<?php
/**
 * Typed plugin settings.
 *
 * @package MazeAi
 * @since   0.1.0
 */

declare(strict_types=1);

namespace MazeAi\Support;

defined('ABSPATH') || exit;

use Illuminate\MazeAssistant\WordPress\Settings\SettingsRepository;

/**
 * The plugin's settings with their defaults, read and written through the framework's settings store. No setting
 * holds a secret: provider keys belong to WordPress's Connectors screen.
 *
 * @since 0.1.0
 */
class Settings
{
    /**
     * Every setting and its default.
     *
     * @since 0.1.0
     * @var array<string, mixed>
     */
    public const DEFAULTS = [
        'enabled'                  => true,  // Site switch: off stops every new run. MAZE_GRAPH_DISABLED forces it off.
        'default_model'            => '',    // "provider:model"; empty lets WordPress pick the first capable model.
        'site_instructions'        => '',    // Added to every session's system prompt (max 4,000 characters).
        'tools_enabled'            => true,  // Offer the site's read-only abilities to the model.
        'tool_overrides'           => [],    // Ability name => bool; unset follows the default (core/* and maze-graph/* on).
        'assistant_all_enabled_tools' => false, // Let only the built-in main assistant use all enabled tools, subject to policy.
        'allowed_roles'            => ['administrator'], // Roles that may chat; administrators always may (Support\Access).
        'max_steps'                => 8,     // Model calls per reply, tool rounds included.
        'max_output_tokens'        => 0,     // 0 leaves the model's own limit.
        'daily_token_cap'          => 500000, // Site-wide tokens per day; 0 is no cap.
        'retention_days'           => 0,     // 0 keeps sessions until deleted.
        'log_retention_days'       => 7,     // Operational event logs expire after a week by default; max 365 days.
        'delete_data_on_uninstall' => false,
        'runs_per_hour'            => 60,    // Replies one person may start per hour; 0 is no limit.
        'context_strategy'         => 'window', // History handling: window, clear (old tool results) or compact (summaries).
        'mcp_share_read_tools'     => false, // Mark MazeGraph's read-only tools public for WordPress's MCP Adapter (decision 038).
        'modules'                  => [],    // Module id => bool; unset follows the module's default (decision 043).
        'debug_timing'             => false, // Collect client-side request timings for troubleshooting.
    ];

    public const INSTRUCTIONS_LIMIT = 4000;

    public function __construct(protected SettingsRepository $store)
    {
    }

    /**
     * One setting, cast to the type of its default.
     *
     * @since 0.1.0
     */
    public function get(string $key): mixed
    {
        if (!array_key_exists($key, self::DEFAULTS)) {
            throw new \InvalidArgumentException(esc_html("Unknown MazeGraph setting \"{$key}\"."));
        }

        return $this->cast($key, $this->store->get($key, self::DEFAULTS[$key]));
    }

    /**
     * Every setting.
     *
     * @since 0.1.0
     * @return array<string, mixed>
     */
    public function all(): array
    {
        $values = [];
        foreach (array_keys(self::DEFAULTS) as $key) {
            $values[$key] = $this->get($key);
        }

        return $values;
    }

    /**
     * Save known settings; unknown keys are ignored.
     *
     * @since 0.1.0
     * @param array<string, mixed> $values
     */
    public function update(array $values): void
    {
        foreach ($values as $key => $value) {
            if (array_key_exists($key, self::DEFAULTS)) {
                $this->store->set($key, $this->cast($key, $value));
            }
        }
    }

    public function bool(string $key): bool
    {
        return (bool) $this->get($key);
    }

    public function int(string $key): int
    {
        return (int) $this->get($key);
    }

    public function string(string $key): string
    {
        return (string) $this->get($key);
    }

    /**
     * Whether new runs may start: the setting, unless the `MAZE_GRAPH_DISABLED` constant forces the plugin off.
     *
     * @since 0.1.0
     */
    public function runsAllowed(): bool
    {
        return !(defined('MAZE_GRAPH_DISABLED') && MAZE_GRAPH_DISABLED) && $this->bool('enabled');
    }

    protected function cast(string $key, mixed $value): mixed
    {
        return match (gettype(self::DEFAULTS[$key])) {
            'boolean' => filter_var($value, FILTER_VALIDATE_BOOLEAN),
            'integer' => max(0, (int) $value),
            'array'   => match ($key) {
                'tool_overrides' => $this->castOverrides($value),
                'modules'        => $this->castOverrides($value, '#^[a-z0-9-]+(/[a-z0-9-]+)?$#'),
                default          => $this->castList($value),
            },
            default   => is_scalar($value) ? (string) $value : '',
        };
    }

    /**
     * A list of slugs (role names).
     *
     * @return list<string>
     */
    protected function castList(mixed $value): array
    {
        if (is_string($value)) {
            $value = json_decode($value, true);
        }

        return array_values(array_unique(array_filter(array_map(
            static fn ($item): string => is_string($item) ? sanitize_key($item) : '',
            is_array($value) ? $value : []
        ))));
    }

    /**
     * @return array<string, bool>
     */
    protected function castOverrides(mixed $value, string $pattern = '#^[a-z0-9-]+/[a-z0-9-]+$#'): array
    {
        if (is_string($value)) {
            $value = json_decode($value, true);
        }
        $clean = [];
        foreach (is_array($value) ? $value : [] as $name => $on) {
            if (is_string($name) && preg_match($pattern, $name)) {
                $clean[$name] = filter_var($on, FILTER_VALIDATE_BOOLEAN);
            }
        }

        return $clean;
    }
}