"""
数据库迁移脚本：为对外API功能扩展projects表结构

添加以下字段：
- status: 项目状态 (draft, configuring, ready, in_progress, completed)
- source: 项目来源 (internal, external)
- task_type: 任务类型 (text_classification, image_classification, object_detection, ner)
- updated_at: 更新时间
- external_id: 外部系统的项目ID

使用方法：
    cd backend
    python scripts/migrate_external_api.py
"""
import sys
import os

# 添加父目录到路径
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from database import get_db_connection, db_config
import logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)


def check_column_exists(cursor, table: str, column: str) -> bool:
    """检查列是否存在"""
    if db_config.db_type == 'mysql':
        cursor.execute("""
            SELECT COUNT(*) as cnt FROM information_schema.columns 
            WHERE table_schema = %s AND table_name = %s AND column_name = %s
        """, (db_config.database, table, column))
        row = cursor.fetchone()
        return row['cnt'] > 0 if row else False
    else:
        cursor.execute(f"PRAGMA table_info({table})")
        columns = cursor.fetchall()
        return any(col['name'] == column for col in columns)


def migrate_mysql():
    """MySQL数据库迁移"""
    with get_db_connection() as conn:
        cursor = conn.cursor()
        
        # 添加 status 字段
        if not check_column_exists(cursor, 'projects', 'status'):
            logger.info("添加 projects.status 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN status VARCHAR(20) DEFAULT 'draft'
            """)
            cursor.execute("CREATE INDEX idx_projects_status ON projects(status)")
            logger.info("✓ status 字段添加成功")
        else:
            logger.info("○ status 字段已存在，跳过")
        
        # 添加 source 字段
        if not check_column_exists(cursor, 'projects', 'source'):
            logger.info("添加 projects.source 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN source VARCHAR(20) DEFAULT 'internal'
            """)
            cursor.execute("CREATE INDEX idx_projects_source ON projects(source)")
            logger.info("✓ source 字段添加成功")
        else:
            logger.info("○ source 字段已存在，跳过")
        
        # 添加 task_type 字段
        if not check_column_exists(cursor, 'projects', 'task_type'):
            logger.info("添加 projects.task_type 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN task_type VARCHAR(50)
            """)
            logger.info("✓ task_type 字段添加成功")
        else:
            logger.info("○ task_type 字段已存在，跳过")
        
        # 添加 updated_at 字段
        if not check_column_exists(cursor, 'projects', 'updated_at'):
            logger.info("添加 projects.updated_at 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
            """)
            logger.info("✓ updated_at 字段添加成功")
        else:
            logger.info("○ updated_at 字段已存在，跳过")
        
        # 添加 external_id 字段
        if not check_column_exists(cursor, 'projects', 'external_id'):
            logger.info("添加 projects.external_id 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN external_id VARCHAR(100)
            """)
            cursor.execute("CREATE INDEX idx_projects_external_id ON projects(external_id)")
            logger.info("✓ external_id 字段添加成功")
        else:
            logger.info("○ external_id 字段已存在，跳过")
        
        logger.info("MySQL 迁移完成！")


def migrate_sqlite():
    """SQLite数据库迁移"""
    with get_db_connection() as conn:
        cursor = conn.cursor()
        
        # 添加 status 字段
        if not check_column_exists(cursor, 'projects', 'status'):
            logger.info("添加 projects.status 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN status TEXT DEFAULT 'draft'
            """)
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_projects_status ON projects(status)")
            logger.info("✓ status 字段添加成功")
        else:
            logger.info("○ status 字段已存在，跳过")
        
        # 添加 source 字段
        if not check_column_exists(cursor, 'projects', 'source'):
            logger.info("添加 projects.source 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN source TEXT DEFAULT 'internal'
            """)
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_projects_source ON projects(source)")
            logger.info("✓ source 字段添加成功")
        else:
            logger.info("○ source 字段已存在，跳过")
        
        # 添加 task_type 字段
        if not check_column_exists(cursor, 'projects', 'task_type'):
            logger.info("添加 projects.task_type 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN task_type TEXT
            """)
            logger.info("✓ task_type 字段添加成功")
        else:
            logger.info("○ task_type 字段已存在，跳过")
        
        # 添加 updated_at 字段
        if not check_column_exists(cursor, 'projects', 'updated_at'):
            logger.info("添加 projects.updated_at 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN updated_at TIMESTAMP
            """)
            logger.info("✓ updated_at 字段添加成功")
        else:
            logger.info("○ updated_at 字段已存在，跳过")
        
        # 添加 external_id 字段
        if not check_column_exists(cursor, 'projects', 'external_id'):
            logger.info("添加 projects.external_id 字段...")
            cursor.execute("""
                ALTER TABLE projects 
                ADD COLUMN external_id TEXT
            """)
            cursor.execute("CREATE INDEX IF NOT EXISTS idx_projects_external_id ON projects(external_id)")
            logger.info("✓ external_id 字段添加成功")
        else:
            logger.info("○ external_id 字段已存在，跳过")
        
        logger.info("SQLite 迁移完成！")


def main():
    """执行迁移"""
    logger.info(f"开始数据库迁移，数据库类型: {db_config.db_type}")
    
    if db_config.db_type == 'mysql':
        migrate_mysql()
    else:
        migrate_sqlite()
    
    logger.info("=" * 50)
    logger.info("迁移完成！新增字段：")
    logger.info("  - status: 项目状态 (draft/configuring/ready/in_progress/completed)")
    logger.info("  - source: 项目来源 (internal/external)")
    logger.info("  - task_type: 任务类型")
    logger.info("  - updated_at: 更新时间")
    logger.info("  - external_id: 外部系统项目ID")


if __name__ == "__main__":
    main()