from dataclasses import dataclass, field
from typing import List, Optional, Dict, Any
from datetime import datetime

@dataclass
class Ticket:
 """
    Represents a discrete unit of work within a track.
    """
 id: str
 description: str
 status: str
 assigned_to: str
 target_file: Optional[str] = None
 context_requirements: List[str] = field(default_factory=list)
 depends_on: List[str] = field(default_factory=list)
 blocked_reason: Optional[str] = None
 step_mode: bool = False
 retry_count: int = 0

 def mark_blocked(self, reason: str) -> None:
  """Sets the ticket status to 'blocked' and records the reason."""
  self.status = "blocked"
  self.blocked_reason = reason

 def mark_complete(self) -> None:
  """Sets the ticket status to 'completed'."""
  self.status = "completed"

 def get(self, key: str, default: Any = None) -> Any:
  """Helper to provide dictionary-like access to dataclass fields."""
  return getattr(self, key, default)

 def to_dict(self) -> Dict[str, Any]:
  return {
   "id": self.id,
   "description": self.description,
   "status": self.status,
   "assigned_to": self.assigned_to,
   "target_file": self.target_file,
   "context_requirements": self.context_requirements,
   "depends_on": self.depends_on,
   "blocked_reason": self.blocked_reason,
   "step_mode": self.step_mode,
   "retry_count": self.retry_count,
  }

 @classmethod
 def from_dict(cls, data: Dict[str, Any]) -> "Ticket":
  return cls(
   id=data["id"],
   description=data.get("description"),
   status=data.get("status"),
   assigned_to=data.get("assigned_to"),
   target_file=data.get("target_file"),
   context_requirements=data.get("context_requirements", []),
   depends_on=data.get("depends_on", []),
   blocked_reason=data.get("blocked_reason"),
   step_mode=data.get("step_mode", False),
   retry_count=data.get("retry_count", 0),
  )

@dataclass
class Track:
 """
    Represents a collection of tickets that together form an architectural track or epic.
    """
 id: str
 description: str
 tickets: List[Ticket] = field(default_factory=list)

 def get_executable_tickets(self) -> List[Ticket]:
  """
        Returns all 'todo' tickets whose dependencies are all 'completed'.
        """
  # Map ticket IDs to their current status for efficient lookup
  status_map = {t.id: t.status for t in self.tickets}
  executable = []
  for ticket in self.tickets:
   if ticket.status != "todo":
    continue
    # Check if all dependencies are completed
   all_deps_completed = True
   for dep_id in ticket.depends_on:
   # If a dependency is missing from the track, we treat it as not completed (or we could raise an error)
    if status_map.get(dep_id) != "completed":
     all_deps_completed = False
     break
   if all_deps_completed:
    executable.append(ticket)
  return executable

@dataclass
class WorkerContext:
 """
    Represents the context provided to a Tier 3 Worker for a specific ticket.
    """
 ticket_id: str
 model_name: str
 messages: List[dict]

@dataclass
class Metadata:
 id: str
 name: str
 status: str
 created_at: datetime
 updated_at: datetime

 def to_dict(self) -> Dict[str, Any]:
  return {
   "id": self.id,
   "name": self.name,
   "status": self.status,
   "created_at": self.created_at.isoformat() if self.created_at else None,
   "updated_at": self.updated_at.isoformat() if self.updated_at else None,
  }

 @classmethod
 def from_dict(cls, data: Dict[str, Any]) -> "Metadata":
  return cls(
   id=data["id"],
   name=data["name"],
   status=data.get("status"),
   created_at=datetime.fromisoformat(data['created_at']) if data.get('created_at') else None,
   updated_at=datetime.fromisoformat(data['updated_at']) if data.get('updated_at') else None,
  )

@dataclass
class TrackState:
 metadata: Metadata
 discussion: List[Dict[str, Any]]
 tasks: List[Ticket]

 def to_dict(self) -> Dict[str, Any]:
  return {
   "metadata": self.metadata.to_dict(),
   "discussion": [
    {
     k: v.isoformat() if isinstance(v, datetime) else v
     for k, v in item.items()
    }
    for item in self.discussion
   ],
   "tasks": [task.to_dict() for task in self.tasks],
  }

 @classmethod
 def from_dict(cls, data: Dict[str, Any]) -> "TrackState":
  metadata = Metadata.from_dict(data["metadata"])
  tasks = [Ticket.from_dict(task_data) for task_data in data["tasks"]]
  return cls(
   metadata=metadata,
   discussion=[
    {
     k: datetime.fromisoformat(v) if isinstance(v, str) and 'T' in v else v # Basic check for ISO format
     for k, v in item.items()
    }
    for item in data["discussion"]
   ],
   tasks=tasks,
  )