package com.mydreamjob.integration;

import org.flywaydb.core.Flyway;
import org.flywaydb.core.api.MigrationVersion;
import org.flywaydb.core.api.output.MigrateResult;
import org.junit.jupiter.api.Test;
import org.testcontainers.DockerClientFactory;
import org.testcontainers.containers.MySQLContainer;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assumptions.assumeTrue;

/**
 * V57 展示字段在**真实 MySQL** 上的迁移验证（隔离容器，容器/库名带 b01 前缀）。
 *
 * <p>逐项覆盖：数据库版本记录；从 V56 基线升级到 V57；旧数据保留、新列为 NULL；
 * 新字段写入与重新查询；更新清空语义（NULL）；重复迁移无待执行项且 V57 只有一条历史；
 * 空库（独立容器）从零完整迁移到 V57。</p>
 *
 * <p>连接统一追加 {@code characterEncoding=UTF-8}，避免 MySQL 5.7 服务器默认字符集导致的种子中文写入失败。
 * Docker 不可用时环境性跳过（不宣称通过）。</p>
 */
class JobCompanyDisplayFieldsMysqlMigrationTest {

    private static final String MIG = "classpath:db/migration";

    @Test
    void mysql57StagedUpgradeAndEmptyDatabase() throws Exception {
        verifyMigration(System.getProperty("b01.mysql.image57", "mysql:5.7.36"), "57");
    }

    @Test
    void mysql8StagedUpgradeAndEmptyDatabase() throws Exception {
        verifyMigration(System.getProperty("b01.mysql.image8", "mysql:8.4"), "8");
    }

    private void verifyMigration(String image, String tag) throws Exception {
        assumeTrue(dockerAvailable(), "Docker 不可用，跳过真实 MySQL 迁移验证");

        String version;
        // ── 阶段一：V56 基线 → 旧数据 → 升级 V57 ──────────────────
        try (MySQLContainer<?> mysql = new MySQLContainer<>(image)
                .withDatabaseName("mydreamjob_b01_" + tag)
                .withUsername("b01")
                .withPassword("b01-test-only")) {
            mysql.start();
            String url = charset(mysql.getJdbcUrl());
            String user = mysql.getUsername();
            String pass = mysql.getPassword();
            // MySQL 5.7 服务器默认字符集为 latin1；与真实部署一致，先把库默认字符集设为 utf8mb4，
            // 使未显式指定字符集的迁移建表（如 V37）可写入中文种子数据。
            ensureUtf8mb4(url, user, pass, mysql.getDatabaseName());

            version = scalar(url, user, pass, "SELECT VERSION()");
            System.out.println("[B01][" + image + "] SELECT VERSION() = " + version);
            assertNotNull(version);

            // 1) 只迁移到 V56 基线
            MigrateResult to56 = flyway(url, user, pass, "56").migrate();
            assertTrue(to56.success, "迁移到 V56 应成功");
            assertEquals(0, count(url, user, pass,
                    "SELECT count(*) FROM flyway_schema_history WHERE version = '57'"), "V56 基线不应含 V57");

            // 2) 旧企业与旧岗位数据
            try (Connection c = DriverManager.getConnection(url, user, pass); Statement st = c.createStatement()) {
                st.executeUpdate("INSERT INTO users(phone, role, is_active, is_verified) "
                        + "VALUES('19900009001','COMPANY',1,1)");
                st.executeUpdate("INSERT INTO companies(owner_user_id, name, description, industry, verified) "
                        + "SELECT id,'B01旧企业','旧简介','旧行业',1 FROM users WHERE phone='19900009001'");
                st.executeUpdate("INSERT INTO jobs(company_id, title, description, requirements, city, "
                        + "employment_type, salary_min, salary_max, status) SELECT c.id,'B01旧岗位','旧描述','旧要求',"
                        + "'北京','FULL_TIME',10000,20000,'PUBLISHED' FROM companies c WHERE c.name='B01旧企业'");
            }

            // 3) 升级到 V57
            MigrateResult latest = flyway(url, user, pass, "57").migrate();
            assertTrue(latest.success, "升级到 V57 应成功");
            assertEquals(1, latest.migrationsExecuted, "从 V56 升级应只执行一条迁移（V57）");

            // 4) 旧数据保留、新列为 NULL
            assertEquals(1, count(url, user, pass, "SELECT count(*) FROM companies WHERE name='B01旧企业'"));
            assertEquals(1, count(url, user, pass, "SELECT count(*) FROM jobs WHERE title='B01旧岗位'"));
            assertNull(scalar(url, user, pass, "SELECT company_size FROM companies WHERE name='B01旧企业'"));
            assertNull(scalar(url, user, pass, "SELECT experience FROM jobs WHERE title='B01旧岗位'"));
            assertNull(scalar(url, user, pass, "SELECT benefits_json FROM jobs WHERE title='B01旧岗位'"));
            assertNull(scalar(url, user, pass, "SELECT salary_months FROM jobs WHERE title='B01旧岗位'"));
            assertNull(scalar(url, user, pass, "SELECT work_location FROM jobs WHERE title='B01旧岗位'"));

            // 5) 新增字段写入 + 重新查询 + 更新清空语义（NULL）
            try (Connection c = DriverManager.getConnection(url, user, pass); Statement st = c.createStatement()) {
                st.executeUpdate("UPDATE companies SET company_size='100-499人' WHERE name='B01旧企业'");
                st.executeUpdate("UPDATE jobs SET experience='3-5年', education='本科', "
                        + "benefits_json='[\"五险一金\",\"弹性工作\"]', salary_months=14, work_location='上海市浦东新区' "
                        + "WHERE title='B01旧岗位'");
            }
            assertEquals("100-499人", scalar(url, user, pass,
                    "SELECT company_size FROM companies WHERE name='B01旧企业'"));
            assertEquals("[\"五险一金\",\"弹性工作\"]", scalar(url, user, pass,
                    "SELECT benefits_json FROM jobs WHERE title='B01旧岗位'"));
            assertEquals("14", scalar(url, user, pass,
                    "SELECT salary_months FROM jobs WHERE title='B01旧岗位'"));

            try (Connection c = DriverManager.getConnection(url, user, pass); Statement st = c.createStatement()) {
                st.executeUpdate("UPDATE companies SET company_size=NULL WHERE name='B01旧企业'");
                st.executeUpdate("UPDATE jobs SET benefits_json=NULL, salary_months=NULL WHERE title='B01旧岗位'");
            }
            assertNull(scalar(url, user, pass, "SELECT company_size FROM companies WHERE name='B01旧企业'"));
            assertNull(scalar(url, user, pass, "SELECT benefits_json FROM jobs WHERE title='B01旧岗位'"));
            assertNull(scalar(url, user, pass, "SELECT salary_months FROM jobs WHERE title='B01旧岗位'"));

            // 6) 重复迁移无待执行项；V57 只有一条历史且成功；新增列不重复
            MigrateResult again = flyway(url, user, pass, "57").migrate();
            assertEquals(0, again.migrationsExecuted, "再次迁移应无待执行项");
            assertEquals(1, count(url, user, pass,
                    "SELECT count(*) FROM flyway_schema_history WHERE version='57' AND success=1"),
                    "flyway_schema_history 中 V57 应只有一条");
            assertEquals(6, count(url, user, pass, newColumnCountSql()), "新增 6 列应恰好各一列，不重复增加");

            System.out.println("[B01][" + image + "] staged upgrade verified: version=" + version
                    + ", to56=" + to56.migrationsExecuted + ", upgrade=" + latest.migrationsExecuted
                    + ", rerun=" + again.migrationsExecuted);
        }

        // ── 阶段二：空库（独立容器）从零完整迁移到 V57 ────────────
        try (MySQLContainer<?> empty = new MySQLContainer<>(image)
                .withDatabaseName("mydreamjob_b01_empty_" + tag)
                .withUsername("b01")
                .withPassword("b01-test-only")) {
            empty.start();
            String url = charset(empty.getJdbcUrl());
            String user = empty.getUsername();
            String pass = empty.getPassword();
            ensureUtf8mb4(url, user, pass, empty.getDatabaseName());

            MigrateResult fromScratch = flyway(url, user, pass, "57").migrate();
            assertTrue(fromScratch.success, "空库应能完整迁移到 V57");
            assertEquals("57", scalar(url, user, pass,
                    "SELECT version FROM flyway_schema_history ORDER BY installed_rank DESC LIMIT 1"),
                    "空库迁移后的最高版本应为 57");
            assertEquals(6, count(url, user, pass, newColumnCountSql()), "空库迁移后新增 6 列存在");
            System.out.println("[B01][" + image + "] empty-db migration verified: executed="
                    + fromScratch.migrationsExecuted);
        }
    }

    private static String newColumnCountSql() {
        return "SELECT count(*) FROM information_schema.columns "
                + "WHERE table_schema = DATABASE() AND ((table_name='companies' AND column_name='company_size') "
                + "OR (table_name='jobs' AND column_name IN ('experience','education','benefits_json',"
                + "'salary_months','work_location')))";
    }

    private static String charset(String url) {
        return url + (url.contains("?") ? "&" : "?") + "useUnicode=true&characterEncoding=UTF-8";
    }

    private static void ensureUtf8mb4(String url, String user, String pass, String database) throws Exception {
        try (Connection c = DriverManager.getConnection(url, user, pass); Statement st = c.createStatement()) {
            st.executeUpdate("ALTER DATABASE `" + database + "` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci");
        }
    }

    private Flyway flyway(String url, String user, String pass, String target) {
        var cfg = Flyway.configure().dataSource(url, user, pass).locations(MIG);
        // 与生产启动路径一致：应用 MySQL 5.7 兼容钩子（仅替换 V49；MySQL 8/H2 下为空操作）。
        com.mydreamjob.config.MySql57MigrationConfiguration.configure(cfg);
        if (target != null) {
            cfg = cfg.target(MigrationVersion.fromVersion(target));
        }
        return cfg.load();
    }

    private String scalar(String url, String user, String pass, String sql) throws Exception {
        try (Connection c = DriverManager.getConnection(url, user, pass);
             Statement st = c.createStatement();
             ResultSet rs = st.executeQuery(sql)) {
            return rs.next() ? rs.getString(1) : null;
        }
    }

    private int count(String url, String user, String pass, String sql) throws Exception {
        return Integer.parseInt(scalar(url, user, pass, sql));
    }

    private boolean dockerAvailable() {
        try {
            return DockerClientFactory.instance().isDockerAvailable();
        } catch (Throwable ignored) {
            return false;
        }
    }
}