import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.regex.Pattern;

/**
 * 执行 sql/ 目录下的脚本（按 GO 分批），用于建表 / 索引 / 视图。
 *
 * 用法（在 fms-api 目录下运行）：
 *   java -cp "tools/migration/mssql-jdbc-13.4.0.jre11.jar" tools/migration/RunSqlFile.java <sql文件> [--dry-run]
 *
 * 说明：
 * - 目标库固定取 config/dbconfigs/G3HD.properties，执行前校验 catalog 必须是 FMS。
 * - 含「重建」段落（drop ... if exists）的脚本请确认表数据已不需要后再执行。
 * - DDL 在单个事务中执行，任一批次失败整体回滚。
 */
public final class RunSqlFile {
    private static final Pattern GO = Pattern.compile("(?im)^\\s*GO\\s*;?\\s*$");

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.out.println("用法: RunSqlFile <sqlFile> [--dry-run]");
            return;
        }
        Path script = Path.of(args[0]).toAbsolutePath().normalize();
        boolean dryRun = args.length > 1 && "--dry-run".equalsIgnoreCase(args[1]);

        Path apiRoot = Path.of("").toAbsolutePath().normalize();
        Properties properties = new Properties();
        try (InputStream input = Files.newInputStream(apiRoot.resolve("config/dbconfigs/G3HD.properties"))) {
            properties.load(input);
        }

        List<String> batches = new ArrayList<>();
        for (String batch : GO.split(Files.readString(script, StandardCharsets.UTF_8))) {
            String trimmed = batch.trim();
            if (!trimmed.isEmpty()) {
                batches.add(trimmed);
            }
        }

        System.out.println("脚本: " + script);
        System.out.println("批次: " + batches.size() + (dryRun ? "（dry-run，不执行）" : ""));
        for (String batch : batches) {
            System.out.println("  - " + firstLine(batch));
        }
        if (dryRun) {
            return;
        }

        try (Connection connection = DriverManager.getConnection(
                properties.getProperty("url"),
                properties.getProperty("username"),
                properties.getProperty("password"))) {
            if (!"FMS".equalsIgnoreCase(connection.getCatalog())) {
                throw new IllegalStateException("Refusing to run on database: " + connection.getCatalog());
            }
            connection.setAutoCommit(false);
            int applied = 0;
            try {
                for (String batch : batches) {
                    try (Statement statement = connection.createStatement()) {
                        statement.execute(batch);
                    }
                    applied++;
                    System.out.println("APPLIED|" + firstLine(batch));
                }
                connection.commit();
            } catch (Exception e) {
                connection.rollback();
                throw new IllegalStateException("第 " + (applied + 1) + " 批失败，已回滚: " + e.getMessage(), e);
            }
            System.out.println("OK|batches=" + applied);
        }
    }

    private static String firstLine(String batch) {
        for (String line : batch.split("\\R")) {
            String trimmed = line.trim();
            if (!trimmed.isEmpty() && !trimmed.startsWith("--") && !trimmed.startsWith("/*")) {
                return trimmed.length() > 90 ? trimmed.substring(0, 90) + "..." : trimmed;
            }
        }
        return batch.split("\\R")[0].trim();
    }
}