import uuid
import enum
from datetime import datetime, timezone
from sqlalchemy import String, Boolean, DateTime, Enum as SAEnum, ForeignKey, Text, Numeric, Integer
from sqlalchemy.orm import Mapped, mapped_column, relationship
from app.database import Base

class SmsJobStatus(str, enum.Enum):
    pending = "pending"
    processing = "processing"
    sent = "sent"
    failed = "failed"
    cancelled = "cancelled"

class SmsCreditTx(str, enum.Enum):
    topup = "topup"
    deduct = "deduct"
    refund = "refund"
    adjustment = "adjustment"

class SmsJob(Base):
    __tablename__ = "sms_jobs"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    school_id: Mapped[str] = mapped_column(String(36), ForeignKey("schools.id", ondelete="CASCADE"), nullable=False, index=True)
    recipient_phone: Mapped[str] = mapped_column(String(20), nullable=False)
    message: Mapped[str] = mapped_column(Text, nullable=False)
    sender_name: Mapped[str] = mapped_column(String(11), nullable=False)
    status: Mapped[SmsJobStatus] = mapped_column(SAEnum(SmsJobStatus), default=SmsJobStatus.pending, nullable=False, index=True)
    trigger: Mapped[str | None] = mapped_column(String(50), nullable=True)  # "absent", "late", "manual"
    semaphore_message_id: Mapped[str | None] = mapped_column(String(100), nullable=True)
    error_message: Mapped[str | None] = mapped_column(Text, nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))
    sent_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    retry_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)

    school: Mapped["School"] = relationship("School", back_populates="sms_jobs")

class SmsCreditLedger(Base):
    __tablename__ = "sms_credit_ledger"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    school_id: Mapped[str] = mapped_column(String(36), ForeignKey("schools.id", ondelete="CASCADE"), nullable=False, index=True)
    tx_type: Mapped[SmsCreditTx] = mapped_column(SAEnum(SmsCreditTx), nullable=False)
    amount: Mapped[float] = mapped_column(Numeric(12, 2), nullable=False)
    balance_after: Mapped[float] = mapped_column(Numeric(12, 2), nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)
    reference_id: Mapped[str | None] = mapped_column(String(36), nullable=True)  # invoice_id or sms_job_id
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))
    created_by: Mapped[str | None] = mapped_column(String(36), nullable=True)  # hub_user_id