"""
Tool_OCR - Translation Log Model
Tracks translation usage statistics for billing and monitoring
"""

from sqlalchemy import Column, Integer, String, DateTime, Float, ForeignKey
from sqlalchemy.orm import relationship
from datetime import datetime

from app.core.database import Base


class TranslationLog(Base):
    """
    Translation log model for tracking API usage and costs.

    Each record represents a single translation job completion,
    storing token usage and estimated costs for billing purposes.
    """

    __tablename__ = "tool_ocr_translation_logs"

    id = Column(Integer, primary_key=True, index=True, autoincrement=True)
    user_id = Column(Integer, ForeignKey("tool_ocr_users.id", ondelete="CASCADE"),
                    nullable=False, index=True,
                    comment="Foreign key to users table")
    task_id = Column(String(255), nullable=False, index=True,
                    comment="Task UUID that was translated")
    target_lang = Column(String(10), nullable=False, index=True,
                        comment="Target language code (e.g., 'en', 'ja', 'zh-TW')")
    source_lang = Column(String(10), nullable=True,
                        comment="Source language code (or 'auto')")

    # Token usage statistics
    input_tokens = Column(Integer, default=0, nullable=False,
                         comment="Number of input tokens used")
    output_tokens = Column(Integer, default=0, nullable=False,
                          comment="Number of output tokens generated")
    total_tokens = Column(Integer, default=0, nullable=False,
                         comment="Total tokens (input + output)")

    # Translation statistics
    total_elements = Column(Integer, default=0, nullable=False,
                           comment="Total elements in document")
    translated_elements = Column(Integer, default=0, nullable=False,
                                comment="Number of elements translated")
    total_characters = Column(Integer, default=0, nullable=False,
                             comment="Total characters translated")

    # Cost tracking (estimated based on token pricing)
    estimated_cost = Column(Float, default=0.0, nullable=False,
                           comment="Estimated cost in USD")

    # Processing info
    processing_time_seconds = Column(Float, default=0.0, nullable=False,
                                    comment="Translation processing time")
    provider = Column(String(50), default="dify", nullable=False,
                     comment="Translation provider (e.g., 'dify')")

    # Timestamps
    created_at = Column(DateTime, default=datetime.utcnow, nullable=False, index=True)

    # Relationships
    user = relationship("User", back_populates="translation_logs")

    def __repr__(self):
        return f"<TranslationLog(id={self.id}, task_id='{self.task_id}', target_lang='{self.target_lang}', tokens={self.total_tokens})>"

    def to_dict(self):
        """Convert translation log to dictionary"""
        return {
            "id": self.id,
            "user_id": self.user_id,
            "task_id": self.task_id,
            "target_lang": self.target_lang,
            "source_lang": self.source_lang,
            "input_tokens": self.input_tokens,
            "output_tokens": self.output_tokens,
            "total_tokens": self.total_tokens,
            "total_elements": self.total_elements,
            "translated_elements": self.translated_elements,
            "total_characters": self.total_characters,
            "estimated_cost": self.estimated_cost,
            "processing_time_seconds": self.processing_time_seconds,
            "provider": self.provider,
            "created_at": self.created_at.isoformat() if self.created_at else None
        }