<?php

/**
 * Settings service.
 *
 * Registers the AgentMod settings page via Native Custom Fields and bridges
 * saved values to the plugin's filterable constants.
 *
 * @package AgentMod
 * @subpackage Services
 * @since 1.0.0
 */

namespace AgentMod\Services;

use AgentMod\Common\Constants;
use AgentMod\Services\AI\AbilityResolver;
use AgentMod\Services\AI\ProviderInfoService;

defined('ABSPATH') || exit;

final class SettingsService
{
	/**
	 * WordPress option key where NCF stores all field values for this page.
	 *
	 * @var string
	 * @since 1.0.0
	 */
	public string $optionKey;

	/**
	 * Constructor (PHP-DI autowired). Registers all hooks immediately.
	 *
	 * @since 1.0.0
	 */
	public function __construct(string $optionKey = 'agent_mod_settings')
	{
		$this->optionKey = $optionKey;

		add_filter('ncf_sanitize_field_value', [$this, 'allowHtmlInMarkdownFields'], 10, 4);
	}

	/**
	 * Allows HTML in the markdown-editor-backed textarea fields.
	 *
	 * NCF's default textarea sanitizer strips HTML; the "agent-mod-md-" fields
	 * on the settings page are rendered with EasyMDE and expect their HTML
	 * output preserved on save.
	 *
	 * @param mixed  $sanitized  NCF's default sanitized value.
	 * @param mixed  $raw_value  Raw, unslashed input value.
	 * @param string $field_type NCF field type.
	 * @param string $field_name NCF field (meta key) name.
	 *
	 * @return mixed
	 * @since 1.0.8
	 */
	public function allowHtmlInMarkdownFields($sanitized, $raw_value, string $field_type, string $field_name)
	{
		$markdown_fields = ['role', 'goal', 'global_system_prompt'];

		if ('textarea' === $field_type && in_array($field_name, $markdown_fields, true)) {
			return wp_kses_post($raw_value);
		}

		return $sanitized;
	}

	// -------------------------------------------------------------------------
	// Settings Getters — each reads the saved setting and returns it when set,
	// applying backwards-compatible filters.
	// -------------------------------------------------------------------------

	/**
	 * @return int
	 * @since 1.0.0
	 */
	public function getMaxToolCalls(): int
	{
		$saved = (int) ($this->getSettings()['agent_mod_ai_limits']['max_tool_calls'] ?? 0);
		$value = $saved > 0 ? $saved : Constants::AI_MAX_TOOL_CALLS;
		return (int) $value;
	}

	/**
	 * @return int
	 * @since 1.0.0
	 */
	public function getMaxSearchResults(): int
	{
		$saved = (int) ($this->getSettings()['agent_mod_ai_limits']['max_search_results'] ?? 0);
		$value = $saved > 0 ? $saved : Constants::AI_MAX_SEARCH_RESULTS;
		return (int) $value;
	}

	/**
	 * Short schema hint telling the model how many items a list ability returns per call.
	 *
	 * @return string
	 * @since 1.3.2
	 */
	public function getSearchLimitHint(): string
	{
		return sprintf(
			/* translators: %d: Max Search Results setting value. */
			__('Returns at most %d items per call (Max Search Results setting).', 'agent-mod'),
			$this->getMaxSearchResults()
		);
	}

	/**
	 * Notice added to a list ability result that hit the Max Search Results cap.
	 *
	 * Tells the model where the cap comes from so it can point the user at the
	 * setting instead of retrying the same call.
	 *
	 * @param int  $limit     The cap that was applied.
	 * @param bool $paginated Whether the ability can page past the cap.
	 *
	 * @return string
	 * @since 1.3.2
	 */
	public function getSearchLimitNotice(int $limit, bool $paginated = false): string
	{
		if ($paginated) {
			return sprintf(
				/* translators: %d: Max Search Results setting value. */
				__('Results are limited to %d per call by the "Max Search Results" setting (AgentMod > Settings > AI Limits). Fetch the remaining pages with "paged" while pagination.has_more is true; never repeat a call with the same arguments. If many pages remain, tell the user about this limit and suggest raising that setting or narrowing the request.', 'agent-mod'),
				$limit
			);
		}

		return sprintf(
			/* translators: %d: Max Search Results setting value. */
			__('Results are limited to %d per call by the "Max Search Results" setting (AgentMod > Settings > AI Limits). If the user asked for all items, tell them about this limit and suggest raising that setting or narrowing the request; do not retry the same call.', 'agent-mod'),
			$limit
		);
	}

	/**
	 * @return int
	 * @since 1.0.0
	 */
	public function getMaxFullContentPosts(): int
	{
		$saved = (int) ($this->getSettings()['agent_mod_ai_limits']['max_full_content_posts'] ?? 0);
		$value = $saved > 0 ? $saved : Constants::AI_MAX_FULL_CONTENT_POSTS;
		return (int) $value;
	}

	/**
	 * Maximum length (characters) of a free-text answer to an ask-user or
	 * request-approval dialog.
	 *
	 * @return int
	 * @since 1.3.2
	 */
	public function getMaxAnswerLength(): int
	{
		$saved = (int) ($this->getSettings()['agent_mod_ai_limits']['max_answer_length'] ?? 0);
		return $saved > 0 ? $saved : Constants::AI_MAX_ANSWER_LENGTH;
	}

	/**
	 * @return int
	 * @since 1.0.0
	 */
	public function getAttachmentMaxBytes(): int
	{
		$saved = (int) ($this->getSettings()['agent_mod_attachments']['attachment_max_bytes'] ?? 0);
		$value = $saved > 0 ? $saved : Constants::AI_ATTACHMENT_MAX_BYTES;
		return (int) $value;
	}

	/**
	 * @return int
	 * @since 1.0.0
	 */
	public function getAttachmentMaxCount(): int
	{
		$saved = (int) ($this->getSettings()['agent_mod_attachments']['attachment_max_count'] ?? 0);
		$value = $saved > 0 ? $saved : Constants::AI_ATTACHMENT_MAX_COUNT;
		return (int) $value;
	}

	/**
	 * @return string[]
	 * @since 1.0.0
	 */
	public function getAttachmentMimeTypes(): array
	{
		$raw = trim((string) ($this->getSettings()['agent_mod_attachments']['attachment_mime_types'] ?? ''));
		if ('' === $raw) {
			$value = Constants::AI_ATTACHMENT_MIME_TYPES;
		} else {
			$value = array_values(array_filter(array_map('trim', explode("\n", $raw))));
			if (empty($value)) {
				$value = Constants::AI_ATTACHMENT_MIME_TYPES;
			}
		}
		return (array) $value;
	}

	/**
	 * Returns the user-managed base system prompt when saved, else the default.
	 *
	 * @return string
	 * @since 1.0.0
	 */
	public function getSystemPrompt(): string
	{
		$saved = trim((string) ($this->getSettings()['agent_mod_chat_behaviour']['global_system_prompt'] ?? ''));
		$value = '' !== $saved ? $saved : Constants::aiDefaultSystemPrompt();
		return (string) $value;
	}

	/**
	 * @return bool
	 * @since 1.0.6
	 */
	public function isSiteContextEnabled(): bool
	{
		$saved = $this->getSettings()['agent_mod_chat_behaviour']['site_context_enabled'] ?? null;
		$value = $saved !== null ? (bool) $saved : Constants::AI_CONTEXT_ENABLED;
		return (bool) $value;
	}

	/**
	 * @return bool
	 * @since 1.0.6
	 */
	public function isWebSearchEnabled(): bool
	{
		$saved = $this->getSettings()['agent_mod_chat_behaviour']['web_search_enabled'] ?? null;
		$value = $saved !== null ? (bool) $saved : Constants::AI_WEB_SEARCH_ENABLED;
		return (bool) $value;
	}

	/**
	 * @return string
	 * @since 1.0.5
	 */
	public function getRole(): string
	{
		$saved = trim((string) ($this->getSettings()['agent_mod_chat_behaviour']['role'] ?? ''));
		$value = '' !== $saved ? $saved : Constants::AI_AGENT_DEFAULT_ROLE;
		return (string) $value;
	}

	/**
	 * @return string
	 * @since 1.0.5
	 */
	public function getGoal(): string
	{
		$saved = trim((string) ($this->getSettings()['agent_mod_chat_behaviour']['goal'] ?? ''));
		$value = '' !== $saved ? $saved : Constants::AI_AGENT_DEFAULT_GOAL;
		return (string) $value;
	}

	/**
	 * Ability source of the settings-based (default) agent.
	 *
	 * Always 'all' since dynamic tool loading: the agent finds the abilities it
	 * needs itself, so the settings page no longer offers a selection. A saved
	 * 'selected' value from earlier versions is ignored on purpose. Agents that
	 * carry their own ability list (e.g. PRO agents) still pass it explicitly.
	 *
	 * @return string
	 * @since 1.1.0
	 */
	public function getAbilitySource(): string
	{
		return 'all';
	}

	/**
	 * Allowed abilities of the settings-based (default) agent.
	 *
	 * Always empty: see getAbilitySource(). Returning the stale saved list would
	 * let a selection the settings page no longer shows leak into agents that
	 * fall back to it.
	 *
	 * @return string[]
	 * @since 1.1.0
	 */
	public function getAllowedAbilities(): array
	{
		return [];
	}

	/**
	 * Tool loading strategy: 'dynamic' or 'all'.
	 *
	 * @return string
	 * @since 1.3.4
	 */
	public function getToolLoading(): string
	{
		$saved = (string) ($this->getSettings()['agent_mod_abilities']['tool_loading'] ?? '');

		return in_array($saved, ['dynamic', 'all'], true) ? $saved : Constants::AI_TOOL_LOADING;
	}

	/**
	 * Resolves the allowed abilities to their display details.
	 *
	 * Uses wp_get_abilities() to index the registry once (not the REST
	 * abilities list), so an allowed ability is always included here even
	 * when it is excluded from REST discovery (e.g. core/get-user-info,
	 * which core registers with show_in_rest => false for privacy reasons).
	 * Names that are no longer registered (stale entries, or garbage values
	 * such as a select field's placeholder) are dropped without calling
	 * wp_get_ability() per name, which would raise a _doing_it_wrong notice
	 * for every unregistered name.
	 *
	 * @return array<int, array{name: string, label: string, meta: array{annotations: array{readonly: bool}}}>
	 * @since 1.0.5
	 */
	public function getAllowedAbilitiesDetailed(): array
	{
		if (! function_exists('wp_get_abilities')) {
			return [];
		}

		$registry = [];
		foreach (wp_get_abilities() as $ability) {
			$registry[$ability->get_name()] = $ability;
		}

		$details = [];

		foreach ($this->getAllowedAbilities() as $name) {
			$ability = $registry[(string) $name] ?? null;

			if (null === $ability) {
				continue;
			}

			$details[] = [
				'name'  => $ability->get_name(),
				'label' => $ability->get_label(),
				'meta'  => [
					'annotations' => [
						'readonly' => AbilityResolver::isReadonly($ability),
					],
				],
			];
		}

		return $details;
	}

	/**
	 * Returns the site-wide default AI model together with its provider.
	 *
	 * The setting stores a single opaque "<provider>:<model>" value, so the two
	 * can never drift apart. An empty provider means "Use Auto" — let the AI
	 * Client pick.
	 *
	 * @return array{provider: string, model: string|null}
	 * @since 1.1.0
	 */
	public function getDefaultModel(): array
	{
		return ProviderInfoService::splitModelValue(
			(string) ($this->getSettings()['agent_mod_ai_model']['default_model'] ?? '')
		);
	}

	/**
	 * @return string[]
	 * @since 1.1.0
	 */
	public function getPersonalityTraits(): array
	{
		$saved = $this->getSettings()['agent_mod_chat_behaviour']['personality_traits'] ?? [];
		
		// Token field values can sometimes come as a comma separated string if not handled natively as an array,
		// but NCF's token_field normally saves as an array or comma string. We'll handle both.
		if (is_string($saved)) {
			$saved = array_filter(array_map('trim', explode(',', $saved)));
		}
		
		return is_array($saved) ? $saved : [];
	}

	/**
	 * Returns the configured preset prompts for the chat composer.
	 *
	 * The NCF repeater stores its rows as a JSON string (older saves may hold a
	 * real array) — both shapes are accepted. Rows without a prompt are
	 * dropped; a missing label falls back to a truncated prompt excerpt.
	 *
	 * @return array<int, array{label: string, prompt: string}>
	 * @since 1.0.7
	 */
	public function getPresetPrompts(): array
	{
		$raw = $this->getSettings()['agent_mod_chat_panel']['preset_prompts'] ?? [];

		if (is_string($raw)) {
			$decoded = json_decode($raw, true);
			$raw     = is_array($decoded) ? $decoded : [];
		}

		if (! is_array($raw)) {
			return [];
		}

		$presets = [];

		foreach ($raw as $row) {
			if (! is_array($row)) {
				continue;
			}

			$prompt = sanitize_textarea_field((string) ($row['prompt'] ?? ''));

			if ('' === trim($prompt)) {
				continue;
			}

			$label = sanitize_text_field((string) ($row['label'] ?? ''));

			if ('' === trim($label)) {
				$label = wp_html_excerpt($prompt, 30, '…');
			}

			$presets[] = [
				'label'  => $label,
				'prompt' => $prompt,
			];
		}

		$value = ! empty($presets) ? $presets : Constants::aiDefaultPresetPrompts();

		return $value;
	}

	/**
	 * Returns the saved settings array, or an empty array when no settings are saved yet.
	 *
	 * @return array<string, mixed>
	 * @since 1.0.0
	 */
	private function getSettings(): array
	{
		return (array) get_option($this->optionKey, []);
	}
}