// Copyright (c) 2023 The Bitcoin Core developers

// Distributed under the MIT software license, see the accompanying

// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <common/args.h>

#include <common/settings.h>

#include <logging.h>

#include <sync.h>

#include <tinyformat.h>

#include <univalue.h>

#include <util/chaintype.h>

#include <util/fs.h>

#include <util/string.h>

#include <algorithm>

#include <cassert>

#include <cstdlib>

#include <filesystem>

#include <fstream>

#include <iostream>

#include <list>

#include <map>

#include <memory>

#include <optional>

#include <string>

#include <string_view>

#include <utility>

#include <vector>

using util::TrimString;

using util::TrimStringView;

static bool GetConfigOptions(std::istream& stream, const std::string& filepath, std::string& error, std::vector<std::pair<std::string, std::string>>& options, std::list<SectionInfo>& sections)

{

    std::string str, prefix;

    std::string::size_type pos;

    int linenr = 1;

    while (std::getline(stream, str)) {

        bool used_hash = false;

        if ((pos = str.find('#')) != std::string::npos) {

            str = str.substr(0, pos);

            used_hash = true;

        }

        const static std::string pattern = " \t\r\n";

        str = TrimString(str, pattern);

        if (!str.empty()) {

            if (*str.begin() == '[' && *str.rbegin() == ']') {

                const std::string section = str.substr(1, str.size() - 2);

                sections.emplace_back(SectionInfo{section, filepath, linenr});

                prefix = section + '.';

            } else if (*str.begin() == '-') {

                error = strprintf("parse error on line %i: %s, options in configuration file must be specified without leading -", linenr, str);

                return false;

            } else if ((pos = str.find('=')) != std::string::npos) {

                std::string name = prefix + TrimString(std::string_view{str}.substr(0, pos), pattern);

                std::string_view value = TrimStringView(std::string_view{str}.substr(pos + 1), pattern);

                if (used_hash && name.find("rpcpassword") != std::string::npos) {

                    error = strprintf("parse error on line %i, using # in rpcpassword can be ambiguous and should be avoided", linenr);

                    return false;

                }

                options.emplace_back(name, value);

                if ((pos = name.rfind('.')) != std::string::npos && prefix.length() <= pos) {

                    sections.emplace_back(SectionInfo{name.substr(0, pos), filepath, linenr});

                }

            } else {

                error = strprintf("parse error on line %i: %s", linenr, str);

                if (str.size() >= 2 && str.starts_with("no")) {

                    error += strprintf(", if you intended to specify a negated option, use %s=1 instead", str);

                }

                return false;

            }

        }

        ++linenr;

    }

    return true;

}

bool IsConfSupported(KeyInfo& key, std::string& error) {

    if (key.name == "conf") {

        error = "conf cannot be set in the configuration file; use includeconf= if you want to include additional config files";

        return false;

    }

    if (key.name == "reindex") {

        // reindex can be set in a config file but it is strongly discouraged as this will cause the node to reindex on

        // every restart. Allow the config but throw a warning

        LogPrintf("Warning: reindex=1 is set in the configuration file, which will significantly slow down startup. Consider removing or commenting out this option for better performance, unless there is currently a condition which makes rebuilding the indexes necessary\n");

        return true;

    }

    return true;

}

bool ArgsManager::ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys)

{

    LOCK(cs_args);

    std::vector<std::pair<std::string, std::string>> options;

    if (!GetConfigOptions(stream, filepath, error, options, m_config_sections)) {

        return false;

    }

    for (const std::pair<std::string, std::string>& option : options) {

        KeyInfo key = InterpretKey(option.first);

        std::optional<unsigned int> flags = GetArgFlags('-' + key.name);

        if (!IsConfSupported(key, error)) return false;

        if (flags) {

            std::optional<common::SettingsValue> value = InterpretValue(key, &option.second, *flags, error);

            if (!value) {

                return false;

            }

            m_settings.ro_config[key.section][key.name].push_back(*value);

        } else {

            if (ignore_invalid_keys) {

                LogPrintf("Ignoring unknown configuration value %s\n", option.first);

            } else {

                error = strprintf("Invalid configuration value %s", option.first);

                return false;

            }

        }

    }

    return true;

}

bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)

{

    {

        LOCK(cs_args);

        m_settings.ro_config.clear();

        m_config_sections.clear();

        m_config_path = AbsPathForConfigVal(*this, GetPathArg("-conf", BITCOIN_CONF_FILENAME), /*net_specific=*/false);

    }

    const auto conf_path{GetConfigFilePath()};

    std::ifstream stream;

    if (!conf_path.empty()) { // path is empty when -noconf is specified

        if (fs::is_directory(conf_path)) {

            error = strprintf("Config file \"%s\" is a directory.", fs::PathToString(conf_path));

            return false;

        }

        stream = std::ifstream{conf_path};

        // If the file is explicitly specified, it must be readable

        if (IsArgSet("-conf") && !stream.good()) {

            error = strprintf("specified config file \"%s\" could not be opened.", fs::PathToString(conf_path));

            return false;

        }

    }

    // ok to not have a config file

    if (stream.good()) {

        if (!ReadConfigStream(stream, fs::PathToString(conf_path), error, ignore_invalid_keys)) {

            return false;

        }

        // `-includeconf` cannot be included in the command line arguments except

        // as `-noincludeconf` (which indicates that no included conf file should be used).

        bool use_conf_file{true};

        {

            LOCK(cs_args);

            if (auto* includes = common::FindKey(m_settings.command_line_options, "includeconf")) {

                // ParseParameters() fails if a non-negated -includeconf is passed on the command-line

                assert(common::SettingsSpan(*includes).last_negated());

                use_conf_file = false;

            }

        }

        if (use_conf_file) {

            std::string chain_id = GetChainTypeString();

            std::vector<std::string> conf_file_names;

            auto add_includes = [&](const std::string& network, size_t skip = 0) {

                size_t num_values = 0;

                LOCK(cs_args);

                if (auto* section = common::FindKey(m_settings.ro_config, network)) {

                    if (auto* values = common::FindKey(*section, "includeconf")) {

                        for (size_t i = std::max(skip, common::SettingsSpan(*values).negated()); i < values->size(); ++i) {

                            conf_file_names.push_back((*values)[i].get_str());

                        }

                        num_values = values->size();

                    }

                }

                return num_values;

            };

            // We haven't set m_network yet (that happens in SelectParams()), so manually check

            // for network.includeconf args.

            const size_t chain_includes = add_includes(chain_id);

            const size_t default_includes = add_includes({});

            for (const std::string& conf_file_name : conf_file_names) {

                const auto include_conf_path{AbsPathForConfigVal(*this, fs::PathFromString(conf_file_name), /*net_specific=*/false)};

                if (fs::is_directory(include_conf_path)) {

                    error = strprintf("Included config file \"%s\" is a directory.", fs::PathToString(include_conf_path));

                    return false;

                }

                std::ifstream conf_file_stream{include_conf_path};

                if (conf_file_stream.good()) {

                    if (!ReadConfigStream(conf_file_stream, conf_file_name, error, ignore_invalid_keys)) {

                        return false;

                    }

                    LogPrintf("Included configuration file %s\n", conf_file_name);

                } else {

                    error = "Failed to include configuration file " + conf_file_name;

                    return false;

                }

            }

            // Warn about recursive -includeconf

            conf_file_names.clear();

            add_includes(chain_id, /* skip= */ chain_includes);

            add_includes({}, /* skip= */ default_includes);

            std::string chain_id_final = GetChainTypeString();

            if (chain_id_final != chain_id) {

                // Also warn about recursive includeconf for the chain that was specified in one of the includeconfs

                add_includes(chain_id_final);

            }

            for (const std::string& conf_file_name : conf_file_names) {

                tfm::format(std::cerr, "warning: -includeconf cannot be used from included files; ignoring -includeconf=%s\n", conf_file_name);

            }

        }

    }

    // If datadir is changed in .conf file:

    ClearPathCache();

    if (!CheckDataDirOption(*this)) {

        error = strprintf("specified data directory \"%s\" does not exist.", GetArg("-datadir", ""));

        return false;

    }

    return true;

}

fs::path AbsPathForConfigVal(const ArgsManager& args, const fs::path& path, bool net_specific)

{

    if (path.is_absolute() || path.empty()) {

        return path;

    }

    return fsbridge::AbsPathJoin(net_specific ? args.GetDataDirNet() : args.GetDataDirBase(), path);

}