#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""DDL 迁移基座执行器（T01/T02）：幂等导入 models JSON 生成的 DDL 至 MariaDB hrs 库。
特性：
  - CREATE TABLE IF NOT EXISTS（可重跑）；
  - 缺索引自动补建（先查 information_schema.STATISTICS）；
  - 迁移台账写入 hrs.schema_migration（version/表数/时间/校验和），重复执行只记一条最新；
  - 依赖 mysql 客户端或 pymysql，自动探测。
用法：
  python3 scripts/apply_ddl.py [--host 127.0.0.1] [--user test] [--password test123] [--db hrs] [--models models] [--version T01]
"""
import argparse, glob, hashlib, json, os, shutil, subprocess, sys

BASE = os.path.join(os.path.dirname(__file__), "..")
sys.path.insert(0, os.path.join(BASE, "scripts"))
from json2ddl import gen_table_ddl, gen_index_guard_sql  # noqa: E402

def run_sql_cli(sql, args):
    cmd = ["mysql", f"-h{args.host}", f"-P{args.port}", f"-u{args.user}", f"-p{args.password}", args.db]
    p = subprocess.run(cmd, input=sql.encode("utf-8"), capture_output=True)
    if p.returncode != 0:
        raise RuntimeError(p.stderr.decode("utf-8", "ignore"))
    return p.stdout.decode("utf-8", "ignore")

def exec_sql(sql, args):
    try:
        import pymysql
        conn = pymysql.connect(host=args.host, port=args.port, user=args.user,
                               password=args.password, database=args.db, charset="utf8mb4")
        try:
            with conn.cursor() as cur:
                cur.execute(sql)
            conn.commit()
            return None
        finally:
            conn.close()
    except ImportError:
        run_sql_cli(sql, args)
        return None

def query_sql(sql, args):
    if shutil.which("mysql"):
        out = run_sql_cli(sql + "\n", args)
        return [ln.split("\t") for ln in out.strip().splitlines() if ln]
    import pymysql
    conn = pymysql.connect(host=args.host, port=args.port, user=args.user,
                           password=args.password, database=args.db, charset="utf8mb4")
    try:
        with conn.cursor() as cur:
            cur.execute(sql)
            return [list(r) for r in cur.fetchall()]
    finally:
        conn.close()

def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--host", default="127.0.0.1")
    ap.add_argument("--port", default=3306, type=int)
    ap.add_argument("--user", default="test")
    ap.add_argument("--password", default="test123")
    ap.add_argument("--db", default="hrs")
    ap.add_argument("--models", default=os.path.join(BASE, "models"))
    ap.add_argument("--version", default="T01")
    args = ap.parse_args()

    # 0) 迁移台账表
    exec_sql("""CREATE TABLE IF NOT EXISTS `schema_migration` (
  `version` VARCHAR(32) NOT NULL COMMENT '迁移版本号',
  `applied_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '执行时间',
  `table_count` INT NOT NULL DEFAULT 0 COMMENT '本次管理表数',
  `checksum` VARCHAR(64) DEFAULT NULL COMMENT 'models JSON 合并校验和',
  `operator` VARCHAR(64) DEFAULT 'agent.develop' COMMENT '执行人',
  PRIMARY KEY (`version`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='DDL迁移台账(幂等可重跑)';""", args)

    # 1) 收集全部 models JSON，逐表建表 + 补索引
    created, index_added, total = [], [], 0
    h = hashlib.sha256()
    jobs = []
    for moddir in sorted(glob.glob(os.path.join(args.models, "*"))):
        if not os.path.isdir(moddir):
            continue
        for p in sorted(glob.glob(os.path.join(moddir, "*.json"))):
            doc = json.load(open(p, encoding="utf-8"))
            h.update(open(p, "rb").read())
            table, ddl = gen_table_ddl(p)
            jobs.append((os.path.basename(moddir), table, ddl, doc))
            total += 1

    for mod, table, ddl, doc in jobs:
        before = query_sql(f"SELECT COUNT(*) FROM information_schema.TABLES WHERE TABLE_SCHEMA='{args.db}' AND TABLE_NAME='{table}'", args)
        n_exist = int(before[0][0]) if before else 0
        exec_sql(ddl, args)
        if not n_exist:
            created.append(table)
        # 索引补建（幂等）
        rows = query_sql(f"SELECT INDEX_NAME FROM information_schema.STATISTICS WHERE TABLE_SCHEMA='{args.db}' AND TABLE_NAME='{table}'", args)
        existing_idx = {r[0] for r in rows}
        for idx in doc.get("indexes", []):
            if idx["name"] not in existing_idx:
                exec_sql(gen_index_guard_sql(table, idx), args)
                index_added.append(f"{table}.{idx['name']}")

    checksum = h.hexdigest()[:16]
    # 2) 登记迁移台账（幂等 upsert）
    exec_sql(f"""INSERT INTO schema_migration (version, table_count, checksum)
VALUES ('{args.version}', {total}, '{checksum}')
ON DUPLICATE KEY UPDATE applied_at=CURRENT_TIMESTAMP, table_count={total}, checksum='{checksum}';""", args)

    # 3) 校验
    rows = query_sql(f"SELECT COUNT(*) FROM information_schema.TABLES WHERE TABLE_SCHEMA='{args.db}'", args)
    print(f"[apply_ddl] 管理业务表 {total} 张；新建 {len(created)} 张；补索引 {len(index_added)} 个")
    print(f"[apply_ddl] 新建表: {', '.join(created) if created else '(无，全部已存在，幂等重跑)'}")
    print(f"[apply_ddl] schema_migration version={args.version} table_count={total} checksum={checksum}")
    print(f"[apply_ddl] 库 {args.db} 当前表总数: {rows[0][0]}")

if __name__ == "__main__":
    main()