<?php

namespace SoftminalCache\Framework\Support;

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

/**
 * A fluent wrapper around the WordPress object cache (wp_cache_*).
 *
 * Values are stored in a plugin-owned group. Because the object cache may be
 * non-persistent (no external cache plugin), treat this as a best-effort cache
 * — never the source of truth.
 *
 * PHP 7.4 compatible.
 */
class Cache
{
    private string $group = 'softminal_cache_cache';
    private int $defaultTtl = 300;

    /**
     * A sentinel distinct from any real cached value, so we can tell a genuine
     * cache miss from a stored false/null.
     */
    private const MISS = "\0__softminal_cache_cache_miss__\0";

    public function __construct(?string $group = null, ?int $defaultTtl = null)
    {
        if ($group !== null) {
            $this->group = $group;
        }
        if ($defaultTtl !== null) {
            $this->defaultTtl = $defaultTtl;
        }
    }

    public static function store(?string $group = null): self
    {
        return new self($group);
    }

    public function has(string $key): bool
    {
        $found = false;
        wp_cache_get($key, $this->group, false, $found);
        return (bool) $found;
    }

    /**
     * @param mixed $default
     * @return mixed
     */
    public function get(string $key, $default = null)
    {
        $found = false;
        $value = wp_cache_get($key, $this->group, false, $found);
        if ($found) {
            return $value;
        }
        return $default instanceof \Closure ? $default() : $default;
    }

    /**
     * @param mixed $value
     */
    public function put(string $key, $value, ?int $ttl = null): bool
    {
        return wp_cache_set($key, $value, $this->group, $ttl ?? $this->defaultTtl);
    }

    public function set(string $key, $value, ?int $ttl = null): bool
    {
        return $this->put($key, $value, $ttl);
    }

    /**
     * Store only if the key is not already present.
     *
     * @param mixed $value
     */
    public function add(string $key, $value, ?int $ttl = null): bool
    {
        if ($this->has($key)) {
            return false;
        }
        return $this->put($key, $value, $ttl);
    }

    public function forever(string $key, $value): bool
    {
        return $this->put($key, $value, 0);
    }

    /**
     * Return the cached value or compute, store, and return it.
     *
     * @return mixed
     */
    public function remember(string $key, callable $callback, ?int $ttl = null)
    {
        $found = false;
        $value = wp_cache_get($key, $this->group, false, $found);
        if ($found) {
            return $value;
        }

        $value = $callback();
        $this->put($key, $value, $ttl);
        return $value;
    }

    public function rememberForever(string $key, callable $callback)
    {
        return $this->remember($key, $callback, 0);
    }

    /**
     * Retrieve and delete a key in one call.
     *
     * @param mixed $default
     * @return mixed
     */
    public function pull(string $key, $default = null)
    {
        $value = $this->get($key, self::MISS);
        if ($value === self::MISS) {
            return $default instanceof \Closure ? $default() : $default;
        }
        $this->forget($key);
        return $value;
    }

    public function increment(string $key, int $by = 1)
    {
        return wp_cache_incr($key, $by, $this->group);
    }

    public function decrement(string $key, int $by = 1)
    {
        return wp_cache_decr($key, $by, $this->group);
    }

    public function forget(string $key): bool
    {
        return wp_cache_delete($key, $this->group);
    }

    /**
     * Flush this cache group. Returns false when the object cache cannot flush
     * a single group (WordPress < 6.1, or a drop-in without support): wiping
     * the whole site's cache from one plugin is never done implicitly.
     */
    public function flush(): bool
    {
        if (!function_exists('wp_cache_flush_group')) {
            return false;
        }
        if (function_exists('wp_cache_supports') && !wp_cache_supports('flush_group')) {
            return false;
        }
        return wp_cache_flush_group($this->group);
    }
}