import { z } from "zod"

// Treats null/undefined as missing so validation surfaces one clear
// "required" message instead of a generic type error.
function requiredString(message: string) {
	return z.preprocess(
		(val) => (val === null || val === undefined ? "" : val),
		z.string().min(1, message)
	)
}

// Email validation schema
export const emailSchema = z.preprocess(
	(val) => (val === null || val === undefined ? "" : val),
	z.string().min(1, "Email is required").email("Enter a valid email")
)

// Login schema (email + password) for reuse across the app.
// Password strength is intentionally NOT re-validated here: an existing
// account's password may predate current complexity rules, and only the
// server can judge whether credentials are actually correct. Complexity
// rules belong on registration/reset-password, not on login.
export const loginSchema = z.object({
	email: emailSchema,
	password: requiredString("Password is required"),
})

export type LoginValues = z.infer<typeof loginSchema>

// Helper to validate email synchronously
export function validateEmail(value: unknown) {
	const result = emailSchema.safeParse(value)
	return result.success ? { valid: true, value: result.data } : { valid: false, error: result.error }
}

export default {
	emailSchema,
	loginSchema,
	validateEmail,
}