check if variadic
					is_variadic = spec and spec.get("variadic", False)
					if is_variadic:
						if canonical_name not in result:
							result[canonical_name] = []
						elif not isinstance(result[canonical_name], list):
							result[canonical_name] = [result[canonical_name]]
						result[canonical_name].append(value)
					else:
						result[canonical_name] = value
					i += 2
				else:
					i += 1
		# Otherwise treat as positional if we have positional args remaining
		elif positional_index < len(positional_args):
			positional_spec = positional_args[positional_index]
			canonical_name = str(positional_spec.get("name", "")).lstrip("-")
			is_variadic = positional_spec.get("variadic", False)
			
			if is_variadic:
				# For variadic args, append to a list
				if canonical_name not in result:
					result[canonical_name] = []
				elif not isinstance(result[canonical_name], list):
					# Should not happen if logic is correct, but safety check
					result[canonical_name] = [result[canonical_name]]
				
				result[canonical_name].append(token)
				# Do not increment positional_index so subsequent tokens also match this arg
				# Note: Variadic args should typically be the last positional argument
				i += 1
			else:
				result[canonical_name] = token
				positional_index += 1
				i += 1
		else:
			# Unknown token, skip it
			i += 1
	
	return result


def normalize_hash(hash_hex: Optional[str]) -> Optional[str]:
	"""Normalize a hash string to lowercase, or return None if invalid.
	
	Args:
		hash_hex: String that should be a hex hash
		
	Returns:
		Lowercase hash string, or None if input is not a string or is empty
	"""
	if not isinstance(hash_hex, str):
		return None
	text = hash_hex.strip()
	return text.lower() if text else None


def looks_like_hash(candidate: Optional[str]) -> bool:
	"""Check if a string looks like a SHA256 hash (64 hex chars).
	
	Args:
		candidate: String to test
		
	Returns:
		True if the string is 64 lowercase hex characters
	"""
	if not isinstance(candidate, str):
		return False
	text = candidate.strip().lower()
	return len(text) == 64 and all(ch in "0123456789abcdef" for ch in text)


def pipeline_item_local_path(item: Any) -> Optional[str]:
	"""Extract local file path from a pipeline item.
	
	Supports both dataclass objects with .target attribute and dicts.
	Returns None for HTTP/HTTPS URLs.
	
	Args:
		item: Pipeline item (PipelineItem dataclass, dict, or other)
		
	Returns:
		Local file path string, or None if item is not a local file
	"""
	target: Optional[str] = None
	if hasattr(item, "target"):
		target = getattr(item, "target", None)
	elif isinstance(item, dict):
		raw = item.get("target") or item.get("path") or item.get("url")
		target = str(raw) if raw is not None else None
	if not isinstance(target, str):
		return None
	text = target.strip()
	if not text:
		return None
	if text.lower().startswith(("http://", "https://")):
		return None
	return text


def collect_relationship_labels(payload: Any, label_stack: List[str] | None = None, mapping: Dict[str, str] | None = None) -> Dict[str, str]:
	"""Recursively extract hash-to-label mappings from nested relationship data.
	
	Walks through nested dicts/lists looking for sha256-like strings (64 hex chars)
	and builds a mapping from hash to its path in the structure.
	
	Example:
		data = {
			"duplicates": [
				"abc123...",  # Will be mapped to "duplicates"
				{"type": "related", "items": ["def456..."]}  # Will be mapped to "duplicates / type / items"
			]
		}
		result = collect_relationship_labels(data)
		# result = {"abc123...": "duplicates", "def456...": "duplicates / type / items"}
	
	Args:
		payload: Nested data structure (dict, list, string, etc.)
		label_stack: Internal use - tracks path during recursion
		mapping: Internal use - accumulates hash->label mappings
		
	Returns:
		Dict mapping hash strings to their path labels
	"""
	if label_stack is None:
		label_stack = []
	if mapping is None:
		mapping = {}
	
	if isinstance(payload, dict):
		for key, value in payload.items():
			next_stack = label_stack
			if isinstance(key, str) and key:
				formatted = key.replace('_', ' ').strip()
				next_stack = label_stack + [formatted]
			collect_relationship_labels(value, next_stack, mapping)
	elif isinstance(payload, (list, tuple, set)):
		for value in payload:
			collect_relationship_labels(value, label_stack, mapping)
	elif isinstance(payload, str) and looks_like_hash(payload):
		hash_value = payload.lower()
		if label_stack:
			label = " / ".join(item for item in label_stack if item)
		else:
			label = "related"
		mapping.setdefault(hash_value, label)
	
	return mapping


def parse_tag_arguments(arguments: Sequence[str]) -> List[str]:
	"""Parse tag arguments from command line tokens.
	
	Handles both space-separated and comma-separated tags.
	Example: parse_tag_arguments(["tag1,tag2", "tag3"]) -> ["tag1", "tag2", "tag3"]
	
	Args:
		arguments: Sequence of argument strings
		
	Returns:
		List of normalized tag strings (empty strings filtered out)
	"""
	tags: List[str] = []
	for argument in arguments:
		for token in argument.split(','):
			text = token.strip()
			if text:
				tags.append(text)
	return tags


def fmt_bytes(n: Optional[int]) -> str:
	"""Format bytes as human-readable with 1 decimal place (MB/GB).
	
	Args:
		n: Number of bytes, or None
		
	Returns:
		Formatted string like "1.5 MB" or "2.0 GB", or "unknown"
	"""
	if n is None or n < 0:
		return "unknown"
	gb = n / (1024.0 * 1024.0 * 1024.0)
	if gb >= 1.0:
		return f"{gb:.1f} GB"
	mb = n / (1024.0 * 1024.0)
	return f"{mb:.1f} MB"


def _normalise_tag_group_entry(value: Any) -> Optional[str]:
	"""Internal: Normalize a single tag group entry."""
	if not isinstance(value, str):
		value = str(value)
	text = value.strip()
	return text or None


def _load_tag_groups() -> Dict[str, List[str]]:
	"""Load tag group definitions from JSON file with caching."""
	global _TAG_GROUPS_CACHE, _TAG_GROUPS_MTIME, TAG_GROUPS_PATH
	
	# Auto-discover adjective.json if not set
	if TAG_GROUPS_PATH is None:
		# Try to find adjective.json in the script directory or helper subdirectory
		try:
			script_dir = Path(__file__).parent.parent
			
			# Check root directory
			candidate = script_dir / "adjective.json"
			if candidate.exists():
				TAG_GROUPS_PATH = candidate
			else:
				# Check helper directory
				candidate = script_dir / "helper" / "adjective.json"
				if candidate.exists():
					TAG_GROUPS_PATH = candidate
		except Exception:
			pass
	
	if TAG_GROUPS_PATH is None:
		return {}
	
	path = TAG_GROUPS_PATH
	try:
		stat_result = path.stat()
	except FileNotFoundError:
		_TAG_GROUPS_CACHE = {}
		_TAG_GROUPS_MTIME = None
		return {}
	except OSError as exc:
		log(f"Failed to read tag groups: {exc}", file=sys.stderr)
		_TAG_GROUPS_CACHE = {}
		_TAG_GROUPS_MTIME = None
		return {}
	
	mtime = stat_result.st_mtime
	if _TAG_GROUPS_CACHE is not None and _TAG_GROUPS_MTIME == mtime:
		return _TAG_GROUPS_CACHE
	
	try:
		payload = json.loads(path.read_text(encoding="utf-8"))
	except (OSError, json.JSONDecodeError) as exc:
		log(f"Invalid tag group JSON ({path}): {exc}", file=sys.stderr)
		_TAG_GROUPS_CACHE = {}
		_TAG_GROUPS_MTIME = mtime
		return {}
	
	groups: Dict[str, List[str]] = {}
	if isinstance(payload, dict):
		for key, value in payload.items():
			if not isinstance(key, str):
				continue
			name = key.strip().lower()
			if not name:
				continue
			members: List[str] = []
			if isinstance(value, list):
				for entry in value:
					normalised = _normalise_tag_group_entry(entry)
					if normalised:
						members.append(normalised)
			elif isinstance(value, str):
				normalised = _normalise_tag_group_entry(value)
				if normalised:
					members.extend(token.strip() for token in normalised.split(",") if token.strip())
			if members:
				groups[name] = members
	
	_TAG_GROUPS_CACHE = groups
	_TAG_GROUPS_MTIME = mtime
	return groups


def expand_tag_groups(raw_tags: Iterable[str]) -> List[str]:
	"""Expand tag group references (e.g., {my_group}) into member tags.
	
	Tag groups are defined in JSON and can be nested. Groups are referenced
	with curly braces: {group_name}.
	
	Args:
		raw_tags: Sequence of tag strings, some may reference groups like "{group_name}"
		
	Returns:
		List of expanded tags with group references replaced
	"""
	groups = _load_tag_groups()
	if not groups:
		return [tag for tag in raw_tags if isinstance(tag, str) and tag.strip()]
	
	def _expand(tokens: Iterable[str], seen: Set[str]) -> List[str]:
		result: List[str] = []
		for token in tokens:
			if not isinstance(token, str):
				continue
			candidate = token.strip()
			if not candidate:
				continue
			if candidate.startswith("{") and candidate.endswith("}") and len(candidate) > 2:
				name = candidate[1:-1].strip().lower()
				if not name:
					continue
				if name in seen:
					log(f"Tag group recursion detected for {{{name}}}; skipping", file=sys.stderr)
					continue
				members = groups.get(name)
				if not members:
					log(f"Unknown tag group {{{name}}}", file=sys.stderr)
					result.append(candidate)
					continue
				result.extend(_expand(members, seen | {name}))
			else:
				result.append(candidate)
		return result
	
	return _expand(raw_tags, set())


def first_title_tag(source: Optional[Iterable[str]]) -> Optional[str]:
	"""Find the first tag starting with "title:" in a collection.
	
	Args:
		source: Iterable of tag strings
		
	Returns:
		First title: tag found, or None
	"""
	if not source:
		return None
	for item in source:
		if not isinstance(item, str):
			continue
		candidate = item.strip()
		if candidate and candidate.lower().startswith("title:"):
			return candidate
	return None


def apply_preferred_title(tags: List[str], preferred: Optional[str]) -> List[str]:
	"""Replace any title: tags with a preferred title tag.
	
	Args:
		tags: List of tags (may contain multiple "title:" entries)
		preferred: Preferred title tag to use (full "title: ..." format)
		
	Returns:
		List with old title tags removed and preferred title added (at most once)
	"""
	if not preferred:
		return tags
	preferred_clean = preferred.strip()
	if not preferred_clean:
		return tags
	preferred_lower = preferred_clean.lower()
	filtered: List[str] = []
	has_preferred = False
	for tag in tags:
		candidate = tag.strip()
		if not candidate:
			continue
		if candidate.lower().startswith("title:"):
			if candidate.lower() == preferred_lower:
				if not has_preferred:
					filtered.append(candidate)
					has_preferred = True
			continue
		filtered.append(candidate)
	if not has_preferred:
		filtered.append(preferred_clean)
	return filtered


# ============================================================================
# PIPEOBJECT UTILITIES (for chainable cmdlets and multi-action pipelines)
# ============================================================================

def create_pipe_object_result(
	source: str,
	identifier: str,
	file_path: str,
	cmdlet_name: str,
	title: Optional[str] = None,
	file_hash: Optional[str] = None,
	is_temp: bool = False,
	parent_hash: Optional[str] = None,
	tags: Optional[List[str]] = None,
	**extra: Any
) -> Dict[str, Any]:
	"""Create a PipeObject-compatible result dict for pipeline chaining.
	
	This is a helper to emit results in the standard format that downstream
	cmdlets can process (filter, tag, cleanup, etc.).
	
	Args:
		source: Source system (e.g., 'local', 'hydrus', 'download')
		identifier: Unique ID from source
		file_path: Path to the file
		cmdlet_name: Name of the cmdlet that created this (e.g., 'download-data', 'screen-shot')
		title: Human-readable title
		file_hash: SHA-256 hash of file (for integrity)
		is_temp: If True, this is a temporary/intermediate artifact
		parent_hash: Hash of the parent file in the chain (for provenance)
		tags: List of tags to apply
		**extra: Additional fields
		
	Returns:
		Dict with all PipeObject fields for emission
	"""
	result = {
		'source': source,
		'id': identifier,
		'file_path': file_path,
		'action': f'cmdlet:{cmdlet_name}',  # Format: cmdlet:cmdlet_name
	}
	
	if title:
		result['title'] = title
	if file_hash:
		result['file_hash'] = file_hash
	if is_temp:
		result['is_temp'] = True
	if parent_hash:
		result['parent_id'] = parent_hash  # parent_id is the parent's file_hash
	if tags:
		result['tags'] = tags
	
	# Add any extra fields
	result.update(extra)
	
	return result


def mark_as_temp(pipe_object: Dict[str, Any]) -> Dict[str, Any]:
	"""Mark a PipeObject dict as temporary (intermediate artifact).
	
	Args:
		pipe_object: Result dict from cmdlet emission
		
	Returns:
		Modified dict with is_temp=True
	"""
	pipe_object['is_temp'] = True
	return pipe_object


def set_parent_id(pipe_object: Dict[str, Any], parent_hash: str) -> Dict[str, Any]:
	"""Set the parent_id for provenance tracking.
	
	Args:
		pipe_object: Result dict
		parent_hash: Parent file's hash
		
	Returns:
		Modified dict with parent_id set to the hash
	"""
	pipe_object['parent_id'] = parent_hash
	return pipe_object


def get_pipe_object_path(pipe_object: Any) -> Optional[str]:
	"""Extract file path from PipeObject, dict, or pipeline-friendly object."""
	if pipe_object is None:
		return None
	for attr in ('file_path', 'path', 'target'):
		if hasattr(pipe_object, attr):
			value = getattr(pipe_object, attr)
			if value:
				return value
	if isinstance(pipe_object, dict):
		for key in ('file_path', 'path', 'target'):
			value = pipe_object.get(key)
			if value:
				return value
	return None


def get_pipe_object_hash(pipe_object: Any) -> Optional[str]:
	"""Extract file hash from PipeObject, dict, or pipeline-friendly object."""
	if pipe_object is None:
		return None
	for attr in ('file_hash', 'hash_hex', 'hash'):
		if hasattr(pipe_object, attr):
			value = getattr(pipe_object, attr)
			if value:
				return value
	if isinstance(pipe_object, dict):
		for key in ('file_hash', 'hash_hex', 'hash'):
			value = pipe_object.get(key)
			if value:
				return value
	return None


def normalize_result_input(result: Any) -> List[Dict[str, Any]]:
	"""Normalize input result to a list of dicts.
	
	Handles:
	- None -> []
	- Dict -> [dict]
	- List of dicts -> list as-is
	- PipeObject -> [dict]
	- List of PipeObjects -> list of dicts
	
	Args:
		result: Result from piped input
		
	Returns:
		List of result dicts (may be empty)
	"""
	if result is None:
		return []
	
	# Single dict
	if isinstance(result, dict):
		return [result]
	
	# List - convert each item to dict if needed
	if isinstance(result, list):
		output = []
		for item in result:
			if isinstance(item, dict):
				output.append(item)
			elif hasattr(item, 'to_dict'):
				output.append(item.to_dict())
			else:
				# Try as-is
				output.append(item)
		return output
	
	# PipeObject or other object with to_dict
	if hasattr(result, 'to_dict'):
		return [result.to_dict()]
	
	# Fallback: wrap it
	if isinstance(result, dict):
		return [result]
	
	return []


def filter_results_by_temp(results: List[Any], include_temp: bool = False) -> List[Any]:
	"""Filter results by temporary status.
	
	Args:
		results: List of result dicts or PipeObjects
		include_temp: If True, keep temp files; if False, exclude them
		
	Returns:
		Filtered list
	"""
	if include_temp:
		return results
	
	filtered = []
	for result in results:
		is_temp = False
		
		# Check PipeObject
		if hasattr(result, 'is_temp'):
			is_temp = result.is_temp
		# Check dict
		elif isinstance(result, dict):
			is_temp = result.get('is_temp', False)
		
		if not is_temp:
			filtered.append(result)
	
	return filtered


def merge_sequences(*sources: Optional[Iterable[Any]], case_sensitive: bool = True) -> list[str]:
    """Merge iterable sources while preserving order and removing duplicates."""
    seen: set[str] = set()
    merged: list[str] = []
    for source in sources:
        if not source:
            continue
        if isinstance(source, str) or not isinstance(source, IterableABC):
            iterable = [source]
        else:
            iterable = source
        for value in iterable:
            if value is None:
                continue
            text = str(value).strip()
            if not text:
                continue
            key = text if case_sensitive else text.lower()
            if key in seen:
                continue
            seen.add(key)
            merged.append(text)
    return merged


def extract_tags_from_result(result: Any) -> list[str]:
    tags: list[str] = []
    if isinstance(result, models.PipeObject):
        tags.extend(result.tags or [])
        tags.extend(result.extra.get('tags', []))
    elif hasattr(result, 'tags'):
        # Handle objects with tags attribute (e.g. SearchResult)
        val = getattr(result, 'tags')
        if isinstance(val, (list, set, tuple)):
            tags.extend(val)
        elif isinstance(val, str):
            tags.append(val)
            
    if isinstance(result, dict):
        raw_tags = result.get('tags')
        if isinstance(raw_tags, list):
            tags.extend(raw_tags)
        elif isinstance(raw_tags, str):
            tags.append(raw_tags)
        extra = result.get('extra')
        if isinstance(extra, dict):
            extra_tags = extra.get('tags')
            if isinstance(extra_tags, list):
                tags.extend(extra_tags)
            elif isinstance(extra_tags, str):
                tags.append(extra_tags)
    return merge_sequences(tags, case_sensitive=True)


def extract_title_from_result(result: Any) -> Optional[str]:
    """Extract the title from a result dict or PipeObject."""
    if isinstance(result, models.PipeObject):
        return result.title
    elif hasattr(result, 'title'):
        return getattr(result, 'title')
    elif isinstance(result, dict):
        return result.get('title')
    return None


def extract_known_urls_from_result(result: Any) -> list[str]:
    urls: list[str] = []

    def _extend(candidate: Any) -> None:
        if not candidate:
            return
        if isinstance(candidate, list):
            urls.extend(candidate)
        elif isinstance(candidate, str):
            urls.append(candidate)

    if isinstance(result, models.PipeObject):
        _extend(result.extra.get('known_urls'))
        if isinstance(result.metadata, dict):
            _extend(result.metadata.get('known_urls'))
            _extend(result.metadata.get('urls'))
    elif hasattr(result, 'known_urls') or hasattr(result, 'urls'):
         # Handle objects with known_urls/urls attribute
         _extend(getattr(result, 'known_urls', None))
         _extend(getattr(result, 'urls', None))

    if isinstance(result, dict):
        _extend(result.get('known_urls'))
        _extend(result.get('urls'))
        extra = result.get('extra')
        if isinstance(extra, dict):
            _extend(extra.get('known_urls'))
            _extend(extra.get('urls'))
            
    return merge_sequences(urls, case_sensitive=True)


def extract_relationships(result: Any) -> Optional[Dict[str, Any]]:
    if isinstance(result, models.PipeObject):
        relationships = result.get_relationships()
        return relationships or None
    if isinstance(result, dict):
        relationships = result.get('relationships')
        if isinstance(relationships, dict) and relationships:
            return relationships
    return None


def extract_duration(result: Any) -> Optional[float]:
    duration = None
    if isinstance(result, models.PipeObject):
        duration = result.duration
    elif isinstance(result, dict):
        duration = result.get('duration')
        if duration is None:
            metadata = result.get('metadata')
            if isinstance(metadata, dict):
                duration = metadata.get('duration')
    if duration is None:
        return None
    try:
        return float(duration)
    except (TypeError, ValueError):
        return None