from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
import os
from pathlib import Path

PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent.parent

USE_POSTGRES = os.getenv('USE_POSTGRES', 'true').lower() == 'true'

if USE_POSTGRES:
    POSTGRES_CONFIG = {
        'host': os.getenv('PG_HOST', '127.0.0.1'),
        'port': os.getenv('PG_PORT', '5432'),
        'database': os.getenv('PG_DATABASE', 'yzr_nr'),
        'user': os.getenv('PG_USER', 'yzr_nr'),
        'password': os.getenv('PG_PASSWORD', 'aTX3WKKnPfRnM5PC')
    }
    SQLALCHEMY_DATABASE_URL = (
        f"postgresql://{POSTGRES_CONFIG['user']}:{POSTGRES_CONFIG['password']}"
        f"@{POSTGRES_CONFIG['host']}:{POSTGRES_CONFIG['port']}/{POSTGRES_CONFIG['database']}"
    )
    engine = create_engine(
        SQLALCHEMY_DATABASE_URL,
        pool_pre_ping=True,
        pool_size=10,
        max_overflow=20
    )
else:
    DATA_DIR = os.getenv('DATA_DIR', str(PROJECT_ROOT / 'data'))
    os.makedirs(DATA_DIR, exist_ok=True)
    DB_PATH = os.path.join(DATA_DIR, 'yzr.db')
    SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_PATH}"
    engine = create_engine(SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False})

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()

def init_db():
    Base.metadata.create_all(bind=engine)
    from sqlalchemy import text
    try:
        with engine.connect() as conn:
            # 迁移：为已有表添加列
            conn.execute(text("ALTER TABLE users ADD COLUMN IF NOT EXISTS last_login TIMESTAMP"))
            conn.execute(text("ALTER TABLE llm_configs ADD COLUMN IF NOT EXISTS provider VARCHAR DEFAULT 'opencode-go'"))
            conn.execute(text("ALTER TABLE llm_configs ADD COLUMN IF NOT EXISTS base_url VARCHAR"))
            conn.execute(text("ALTER TABLE llm_configs ADD COLUMN IF NOT EXISTS api_key VARCHAR"))
            try:
                conn.execute(text("ALTER TABLE articles ADD COLUMN IF NOT EXISTS images JSON DEFAULT '{}'::json"))
            except Exception:
                conn.execute(text("ALTER TABLE articles ADD COLUMN IF NOT EXISTS images TEXT DEFAULT '{}'"))
            for table, col, typ in [
                ("users", "org_id", "VARCHAR DEFAULT 'default'"),
                ("topics", "org_id", "VARCHAR DEFAULT 'default'"),
                ("platform_configs", "requires_image", "BOOLEAN DEFAULT FALSE"),
                ("platform_configs", "image_count_min", "INTEGER DEFAULT 0"),
                ("platform_configs", "image_count_max", "INTEGER DEFAULT 0"),
                ("platform_configs", "image_width", "INTEGER DEFAULT 0"),
                ("platform_configs", "image_height", "INTEGER DEFAULT 0"),
                ("platform_configs", "min_words", "INTEGER DEFAULT 0"),
                ("platform_configs", "max_words", "INTEGER DEFAULT 0"),
            ]:
                try:
                    conn.execute(text(f"ALTER TABLE {table} ADD COLUMN IF NOT EXISTS {col} {typ}"))
                except Exception:
                    try:
                        conn.execute(text(f"ALTER TABLE {table} ADD COLUMN {col} {typ}"))
                    except Exception:
                        pass
            conn.commit()
    except Exception:
        pass  # SQLite 不支持 IF NOT EXISTS，但 create_all 对 SQLite 够用，这里仅为 PostgreSQL 迁移

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