from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, Enum, Time
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func
from app.core.config import Base
import enum

class TaskStatus(str, enum.Enum):
    OPEN = "open"
    PENDING = "pending"
    UNDERGOING = "undergoing"
    COMPLETED = "completed"
    CLOSED = "closed"

class TaskPriority(str, enum.Enum):
    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"
    CRITICAL = "critical"

class Task(Base):
    __tablename__ = "tasks"
    
    id = Column(Integer, primary_key=True, index=True)
    title = Column(String(255), nullable=False)
    description = Column(Text, nullable=True)
    status = Column(Enum(TaskStatus), default=TaskStatus.OPEN)
    priority = Column(Enum(TaskPriority), default=TaskPriority.MEDIUM)
    task_code = Column(String(64), nullable=True, unique=True, index=True)
    
    # Task type/subtype (replaces old issue_type/issue_subtype)
    task_type = Column(String(32), default="issue")  # P7.1: default changed from 'task' to 'issue'
    task_subtype = Column(String(64), nullable=True)
    
    project_id = Column(Integer, ForeignKey("projects.id"), nullable=False)
    milestone_id = Column(Integer, ForeignKey("milestones.id"), nullable=False)
    reporter_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    assignee_id = Column(Integer, ForeignKey("users.id"), nullable=True)
    created_by_id = Column(Integer, ForeignKey("users.id"), nullable=True)
    
    # Tags (comma-separated)
    tags = Column(String(500), nullable=True)
    
    # Dependencies
    depend_on = Column(Text, nullable=True)
    related_tasks = Column(Text, nullable=True)
    
    # Effort tracking
    estimated_effort = Column(Integer, nullable=True)
    estimated_working_time = Column(Time, nullable=True)
    started_on = Column(DateTime(timezone=True), nullable=True)
    finished_on = Column(DateTime(timezone=True), nullable=True)
    
    # Resolution specific fields (for task_type="resolution")
    resolution_summary = Column(Text, nullable=True)
    positions = Column(Text, nullable=True)
    pending_matters = Column(Text, nullable=True)
    
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
    
    comments = relationship("Comment", foreign_keys="Comment.task_id", cascade="all, delete-orphan")