-- ============================================================================
-- ServerManager Database Schema
-- MySQL/MariaDB 10.5+
-- ============================================================================

CREATE DATABASE IF NOT EXISTS `servermanager`
    CHARACTER SET utf8mb4
    COLLATE utf8mb4_unicode_ci;

USE `servermanager`;

-- ============================================================================
-- Users Table
-- ============================================================================

CREATE TABLE IF NOT EXISTS `users` (
    `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
    `username` VARCHAR(50) NOT NULL,
    `email` VARCHAR(255) NOT NULL,
    `password_hash` VARCHAR(255) NOT NULL,
    `role` ENUM('super_admin', 'admin', 'operator') NOT NULL DEFAULT 'operator',
    `api_token` VARCHAR(64) DEFAULT NULL,
    `is_active` TINYINT(1) NOT NULL DEFAULT 1,
    `last_login_at` DATETIME DEFAULT NULL,
    `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `updated_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    UNIQUE KEY `uk_username` (`username`),
    UNIQUE KEY `uk_email` (`email`),
    UNIQUE KEY `uk_api_token` (`api_token`),
    KEY `idx_role` (`role`),
    KEY `idx_is_active` (`is_active`),
    KEY `idx_created_at` (`created_at`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Servers Table
-- ============================================================================

CREATE TABLE IF NOT EXISTS `servers` (
    `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
    `name` VARCHAR(100) NOT NULL,
    `description` TEXT DEFAULT NULL,
    `ip_address` VARCHAR(255) NOT NULL,
    `ssh_port` INT UNSIGNED NOT NULL DEFAULT 22,
    `ssh_user` VARCHAR(50) NOT NULL,
    `ssh_password` TEXT DEFAULT NULL COMMENT 'AES-256-CBC encrypted',
    `ssh_key` TEXT DEFAULT NULL COMMENT 'AES-256-CBC encrypted',
    `group_name` VARCHAR(50) DEFAULT NULL,
    `is_active` TINYINT(1) NOT NULL DEFAULT 1,
    `current_status` ENUM('online', 'offline', 'unknown') NOT NULL DEFAULT 'unknown',
    `cpu_usage` DECIMAL(5,2) DEFAULT NULL,
    `ram_usage` DECIMAL(5,2) DEFAULT NULL,
    `disk_usage` DECIMAL(5,2) DEFAULT NULL,
    `load_average` DECIMAL(8,4) DEFAULT NULL,
    `uptime` VARCHAR(50) DEFAULT NULL,
    `last_check_at` DATETIME DEFAULT NULL,
    `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `updated_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    KEY `idx_name` (`name`),
    KEY `idx_ip_address` (`ip_address`),
    KEY `idx_group_name` (`group_name`),
    KEY `idx_is_active` (`is_active`),
    KEY `idx_current_status` (`current_status`),
    KEY `idx_last_check_at` (`last_check_at`),
    KEY `idx_created_at` (`created_at`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Command History Table
-- ============================================================================

CREATE TABLE IF NOT EXISTS `command_history` (
    `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
    `server_id` INT UNSIGNED NOT NULL,
    `user_id` INT UNSIGNED NOT NULL,
    `command` TEXT NOT NULL,
    `output` MEDIUMTEXT DEFAULT NULL,
    `exit_status` INT NOT NULL DEFAULT 0,
    `executed_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    KEY `idx_server_id` (`server_id`),
    KEY `idx_user_id` (`user_id`),
    KEY `idx_executed_at` (`executed_at`),
    CONSTRAINT `fk_command_history_server` FOREIGN KEY (`server_id`)
        REFERENCES `servers` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
    CONSTRAINT `fk_command_history_user` FOREIGN KEY (`user_id`)
        REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Audit Logs Table
-- ============================================================================

CREATE TABLE IF NOT EXISTS `audit_logs` (
    `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
    `user_id` INT UNSIGNED DEFAULT NULL,
    `username` VARCHAR(50) DEFAULT NULL,
    `action` VARCHAR(100) NOT NULL,
    `entity_type` VARCHAR(50) DEFAULT NULL,
    `entity_id` INT UNSIGNED DEFAULT NULL,
    `details` JSON DEFAULT NULL,
    `ip_address` VARCHAR(45) DEFAULT NULL,
    `user_agent` VARCHAR(500) DEFAULT NULL,
    `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    KEY `idx_user_id` (`user_id`),
    KEY `idx_action` (`action`),
    KEY `idx_entity_type` (`entity_type`),
    KEY `idx_entity_id` (`entity_id`),
    KEY `idx_created_at` (`created_at`),
    KEY `idx_action_entity` (`action`, `entity_type`),
    CONSTRAINT `fk_audit_logs_user` FOREIGN KEY (`user_id`)
        REFERENCES `users` (`id`) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Monitoring History Table
-- ============================================================================

CREATE TABLE IF NOT EXISTS `monitoring_history` (
    `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
    `server_id` INT UNSIGNED NOT NULL,
    `status` ENUM('online', 'offline') NOT NULL DEFAULT 'offline',
    `cpu_usage` DECIMAL(5,2) NOT NULL DEFAULT 0,
    `ram_usage` DECIMAL(5,2) NOT NULL DEFAULT 0,
    `disk_usage` DECIMAL(5,2) NOT NULL DEFAULT 0,
    `load_average` DECIMAL(8,4) NOT NULL DEFAULT 0,
    `uptime` VARCHAR(50) DEFAULT NULL,
    `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    KEY `idx_server_id` (`server_id`),
    KEY `idx_created_at` (`created_at`),
    KEY `idx_server_created` (`server_id`, `created_at`),
    CONSTRAINT `fk_monitoring_history_server` FOREIGN KEY (`server_id`)
        REFERENCES `servers` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- API Tokens Table (for rate limiting and token management)
-- ============================================================================

CREATE TABLE IF NOT EXISTS `api_tokens` (
    `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
    `user_id` INT UNSIGNED NOT NULL,
    `name` VARCHAR(100) NOT NULL,
    `token` VARCHAR(64) NOT NULL,
    `last_used_at` DATETIME DEFAULT NULL,
    `expires_at` DATETIME DEFAULT NULL,
    `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    UNIQUE KEY `uk_token` (`token`),
    KEY `idx_user_id` (`user_id`),
    KEY `idx_expires_at` (`expires_at`),
    CONSTRAINT `fk_api_tokens_user` FOREIGN KEY (`user_id`)
        REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Rate Limiting Table
-- ============================================================================

CREATE TABLE IF NOT EXISTS `rate_limits` (
    `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
    `identifier` VARCHAR(255) NOT NULL,
    `action` VARCHAR(100) NOT NULL,
    `attempts` INT UNSIGNED NOT NULL DEFAULT 1,
    `first_attempt_at` DATETIME NOT NULL,
    `last_attempt_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    KEY `idx_identifier_action` (`identifier`, `action`),
    KEY `idx_last_attempt_at` (`last_attempt_at`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Session Table (for server-side session storage)
-- ============================================================================

CREATE TABLE IF NOT EXISTS `sessions` (
    `id` VARCHAR(128) NOT NULL,
    `user_id` INT UNSIGNED DEFAULT NULL,
    `ip_address` VARCHAR(45) DEFAULT NULL,
    `user_agent` TEXT DEFAULT NULL,
    `payload` LONGTEXT NOT NULL,
    `last_activity` INT UNSIGNED NOT NULL,
    PRIMARY KEY (`id`),
    KEY `idx_user_id` (`user_id`),
    KEY `idx_last_activity` (`last_activity`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Events table for scheduled tasks and cron jobs tracking
-- ============================================================================

CREATE TABLE IF NOT EXISTS `scheduled_tasks` (
    `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
    `name` VARCHAR(100) NOT NULL,
    `description` VARCHAR(255) DEFAULT NULL,
    `command` VARCHAR(500) NOT NULL,
    `interval_seconds` INT UNSIGNED NOT NULL DEFAULT 3600,
    `last_run_at` DATETIME DEFAULT NULL,
    `next_run_at` DATETIME DEFAULT NULL,
    `is_active` TINYINT(1) NOT NULL DEFAULT 1,
    `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    KEY `idx_next_run_at` (`next_run_at`),
    KEY `idx_is_active` (`is_active`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ============================================================================
-- Seed Data: Default Super Admin User
-- Password: Admin@123 (change immediately after first login)
-- Argon2id hash for 'Admin@123'
-- ============================================================================

INSERT INTO `users` (`username`, `email`, `password_hash`, `role`, `is_active`, `api_token`, `created_at`)
VALUES (
    'admin',
    'admin@localhost',
    '$argon2id$v=19$m=65536,t=4,p=3$Y0hBM2QxZ1R4V1pLY2xPTw$iT3DnBqG8pGkOZ7j6QFUwL5XhR0sMvW3a2eX4bN1c8Y',
    'super_admin',
    1,
    'sample_token_replace_in_production_please_change_me_1234567890ab',
    NOW()
);

-- ============================================================================
-- Seed Data: Sample Scheduled Task (Monitoring)
-- ============================================================================

INSERT INTO `scheduled_tasks` (`name`, `description`, `command`, `interval_seconds`, `next_run_at`, `is_active`)
VALUES (
    'collect_metrics',
    'Collect monitoring metrics from all active servers',
    'php bin/monitor.php',
    30,
    NOW(),
    1
);

-- ============================================================================
-- Cleanup: Create event to auto-clean old monitoring data
-- ============================================================================

DELIMITER //

CREATE EVENT IF NOT EXISTS `cleanup_monitoring_history`
ON SCHEDULE EVERY 1 DAY
STARTS CURRENT_TIMESTAMP
DO
BEGIN
    DELETE FROM `monitoring_history`
    WHERE `created_at` < DATE_SUB(NOW(), INTERVAL 30 DAY);

    DELETE FROM `rate_limits`
    WHERE `last_attempt_at` < DATE_SUB(NOW(), INTERVAL 24 HOUR);

    DELETE FROM `sessions`
    WHERE `last_activity` < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 24 HOUR));
END//

DELIMITER ;

-- ============================================================================
-- Verify setup
-- ============================================================================

SELECT 'ServerManager database created successfully!' AS status;
SELECT 'Default admin user: admin / Admin@123 (CHANGE IMMEDIATELY)' AS note;
SELECT 'IMPORTANT: Generate master encryption key before use!' AS warning;