/**
 * Environment variable validation utilities
 */

import { z } from 'zod';

/**
 * Common environment variable schemas
 */
export const envSchemas = {
	/** URL schema */
	url: z.string().url(),

	/** Non-empty string schema */
	nonEmpty: z.string().min(1),

	/** Optional string schema */
	optional: z.string().optional(),

	/** Port number schema */
	port: z.coerce.number().int().min(1).max(65535),

	/** Boolean schema (accepts various formats) */
	boolean: z.preprocess((val) => {
		if (typeof val === 'boolean') return val;
		if (typeof val === 'string') {
			return ['true', '1', 'yes', 'on'].includes(val.toLowerCase());
		}
		return false;
	}, z.boolean()),

	/** Number schema */
	number: z.coerce.number(),

	/** Positive integer schema */
	positiveInt: z.coerce.number().int().positive(),

	/** Email schema */
	email: z.string().email(),

	/** Node environment schema */
	nodeEnv: z.enum(['development', 'production', 'test']).default('development'),
};

/**
 * Common Supabase environment schema
 */
export const supabaseEnvSchema = z.object({
	SUPABASE_URL: envSchemas.url,
	SUPABASE_ANON_KEY: envSchemas.nonEmpty,
	SUPABASE_SERVICE_ROLE_KEY: envSchemas.nonEmpty.optional(),
});

/**
 * Common app environment schema
 */
export const appEnvSchema = z.object({
	NODE_ENV: envSchemas.nodeEnv,
	PORT: envSchemas.port.default(3000),
});

/**
 * Create an environment config from schema
 */
export function createEnvConfig<T extends z.ZodTypeAny>(
	schema: T,
	env: NodeJS.ProcessEnv = process.env
): z.infer<T> {
	const result = schema.safeParse(env);

	if (!result.success) {
		const errors = result.error.errors
			.map((err) => `  ${err.path.join('.')}: ${err.message}`)
			.join('\n');

		throw new Error(`Environment validation failed:\n${errors}`);
	}

	return result.data;
}

/**
 * Validate environment variables with custom schema
 */
export function validateEnv<T extends z.ZodRawShape>(
	schema: z.ZodObject<T>,
	env: NodeJS.ProcessEnv = process.env
): z.infer<z.ZodObject<T>> {
	return createEnvConfig(schema, env);
}

/**
 * Get required environment variable with type safety
 */
export function getRequiredEnv(key: string, env: NodeJS.ProcessEnv = process.env): string {
	const value = env[key];

	if (value === undefined || value === '') {
		throw new Error(`Required environment variable "${key}" is not set`);
	}

	return value;
}

/**
 * Get optional environment variable with default
 */
export function getEnv(
	key: string,
	defaultValue: string,
	env: NodeJS.ProcessEnv = process.env
): string {
	return env[key] ?? defaultValue;
}

/**
 * Get boolean environment variable
 */
export function getBoolEnv(
	key: string,
	defaultValue = false,
	env: NodeJS.ProcessEnv = process.env
): boolean {
	const value = env[key];

	if (value === undefined) {
		return defaultValue;
	}

	return ['true', '1', 'yes', 'on'].includes(value.toLowerCase());
}

/**
 * Get number environment variable
 */
export function getNumEnv(
	key: string,
	defaultValue: number,
	env: NodeJS.ProcessEnv = process.env
): number {
	const value = env[key];

	if (value === undefined) {
		return defaultValue;
	}

	const parsed = Number(value);
	return isNaN(parsed) ? defaultValue : parsed;
}

/**
 * Check if running in development
 */
export function isDevelopment(env: NodeJS.ProcessEnv = process.env): boolean {
	return env.NODE_ENV === 'development';
}

/**
 * Check if running in production
 */
export function isProduction(env: NodeJS.ProcessEnv = process.env): boolean {
	return env.NODE_ENV === 'production';
}

/**
 * Check if running in test
 */
export function isTest(env: NodeJS.ProcessEnv = process.env): boolean {
	return env.NODE_ENV === 'test';
}