<?php
/**
 * Create ticket_dependencies table if it doesn't exist
 * Run once: php scripts/create_dependencies_table.php
 */

require_once dirname(__DIR__) . '/config/config.php';

$conn = new mysqli(
    $GLOBALS['config']['DB_HOST'],
    $GLOBALS['config']['DB_USER'],
    $GLOBALS['config']['DB_PASS'],
    $GLOBALS['config']['DB_NAME']
);

if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error . "\n");
}

echo "Connected to database successfully.\n";

// Check if table exists
$tableCheck = $conn->query("SHOW TABLES LIKE 'ticket_dependencies'");
if ($tableCheck->num_rows > 0) {
    echo "Table 'ticket_dependencies' already exists.\n";
    $conn->close();
    exit(0);
}

// Create the table
$sql = "CREATE TABLE ticket_dependencies (
    dependency_id INT AUTO_INCREMENT PRIMARY KEY,
    ticket_id VARCHAR(9) NOT NULL,
    depends_on_id VARCHAR(9) NOT NULL,
    dependency_type ENUM('blocks', 'blocked_by', 'relates_to', 'duplicates') NOT NULL DEFAULT 'blocks',
    created_by INT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (ticket_id) REFERENCES tickets(ticket_id) ON DELETE CASCADE,
    FOREIGN KEY (depends_on_id) REFERENCES tickets(ticket_id) ON DELETE CASCADE,
    FOREIGN KEY (created_by) REFERENCES users(user_id) ON DELETE SET NULL,
    UNIQUE KEY unique_dependency (ticket_id, depends_on_id, dependency_type),
    INDEX idx_ticket_id (ticket_id),
    INDEX idx_depends_on_id (depends_on_id),
    INDEX idx_dependency_type (dependency_type)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci";

if ($conn->query($sql) === TRUE) {
    echo "Table 'ticket_dependencies' created successfully.\n";
} else {
    echo "Error creating table: " . $conn->error . "\n";
}

$conn->close();