/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */
module;

#include <cstdint>
#include <sqlite3.h>
#include <string.h>
#include <gio/gio.h>
#include <curl/curl.h>
#include <sqlite3.h>

export module katja.utils;

export namespace katja
{
enum class Info
{
    // Error.
    unknown,
    // Installed in the same version.
    installed,
    // A different version is installed.
    updating,
    // Available, but not installed.
    installing,
    // Available.
    available
};

struct JobData
{
    sqlite3 *db;
    CURL *curl;

    virtual void package(Info info, const char *package_id, const char *summary) = 0;
    virtual void files(char **) = 0;
    virtual void details(char *package_id,
            const char *group, const char *description, const char *homepage, int uncompressed) = 0;
    virtual void set_percentage(double) = 0;
};

/**
 * katja::get_file:
 * @curl: curl easy handle.
 * @source_url: source url.
 * @dest: destination.
 *
 * Download the file.
 *
 * Returns: CURLE_OK (zero) on success, non-zero otherwise.
 **/
CURLcode get_file(CURL **curl, char *source_url, char *dest)
{
    char *dest_dir_name;
    FILE *fout = nullptr;
    CURLcode ret;
    glong response_code;

    if ((*curl == nullptr) && (!(*curl = curl_easy_init())))
    {
        return CURLE_BAD_FUNCTION_ARGUMENT;
    }

    curl_easy_setopt(*curl, CURLOPT_FOLLOWLOCATION, 1L);
    curl_easy_setopt(*curl, CURLOPT_URL, source_url);

    if (dest == nullptr)
    {
        curl_easy_setopt(*curl, CURLOPT_NOBODY, 1L);
        curl_easy_setopt(*curl, CURLOPT_HEADER, 1L);
        ret = curl_easy_perform(*curl);
        curl_easy_getinfo(*curl, CURLINFO_RESPONSE_CODE, &response_code);

        if (response_code != 200)
        {
            ret = CURLE_REMOTE_FILE_NOT_FOUND;
        }
    }
    else
    {
        if (g_file_test(dest, G_FILE_TEST_IS_DIR))
        {
            dest_dir_name = dest;
            dest = g_strconcat(dest_dir_name, g_strrstr(source_url, "/"), nullptr);
            g_free(dest_dir_name);
        }
        if ((fout = fopen(dest, "ab")) == nullptr)
        {
            return CURLE_WRITE_ERROR;
        }
        curl_easy_setopt(*curl, CURLOPT_WRITEDATA, fout);
        ret = curl_easy_perform(*curl);
    }
    curl_easy_reset(*curl);
    if (fout != nullptr)
    {
        fclose(fout);
    }
    return ret;
}

/**
 * katja::split_package_name:
 * Got the name of a package, without version-arch-release data.
 **/
char **split_package_name(const char *pkg_filename)
{
    char *pkg_full_name;
    char **pkg_tokens;

    g_return_val_if_fail(pkg_filename != nullptr, nullptr);

    int len = strlen(pkg_filename);
    if (len < 4)
    {
        return nullptr;
    }

    if (pkg_filename[len - 4] == '.')
    {
        pkg_tokens = static_cast<char **>(g_malloc_n (6, sizeof (char *)));

        /* Full name without extension */
        len -= 4;
        pkg_full_name = g_strndup(pkg_filename, len);
        pkg_tokens[3] = g_strdup(pkg_full_name);

        /* The last 3 characters should be the file extension */
        pkg_tokens[4] = g_strdup(pkg_filename + len + 1);
        pkg_tokens[5] = nullptr;
    }
    else
    {
        pkg_tokens = static_cast<char **>(g_malloc_n (4, sizeof (char *)));
        pkg_full_name = g_strdup(pkg_filename);
        pkg_tokens[3] = nullptr;
    }

    /* Reverse all of the bytes in the package filename to get the name, version and the architecture */
    g_strreverse (pkg_full_name);
    char **reversed_tokens = g_strsplit(pkg_full_name, "-", 4);
    pkg_tokens[0] = g_strreverse(reversed_tokens[3]); /* Name */
    pkg_tokens[1] = g_strreverse(reversed_tokens[2]); /* Version */
    pkg_tokens[2] = g_strreverse(reversed_tokens[1]); /* Architecture */

    g_free(reversed_tokens[0]); /* Build number */
    g_free(reversed_tokens);
    g_free(pkg_full_name);

    return pkg_tokens;
}

/**
 * katja::is_installed:
 * Checks if a package is already installed in the system.
 *
 * @pkg_fullname: Package name should be looked for.
 *
 * Returns: Package installation information.
 **/
Info is_installed(const char *pkg_fullname)
{
    GFileEnumerator *pkg_metadata_enumerator;
    GFileInfo *pkg_metadata_file_info;
    GFile *pkg_metadata_dir;
    Info ret = Info::installing;
    const char *it;
    std::uint8_t dashes = 0;
    ptrdiff_t pkg_name;

    g_return_val_if_fail(pkg_fullname != nullptr, Info::unknown);

    // We want to find the package name without version for the package we're
    // looking for.
    g_debug("Looking if %s is installed", pkg_fullname);

    for (it = pkg_fullname + strlen(pkg_fullname); it != pkg_fullname; --it)
    {
        if (*it == '-')
        {
            if (dashes == 2)
            {
                break;
            }
            ++dashes;
        }
    }
    if (dashes < 2)
    {
        return Info::unknown;
    }
    pkg_name = it - pkg_fullname;

    // Read the package metadata directory and comprare all installed packages
    // with ones in the cache.
    pkg_metadata_dir = g_file_new_for_path("/var/log/packages");
    if (!(pkg_metadata_enumerator = g_file_enumerate_children(pkg_metadata_dir,
                                                              "standard::name",
                                                              G_FILE_QUERY_INFO_NONE,
                                                              nullptr,
                                                              nullptr)))
    {
        g_object_unref(pkg_metadata_dir);
        return Info::unknown;
    }

    while ((pkg_metadata_file_info = g_file_enumerator_next_file(pkg_metadata_enumerator, nullptr, nullptr)))
    {
        const char *dir = g_file_info_get_name(pkg_metadata_file_info);
        dashes = 0;

        if (strcmp(dir, pkg_fullname) == 0)
        {
            ret = Info::installed;
        }
        else
        {
            for (it = dir + strlen(dir); it != dir; --it)
            {
                if (*it == '-')
                {
                    if (dashes == 2)
                    {
                        break;
                    }
                    ++dashes;
                }
            }
            if (pkg_name == (it - dir) && strncmp(pkg_fullname, dir, pkg_name) == 0)
            {
                ret = Info::updating;
            }
        }
        g_object_unref(pkg_metadata_file_info);

        if (ret != Info::installing) /* If installed */
        {
            break;
        }
    }
    g_object_unref(pkg_metadata_enumerator);
    g_object_unref(pkg_metadata_dir);

    return ret;
}

}