#include "../../filesystem.hpp"
#include <cstring>
#include <sys/stat.h>
#include <unistd.h>
#ifdef __APPLE__
#include <sys/syslimits.h>
#endif
#include <stdexcept>
#include <iostream>

char FSLib::dir_divisor = '/';

FSLib::Directory::Directory(const string &path_) : dir_path(path_) {}

FSLib::Directory::Iterator::Iterator(const Directory &d_)
        : d(opendir(d_.path())) {
    if (!exists(d_.path()) || !isDirectory(d_.path())) {
        throw std::runtime_error(std::string("Directory ") + d_.path() +
                                 " either doesn't exist or isn't a directory");
    }

    current_entry = readdir(d);

    // skip "." and ".."
    if (current_entry != nullptr && (!strcmp(current_entry->d_name, ".") ||
                                     !strcmp(current_entry->d_name, "..")))
        ++(*this);
}

FSLib::Directory::Iterator::Iterator(const Directory &d_,
                                     const struct dirent *current_entry_)
        : d(opendir(d_.path())), current_entry(current_entry_) {}

FSLib::Directory::Iterator::~Iterator() {
    if (d)
        closedir(d);
}

bool FSLib::exists(const string &path) {
    struct stat path_stat;
    return stat(path.c_str(), &path_stat) == 0;
}

string FSLib::canonical(const string &path) {
    char_t *canonical_path = new char_t[PATH_MAX];
    auto failed = realpath(path.c_str(), canonical_path) == nullptr;

    if (failed) {
        delete[] canonical_path;
        return string();
    }

    string canonical_string{ canonical_path };
    delete[] canonical_path;
    return canonical_string;
}

bool FSLib::isDirectory(const string &path) {
    struct stat path_stat;

    if (stat(path.c_str(), &path_stat) != 0)
        return false;

    return S_ISDIR(path_stat.st_mode);
}

bool FSLib::rename(const string &file_a, const string &file_b) {
    return ::rename(file_a.c_str(), file_b.c_str()) == 0;
}

// TODO do windows version
bool deleteRecursive(const string &dir) {
    for (const auto &file : FSLib::Directory(dir)) {
        auto path = dir + "/" + file;
        if (FSLib::isDirectory(path)) {
            if (!deleteRecursive(path)) {
                return false;
            }
        } else if (unlink(path.c_str()) != 0) {
            return false;
        }
    }
    return rmdir(dir.c_str()) == 0;
}

bool FSLib::deleteFile(const string &file) {
    // TODO log
    auto canon = canonical(file);
    if (canon.empty()) {
        return false;
    }

    if (isDirectory(canon)) {
        return deleteRecursive(canon);
    }
    return unlink(canon.c_str()) == 0;
}

bool FSLib::createDirectoryFull(const string &path) {
    uint64_t pos{};
    // go through all directories leading to the last one
    // and create them if they don't exist
    do {
        // get partial directory path
        pos = path.find_first_of("/", pos);
        if (pos > 0) {
            auto dirname = path.substr(0, pos);
            // create it if it doesn't exist
            if (!FSLib::exists(dirname)) {
                if (mkdir(dirname.c_str(),
                          S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) != 0)
                    return false;
            }
        }
        pos++;
    } while (pos < path.length() && pos != 0);
    return true;
}

FSLib::Directory::iterator FSLib::Directory::end() {
    return Iterator(*this, nullptr);
}

FSLib::Directory::const_iterator FSLib::Directory::end() const {
    return Iterator(*this, nullptr);
}

char_t const *FSLib::Directory::Iterator::operator*() const {
    return current_entry->d_name;
}

FSLib::Directory::Iterator &FSLib::Directory::Iterator::operator++() {
    if (current_entry == nullptr)
        return *this;
    current_entry = readdir(d);
    // skip . and ..
    if (current_entry != nullptr && (!strcmp(current_entry->d_name, ".") ||
                                     !strcmp(current_entry->d_name, "..")))
        return operator++();
    return *this;
}

bool FSLib::Directory::Iterator::operator==(const Iterator &i_other) const {
    return i_other.current_entry == current_entry;
}

string FSLib::getContainingDirectory(const string &path) {
    auto pos = path.find_last_of('/');
    if (pos == string::npos) {
        return ".";
    }
    return path.substr(0, pos);
}

string FSLib::getFileName(const string &path) {
    auto pos = path.find_last_of('/');
    if (pos == string::npos) {
        return path;
    }
    return path.substr(pos + 1);
}

string FSLib::getFileExtension(const string &path) {
    auto pos = path.find_last_of('.');
    if (pos == string::npos) {
        return "";
    }
    return path.substr(pos + 1);
}