/**
 * OIDC configuration enhancement and self-healing
 * Automatically fixes common configuration issues and provides helpful guidance
 */

export interface OidcEnhancementResult {
	config: any;
	fixes: string[];
	warnings: string[];
}

/**
 * Enhance OIDC configuration with smart defaults and auto-fixes
 */
export function enhanceOidcConfig(config: any): OidcEnhancementResult {
	const enhanced = { ...config };
	const fixes: string[] = [];
	const warnings: string[] = [];

	// Auto-add groups scope if missing
	if (enhanced.scope && !enhanced.scope.includes('groups')) {
		enhanced.scope = enhanced.scope.trim() + ' groups';
		fixes.push('✓ Added "groups" to scope for role mapping');
	}

	// Auto-detect optimal scope based on issuer
	if (!enhanced.scope && enhanced.issuer) {
		enhanced.scope = detectOptimalScope(enhanced.issuer);
		fixes.push(`✓ Auto-detected optimal scope: ${enhanced.scope}`);
	}

	// Auto-generate redirect_uri if missing
	if (!enhanced.redirect_uri) {
		const baseUrl =
			process.env.PUBLIC_URL ||
			process.env.HEADPLANE_URL ||
			'http://localhost:3000';
		enhanced.redirect_uri = `${baseUrl}/admin/oidc/callback`;
		fixes.push(`✓ Auto-generated redirect_uri: ${enhanced.redirect_uri}`);
	}

	// Provider-specific warnings and optimizations
	if (enhanced.issuer) {
		const providerInsights = getProviderInsights(enhanced.issuer);
		warnings.push(...providerInsights);
	}

	// Environment variable guidance
	const envVars = getRecommendedEnvVars();
	if (envVars.length > 0) {
		warnings.push(
			'💡 For easier configuration, consider using environment variables:',
		);
		warnings.push(...envVars);
	}

	return { config: enhanced, fixes, warnings };
}

/**
 * Detect optimal OIDC scope based on identity provider
 */
function detectOptimalScope(issuer: string): string {
	const baseScope = 'openid email profile';

	if (!issuer) return baseScope;

	// Provider-specific optimizations
	if (issuer.includes('accounts.google.com')) {
		return baseScope; // Google Workspace needs special setup for groups
	}

	if (issuer.includes('login.microsoftonline.com')) {
		return baseScope + ' groups'; // Azure AD supports groups scope
	}

	if (issuer.includes('keycloak') || issuer.includes('auth.')) {
		return baseScope + ' groups roles'; // Keycloak supports both
	}

	if (issuer.includes('okta.com') || issuer.includes('oktapreview.com')) {
		return baseScope + ' groups'; // Okta supports groups scope
	}

	if (issuer.includes('auth0.com')) {
		return baseScope + ' groups'; // Auth0 supports groups scope
	}

	// Safe default for unknown providers
	return baseScope + ' groups';
}

/**
 * Get provider-specific insights and configuration tips
 */
function getProviderInsights(issuer: string): string[] {
	const insights: string[] = [];

	if (issuer.includes('accounts.google.com')) {
		insights.push(
			'ℹ️  Google: Groups require Google Workspace admin console configuration',
		);
		insights.push(
			'   Consider using: HEADPLANE_ADMIN_GROUPS="admin@yourcompany.com"',
		);
	}

	if (issuer.includes('login.microsoftonline.com')) {
		insights.push(
			'ℹ️  Azure AD: Add "groups" claim to token configuration in Azure portal',
		);
		insights.push('   May require GroupMember.Read.All API permission');
	}

	if (issuer.includes('keycloak')) {
		insights.push(
			'ℹ️  Keycloak: Configure group membership mapper in client settings',
		);
		insights.push('   Groups appear in resource_access or realm_access claims');
	}

	if (issuer.includes('okta.com')) {
		insights.push(
			'ℹ️  Okta: Enable group claims in authorization server settings',
		);
		insights.push('   Groups appear in standard "groups" claim');
	}

	if (issuer.includes('auth0.com')) {
		insights.push('ℹ️  Auth0: Configure group claims in rules or actions');
		insights.push('   Groups appear in custom namespace or "groups" claim');
	}

	return insights;
}

/**
 * Get recommended environment variables for easier configuration
 */
function getRecommendedEnvVars(): string[] {
	const hasEnvMapping = [
		'HEADPLANE_OWNER_GROUPS',
		'HEADPLANE_ADMIN_GROUPS',
		'HEADPLANE_NETWORK_ADMIN_GROUPS',
		'HEADPLANE_IT_ADMIN_GROUPS',
		'HEADPLANE_AUDITOR_GROUPS',
	].some((env) => process.env[env]);

	if (hasEnvMapping) {
		return []; // Already using environment variables
	}

	return [
		'   HEADPLANE_ADMIN_GROUPS="admin,administrators,managers"',
		'   HEADPLANE_OWNER_GROUPS="ceo,cto,founders"',
		'   HEADPLANE_NETWORK_ADMIN_GROUPS="devops,network,sre"',
	];
}

/**
 * Validate configuration and provide helpful error messages
 */
export function validateOidcConfig(config: any): {
	valid: boolean;
	errors: string[];
} {
	const errors: string[] = [];

	if (!config.issuer) {
		errors.push('❌ Missing issuer URL');
		errors.push(
			'   Example: https://your-provider.com or https://login.microsoftonline.com/tenant/v2.0',
		);
	}

	if (!config.client_id) {
		errors.push('❌ Missing client_id');
		errors.push('   This should be provided by your identity provider');
	}

	if (!config.client_secret && !config.client_secret_path) {
		errors.push('❌ Missing client_secret or client_secret_path');
		errors.push('   For security, consider using client_secret_path');
	}

	// URL validation
	if (config.issuer && !isValidUrl(config.issuer)) {
		errors.push('❌ Invalid issuer URL format');
		errors.push('   Must be a valid HTTPS URL');
	}

	if (config.redirect_uri && !isValidUrl(config.redirect_uri)) {
		errors.push('❌ Invalid redirect_uri format');
		errors.push('   Must be a valid HTTPS URL (or HTTP for localhost)');
	}

	return {
		valid: errors.length === 0,
		errors,
	};
}

function isValidUrl(urlString: string): boolean {
	try {
		const url = new URL(urlString);
		return (
			url.protocol === 'https:' ||
			(url.hostname === 'localhost' && url.protocol === 'http:')
		);
	} catch {
		return false;
	}
}

/**
 * Create development OIDC configuration with mock provider
 */
export function createDevOidcConfig() {
	if (process.env.NODE_ENV !== 'development') {
		return null;
	}

	return {
		issuer: 'http://localhost:3001/dev-oidc',
		client_id: 'dev-headplane',
		client_secret: 'dev-secret',
		scope: 'openid email profile groups',
		redirect_uri: 'http://localhost:3000/admin/oidc/callback',
		mock_users: [
			{
				sub: 'dev-admin',
				email: 'admin@dev.local',
				name: 'Dev Admin',
				groups: ['admin', 'developers'],
			},
			{
				sub: 'dev-user',
				email: 'user@dev.local',
				name: 'Dev User',
				groups: ['developers'],
			},
			{
				sub: 'dev-owner',
				email: 'owner@dev.local',
				name: 'Dev Owner',
				groups: ['ceo', 'founders'],
			},
		],
	};
}