import datetime
from sqlalchemy import String, Text, DateTime, Integer, ForeignKey, Boolean
from sqlalchemy.orm import Mapped, mapped_column, relationship
from app.database import Base


class Job(Base):
    __tablename__ = "jobs"

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    title: Mapped[str] = mapped_column(String(300), index=True)
    description: Mapped[str] = mapped_column(Text)
    institution: Mapped[str] = mapped_column(String(300))
    location: Mapped[str | None] = mapped_column(String(300), nullable=True)
    job_type: Mapped[str] = mapped_column(String(50), default="full-time")
    salary_range: Mapped[str | None] = mapped_column(String(100), nullable=True)
    application_url: Mapped[str | None] = mapped_column(String(500), nullable=True)
    application_email: Mapped[str | None] = mapped_column(String(255), nullable=True)
    deadline: Mapped[datetime.datetime | None] = mapped_column(DateTime, nullable=True)
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
    posted_by_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    field_id: Mapped[int | None] = mapped_column(ForeignKey("fields.id"), nullable=True, index=True)
    created_at: Mapped[datetime.datetime] = mapped_column(DateTime, default=datetime.datetime.utcnow, index=True)

    posted_by = relationship("User", back_populates="jobs_posted")
    field = relationship("Field", back_populates="jobs")
    applications = relationship("JobApplication", back_populates="job", cascade="all, delete-orphan")


class JobApplication(Base):
    __tablename__ = "job_applications"

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    job_id: Mapped[int] = mapped_column(ForeignKey("jobs.id", ondelete="CASCADE"), index=True)
    applicant_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    cover_letter: Mapped[str | None] = mapped_column(Text, nullable=True)
    status: Mapped[str] = mapped_column(String(50), default="pending")
    created_at: Mapped[datetime.datetime] = mapped_column(DateTime, default=datetime.datetime.utcnow)

    job = relationship("Job", back_populates="applications")
    applicant = relationship("User")