<?php
/**
 * WooCommerce → Settings → Fitzaro.
 *
 * @package Fitzaro
 */

namespace Fitzaro\Admin;

use Fitzaro\Job\Jobs;
use Fitzaro\Prompt\ProductType;
use Fitzaro\Provider\OpenAi\OpenAiKey;
use Fitzaro\Provider\OpenAi\OpenAiProvider;
use Fitzaro\Provider\Registry;
use Fitzaro\Limits\BudgetNotice;
use Fitzaro\Limits\Limits;
use Fitzaro\Limits\Money;
use Fitzaro\Settings;

defined( 'ABSPATH' ) || exit;

/**
 * Uses the WooCommerce settings API, so the page, its nonce and the manage_woocommerce check come
 * from WooCommerce. The full settings screen (provider, key, products) comes with the React admin.
 */
final class SettingsTab {

	public const TAB = 'fitzaro';

	public const BUDGET_FIELD = Settings::OPTION_LIMITS . '[monthly_budget]';

	public const KEY_FIELD = 'fitzaro_openai_key_input';

	public const CLEAR_FIELD = 'fitzaro_openai_key_clear';

	/**
	 * What changed to the key during this save: 'saved', 'cleared' or ''.
	 *
	 * @var string
	 */
	private static $key_change = '';

	/**
	 * Hooks the tab.
	 */
	public static function register(): void {
		add_filter( 'woocommerce_settings_tabs_array', array( self::class, 'add_tab' ), 50 );
		add_action( 'woocommerce_settings_tabs_' . self::TAB, array( self::class, 'output' ) );
		add_action( 'woocommerce_update_options_' . self::TAB, array( self::class, 'save' ) );
		add_filter( 'woocommerce_admin_settings_sanitize_option', array( self::class, 'sanitize' ), 10, 3 );
	}

	/**
	 * Adds the tab to WooCommerce settings.
	 *
	 * @param mixed $tabs Tabs, keyed by ID.
	 * @return mixed
	 */
	public static function add_tab( $tabs ) {
		if ( is_array( $tabs ) ) {
			$tabs[ self::TAB ] = __( 'Fitzaro', 'fitzaro' );
		}

		return $tabs;
	}

	/**
	 * Renders the fields.
	 */
	public static function output(): void {
		woocommerce_admin_fields( self::fields() );
	}

	/**
	 * Saves the fields. Clears the "budget reached" notice so a raised budget takes effect visibly,
	 * and checks the key with a free call when the key or the model changed.
	 */
	public static function save(): void {
		$model = Settings::openai_model();

		self::$key_change = '';
		woocommerce_update_options( self::fields() );
		delete_option( BudgetNotice::OPTION );

		if ( 'cleared' === self::key_change() ) {
			ProviderNotice::clear();
			\WC_Admin_Settings::add_message( __( 'The OpenAI key was removed.', 'fitzaro' ) );
			return;
		}

		if ( ( 'saved' === self::key_change() || Settings::openai_model() !== $model ) && '' !== OpenAiKey::get() ) {
			ProviderNotice::clear();
			$code    = Registry::openai()->verify();
			$message = ProviderNotice::message( $code, Settings::openai_model() );

			if ( '' === $code ) {
				\WC_Admin_Settings::add_message( $message );
			} else {
				\WC_Admin_Settings::add_error( $message );
			}
		}
	}

	/**
	 * Sanitises the budget field; other fields pass through.
	 *
	 * @param mixed $value  Value WooCommerce prepared.
	 * @param mixed $option Field definition.
	 * @param mixed $raw    Submitted value.
	 * @return mixed
	 */
	public static function sanitize( $value, $option, $raw ) {
		$id = is_array( $option ) ? ( $option['id'] ?? '' ) : '';

		if ( self::KEY_FIELD === $id ) {
			self::save_key( is_string( $raw ) ? trim( $raw ) : '' );
			return null; // Never stored by WooCommerce in plain text.
		}

		if ( self::CLEAR_FIELD === $id ) {
			if ( 'saved' !== self::$key_change && ( '1' === $raw || 'yes' === $raw ) && ! OpenAiKey::from_constant() ) {
				OpenAiKey::clear();
				self::$key_change = 'cleared';
			}
			return null;
		}

		if ( self::BUDGET_FIELD !== $id ) {
			return $value;
		}

		$saved = get_option( Settings::OPTION_LIMITS, array() );
		$saved = is_array( $saved ) && isset( $saved['monthly_budget'] ) && is_scalar( $saved['monthly_budget'] ) ? (string) $saved['monthly_budget'] : (string) Limits::DEFAULTS['monthly_budget'];

		return BudgetField::sanitize( $raw, $saved );
	}

	/**
	 * Stores a newly entered key; an empty field keeps the saved one.
	 *
	 * @param string $key Submitted key.
	 */
	private static function save_key( string $key ): void {
		if ( '' === $key || OpenAiKey::from_constant() ) {
			return;
		}

		if ( ! OpenAiKey::looks_valid( $key ) ) {
			\WC_Admin_Settings::add_error( __( 'That does not look like an OpenAI API key (it should start with "sk-"). The saved key was kept.', 'fitzaro' ) );
			return;
		}

		OpenAiKey::save( $key );
		self::$key_change = 'saved';
	}

	/**
	 * What the sanitize callbacks did to the key during the last save.
	 */
	private static function key_change(): string {
		return self::$key_change;
	}

	/**
	 * Field definitions.
	 *
	 * @return list<array<string, mixed>>
	 */
	private static function fields(): array {
		return array_merge( self::storefront_fields(), self::provider_fields(), self::spending_fields() );
	}

	/**
	 * Master switch and product types.
	 *
	 * @return list<array<string, mixed>>
	 */
	private static function storefront_fields(): array {
		return array(
			array(
				'id'    => 'fitzaro_storefront_section',
				'type'  => 'title',
				'title' => __( 'Storefront', 'fitzaro' ),
				'desc'  => __( 'Each product and product category also has a Virtual try-on setting, to turn it off or to say what a product is.', 'fitzaro' ),
			),
			array(
				'id'      => Settings::OPTION_ENABLED,
				'type'    => 'checkbox',
				'title'   => __( 'Virtual try-on', 'fitzaro' ),
				'desc'    => __( 'Show the Try it on button on product pages', 'fitzaro' ),
				'default' => 'yes',
			),
			array(
				'id'       => Settings::OPTION_TYPES,
				'type'     => 'multiselect',
				'title'    => __( 'Product types', 'fitzaro' ),
				'class'    => 'wc-enhanced-select',
				'css'      => 'min-width: 24em;',
				'options'  => array(
					ProductType::TOP     => __( 'Tops', 'fitzaro' ),
					ProductType::DRESS   => __( 'Dresses', 'fitzaro' ),
					ProductType::EYEWEAR => __( 'Eyewear', 'fitzaro' ),
				),
				'default'  => array( ProductType::TOP, ProductType::DRESS, ProductType::EYEWEAR ),
				'desc_tip' => __( 'Try-on is only offered for these kinds of products.', 'fitzaro' ),
			),
			array(
				'id'   => 'fitzaro_storefront_section',
				'type' => 'sectionend',
			),
		);
	}

	/**
	 * Provider, key and model.
	 *
	 * @return list<array<string, mixed>>
	 */
	private static function provider_fields(): array {
		$providers = array(
			''                 => __( 'Automatic', 'fitzaro' ),
			OpenAiProvider::ID => __( 'OpenAI', 'fitzaro' ),
		);
		if ( Registry::mock_allowed( wp_get_environment_type(), defined( 'FITZARO_ENABLE_MOCK' ) && (bool) constant( 'FITZARO_ENABLE_MOCK' ) ) ) {
			$providers['mock'] = __( 'Mock (development only, no AI)', 'fitzaro' );
		}

		$key = OpenAiKey::get();
		if ( OpenAiKey::from_constant() ) {
			$key_field = array(
				'placeholder'       => OpenAiKey::mask( $key ),
				'desc'              => __( 'Set with FITZARO_OPENAI_KEY in wp-config.php.', 'fitzaro' ),
				'custom_attributes' => array( 'disabled' => 'disabled' ),
			);
		} else {
			$key_field = array(
				'placeholder'       => '' === $key ? 'sk-…' : OpenAiKey::mask( $key ),
				'desc'              => '' === $key
					? __( 'Create a key on platform.openai.com → API keys. Try-ons are billed to that account.', 'fitzaro' )
					: __( 'A key is saved (encrypted). Leave the field empty to keep it.', 'fitzaro' ),
				'custom_attributes' => array( 'autocomplete' => 'new-password' ),
			);
		}

		$fields = array(
			array(
				'id'    => 'fitzaro_provider_section',
				'type'  => 'title',
				'title' => __( 'AI provider', 'fitzaro' ),
				'desc'  => __( 'Fitzaro uses your own OpenAI account. Shopper photos and product images are sent to OpenAI to generate each try-on.', 'fitzaro' ),
			),
			array(
				'id'       => Settings::OPTION_PROVIDER,
				'type'     => 'select',
				'title'    => __( 'Provider', 'fitzaro' ),
				'options'  => $providers,
				'default'  => '',
				'desc_tip' => __( 'Automatic uses OpenAI once a key is saved.', 'fitzaro' ),
			),
			array_merge(
				array(
					'id'    => self::KEY_FIELD,
					'type'  => 'password',
					'title' => __( 'OpenAI API key', 'fitzaro' ),
					'css'   => 'width: 24em;',
				),
				$key_field
			),
		);

		if ( '' !== $key && ! OpenAiKey::from_constant() ) {
			$fields[] = array(
				'id'      => self::CLEAR_FIELD,
				'type'    => 'checkbox',
				'title'   => '',
				'desc'    => __( 'Remove the saved key', 'fitzaro' ),
				'default' => 'no',
			);
		}

		$fields[] = array(
			'id'       => Settings::OPTION_MODEL,
			'type'     => 'select',
			'title'    => __( 'Model', 'fitzaro' ),
			'options'  => array_combine( OpenAiProvider::MODELS, OpenAiProvider::MODELS ),
			'default'  => OpenAiProvider::DEFAULT_MODEL,
			'desc_tip' => __( 'gpt-image-2.5-sunburst gives the most faithful results. Older models cost less but change faces and bodies more.', 'fitzaro' ),
		);
		$fields[] = array(
			'id'   => 'fitzaro_provider_section',
			'type' => 'sectionend',
		);

		return $fields;
	}

	/**
	 * Budget.
	 *
	 * @return list<array<string, mixed>>
	 */
	private static function spending_fields(): array {
		return array(
			array(
				'id'    => 'fitzaro_limits_section',
				'type'  => 'title',
				'title' => __( 'Spending', 'fitzaro' ),
				'desc'  => __( 'Every try-on is generated with your AI key and billed to your AI account. The budget stops new try-ons for the rest of the month once it is reached.', 'fitzaro' ),
			),
			array(
				'id'                => self::BUDGET_FIELD,
				'type'              => 'text',
				'title'             => __( 'Monthly budget (USD)', 'fitzaro' ),
				'default'           => (string) Limits::DEFAULTS['monthly_budget'],
				'css'               => 'width: 8em;',
				'desc_tip'          => __( 'Months are counted in UTC. Enter 0 for no budget (not recommended).', 'fitzaro' ),
				'desc'              => self::spent_text(),
				'custom_attributes' => array(
					'inputmode' => 'decimal',
				),
			),
			array(
				'id'   => 'fitzaro_limits_section',
				'type' => 'sectionend',
			),
		);
	}

	/**
	 * "Spent this month" line under the budget field.
	 */
	private static function spent_text(): string {
		$spend = Jobs::requests()->spend_since( Limits::month_start( time() ) );

		$text = sprintf(
			/* translators: %s: amount in USD, e.g. 1.25 */
			__( 'Spent this month: $%s', 'fitzaro' ),
			number_format_i18n( $spend['micros'] / Money::MICROS, 2 )
		);

		if ( $spend['unpriced'] > 0 ) {
			$text .= ' ' . sprintf(
				/* translators: %d: number of try-ons. */
				_n( '(plus %d try-on in progress or without a reported cost)', '(plus %d try-ons in progress or without a reported cost)', $spend['unpriced'], 'fitzaro' ),
				$spend['unpriced']
			);
		}

		return $text;
	}
}