import tomllib
import tomli_w
from pathlib import Path
from typing import Dict, Any, Optional
from src.models import Persona
from src import paths

class PersonaManager:
 """Manages Persona profiles across global and project-specific files."""

 def __init__(self, project_root: Optional[Path] = None):
  self.project_root = project_root

 def _get_path(self, scope: str) -> Path:
  if scope == "global":
   return paths.get_global_personas_path()
  elif scope == "project":
   if not self.project_root:
    raise ValueError("Project root is not set, cannot resolve project scope.")
   return paths.get_project_personas_path(self.project_root)
  else:
   raise ValueError("Invalid scope, must be 'global' or 'project'")

 def load_all(self) -> Dict[str, Persona]:
  """Merges global and project personas into a single dictionary."""
  personas = {}
  
  global_path = paths.get_global_personas_path()
  global_data = self._load_file(global_path)
  for name, data in global_data.get("personas", {}).items():
   personas[name] = Persona.from_dict(name, data)
  
  if self.project_root:
   project_path = paths.get_project_personas_path(self.project_root)
   project_data = self._load_file(project_path)
   for name, data in project_data.get("personas", {}).items():
    personas[name] = Persona.from_dict(name, data)
    
  return personas

 def save_persona(self, persona: Persona, scope: str = "project") -> None:
  path = self._get_path(scope)
  data = self._load_file(path)
  if "personas" not in data:
   data["personas"] = {}
  
  data["personas"][persona.name] = persona.to_dict()
  self._save_file(path, data)

 def get_persona_scope(self, name: str) -> str:
  """Returns the scope ('global' or 'project') of a persona by name."""
  if self.project_root:
   project_path = paths.get_project_personas_path(self.project_root)
   project_data = self._load_file(project_path)
   if name in project_data.get("personas", {}):
    return "project"
  
  global_path = paths.get_global_personas_path()
  global_data = self._load_file(global_path)
  if name in global_data.get("personas", {}):
   return "global"
   
  return "project"

 def delete_persona(self, name: str, scope: str = "project") -> None:
  path = self._get_path(scope)
  data = self._load_file(path)
  if "personas" in data and name in data["personas"]:
   del data["personas"][name]
   self._save_file(path, data)

 def _load_file(self, path: Path) -> Dict[str, Any]:
  if not path.exists():
   return {}
  try:
   with open(path, "rb") as f:
    return tomllib.load(f)
  except Exception:
   return {}

 def _save_file(self, path: Path, data: Dict[str, Any]) -> None:
  path.parent.mkdir(parents=True, exist_ok=True)
  with open(path, "wb") as f:
   tomli_w.dump(data, f)