import os
import urllib.parse
from sqlalchemy import create_engine, Column, Integer, String, Text, DateTime, Boolean, ForeignKey, LargeBinary, Enum as SqlEnum
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, relationship
from dotenv import load_dotenv

# Load environment variables
load_dotenv()

DB_USER = os.getenv("DB_USER", "postgres")
DB_PASSWORD = os.getenv("DB_PASSWORD", "password")
DB_HOST = os.getenv("DB_HOST", "localhost")
DB_PORT = os.getenv("DB_PORT", "5432")
DB_NAME = os.getenv("DB_NAME", "ocr_db")

encoded_user = urllib.parse.quote_plus(DB_USER)
encoded_password = urllib.parse.quote_plus(DB_PASSWORD)

# SQLAlchemy Database URL
DATABASE_URL = f"postgresql://{encoded_user}:{encoded_password}@{DB_HOST}:{DB_PORT}/{DB_NAME}"

engine = create_engine(DATABASE_URL)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

class Vendor(Base):
    __tablename__ = "vendors"
    
    id = Column(Integer, primary_key=True, index=True)
    name = Column(String, unique=True, index=True)
    default_model = Column(String) # 'text' or 'vision'
    created_at = Column(DateTime)

class Document(Base):
    __tablename__ = "documents"
    
    id = Column(Integer, primary_key=True, index=True)
    vendor_id = Column(Integer, ForeignKey("vendors.id"), nullable=True)
    filename = Column(String)
    upload_date = Column(DateTime)
    status = Column(String) # 'pending', 'verified'
    processed_data = Column(JSONB) # Store the verified extraction results
    
    vendor = relationship("Vendor")

class Email(Base):
    __tablename__ = "emails"

    id = Column(Integer, primary_key=True, index=True)
    subject = Column(String, index=True)
    sender = Column(String, index=True)
    body = Column(Text)
    received_date = Column(DateTime)
    is_read = Column(Boolean, default=False)

    attachments = relationship("Attachment", back_populates="email")

class Attachment(Base):
    __tablename__ = "attachments"

    id = Column(Integer, primary_key=True, index=True)
    email_id = Column(Integer, ForeignKey("emails.id"))
    filename = Column(String)
    content_type = Column(String)
    file_content = Column(LargeBinary)
    
    email = relationship("Email", back_populates="attachments")

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()