<?php
/**
 * Friendly error text for AI provider failures.
 *
 * @package Aisentic\Util
 */

namespace Aisentic\Util;

defined( 'ABSPATH' ) || exit;

/**
 * Turns a provider error into a short message the user can act on.
 * Used by the chat and by the Eventin AI tools.
 */
class Ai_Error_Message {

	/**
	 * Translate a caught exception into a specific, actionable, client-safe
	 * message.
	 *
	 * A blanket "Something went wrong" leaves the user with no idea what to do,
	 * which is why intermittent failures read as random breakage. The common
	 * streaming failures each have a clear remedy: an overgrown conversation
	 * exceeding the model's context window (start a new chat), provider rate
	 * limits (wait), network timeouts on long tasks (retry/split), and auth
	 * problems (reconnect). Detect these from the provider error text and return
	 * guidance; fall back to the generic message for anything unrecognised. The
	 * real cause is always logged separately by the caller.
	 *
	 * @param \Throwable $e       The caught exception.
	 * @param string     $generic Fallback message for unrecognised errors.
	 * @return string Client-safe message.
	 */
	public static function from_throwable( \Throwable $e, string $generic ): string {
		$text = strtolower( $e->getMessage() );

		// Match on descriptive words/codes rather than bare numbers: a needle like
		// '429' or '401' would collide with digits inside token counts or request
		// ids (e.g. 'input token count (34291)') and mis-route the guidance.
		$has = static function ( array $needles ) use ( $text ): bool {
			foreach ( $needles as $needle ) {
				if ( false !== strpos( $text, $needle ) ) {
					return true;
				}
			}
			return false;
		};

		// Context window exceeded — the conversation is too long. Providers phrase
		// this differently (OpenAI 'context_length_exceeded', Google 'input token
		// count … exceeds the maximum number of tokens'), so match several forms.
		if ( $has(
            [
				'context_length_exceeded',
				'context length',
				'context window',
				'maximum context',
				'maximum number of tokens',
				'exceeds the maximum',
				'too many tokens',
				'prompt is too long',
				'reduce the length',
            ]
		) ) {
			return __( 'This conversation has grown too long for the current AI model to process. Please start a new chat to continue. Choosing a model with a larger context window in Settings can also help.', 'aisentic' );
		}

		// Billing / quota exhausted — a persistent condition that waiting will not
		// fix; the account needs attention. Checked before the rate-limit branch so
		// 'insufficient_quota' is not mistaken for a transient throttle.
		if ( $has(
            [
				'insufficient_quota',
				'exceeded your current quota',
				'billing',
				'payment required',
				'check your plan',
				'used all of this month',
            ]
		) ) {
			return __( 'Your Aisentic AI plan has run out of available usage. Please check your plan and billing details, then try again once more usage is available.', 'aisentic' );
		}

		// Rate limited / overloaded — transient; retrying shortly usually works.
		if ( $has(
            [
				'rate limit',
				'rate_limit',
				'ratelimit',
				'too many requests',
				'resource_exhausted',
				'resource has been exhausted',
				'overloaded',
            ]
		) ) {
			return __( 'The AI service is handling too many requests right now. Please wait a few seconds and try again.', 'aisentic' );
		}

		if ( $has( [ 'timed out', 'timeout', 'curl error 28', 'network error', 'operation timed out' ] ) ) {
			return __( 'The AI service took too long to respond. Please try again — breaking a large task into smaller steps can help.', 'aisentic' );
		}

		if ( $has( [ 'invalid_api_key', 'incorrect api key', 'invalid authentication', 'unauthorized', 'authentication' ] ) ) {
			return __( 'The Aisentic AI connection is not authorized. Please reconnect your account from Settings.', 'aisentic' );
		}

		return $generic;
	}
}