/**
 * Copyright (c) 2007-2012, Timothy Stack
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @file log_format.hh
 */

#ifndef log_format_hh
#define log_format_hh

#include <stdint.h>
#include <sys/time.h>
#include <time.h>
#define __STDC_FORMAT_MACROS
#include <limits>
#include <memory>
#include <set>
#include <string>
#include <utility>
#include <vector>

#include <inttypes.h>
#include <sys/types.h>

#include "base/date_time_scanner.hh"
#include "base/intern_string.hh"
#include "base/lnav_log.hh"
#include "base/log_level_enum.hh"
#include "highlighter.hh"
#include "line_buffer.hh"
#include "log_format_fwd.hh"
#include "logfile.hh"
#include "pcrepp/pcre2pp.hh"
#include "robin_hood/robin_hood.h"
#include "shared_buffer.hh"

struct sqlite3;
class logfile;
class log_vtab_manager;
struct exec_context;

struct logline_value_name_cmp {
    explicit logline_value_name_cmp(const intern_string_t* name)
        : lvc_name(name)
    {
    }

    bool operator()(const logline_value& lv) const
    {
        return (*this->lvc_name) == lv.lv_meta.lvm_name;
    }

    const intern_string_t* lvc_name;
};

struct logline_value_col_eq {
    explicit logline_value_col_eq(const logline_value_meta::table_column& col)
        : lvc_column(col)
    {
    }

    bool operator()(const logline_value& lv) const
    {
        if (lv.lv_meta.lvm_column.is<logline_value_meta::table_column>()) {
            return this->lvc_column
                == lv.lv_meta.lvm_column
                       .get<logline_value_meta::table_column>();
        }
        return false;
    }

    const logline_value_meta::table_column& lvc_column;
};

class log_vtab_impl;

/**
 * Base class for implementations of log format parsers.
 */
class log_format : public std::enable_shared_from_this<log_format> {
public:
    /**
     * @return The collection of builtin log formats.
     */
    static std::vector<std::shared_ptr<log_format>>& get_root_formats();

    static std::shared_ptr<log_format> find_root_format(const char* name);

    struct sample_t {
        positioned_property<std::string> s_line;
        std::string s_description;
        log_level_t s_level{LEVEL_UNKNOWN};
        std::set<std::string> s_matched_regexes;
    };

    struct action_def {
        std::string ad_name;
        std::string ad_label;
        std::vector<std::string> ad_cmdline;
        bool ad_capture_output{false};

        bool operator<(const action_def& rhs) const
        {
            return this->ad_name < rhs.ad_name;
        }
    };

    virtual ~log_format() = default;

    virtual void clear()
    {
        this->lf_date_time.clear();
        this->lf_time_scanner.clear();
    }

    /**
     * Get the name of this log format.
     *
     * @return The log format name.
     */
    virtual const intern_string_t get_name() const = 0;

    struct name_matched {};
    struct name_mismatched {
        size_t nm_partial;
        std::string nm_pattern;
    };

    using match_name_result
        = mapbox::util::variant<name_matched, name_mismatched>;

    virtual match_name_result match_name(const std::string& filename)
    {
        return name_matched{};
    }

    using scan_match = log_format_scan_match;

    struct scan_error {
        std::string se_message;
    };

    struct scan_no_match {
        const char* snm_reason{nullptr};
    };

    struct scan_incomplete {};

    using scan_result_t = mapbox::util::
        variant<scan_match, scan_no_match, scan_error, scan_incomplete>;

    virtual scan_result_t test_line(
        sample_t& sample, std::vector<lnav::console::user_message>& msgs);

    /**
     * Scan a log line to see if it matches this log format.
     *
     * @param dst The vector of loglines that the formatter should append to
     *   if it detected a match.
     * @param offset The offset in the file where this line is located.
     * @param prefix The contents of the line.
     * @param len The length of the prefix string.
     */
    virtual scan_result_t scan(logfile& lf,
                               std::vector<logline>& dst,
                               const line_info& li,
                               shared_buffer_ref& sbr,
                               scan_batch_context& sbc) = 0;

    virtual bool scan_for_partial(const log_format_file_state& lffs,
                                  shared_buffer_ref& sbr,
                                  size_t& len_out) const
    {
        return false;
    }

    /**
     * Remove redundant data from the log line string.
     *
     * XXX We should probably also add some attributes to the line here, so we
     * can highlight things like the date.
     *
     * @param line The log line to edit.
     */
    virtual void scrub(std::string& line) {}

    virtual void annotate(logfile* lf,
                          uint64_t line_number,
                          string_attrs_t& sa,
                          logline_value_vector& values) const;

    virtual void rewrite(exec_context& ec,
                         shared_buffer_ref& line,
                         string_attrs_t& sa,
                         std::string& value_out)
    {
        value_out.assign(line.get_data(), line.length());
    }

    virtual std::optional<size_t> stats_index_for_value(
        const intern_string_t& name) const
    {
        return std::nullopt;
    }

    virtual std::shared_ptr<log_format> specialized(int fmt_lock = -1) = 0;

    virtual std::shared_ptr<log_vtab_impl> get_vtab_impl() const
    {
        return nullptr;
    }

    virtual void get_subline(const log_format_file_state& lffs,
                             const logline& ll,
                             shared_buffer_ref& sbr,
                             subline_options opts = subline_options{})
    {
    }

    virtual const std::vector<std::string>* get_actions(
        const logline_value& lv) const
    {
        return nullptr;
    }

    virtual std::set<std::string> get_source_path() const
    {
        std::set<std::string> retval;

        retval.insert("default");

        return retval;
    }

    virtual bool hide_field(const intern_string_t field_name, bool val)
    {
        return false;
    }

    virtual std::map<intern_string_t, logline_value_meta> get_field_states()
    {
        return {};
    }

    const char* const* get_timestamp_formats() const
    {
        if (this->lf_timestamp_format.empty()) {
            return nullptr;
        }

        return &this->lf_timestamp_format[0];
    }

    date_time_scanner build_time_scanner() const;

    void check_for_new_year(std::vector<logline>& dst,
                            exttm log_tv,
                            timeval timeval1) const;

    virtual std::string get_pattern_path(const pattern_locks& pl,
                                         uint64_t line_number) const;

    virtual intern_string_t get_pattern_name(const pattern_locks& pl,
                                             uint64_t line_number) const;

    virtual std::string get_pattern_regex(const pattern_locks& pl,
                                          uint64_t line_number) const
    {
        return "";
    }

    virtual std::vector<logline_value_meta> get_value_metadata() const
    {
        return {};
    }

    virtual bool format_changed() { return false; }

    bool operator<(const log_format& rhs) const
    {
        return this->get_name() < rhs.get_name();
    }

    static bool name_lt(const std::shared_ptr<const log_format>& lhs,
                        const std::shared_ptr<const log_format>& rhs)
    {
        return intern_string_t::case_lt(lhs->get_name(), rhs->get_name());
    }

    exttm tm_for_display(logfile::iterator ll, string_fragment sf);

    enum class subsecond_unit {
        milli,
        micro,
        nano,
    };

    std::string lf_description;
    log_format* lf_root_format{this};
    uint8_t lf_mod_index{0};
    bool lf_multiline{true};
    bool lf_structured{false};
    bool lf_formatted_lines{false};
    date_time_scanner lf_date_time;
    date_time_scanner lf_time_scanner;
    intern_string_t lf_timestamp_field{intern_string::lookup("timestamp", -1)};
    intern_string_t lf_start_timestamp_field;
    intern_string_t lf_subsecond_field;
    std::optional<subsecond_unit> lf_subsecond_unit;
    intern_string_t lf_time_field;
    std::vector<const char*> lf_timestamp_format;
    unsigned int lf_timestamp_flags{0};
    timestamp_point_of_reference_t lf_timestamp_point_of_reference{
        timestamp_point_of_reference_t::end};
    std::map<std::string, action_def> lf_action_defs;
    std::vector<highlighter> lf_highlighters;
    bool lf_is_self_describing{false};
    bool lf_time_ordered{true};
    bool lf_specialized{false};
    bool lf_level_hideable{true};
    std::optional<uint64_t> lf_max_unrecognized_lines;
    std::map<const intern_string_t, std::shared_ptr<format_tag_def>>
        lf_tag_defs;

    std::map<const intern_string_t, std::shared_ptr<format_partition_def>>
        lf_partition_defs;

    struct opid_descriptor {
        positioned_property<intern_string_t> od_field;
        factory_container<lnav::pcre2pp::code> od_extractor;
        std::optional<std::string> od_prefix;
        std::string od_suffix;
        std::string od_joiner{", "};

        std::optional<std::string> matches(const string_fragment& sf) const;
    };

    struct opid_descriptors {
        intern_string_t od_name;
        std::shared_ptr<std::vector<opid_descriptor>> od_descriptors;
        size_t od_index{0};

        std::string to_string(
            const lnav::map::small<size_t, std::string>& lod) const;
    };

    enum class opid_source_t {
        from_field,
        from_description,
        from_whole_msg,
    };

    std::optional<opid_source_t> lf_opid_source{};

    std::shared_ptr<std::map<intern_string_t, opid_descriptors>>
        lf_opid_description_def{
            std::make_shared<std::map<intern_string_t, opid_descriptors>>()};

    std::shared_ptr<std::map<intern_string_t, opid_descriptors>>
        lf_subid_description_def{
            std::make_shared<std::map<intern_string_t, opid_descriptors>>()};

    std::shared_ptr<std::vector<opid_descriptors*>> lf_opid_description_def_vec{
        std::make_shared<std::vector<opid_descriptors*>>()};

    std::shared_ptr<std::vector<opid_descriptors*>>
        lf_subid_description_def_vec{
            std::make_shared<std::vector<opid_descriptors*>>()};

    ArenaAlloc::Alloc<char> lf_desc_allocator{2 * 1024};

    using desc_field_set
        = robin_hood::unordered_set<intern_string_t,
                                    intern_hasher,
                                    std::equal_to<intern_string_t>>;

    desc_field_set lf_desc_fields;

    using desc_cap_map
        = robin_hood::unordered_map<intern_string_t,
                                    string_fragment,
                                    intern_hasher,
                                    std::equal_to<intern_string_t>>;
    desc_cap_map lf_desc_captures;

    static const intern_string_t LOG_TIME_STR;
    static const intern_string_t LOG_LEVEL_STR;
    static const intern_string_t LOG_OPID_STR;
    static const intern_string_t LOG_THREAD_ID_STR;

protected:
    static std::vector<std::shared_ptr<log_format>> lf_root_formats;

    struct pcre_format {
        template<typename T, std::size_t N>
        explicit pcre_format(const T (&regex)[N])
            : name(regex),
              pcre(lnav::pcre2pp::code::from_const(regex, PCRE2_CASELESS)
                       .to_shared()),
              pf_timestamp_index(this->pcre->name_index("timestamp"))
        {
        }

        pcre_format() = default;

        const char* name{nullptr};
        std::shared_ptr<lnav::pcre2pp::code> pcre;
        int pf_timestamp_index{-1};
    };

    static bool next_format(const pcre_format* fmt,
                            int& index,
                            int& locked_index);

    const char* log_scanf(scan_batch_context& sbc,
                          uint32_t line_number,
                          string_fragment line,
                          const pcre_format* fmt,
                          const char* time_fmt[],
                          struct exttm* tm_out,
                          struct timeval* tv_out,

                          string_fragment* ts_out,
                          std::optional<string_fragment>* level_out);
};

#endif
