import enum, uuid
from sqlalchemy import String, Enum, ForeignKey, Integer, DateTime, JSON
from sqlalchemy.orm import relationship, Mapped, mapped_column
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.sql import func
from app.db import Base

class JobStatus(str, enum.Enum):
    PENDING = "pending"
    QUEUED = "queued"
    RUNNING = "running"
    SUCCESS = "success"
    FAILED = "failed"

class TaskStatus(str, enum.Enum):
    PENDING = "pending"
    QUEUED = "queued"
    RUNNING = "running"
    SUCCESS = "success"
    FAILED = "failed"

class Job(Base):
    __tablename__ = "jobs"
    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    job_type: Mapped[str] = mapped_column(String(64), index=True)
    status: Mapped[JobStatus] = mapped_column(Enum(JobStatus), default=JobStatus.PENDING, index=True)
    domain: Mapped[str] = mapped_column(String(255), index=True)
    payload: Mapped[dict | None] = mapped_column(JSON, nullable=True)
    created_at: Mapped[str] = mapped_column(DateTime(timezone=True), server_default=func.now())
    updated_at: Mapped[str] = mapped_column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())
    tasks: Mapped[list["Task"]] = relationship("Task", back_populates="job", cascade="all, delete-orphan", lazy="selectin")

class Task(Base):
    __tablename__ = "tasks"
    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    job_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("jobs.id", ondelete="CASCADE"), index=True)
    name: Mapped[str] = mapped_column(String(64), index=True)
    status: Mapped[TaskStatus] = mapped_column(Enum(TaskStatus), default=TaskStatus.PENDING, index=True)
    routing_key: Mapped[str] = mapped_column(String(128), index=True)
    retries: Mapped[int] = mapped_column(Integer, default=0)
    max_retries: Mapped[int] = mapped_column(Integer, default=3)
    worker_id: Mapped[str | None] = mapped_column(String(64), nullable=True)
    result: Mapped[dict | None] = mapped_column(JSON, nullable=True)
    error: Mapped[str | None] = mapped_column(String(1024), nullable=True)
    created_at: Mapped[str] = mapped_column(DateTime(timezone=True), server_default=func.now())
    started_at: Mapped[str | None] = mapped_column(DateTime(timezone=True), nullable=True)
    finished_at: Mapped[str | None] = mapped_column(DateTime(timezone=True), nullable=True)

    job: Mapped["Job"] = relationship("Job", back_populates="tasks")

class TaskDependency(Base):
    __tablename__ = "task_dependencies"
    task_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("tasks.id", ondelete="CASCADE"), primary_key=True)
    depends_on_task_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("tasks.id", ondelete="CASCADE"), primary_key=True)