/*
 * Copyright (C) 1996-2024 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */

#ifndef SQUID_SRC_REFRESHPATTERN_H
#define SQUID_SRC_REFRESHPATTERN_H

#include "base/RegexPattern.h"

#include <memory>

/// a representation of a refresh pattern.
class RefreshPattern
{
    MEMPROXY_CLASS(RefreshPattern);

public:

    /*
     * Defaults:
     *      MIN     NONE
     *      PCT     20%
     *      MAX     3 days
     */
#define REFRESH_DEFAULT_MAX static_cast<time_t>(259200)

    using RegexPointer = std::unique_ptr<RegexPattern>;

    // If given a regex, becomes its owner, creating an explicit refresh_pattern
    // rule. Otherwise, creates an implicit/default refresh_pattern rule.
    explicit RefreshPattern(RegexPointer aRegex):
        min(0), pct(0.20), max(REFRESH_DEFAULT_MAX),
        next(nullptr),
        max_stale(-1),
        regex_(std::move(aRegex))
    {
        memset(&flags, 0, sizeof(flags));
    }

    ~RefreshPattern() {
        while (RefreshPattern *t = next) {
            next = t->next;
            t->next = nullptr;
            delete t;
        }
    }

    time_t min;
    double pct;
    time_t max;
    RefreshPattern *next;

    struct {
        bool refresh_ims;
        bool store_stale;
#if USE_HTTP_VIOLATIONS
        bool override_expire;
        bool override_lastmod;
        bool reload_into_ims;
        bool ignore_reload;
        bool ignore_no_store;
        bool ignore_private;
#endif
    } flags;
    int max_stale;

    // statistics about how many matches this pattern has had
    mutable struct stats_ {
        stats_() : matchTests(0), matchCount(0) {}

        uint64_t matchTests;
        uint64_t matchCount;
        // TODO: some stats to indicate how useful/less the flags are would be nice.
    } stats;

    /// reports configuration excluding trailing options
    void printHead(std::ostream &) const;

    /// reports the configured pattern or a fake pattern of the implicit rule
    void printPattern(std::ostream &os) const;

    // TODO: Refactor external refresh_pattern rules iterators to make private.
    /// configured regex; do not use except when iterating configured rules
    const RegexPattern &regex() const;

private:
    /// configured regex or, for the implicit refresh_pattern rule, nil
    RegexPointer regex_;
};

inline std::ostream &
operator <<(std::ostream &os, const RefreshPattern &r)
{
    r.printHead(os);
    return os;
}

#endif /* SQUID_SRC_REFRESHPATTERN_H */