import java.io.FileInputStream;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

public class MigrateRun2 {
    public static void main(String[] args) throws Exception {
        Properties props = new Properties();
        try (FileInputStream in = new FileInputStream(args[0])) { props.load(in); }
        String script = new String(Files.readAllBytes(Paths.get(args[1])), StandardCharsets.UTF_8);

        // split into per-table blocks by "-- ===== " headers
        String[] blocks = script.split("(?m)^-- ===== ");
        List<String> tableNames = new ArrayList<>();
        List<List<String>> tableStmts = new ArrayList<>();
        for (String b : blocks) {
            if (b.isBlank()) continue;
            String[] lines = b.split("\\R", 2);
            String name = lines[0].trim();
            String body = lines.length > 1 ? lines[1] : "";
            if (!body.contains("ALTER TABLE") && !body.contains("EXEC sp_rename")) continue;
            // drop GO lines, split statements by ';'
            StringBuilder sb = new StringBuilder();
            for (String line : body.split("\\R")) {
                if (line.trim().equalsIgnoreCase("GO")) continue;
                sb.append(line).append("\n");
            }
            List<String> stmts = new ArrayList<>();
            for (String s : sb.toString().split(";")) {
                String t = s.trim();
                if (!t.isEmpty()) stmts.add(t);
            }
            tableNames.add(name);
            tableStmts.add(stmts);
        }

        System.out.println("Tables to migrate: " + tableNames.size());
        Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
        int ok = 0;
        try (Connection conn = DriverManager.getConnection(props.getProperty("url"), props.getProperty("username"), props.getProperty("password"))) {
            for (int t = 0; t < tableNames.size(); t++) {
                String tbl = tableNames.get(t);
                List<String> stmts = tableStmts.get(t);
                conn.setAutoCommit(false);
                boolean failed = false;
                for (String s : stmts) {
                    try (Statement st = conn.createStatement()) { st.execute(s); }
                    catch (SQLException e) {
                        System.err.println("FAILED on " + tbl + ": " + e.getMessage());
                        System.err.println("  SQL: " + s.replaceAll("\\s+", " ").trim());
                        failed = true; break;
                    }
                }
                if (failed) { conn.rollback(); System.err.println("  -> ROLLED BACK " + tbl); }
                else { conn.commit(); System.out.println("OK: " + tbl + " (" + stmts.size() + " stmts)"); ok++; }
            }
        }
        System.out.println("\nMigrated OK: " + ok + "/" + tableNames.size());
    }
}