"""V21 MySQL 实测。只允许显式指定 qinghe_integrity_test_ 前缀的独立测试库。"""
import os
import re
import unittest
from pathlib import Path
from urllib.parse import urlsplit


@unittest.skipUnless(os.environ.get("QINGHE_INTEGRITY_TEST_URL"), "未配置独立 MySQL 测试库")
class OrphanMigrationMySqlTest(unittest.TestCase):
    def setUp(self):
        import pymysql
        endpoint = urlsplit(os.environ["QINGHE_INTEGRITY_TEST_URL"].removeprefix("jdbc:"))
        database = endpoint.path.strip("/")
        if not re.fullmatch(r"qinghe_integrity_test_[a-z0-9_]+", database):
            raise ValueError("禁止使用业务数据库运行迁移测试")
        self.connection = pymysql.connect(host=endpoint.hostname, port=endpoint.port or 3306,
            database=database, user=os.environ["QINGHE_INTEGRITY_TEST_USER"],
            password=os.environ["QINGHE_INTEGRITY_TEST_PASSWORD"], charset="utf8mb4")
        self.addCleanup(self.connection.close)
        self.tables = ["moment", "moment_comment", "moment_comment_like", "video_play_record",
                       "moment_comment_bak_v21_orphan", "moment_comment_like_bak_v21_orphan",
                       "video_play_record_bak_v21_orphan"]
        with self.connection.cursor() as cursor:
            for table in reversed(self.tables):
                cursor.execute("DROP TABLE IF EXISTS `" + table + "`")
            cursor.execute("CREATE TABLE moment (id VARCHAR(36) PRIMARY KEY,deleted TINYINT NOT NULL) ENGINE=InnoDB")
            cursor.execute("CREATE TABLE moment_comment (id VARCHAR(36) PRIMARY KEY,moment_id VARCHAR(36),content TEXT) ENGINE=InnoDB")
            cursor.execute("CREATE TABLE moment_comment_like (id VARCHAR(36) PRIMARY KEY,comment_id VARCHAR(36)) ENGINE=InnoDB")
            cursor.execute("CREATE TABLE video_play_record (id VARCHAR(36) PRIMARY KEY,video_id VARCHAR(36),play_position INT) ENGINE=InnoDB")
            cursor.execute("INSERT INTO moment VALUES ('active',0),('soft-deleted',1)")
            cursor.execute("INSERT INTO moment_comment VALUES ('valid','active','保留'),('soft','soft-deleted','软删仍保留'),('orphan','absent','隔离')")
            cursor.execute("INSERT INTO moment_comment_like VALUES ('valid-like','valid'),('orphan-like','orphan'),('missing-comment','absent')")
            cursor.execute("INSERT INTO video_play_record VALUES ('valid-progress','active',10),('soft-progress','soft-deleted',20),('orphan-progress','absent',30)")
        self.connection.commit()

    def run_migration(self, apply=False):
        script = (Path(__file__).resolve().parents[1] /
                  "src/main/resources/db/migration/V21__quarantine_orphan_moment_dependencies.sql").read_text(encoding="utf-8")
        # 本脚本不含存储过程或字符串内分号；先移除整行注释。
        script = "\n".join(line for line in script.splitlines() if not line.lstrip().startswith("--"))
        try:
            with self.connection.cursor() as cursor:
                cursor.execute("SET @qinghe_v21_apply = %s", (1 if apply else 0,))
                for statement in script.split(";"):
                    if statement.strip():
                        cursor.execute(statement)
        except Exception:
            self.connection.rollback()
            raise

    def count(self, table):
        with self.connection.cursor() as cursor:
            cursor.execute("SELECT COUNT(*) FROM `" + table + "`")
            return cursor.fetchone()[0]

    def test_dry_run_does_not_change_business_data_or_create_backups(self):
        self.run_migration()
        self.assertEqual(3, self.count("moment_comment"))
        self.assertEqual(3, self.count("video_play_record"))
        with self.connection.cursor() as cursor:
            cursor.execute("SELECT COUNT(*) FROM information_schema.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME LIKE '%bak_v21%'")
            self.assertEqual(0, cursor.fetchone()[0])

    def test_apply_backs_up_orphans_preserves_soft_deleted_and_can_repeat(self):
        self.run_migration(True)
        for table, count in [("moment_comment",2),("moment_comment_like",1),("video_play_record",2),
                             ("moment_comment_bak_v21_orphan",1),("moment_comment_like_bak_v21_orphan",2),
                             ("video_play_record_bak_v21_orphan",1)]:
            self.assertEqual(count, self.count(table), table)
        self.run_migration(True)
        self.assertEqual(1, self.count("moment_comment_bak_v21_orphan"))
        self.assertEqual(2, self.count("moment_comment"))

    def test_backup_failure_stops_before_deletion(self):
        with self.connection.cursor() as cursor:
            cursor.execute("CREATE TABLE video_play_record_bak_v21_orphan (id VARCHAR(36) PRIMARY KEY) ENGINE=InnoDB")
        with self.assertRaises(Exception):
            self.run_migration(True)
        self.assertEqual(3, self.count("moment_comment"))
        self.assertEqual(3, self.count("video_play_record"))
        self.assertEqual(0, self.count("moment_comment_bak_v21_orphan"))
        self.assertEqual(0, self.count("moment_comment_like_bak_v21_orphan"))


if __name__ == "__main__":
    unittest.main()