from dataclasses import dataclass, field
from typing import List, Optional

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

    def mark_blocked(self, reason: str):
        """Sets the ticket status to 'blocked' and records the reason."""
        self.status = "blocked"
        self.blocked_reason = reason

    def mark_complete(self):
        """Sets the ticket status to 'completed'."""
        self.status = "completed"

@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]