// C++
#include <cerrno>
#include <iostream>
#include <cstdlib>
#include <string>
#include <stdexcept>
#include <vector>
#include <map>
#include <algorithm>

// POSIX
#include <getopt.h>
#include <sys/types.h>
#include <sys/xattr.h>

//libraries
#include <libscstring.hpp>
#include <libscerror.hpp>
#include <libscterm.hpp>

// project
#include "commit.inc"

std::vector<std::string> additions;
std::string change;
std::map<std::string, std::string> changes;
std::vector<std::string> deletions;
bool should_list = false;
bool sort = false;

static void handle_additions(std::vector<std::string>& tags) {
    for (const std::string& tag : additions) {
        tags.push_back(tag);
    }
}

static void handle_changes(std::vector<std::string>& tags) {
    for (const auto& elem : changes) {
        auto it = std::find(tags.begin(), tags.end(), elem.first);
        if (it != tags.end()) {
            *it = elem.second;
        }
    }
}

static void handle_deletions(std::vector<std::string>& tags) {
    for (const std::string& tag : deletions) {
        tags.erase(std::remove(tags.begin(), tags.end(), tag), tags.end());
    }
}

static void process(const char* path) {
    const char* tagname {"user.xdg.tags"};
    std::vector<std::string> tags;
    std::vector<char> buf(1024);
    ssize_t sz = getxattr(path, tagname, buf.data(), buf.size());
    if (sz == -1) {
        if (errno != ENODATA) {
            throw_if_min1(sz);
        }
    } else {
        std::string val(buf.data(), sz);
        tags = sc::split(val, ",");
    }
    bool edits = additions.size() > 0 || changes.size() > 0 || deletions.size() > 0;
    if (edits) {
        if (should_list) {
            std::cout << path << '\n';
            std::cout << "  before: " << sc::io::greenf << sc::join(tags, ", ") << sc::io::reset << '\n';
        }
        handle_deletions(tags);
        handle_changes(tags);
        handle_additions(tags);
        if (sort) {
            std::sort(tags.begin(), tags.end());
        }
        if (should_list) {
            std::cout << "   after: " << sc::io::yellowf << sc::join(tags, ", ") << sc::io::reset << '\n';
        }
        std::string joined {sc::join(tags, ",")};
        throw_if_min1(setxattr(path, tagname, joined.c_str(), joined.size(), 0));
    } else {
        if (should_list) {
            std::cout << path << ": " << sc::io::yellowf << sc::join(tags, ", ") << sc::io::reset << '\n';
        }
    }
}

static void print_help() {
    std::cout << "usage: tagger [-h|--version]\n";
    std::cout << "  -h, --help    show this help text and exit\n";
    std::cout << "  --version     show version number and exit\n";
}

static void print_version() {
    std::cout << "tagger version 1.0";
    if (commit[0] != '\0') {
        std::cout << ", build " << commit;
    }
    std::cout << std::endl;
}

int main(int argc, char* argv[]) {
    try {
        int opt_char, opt_val;
        struct option long_options[] = {
            {"add", required_argument, nullptr, 'a'},
            {"change", required_argument, nullptr, 'c'},
            {"delete", required_argument, nullptr, 'd'},
            {"help", no_argument, nullptr, 'h'},
            {"into", required_argument, nullptr, 'i'},
            {"list", no_argument, nullptr, 'l'},
            {"sort", no_argument, nullptr, 's'},
            {"version", no_argument, &opt_val, 1},
            {nullptr, 0, nullptr, 0}
        };
        while ((opt_char = getopt_long(argc, argv, "a:c:d:hi:ls", long_options, nullptr)) != -1) {
            std::string arg {optarg ? optarg : ""};
            switch (opt_char) {
                case 0: {
                    // handle long-only options here
                    switch (opt_val) {
                        case 1: print_version(); return EXIT_SUCCESS;
                    }
                    break;
                }
                case 'a': additions.push_back(arg); break;
                case 'c': change = arg; break;
                case 'd': deletions.push_back(arg); break;
                case 'h': print_help(); return EXIT_SUCCESS;
                case 'i': changes.emplace(change, arg); break;
                case 'l': should_list = true; break;
                case 's': sort = true; break;
                case '?': throw std::runtime_error("unrecognized option");
            }
        }
        if (optind == argc) {
            // here when no file args
            throw std::runtime_error {"please specify input files"};
        }
        for (int i = optind; i < argc; ++i) {
            try {
                process(argv[i]);
            } catch (const std::runtime_error& ex) {
                std::cerr << "tagger: " << ex.what() << '\n';
            }
        }
    } catch (const std::exception& ex) {
        std::cerr << "tagger: " << ex.what() << '\n';
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}