<?php

require_once __DIR__ . '/mysqli-class.php';

function db(): MysqliDb
{
    static $db = null;
    if ($db instanceof MysqliDb) {
        return $db;
    }

    $user = 'virtualuser';
    $pass = 'ltnwGXZqvQJqXjPPQgmO';
    $dbName = 'shabby_road';
    $host = 'virtualengage.c1qdknkurtfn.ap-south-1.rds.amazonaws.com';
    $port = 3306;

    $attempts = [
        ['socket' => null, 'host' => $host, 'port' => $port],
    ];

    $lastError = '';
    foreach ($attempts as $attempt) {
        try {
            $db = new MysqliDb([
                'host' => $attempt['host'],
                'username' => $user,
                'password' => $pass,
                'db' => $dbName,
                'port' => $attempt['port'],
                'socket' => $attempt['socket'],
                'charset' => 'utf8mb4',
            ]);
            bootstrap_schema($db);
            return $db;
        } catch (Exception $e) {
            $lastError = $e->getMessage();
        }
    }

    throw new Exception('Database connection failed: ' . $lastError);
}

function bootstrap_schema(MysqliDb $db): void
{
    $db->rawQuery("CREATE TABLE IF NOT EXISTS admins (
        id INT AUTO_INCREMENT PRIMARY KEY,
        email VARCHAR(255) NOT NULL UNIQUE,
        password_hash VARCHAR(255) NOT NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    )");

    $resourceTable = ensure_resources_table($db);

    $db->rawQuery("CREATE TABLE IF NOT EXISTS sessions (
        id INT AUTO_INCREMENT PRIMARY KEY,
        title VARCHAR(255) NOT NULL,
        description TEXT NOT NULL,
        tag VARCHAR(50) DEFAULT NULL,
        cta_label VARCHAR(100) DEFAULT 'Register',
        start_date DATE DEFAULT NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    )");

    $db->rawQuery("CREATE TABLE IF NOT EXISTS contacts (
        id INT AUTO_INCREMENT PRIMARY KEY,
        name VARCHAR(255) NOT NULL,
        email VARCHAR(255) NOT NULL,
        organization VARCHAR(255) DEFAULT NULL,
        message TEXT NOT NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    )");

    $db->rawQuery("CREATE TABLE IF NOT EXISTS newsletter_subscriptions (
        id INT AUTO_INCREMENT PRIMARY KEY,
        first_name VARCHAR(255) DEFAULT NULL,
        email VARCHAR(255) NOT NULL UNIQUE,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    )");

    $db->rawQuery("CREATE TABLE IF NOT EXISTS tutorials (
        id INT AUTO_INCREMENT PRIMARY KEY,
        title VARCHAR(255) NOT NULL,
        description TEXT NOT NULL,
        status VARCHAR(50) NOT NULL DEFAULT 'active',
        file_path VARCHAR(255) DEFAULT NULL,
        video_url VARCHAR(255) DEFAULT NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    )");

    seed_default_admin($db);
    seed_sample_resources($db, $resourceTable);
    seed_sample_sessions($db);
    seed_sample_tutorials($db);
}

function seed_default_admin(MysqliDb $db): void
{
    $row = $db->getOne("SELECT 1 FROM admins WHERE email = ?", ['ravi@stratawiz.com']);
    if ($row) {
        return;
    }
    $hash = password_hash('qwerty', PASSWORD_DEFAULT);
    $db->insert('admins', ['email' => 'ravi@stratawiz.com', 'password_hash' => $hash]);
}

function seed_sample_resources(MysqliDb $db, string $table): void
{
    $count = (int) $db->getValue("SELECT COUNT(*) as c FROM `$table`");
    if ($count > 0) {
        return;
    }

    $samples = [
        ['title' => 'Understanding Lung Function in Adult Populations', 'summary' => 'A concise explainer on spirometry metrics and how to interpret lung function assessments in community settings.', 'label' => 'Publication'],
        ['title' => 'Lung Function in India: Overview', 'summary' => 'Key findings from multi-city research that maps prevalence of respiratory conditions across demographic groups.', 'label' => 'Research Brief'],
        ['title' => 'Childhood Lung Function in India', 'summary' => 'Practical guidance for pediatric screening teams and frontline clinicians working with young patients.', 'label' => 'Toolkit'],
        ['title' => 'Understanding Lung Function in Rural Populations', 'summary' => 'Field notes and methodologies for conducting door-to-door lung health studies with limited resources.', 'label' => 'Field Guide'],
    ];

    foreach ($samples as $sample) {
        $db->insert($table, $sample);
    }
}

function seed_sample_sessions(MysqliDb $db): void
{
    $count = (int) $db->getValue("SELECT COUNT(*) as c FROM sessions");
    if ($count > 0) {
        return;
    }

    $samples = [
        ['title' => 'Nutrition guidance for advanced lung conditions', 'description' => 'Upcoming webinar on dietary support for patients with complex respiratory conditions.', 'tag' => 'New'],
        ['title' => 'Workshop: Field data quality for respiratory studies', 'description' => 'Hands-on clinic for research leads to strengthen field protocols and audits.', 'tag' => 'Update'],
        ['title' => 'Training cohort launch: Spirometry essentials', 'description' => 'New batch begins soon with live mentoring and case reviews.', 'tag' => 'Upcoming'],
    ];

    foreach ($samples as $sample) {
        $db->insert('sessions', $sample);
    }
}

function seed_sample_tutorials(MysqliDb $db): void
{
    $count = (int) $db->getValue("SELECT COUNT(*) as c FROM tutorials");
    if ($count > 0) {
        return;
    }

    $samples = [
        ['title' => 'Spirometry Basics', 'description' => 'Step-by-step guide for accurate spirometry setup and testing.', 'status' => 'active'],
        ['title' => 'Inhaler Technique', 'description' => 'Visual walkthrough on patient education for inhaler use.', 'status' => 'active'],
    ];

    foreach ($samples as $sample) {
        $db->insert('tutorials', $sample);
    }
}

function ensure_resources_table(MysqliDb $db): string
{
    $candidates = ['resources_table', 'resources'];

    // Prefer any existing table that already has rows.
    foreach ($candidates as $name) {
        $exists = $db->getValue("SELECT 1 FROM information_schema.tables WHERE table_schema = DATABASE() AND table_name = ?", [$name]);
        if ($exists) {
            $count = (int) $db->getValue("SELECT COUNT(*) FROM `$name`");
            if ($count > 0) {
                add_resource_columns_if_missing($db, $name);
                return $name;
            }
        }
    }

    // Fallback to first existing, even if empty.
    foreach ($candidates as $name) {
        $exists = $db->getValue("SELECT 1 FROM information_schema.tables WHERE table_schema = DATABASE() AND table_name = ?", [$name]);
        if ($exists) {
            add_resource_columns_if_missing($db, $name);
            return $name;
        }
    }

    $name = 'resources';
    $db->rawQuery("CREATE TABLE IF NOT EXISTS `$name` (
        id INT AUTO_INCREMENT PRIMARY KEY,
        title VARCHAR(255) NOT NULL,
        summary TEXT NOT NULL,
        label VARCHAR(100) NOT NULL,
        file_path VARCHAR(255) DEFAULT NULL,
        video_url VARCHAR(255) DEFAULT NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    )");
    add_resource_columns_if_missing($db, $name);
    return $name;
}

function add_resource_columns_if_missing(MysqliDb $db, string $table): void
{
    $columns = [
        'file_path' => 'ALTER TABLE `%s` ADD COLUMN file_path VARCHAR(255) DEFAULT NULL',
        'video_url' => 'ALTER TABLE `%s` ADD COLUMN video_url VARCHAR(255) DEFAULT NULL',
    ];

    foreach ($columns as $column => $alter) {
        $exists = $db->getValue("SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = ? AND column_name = ?", [$table, $column]);
        if (!$exists) {
            $db->rawQuery(sprintf($alter, $table));
        }
    }
}

function resource_table_name(MysqliDb $db): string
{
    static $resolved;
    if ($resolved) {
        return $resolved;
    }
    $resolved = ensure_resources_table($db);
    return $resolved;
}