"""Task model."""
from sqlalchemy import (
    Column, String, Integer, Text, DateTime, ForeignKey, Boolean, JSON
)
from app.models.base import Base, TimestampMixin, TenantMixin


class Task(Base, TimestampMixin, TenantMixin):
    """A task is a work unit within a project.

    Can be assigned to a human user or an AI Worker.
    Status: pending -> assigned -> in_progress -> review -> done -> rejected -> cancelled
    Priority: low, medium, high, urgent
    """
    __tablename__ = "tasks"

    id = Column(Integer, primary_key=True, autoincrement=True)
    project_id = Column(Integer, ForeignKey("projects.id"), nullable=False, index=True)

    title = Column(String(500), nullable=False)
    description = Column(Text, default="")
    status = Column(String(50), nullable=False, default="pending")
    priority = Column(String(20), nullable=False, default="medium")

    # Assignment: assignee is a User (human or AI-linked)
    assignee_id = Column(Integer, ForeignKey("users.id"), nullable=True)

    # If assigned to AI, which worker profile
    worker_id = Column(Integer, ForeignKey("ai_workers.id"), nullable=True)

    # Task type: single_call, agent_loop, multi_agent (MVP: single_call + agent_loop)
    task_type = Column(String(50), default="single_call")

    # Task input (prompt, context, parameters)
    input_data = Column(Text, default="")  # JSON string with prompt/context
    output_data = Column(Text, nullable=True)  # JSON string with result

    # HITL: does this task require human review?
    requires_review = Column(Boolean, default=True)
    review_status = Column(String(50), nullable=True)  # pending, approved, rejected

    # Cost tracking
    token_cost_estimate = Column(Integer, nullable=True)

    # Dependencies (list of task IDs that must complete first)
    depends_on = Column(Text, default="[]")  # JSON array

    # Timeline
    due_date = Column(DateTime, nullable=True)
    started_at = Column(DateTime, nullable=True)
    completed_at = Column(DateTime, nullable=True)

    # Execution metadata (retries, duration, etc.)
    execution_meta = Column(Text, default="{}")  # JSON

    def __repr__(self):
        return f"<Task {self.title} [{self.status}]>"