// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
// under NSF AWARD 1414736 and by the respective contributors.
// All rights reserved.
//
// SPDX-License-Identifier: BSD-3-Clause

#pragma once

#include <algorithm>
#include <fstream>
#include <iostream>
#include <string>
#include <utility>
#include <vector>

#include "App.hpp"
#include "ConfigFwd.hpp"
#include "StringTools.hpp"

namespace CLI {

namespace detail {

inline std::string convert_arg_for_ini(const std::string &arg) {
    if(arg.empty()) {
        return std::string(2, '"');
    }
    // some specifically supported strings
    if(arg == "true" || arg == "false" || arg == "nan" || arg == "inf") {
        return arg;
    }
    // floating point conversion can convert some hex codes, but don't try that here
    if(arg.compare(0, 2, "0x") != 0 && arg.compare(0, 2, "0X") != 0) {
        double val;
        if(detail::lexical_cast(arg, val)) {
            return arg;
        }
    }
    // just quote a single non numeric character
    if(arg.size() == 1) {
        return std::string("'") + arg + '\'';
    }
    // handle hex, binary or octal arguments
    if(arg.front() == '0') {
        if(arg[1] == 'x') {
            if(std::all_of(arg.begin() + 2, arg.end(), [](char x) {
                   return (x >= '0' && x <= '9') || (x >= 'A' && x <= 'F') || (x >= 'a' && x <= 'f');
               })) {
                return arg;
            }
        } else if(arg[1] == 'o') {
            if(std::all_of(arg.begin() + 2, arg.end(), [](char x) { return (x >= '0' && x <= '7'); })) {
                return arg;
            }
        } else if(arg[1] == 'b') {
            if(std::all_of(arg.begin() + 2, arg.end(), [](char x) { return (x == '0' || x == '1'); })) {
                return arg;
            }
        }
    }
    if(arg.find_first_of('"') == std::string::npos) {
        return std::string("\"") + arg + '"';
    } else {
        return std::string("'") + arg + '\'';
    }
}

/// Comma separated join, adds quotes if needed
inline std::string
ini_join(const std::vector<std::string> &args, char sepChar = ',', char arrayStart = '[', char arrayEnd = ']') {
    std::string joined;
    if(args.size() > 1 && arrayStart != '\0') {
        joined.push_back(arrayStart);
    }
    std::size_t start = 0;
    for(const auto &arg : args) {
        if(start++ > 0) {
            joined.push_back(sepChar);
            if(isspace(sepChar) == 0) {
                joined.push_back(' ');
            }
        }
        joined.append(convert_arg_for_ini(arg));
    }
    if(args.size() > 1 && arrayEnd != '\0') {
        joined.push_back(arrayEnd);
    }
    return joined;
}

inline std::vector<std::string> generate_parents(const std::string &section, std::string &name) {
    std::vector<std::string> parents;
    if(detail::to_lower(section) != "default") {
        if(section.find('.') != std::string::npos) {
            parents = detail::split(section, '.');
        } else {
            parents = {section};
        }
    }
    if(name.find('.') != std::string::npos) {
        std::vector<std::string> plist = detail::split(name, '.');
        name = plist.back();
        detail::remove_quotes(name);
        plist.pop_back();
        parents.insert(parents.end(), plist.begin(), plist.end());
    }

    // clean up quotes on the parents
    for(auto &parent : parents) {
        detail::remove_quotes(parent);
    }
    return parents;
}

/// assuming non default segments do a check on the close and open of the segments in a configItem structure
inline void checkParentSegments(std::vector<ConfigItem> &output, const std::string &currentSection) {

    std::string estring;
    auto parents = detail::generate_parents(currentSection, estring);
    if(!output.empty() && output.back().name == "--") {
        std::size_t msize = (parents.size() > 1U) ? parents.size() : 2;
        while(output.back().parents.size() >= msize) {
            output.push_back(output.back());
            output.back().parents.pop_back();
        }

        if(parents.size() > 1) {
            std::size_t common = 0;
            std::size_t mpair = (std::min)(output.back().parents.size(), parents.size() - 1);
            for(std::size_t ii = 0; ii < mpair; ++ii) {
                if(output.back().parents[ii] != parents[ii]) {
                    break;
                }
                ++common;
            }
            if(common == mpair) {
                output.pop_back();
            } else {
                while(output.back().parents.size() > common + 1) {
                    output.push_back(output.back());
                    output.back().parents.pop_back();
                }
            }
            for(std::size_t ii = common; ii < parents.size() - 1; ++ii) {
                output.emplace_back();
                output.back().parents.assign(parents.begin(), parents.begin() + static_cast<std::ptrdiff_t>(ii) + 1);
                output.back().name = "++";
            }
        }
    } else if(parents.size() > 1) {
        for(std::size_t ii = 0; ii < parents.size() - 1; ++ii) {
            output.emplace_back();
            output.back().parents.assign(parents.begin(), parents.begin() + static_cast<std::ptrdiff_t>(ii) + 1);
            output.back().name = "++";
        }
    }

    // insert a section end which is just an empty items_buffer
    output.emplace_back();
    output.back().parents = std::move(parents);
    output.back().name = "++";
}
}  // namespace detail

inline std::vector<ConfigItem> ConfigBase::from_config(std::istream &input) const {
    std::string line;
    std::string section = "default";

    std::vector<ConfigItem> output;
    bool defaultArray = (arrayStart == '\0' || arrayStart == ' ') && arrayStart == arrayEnd;
    char aStart = (defaultArray) ? '[' : arrayStart;
    char aEnd = (defaultArray) ? ']' : arrayEnd;
    char aSep = (defaultArray && arraySeparator == ' ') ? ',' : arraySeparator;

    while(getline(input, line)) {
        std::vector<std::string> items_buffer;
        std::string name;

        detail::trim(line);
        std::size_t len = line.length();
        if(len > 1 && line.front() == '[' && line.back() == ']') {
            if(section != "default") {
                // insert a section end which is just an empty items_buffer
                output.emplace_back();
                output.back().parents = detail::generate_parents(section, name);
                output.back().name = "--";
            }
            section = line.substr(1, len - 2);
            // deal with double brackets for TOML
            if(section.size() > 1 && section.front() == '[' && section.back() == ']') {
                section = section.substr(1, section.size() - 2);
            }
            if(detail::to_lower(section) == "default") {
                section = "default";
            } else {
                detail::checkParentSegments(output, section);
            }
            continue;
        }
        if(len == 0) {
            continue;
        }
        // comment lines
        if(line.front() == ';' || line.front() == '#' || line.front() == commentChar) {
            continue;
        }

        // Find = in string, split and recombine
        auto pos = line.find(valueDelimiter);
        if(pos != std::string::npos) {
            name = detail::trim_copy(line.substr(0, pos));
            std::string item = detail::trim_copy(line.substr(pos + 1));
            if(item.size() > 1 && item.front() == aStart && item.back() == aEnd) {
                items_buffer = detail::split_up(item.substr(1, item.length() - 2), aSep);
            } else if(defaultArray && item.find_first_of(aSep) != std::string::npos) {
                items_buffer = detail::split_up(item, aSep);
            } else if(defaultArray && item.find_first_of(' ') != std::string::npos) {
                items_buffer = detail::split_up(item);
            } else {
                items_buffer = {item};
            }
        } else {
            name = detail::trim_copy(line);
            items_buffer = {"true"};
        }
        if(name.find('.') == std::string::npos) {
            detail::remove_quotes(name);
        }
        // clean up quotes on the items
        for(auto &it : items_buffer) {
            detail::remove_quotes(it);
        }

        std::vector<std::string> parents = detail::generate_parents(section, name);

        if(!output.empty() && name == output.back().name && parents == output.back().parents) {
            output.back().inputs.insert(output.back().inputs.end(), items_buffer.begin(), items_buffer.end());
        } else {
            output.emplace_back();
            output.back().parents = std::move(parents);
            output.back().name = std::move(name);
            output.back().inputs = std::move(items_buffer);
        }
    }
    if(section != "default") {
        // insert a section end which is just an empty items_buffer
        std::string ename;
        output.emplace_back();
        output.back().parents = detail::generate_parents(section, ename);
        output.back().name = "--";
        while(output.back().parents.size() > 1) {
            output.push_back(output.back());
            output.back().parents.pop_back();
        }
    }
    return output;
}

inline std::string
ConfigBase::to_config(const App *app, bool default_also, bool write_description, std::string prefix) const {
    std::stringstream out;
    std::string commentLead;
    commentLead.push_back(commentChar);
    commentLead.push_back(' ');

    std::vector<std::string> groups = app->get_groups();
    bool defaultUsed = false;
    groups.insert(groups.begin(), std::string("Options"));
    if(write_description) {
        out << commentLead << app->get_description() << '\n';
    }
    for(auto &group : groups) {
        if(group == "Options" || group.empty()) {
            if(defaultUsed) {
                continue;
            }
            defaultUsed = true;
        }
        if(write_description && group != "Options" && !group.empty()) {
            out << '\n' << commentLead << group << " Options\n";
        }
        for(const Option *opt : app->get_options({})) {

            // Only process option with a long-name and configurable
            if(!opt->get_lnames().empty() && opt->get_configurable()) {
                if(opt->get_group() != group) {
                    if(!(group == "Options" && opt->get_group().empty())) {
                        continue;
                    }
                }
                std::string name = prefix + opt->get_lnames()[0];
                std::string value = detail::ini_join(opt->reduced_results(), arraySeparator, arrayStart, arrayEnd);

                if(value.empty() && default_also) {
                    if(!opt->get_default_str().empty()) {
                        value = detail::convert_arg_for_ini(opt->get_default_str());
                    } else if(opt->get_expected_min() == 0) {
                        value = "false";
                    }
                }

                if(!value.empty()) {
                    if(write_description && opt->has_description()) {
                        out << '\n';
                        out << commentLead << detail::fix_newlines(commentLead, opt->get_description()) << '\n';
                    }
                    out << name << valueDelimiter << value << '\n';
                }
            }
        }
    }
    auto subcommands = app->get_subcommands({});
    for(const App *subcom : subcommands) {
        if(subcom->get_name().empty()) {
            if(write_description && !subcom->get_group().empty()) {
                out << '\n' << commentLead << subcom->get_group() << " Options\n";
            }
            out << to_config(subcom, default_also, write_description, prefix);
        }
    }

    for(const App *subcom : subcommands) {
        if(!subcom->get_name().empty()) {
            if(subcom->get_configurable() && app->got_subcommand(subcom)) {
                if(!prefix.empty() || app->get_parent() == nullptr) {
                    out << '[' << prefix << subcom->get_name() << "]\n";
                } else {
                    std::string subname = app->get_name() + "." + subcom->get_name();
                    auto p = app->get_parent();
                    while(p->get_parent() != nullptr) {
                        subname = p->get_name() + "." + subname;
                        p = p->get_parent();
                    }
                    out << '[' << subname << "]\n";
                }
                out << to_config(subcom, default_also, write_description, "");
            } else {
                out << to_config(subcom, default_also, write_description, prefix + subcom->get_name() + ".");
            }
        }
    }

    return out.str();
}

}  // namespace CLI
