<?php

declare( strict_types=1 );

namespace AcezSeo\Data;

use AcezSeo\Ai\ApiKeyEncryption;

if ( ! defined( 'ABSPATH' ) )
{
	exit;
}

/**
 * Stores AI provider configuration: which provider is active, per-provider
 * model choice, and per-provider API key (encrypted at rest — see
 * ApiKeyEncryption). Never returns the encrypted blob to callers other than
 * get_api_key(), which decrypts it for immediate, one-time use.
 */
final class AiSettingsRepository implements AiSettingsRepositoryInterface
{
	private const OPTION_NAME = 'acez_seo_ai_settings';

	private ?string $task_context = null;

	public function get_active_provider(): string
	{
		return (string) $this->get()['active_provider'];
	}

	public function set_active_provider( string $provider_id ): bool
	{
		$data                    = $this->get();
		$data['active_provider'] = sanitize_key( $provider_id );

		return update_option( self::OPTION_NAME, $data );
	}

	public function get_model( string $provider_id ): string
	{
		$data = $this->get();

		// Per-task override (M36) wins while a task context is set — this is
		// how the task→model map reaches providers without changing their
		// interface (they all read the model through this method).
		if ( null !== $this->task_context )
		{
			$task_model = (string) ( $data['task_models'][ $this->task_context ] ?? '' );

			if ( '' !== $task_model )
			{
				return $task_model;
			}
		}

		return (string) ( $data['providers'][ $provider_id ]['model'] ?? '' );
	}

	public function set_task_context( ?string $task ): void
	{
		$this->task_context = $task;
	}

	/**
	 * @return array<string, string>
	 */
	public function get_task_models(): array
	{
		return array_map( 'strval', (array) $this->get()['task_models'] );
	}

	/**
	 * Merge-safe: only the tasks present in $map change; every other task
	 * keeps its stored model (a form that doesn't render a task must not
	 * blank it). Keys outside AiGenerationService::TASKS are dropped.
	 *
	 * @param array<string, string> $map
	 */
	public function update_task_models( array $map ): bool
	{
		$data      = $this->get();
		$stored    = (array) ( $data['task_models'] ?? array() );
		$sanitized = array();

		foreach ( \AcezSeo\Ai\AiGenerationService::TASKS as $task )
		{
			$value = array_key_exists( $task, $map ) ? $map[ $task ] : ( $stored[ $task ] ?? '' );

			$sanitized[ $task ] = sanitize_text_field( (string) $value );
		}

		$data['task_models'] = $sanitized;

		return update_option( self::OPTION_NAME, $data );
	}

	public function is_tested( string $provider_id ): bool
	{
		$data = $this->get();

		return (bool) ( $data['providers'][ $provider_id ]['tested'] ?? false );
	}

	public function mark_tested( string $provider_id, bool $tested ): bool
	{
		$provider_id = sanitize_key( $provider_id );
		$data        = $this->get();

		if ( ! isset( $data['providers'][ $provider_id ] ) )
		{
			return false;
		}

		$data['providers'][ $provider_id ]['tested'] = $tested;

		return update_option( self::OPTION_NAME, $data );
	}

	public function is_ready(): bool
	{
		$active = $this->get_active_provider();

		return '' !== $active && $this->has_api_key( $active ) && $this->is_tested( $active );
	}

	public function get_monthly_limit(): int
	{
		return (int) $this->get()['monthly_limit'];
	}

	public function set_monthly_limit( int $limit ): bool
	{
		$data                  = $this->get();
		$data['monthly_limit'] = max( 0, $limit );

		return update_option( self::OPTION_NAME, $data );
	}

	public function get_api_key( string $provider_id ): string
	{
		$data      = $this->get();
		$encrypted = (string) ( $data['providers'][ $provider_id ]['api_key_encrypted'] ?? '' );

		if ( '' === $encrypted )
		{
			return '';
		}

		return ApiKeyEncryption::decrypt( $encrypted );
	}

	public function has_api_key( string $provider_id ): bool
	{
		return '' !== $this->get_api_key( $provider_id );
	}

	/**
	 * @param array{api_key?: string, model?: string} $settings
	 */
	public function update_provider( string $provider_id, array $settings ): bool
	{
		$provider_id = sanitize_key( $provider_id );
		$data        = $this->get();

		if ( ! isset( $data['providers'][ $provider_id ] ) )
		{
			$data['providers'][ $provider_id ] = array(
				'api_key_encrypted' => '',
				'model'             => '',
			);
		}

		if ( isset( $settings['model'] ) )
		{
			$data['providers'][ $provider_id ]['model'] = sanitize_text_field( $settings['model'] );
		}

		// Leave the stored key untouched when the field was submitted empty —
		// re-saving the model shouldn't force re-entering the API key every time.
		// Trimmed: surrounding whitespace is never part of a real API key (it
		// sneaks in when copying) and a whitespace-only value must not silently
		// overwrite a working stored key.
		$api_key = isset( $settings['api_key'] ) ? trim( (string) $settings['api_key'] ) : '';

		if ( '' !== $api_key )
		{
			$data['providers'][ $provider_id ]['api_key_encrypted'] = ApiKeyEncryption::encrypt( $api_key );
		}

		return update_option( self::OPTION_NAME, $data );
	}

	public function disconnect_provider( string $provider_id ): bool
	{
		$provider_id = sanitize_key( $provider_id );
		$data        = $this->get();

		unset( $data['providers'][ $provider_id ] );

		if ( $data['active_provider'] === $provider_id )
		{
			$data['active_provider'] = '';
		}

		return update_option( self::OPTION_NAME, $data );
	}

	/**
	 * @return array{active_provider: string, providers: array<string, array{api_key_encrypted: string, model: string}>, task_models: array<string, string>, monthly_limit: int}
	 */
	private function get(): array
	{
		$stored = get_option( self::OPTION_NAME, array() );

		return wp_parse_args(
			is_array( $stored ) ? $stored : array(),
			array(
				'active_provider' => '',
				'providers'       => array(),
				'task_models'     => array(),
				'monthly_limit'   => 0,
			)
		);
	}
}