"""
查询 MES 表结构信息脚本
用于生成报表开发参考文档
"""

import sys
import io
import os
import json
import argparse
from pathlib import Path

import oracledb

# 设置 UTF-8 编码输出
sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')

# Load .env file
try:
    from dotenv import load_dotenv
    env_path = Path(__file__).resolve().parent.parent / '.env'
    load_dotenv(env_path)
except ImportError:
    pass

# 数据库连接信息 (从环境变量读取，必须在 .env 中设置)
DB_HOST = os.getenv('DB_HOST', '')
DB_PORT = os.getenv('DB_PORT', '1521')
DB_SERVICE = os.getenv('DB_SERVICE', '')
DB_USER = os.getenv('DB_USER', '')
DB_PASSWORD = os.getenv('DB_PASSWORD', '')

DB_CONFIG = {
    'user': DB_USER,
    'password': DB_PASSWORD,
    'dsn': f'(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST={DB_HOST})(PORT={DB_PORT})))(CONNECT_DATA=(SERVICE_NAME={DB_SERVICE})))'
}

# MES 表列表（預設清單）
MES_TABLES = [
    'DW_MES_LOT_V',
    'DW_MES_EQUIPMENTSTATUS_WIP_V',
    'DW_MES_SPEC_WORKCENTER_V',
    'DW_MES_CONTAINER',
    'DW_MES_HOLDRELEASEHISTORY',
    'DW_MES_JOB',
    'DW_MES_LOTREJECTHISTORY',
    'DW_MES_LOTWIPDATAHISTORY',
    'DW_MES_LOTWIPHISTORY',
    'DW_MES_MAINTENANCE',
    'DW_MES_PARTREQUESTORDER',
    'DW_MES_PJ_COMBINEDASSYLOTS',
    'DW_MES_RESOURCESTATUS',
    'DW_MES_RESOURCESTATUS_SHIFT',
    'DW_MES_WIP',
    'DW_MES_HM_LOTMOVEOUT',
    'DW_MES_JOBTXNHISTORY',
    'DW_MES_LOTMATERIALSHISTORY',
    'DW_MES_RESOURCE',
    'ERP_WIP_MOVETXN',
    'ERP_WIP_MOVETXN_DETAIL',
    'ERP_PJ_WIP_SCRAP_REASONS_EXCLUDE',
]

def get_table_schema(cursor, table_name, owner=None):
    """获取表的结构信息"""
    query = """
        SELECT
            COLUMN_NAME,
            DATA_TYPE,
            DATA_LENGTH,
            DATA_PRECISION,
            DATA_SCALE,
            NULLABLE,
            DATA_DEFAULT,
            COLUMN_ID
        FROM ALL_TAB_COLUMNS
        WHERE TABLE_NAME = :table_name
    """
    if owner:
        query += " AND OWNER = :owner ORDER BY COLUMN_ID"
        cursor.execute(query, table_name=table_name, owner=owner)
    else:
        query += " ORDER BY COLUMN_ID"
        cursor.execute(query, table_name=table_name)
    columns = cursor.fetchall()

    schema = []
    for col in columns:
        col_info = {
            'column_name': col[0],
            'data_type': col[1],
            'data_length': col[2],
            'data_precision': col[3],
            'data_scale': col[4],
            'nullable': col[5],
            'default_value': col[6],
            'column_id': col[7]
        }
        schema.append(col_info)

    return schema


def get_table_comments(cursor, table_name, owner=None):
    """获取表和列的注释"""
    # 获取表注释
    table_query = """
        SELECT COMMENTS
        FROM ALL_TAB_COMMENTS
        WHERE TABLE_NAME = :table_name
    """
    if owner:
        table_query += " AND OWNER = :owner"
        cursor.execute(table_query, table_name=table_name, owner=owner)
    else:
        cursor.execute(table_query, table_name=table_name)
    table_comment = cursor.fetchone()

    # 获取列注释
    col_query = """
        SELECT COLUMN_NAME, COMMENTS
        FROM ALL_COL_COMMENTS
        WHERE TABLE_NAME = :table_name
    """
    if owner:
        col_query += " AND OWNER = :owner ORDER BY COLUMN_NAME"
        cursor.execute(col_query, table_name=table_name, owner=owner)
    else:
        col_query += " ORDER BY COLUMN_NAME"
        cursor.execute(col_query, table_name=table_name)
    column_comments = {row[0]: row[1] for row in cursor.fetchall()}

    return table_comment[0] if table_comment else None, column_comments


def get_table_indexes(cursor, table_name, owner=None):
    """获取表的索引信息"""
    query = """
        SELECT
            i.INDEX_NAME,
            i.UNIQUENESS,
            LISTAGG(ic.COLUMN_NAME, ', ') WITHIN GROUP (ORDER BY ic.COLUMN_POSITION) as COLUMNS
        FROM ALL_INDEXES i
        JOIN ALL_IND_COLUMNS ic ON i.INDEX_NAME = ic.INDEX_NAME AND i.TABLE_NAME = ic.TABLE_NAME
        WHERE i.TABLE_NAME = :table_name
        GROUP BY i.INDEX_NAME, i.UNIQUENESS
        ORDER BY i.INDEX_NAME
    """
    if owner:
        query = query.replace(
            "WHERE i.TABLE_NAME = :table_name",
            "WHERE i.TABLE_NAME = :table_name AND i.TABLE_OWNER = :owner",
        )
        cursor.execute(query, table_name=table_name, owner=owner)
    else:
        cursor.execute(query, table_name=table_name)
    return cursor.fetchall()


def get_sample_data(cursor, table_name, owner=None, limit=5):
    """获取表的示例数据"""
    try:
        if owner:
            cursor.execute(f"SELECT * FROM {owner}.{table_name} WHERE ROWNUM <= {limit}")
        else:
            cursor.execute(f"SELECT * FROM {table_name} WHERE ROWNUM <= {limit}")
        columns = [col[0] for col in cursor.description]
        rows = cursor.fetchall()
        return columns, rows
    except Exception as e:
        return None, str(e)


def main():
    """主函数"""
    parser = argparse.ArgumentParser(description="Query Oracle table/view schema information")
    parser.add_argument(
        "--schema",
        help="Schema/owner to scan (e.g. DWH). If set, scans all TABLE/VIEW in that schema.",
    )
    parser.add_argument(
        "--output",
        help="Output JSON path (default: data/table_schema_info.json)",
        default=None,
    )
    args = parser.parse_args()

    print("Connecting to database...")
    connection = oracledb.connect(**DB_CONFIG)
    cursor = connection.cursor()

    all_table_info = {}

    owner = args.schema.strip().upper() if args.schema else None
    if owner:
        cursor.execute(
            """
            SELECT OBJECT_NAME
            FROM ALL_OBJECTS
            WHERE OWNER = :owner
              AND OBJECT_TYPE IN ('TABLE', 'VIEW')
            ORDER BY OBJECT_NAME
            """,
            owner=owner,
        )
        table_list = [row[0] for row in cursor.fetchall()]
    else:
        table_list = MES_TABLES

    print(f"\nQuerying schema information for {len(table_list)} objects...\n")

    for idx, table_name in enumerate(table_list, 1):
        print(f"[{idx}/{len(table_list)}] Processing {table_name}...")

        try:
            # 获取表结构
            schema = get_table_schema(cursor, table_name, owner=owner)

            # 获取注释
            table_comment, column_comments = get_table_comments(cursor, table_name, owner=owner)

            # 获取索引
            indexes = get_table_indexes(cursor, table_name, owner=owner)

            # 获取行数
            if owner:
                cursor.execute(f"SELECT COUNT(*) FROM {owner}.{table_name}")
            else:
                cursor.execute(f"SELECT COUNT(*) FROM {table_name}")
            row_count = cursor.fetchone()[0]

            # 获取示例数据
            sample_columns, sample_data = get_sample_data(cursor, table_name, owner=owner, limit=3)

            all_table_info[table_name] = {
                'owner': owner,
                'table_comment': table_comment,
                'row_count': row_count,
                'schema': schema,
                'column_comments': column_comments,
                'indexes': indexes,
                'sample_columns': sample_columns,
                'sample_data': sample_data
            }

        except Exception as e:
            print(f"   Error: {str(e)}")
            all_table_info[table_name] = {'error': str(e)}

    # 保存到 JSON 文件
    if args.output:
        output_file = Path(args.output)
    else:
        output_file = Path(__file__).resolve().parent.parent / 'data' / 'table_schema_info.json'
    with open(output_file, 'w', encoding='utf-8') as f:
        json.dump(all_table_info, f, ensure_ascii=False, indent=2, default=str)

    print(f"\n[OK] Schema information saved to {output_file}")

    cursor.close()
    connection.close()
    print("[OK] Connection closed")


if __name__ == "__main__":
    main()