// Phase 0 spike: reference client for capturing the Informix SQLI wire protocol.
//
// Drives the official IBM Informix JDBC driver (com.informix.jdbc.IfxDriver)
// through controlled scenarios so that tcpdump captures of localhost:9088
// can be cross-referenced against the decompiled JDBC source. This is the
// "ground truth" client whose traffic IS by definition spec-correct.
//
// Build:
//   javac -cp build/ifxjdbc.jar tests/reference/RefClient.java -d build/
// Run:
//   java -cp build/ifxjdbc.jar:build/ tests.reference.RefClient <scenario>
//
// Scenarios: connect-only, select-1, dml-cycle, all
//
// Connection params can be overridden via env vars; defaults are the
// Informix Developer Edition Docker image defaults documented in
// docs/DECISION_LOG.md.

package tests.reference;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.sql.SQLException;

public class RefClient {

    static final String HOST     = env("IFX_HOST",     "127.0.0.1");
    static final String PORT     = env("IFX_PORT",     "9088");
    static final String SERVER   = env("IFX_SERVER",   "informix");
    static final String DATABASE = env("IFX_DATABASE", "sysmaster");
    static final String USER     = env("IFX_USER",     "informix");
    static final String PASSWORD = env("IFX_PASSWORD", "in4mix");

    public static void main(String[] args) throws Exception {
        Class.forName("com.informix.jdbc.IfxDriver");

        String scenario = args.length > 0 ? args[0] : "connect-only";
        switch (scenario) {
            case "connect-only": runConnectOnly(); break;
            case "select-1":     runSelect1();     break;
            case "dml-cycle":    runDmlCycle();    break;
            case "byte-cycle":   runByteCycle();   break;
            case "blob-cycle":   runBlobCycle();   break;
            case "all":
                runConnectOnly();
                runSelect1();
                runDmlCycle();
                break;
            default:
                System.err.println("Unknown scenario: " + scenario);
                System.err.println("Valid: connect-only | select-1 | dml-cycle | all");
                System.exit(2);
        }
    }

    static String url() {
        return String.format(
            "jdbc:informix-sqli://%s:%s/%s:INFORMIXSERVER=%s",
            HOST, PORT, DATABASE, SERVER
        );
    }

    static void log(String fmt, Object... args) {
        System.out.printf("[ref] " + fmt + "%n", args);
    }

    static String env(String key, String dflt) {
        String v = System.getenv(key);
        return (v == null || v.isEmpty()) ? dflt : v;
    }

    // -------------------------------------------------------------------
    // Scenario A: connect + immediate disconnect
    // -------------------------------------------------------------------
    static void runConnectOnly() throws SQLException {
        log("=== connect-only ===");
        log("URL: %s", url());
        try (Connection c = DriverManager.getConnection(url(), USER, PASSWORD)) {
            log("connected; product=%s", c.getMetaData().getDatabaseProductName());
            // Note: do NOT call getDatabaseProductVersion() — the 4.50.JC10
            // JDBC driver throws NumberFormatException on Informix 15.0's
            // version string ("150."). Connection itself works fine.
        }
        log("disconnected.");
    }

    // -------------------------------------------------------------------
    // Scenario B: connect + SELECT 1 + disconnect
    // -------------------------------------------------------------------
    static void runSelect1() throws SQLException {
        log("=== select-1 ===");
        try (Connection c = DriverManager.getConnection(url(), USER, PASSWORD);
             Statement s = c.createStatement();
             ResultSet rs = s.executeQuery("SELECT 1 FROM systables WHERE tabid = 1")) {

            ResultSetMetaData md = rs.getMetaData();
            log("columns: %d", md.getColumnCount());
            for (int i = 1; i <= md.getColumnCount(); i++) {
                log("  [%d] name=%s type=%d (%s) precision=%d scale=%d",
                    i, md.getColumnName(i), md.getColumnType(i),
                    md.getColumnTypeName(i), md.getPrecision(i), md.getScale(i));
            }
            int rowNum = 0;
            while (rs.next()) {
                rowNum++;
                log("  row %d: col1=%s", rowNum, rs.getObject(1));
            }
            log("rows returned: %d", rowNum);
        }
    }

    // -------------------------------------------------------------------
    // Scenario C: full DML cycle (CREATE / INSERT / SELECT / DROP)
    // Uses a UUID-suffixed table to be safe to re-run.
    // -------------------------------------------------------------------
    static void runDmlCycle() throws SQLException {
        log("=== dml-cycle ===");
        String table = "spike_" + Long.toHexString(System.nanoTime());
        try (Connection c = DriverManager.getConnection(url(), USER, PASSWORD)) {
            c.setAutoCommit(true);  // sysmaster is unlogged; force autocommit

            try (Statement s = c.createStatement()) {
                log("CREATE TEMP TABLE %s", table);
                s.execute("CREATE TEMP TABLE " + table +
                          " (id INTEGER, name VARCHAR(50), val FLOAT)");
            }

            try (PreparedStatement ps = c.prepareStatement(
                    "INSERT INTO " + table + " VALUES (?, ?, ?)")) {
                ps.setInt(1, 42);
                ps.setString(2, "hello");
                ps.setDouble(3, 3.14);
                int n = ps.executeUpdate();
                log("INSERT rowcount=%d", n);
            }

            try (Statement s = c.createStatement();
                 ResultSet rs = s.executeQuery("SELECT id, name, val FROM " + table)) {
                ResultSetMetaData md = rs.getMetaData();
                log("SELECT columns:");
                for (int i = 1; i <= md.getColumnCount(); i++) {
                    log("  [%d] %s : %s", i, md.getColumnName(i), md.getColumnTypeName(i));
                }
                while (rs.next()) {
                    log("  row: id=%d name=%s val=%f",
                        rs.getInt(1), rs.getString(2), rs.getDouble(3));
                }
            }
            // Temp table dropped automatically on disconnect; no DROP needed.
        }
    }

    // -------------------------------------------------------------------
    // Scenario D: BYTE column write+read cycle. Requires:
    //   - logged DB (env IFX_DATABASE=testdb)
    //   - a blobspace named "blobspace1" already created
    // Set IFX_DATABASE=testdb before running.
    // -------------------------------------------------------------------
    static void runByteCycle() throws SQLException {
        log("=== byte-cycle ===");
        String table = "byte_" + Long.toHexString(System.nanoTime());
        try (Connection c = DriverManager.getConnection(url(), USER, PASSWORD)) {
            c.setAutoCommit(true);

            try (Statement s = c.createStatement()) {
                log("CREATE TABLE %s (id INT, data BYTE IN blobspace1)", table);
                s.execute("CREATE TABLE " + table + " (id INT, data BYTE IN blobspace1)");
            }

            byte[] payload = "hello bytes from JDBC".getBytes();
            try (PreparedStatement ps = c.prepareStatement(
                    "INSERT INTO " + table + " VALUES (?, ?)")) {
                ps.setInt(1, 1);
                ps.setBytes(2, payload);
                int n = ps.executeUpdate();
                log("INSERT rowcount=%d (sent %d bytes)", n, payload.length);
            }

            try (Statement s = c.createStatement();
                 ResultSet rs = s.executeQuery("SELECT id, data FROM " + table)) {
                while (rs.next()) {
                    byte[] got = rs.getBytes(2);
                    log("  row: id=%d data.len=%d data=%s", rs.getInt(1),
                        got.length, new String(got));
                }
            }

            try (Statement s = c.createStatement()) {
                s.execute("DROP TABLE " + table);
            }
        }
    }

    // -------------------------------------------------------------------
    // Scenario E: BLOB (smart-LOB) write+read cycle. Requires:
    //   - logged DB (env IFX_DATABASE=testdb)
    //   - sbspace1 (smart-large-object space) already created
    // Set IFX_DATABASE=testdb before running.
    // -------------------------------------------------------------------
    static void runBlobCycle() throws SQLException {
        log("=== blob-cycle ===");
        String table = "blob_" + Long.toHexString(System.nanoTime());
        try (Connection c = DriverManager.getConnection(url(), USER, PASSWORD)) {
            c.setAutoCommit(true);

            try (Statement s = c.createStatement()) {
                log("CREATE TABLE %s (id INT, data BLOB)", table);
                s.execute("CREATE TABLE " + table + " (id INT, data BLOB)");
            }

            byte[] payload = "hello smart-LOB blob from JDBC".getBytes();
            try (PreparedStatement ps = c.prepareStatement(
                    "INSERT INTO " + table + " VALUES (?, ?)")) {
                ps.setInt(1, 1);
                ps.setBytes(2, payload);
                int n = ps.executeUpdate();
                log("INSERT rowcount=%d (sent %d bytes)", n, payload.length);
            }

            try (Statement s = c.createStatement();
                 ResultSet rs = s.executeQuery("SELECT id, data FROM " + table)) {
                while (rs.next()) {
                    byte[] got = rs.getBytes(2);
                    log("  row: id=%d data.len=%d data=%s", rs.getInt(1),
                        got.length, new String(got));
                }
            }

            try (Statement s = c.createStatement()) {
                s.execute("DROP TABLE " + table);
            }
        }
    }
}