/*
 * 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 "config.h"
#include <filesystem>
#include <cstdint>
#include <stdlib.h>
#include <iostream>
#include <zlib.h>
#include <curl/curl.h>
#include <sqlite3.h>
#include <forward_list>
#include <array>
#include <string>
#include <list>
#include <boost/filesystem.hpp>
#include <boost/algorithm/string.hpp>
#include <regex>

export module katja.job;

import katja.utils;
import katja.pkgtools;
import katja.slackpkg;

namespace katja
{
static std::forward_list<std::unique_ptr<Pkgtools>> repos;

void pk_backend_initialize()
{
    int ret;
    std::uint8_t i;
    sqlite3 *db;
    sqlite3_stmt *stmt;

    curl_global_init(CURL_GLOBAL_DEFAULT);

    /* Open the database. We will need it to save the time the configuration file was last modified. */
    auto path = std::filesystem::path(LOCALSTATEDIR) / "cache" / "katja" / "metadata.db";
    if (sqlite3_open(path.c_str(), &db) != SQLITE_OK)
    {
        std::cerr << path.native() << ": " << sqlite3_errmsg(db) << std::endl;
    }

    std::chrono::time_point<std::chrono::file_clock> file_info = std::filesystem::last_write_time(path);
    auto microseconds = std::chrono::duration_cast<std::chrono::microseconds>(file_info.time_since_epoch());

    if ((ret = sqlite3_prepare_v2(db,
                    "UPDATE cache_info SET value = ? WHERE key LIKE 'last_modification'",
                    -1,
                    &stmt,
                    nullptr)) == SQLITE_OK) {
        ret = sqlite3_bind_int(stmt, 1, microseconds.count());
        if (ret == SQLITE_OK)
        {
            ret = sqlite3_step(stmt);
        }
        sqlite3_finalize(stmt);
    }
    if ((ret != SQLITE_OK) && (ret != SQLITE_DONE))
    {
        std::cerr << path.native() << ": " << sqlite3_errstr(ret) << std::endl;
    }
    else if (!sqlite3_changes(db))
    {
        std::cerr << "Failed to update database: " << path.native() << std::endl;
    }
    sqlite3_close_v2(db);
}

void pk_backend_destroy()
{
    repos.clear();
    curl_global_cleanup();
}

JobData *pk_backend_start_job()
{
    JobData *job_data = new DummyJobData();
    auto db_filename = std::filesystem::path(LOCALSTATEDIR) / "cache" / "katja" / "metadata.db";

    if (sqlite3_open(db_filename.native().c_str(), &job_data->db) == SQLITE_OK) { /* Some SQLite settings */
        sqlite3_exec(job_data->db, "PRAGMA foreign_keys = ON", nullptr, nullptr, nullptr);
    }
    else
    {
        std::cerr << db_filename << ": " << sqlite3_errmsg(job_data->db) << std::endl;
    }
    return job_data;
}

void pk_backend_stop_job(JobData *job_data)
{
    if (job_data->curl)
    {
        curl_easy_cleanup(job_data->curl);
    }

    sqlite3_close(job_data->db);
    delete job_data;
}

// for filters -1 means requesting not installed, 1 - installed, 0 - no filters.
void pk_backend_search_thread(JobData *job_data, std::uint64_t filters, const std::vector<std::string>& vals,
        const char *user_data)
{
    std::string search = boost::algorithm::join(vals, "%");
    const char *generate_query = "SELECT (p1.name || ';' || p1.ver || ';' || p1.arch || ';' || r.repo), p1.summary, "
            "p1.full_name FROM pkglist AS p1 NATURAL JOIN repos AS r "
            "WHERE p1.%s LIKE '%%%q%%' AND p1.ext NOT LIKE 'obsolete' AND p1.repo_order = "
            "(SELECT MIN(p2.repo_order) FROM pkglist AS p2 WHERE p2.name = p1.name GROUP BY p2.name)";
    char *query = sqlite3_mprintf(generate_query, user_data, search.c_str());

    sqlite3_stmt *stmt;
    if ((sqlite3_prepare_v2(job_data->db, query, -1, &stmt, nullptr) == SQLITE_OK))
    {
        /* Now we're ready to output all packages */
        while (sqlite3_step(stmt) == SQLITE_ROW)
        {
            katja::Info info = katja::is_installed(
                    reinterpret_cast<const char *>(sqlite3_column_text(stmt, 2)));

            if ((info == katja::Info::installed || info == katja::Info::updating)
                    && filters != -1)
            {
                job_data->package(katja::Info::installed,
                        reinterpret_cast<const char *>(sqlite3_column_text(stmt, 0)),
                        reinterpret_cast<const char *>(sqlite3_column_text(stmt, 1)));
            }
            else if (info == katja::Info::installing && filters != 1)
            {
                job_data->package(katja::Info::available,
                        reinterpret_cast<const char *>(sqlite3_column_text(stmt, 0)),
                        reinterpret_cast<const char *>(sqlite3_column_text(stmt, 1)));
            }
        }
        sqlite3_finalize(stmt);
    }
    else
    {
        std::cerr << sqlite3_errmsg(job_data->db) << std::endl;
    }
    sqlite3_free(query);
}

void pk_backend_search_files(JobData *job_data, const std::vector<std::string>& values)
{
    char *query;
    sqlite3_stmt *stmt;
    Info ret;

    std::string search = boost::algorithm::join(values, "%");

    query = sqlite3_mprintf("SELECT (p.name || ';' || p.ver || ';' || p.arch || ';' || r.repo), p.summary, "
                            "p.full_name FROM filelist AS f NATURAL JOIN pkglist AS p NATURAL JOIN repos AS r "
                            "WHERE f.filename LIKE '%%%q%%' GROUP BY f.full_name", search.c_str());

    if ((sqlite3_prepare_v2(job_data->db, query, -1, &stmt, nullptr) == SQLITE_OK))
    {
        /* Now we're ready to output all packages */
        while (sqlite3_step(stmt) == SQLITE_ROW)
        {
            ret = is_installed((char*) sqlite3_column_text(stmt, 2));
            if ((ret == Info::installed) || (ret == Info::updating))
            {
                job_data->package(katja::Info::installed,
                        (char*) sqlite3_column_text(stmt, 0),
                        (char*) sqlite3_column_text(stmt, 1));
            }
            else if (ret == katja::Info::installing)
            {
                job_data->package(katja::Info::available,
                        (char*) sqlite3_column_text(stmt, 0),
                        (char*) sqlite3_column_text(stmt, 1));
            }
        }
        sqlite3_finalize(stmt);
    }
    else
    {
        std::cerr << sqlite3_errmsg(job_data->db) << std::endl;
    }
    sqlite3_free(query);
}

void pk_backend_get_details(JobData *job_data, char **package_ids)
{
    std::optional<std::string> homepage;
    std::size_t i;
    std::regex expr;
    std::smatch match_info;
    sqlite3_stmt *stmt;
    std::string desc;

    std::vector<std::string> tokens;
    boost::split(tokens, package_ids[i], boost::is_any_of(";"));

    if ((sqlite3_prepare_v2(job_data->db,
                            "SELECT p.desc, p.cat, p.uncompressed FROM pkglist AS p NATURAL JOIN repos AS r "
                            "WHERE name LIKE @name AND r.repo LIKE @repo",
                            -1,
                            &stmt,
                            nullptr) != SQLITE_OK)) {
        std::cerr << sqlite3_errmsg(job_data->db) << std::endl;
        goto out;
    }
    sqlite3_bind_text(stmt, 1, tokens[0].c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(stmt, 2, tokens[3].c_str(), -1, SQLITE_TRANSIENT);

    if (sqlite3_step(stmt) != SQLITE_ROW)
    {
        goto out;
    }
    desc = reinterpret_cast<const char *>(sqlite3_column_text(stmt, 0));

    /* Regular expression for searching a homepage */
    expr = std::regex("(?:http|ftp):\\/\\/[[:word:]\\/\\-\\.]+[[:word:]\\/](?=\\.?$)",
            std::regex::optimize);

    if (std::regex_match(std::cbegin(desc), std::cend(desc), match_info, expr))
    {
        homepage = match_info[0]; /* URL */
        /* Remove the last sentence with the copied URL */
        for (i = desc.size() - 1; i > 0; i--)
        {
            if ((desc[i - 1] == '.') && (desc[i] == ' '))
            {
                desc.erase(std::cbegin(desc) + i);
                break;
            }
        }
    }

    /* Ready */
    job_data->details(package_ids[0],
            (char *) sqlite3_column_text(stmt, 1),
            desc.c_str(),
            homepage.has_value() ? homepage.value().c_str() : nullptr,
            sqlite3_column_int(stmt, 2));

out:
    sqlite3_finalize(stmt);
}

void pk_backend_resolve(JobData *job_data, char **packages)
{
    char **val;
    sqlite3_stmt *stmt;

    if ((sqlite3_prepare_v2(job_data->db,
                            "SELECT (p1.name || ';' || p1.ver || ';' || p1.arch || ';' || r.repo), p1.summary, "
                               "p1.full_name FROM pkglist AS p1 NATURAL JOIN repos AS r "
                            "WHERE p1.name LIKE @search AND p1.repo_order = "
                            "(SELECT MIN(p2.repo_order) FROM pkglist AS p2 WHERE p2.name = p1.name GROUP BY p2.name)",
                            -1,
                            &stmt,
                            nullptr) == SQLITE_OK)) {
        /* Output packages matching each pattern */
        for (val = packages; *val; val++)
        {
            sqlite3_bind_text(stmt, 1, *val, -1, SQLITE_TRANSIENT);

            while (sqlite3_step(stmt) == SQLITE_ROW)
            {
                job_data->package(katja::Info::available,
                        (char *) sqlite3_column_text(stmt, 0),
                        (char *) sqlite3_column_text(stmt, 1));
            }

            sqlite3_clear_bindings(stmt);
            sqlite3_reset(stmt);
        }
        sqlite3_finalize(stmt);
    }
    else
    {
        std::cerr << sqlite3_errmsg(job_data->db) << std::endl;
    }
}

void pk_backend_download_packages(JobData *job_data, char **package_ids, const char *directory)
{
    unsigned i;
    sqlite3_stmt *stmt;

    if ((sqlite3_prepare_v2(job_data->db,
                            "SELECT summary, (full_name || '.' || ext) FROM pkglist NATURAL JOIN repos "
                            "WHERE name LIKE @name AND ver LIKE @ver AND arch LIKE @arch AND repo LIKE @repo",
                            -1,
                            &stmt,
                            nullptr) != SQLITE_OK))
    {
        std::cerr << sqlite3_errmsg(job_data->db) << std::endl;
        goto out;
    }

    for (i = 0; package_ids[i]; ++i)
    {
        std::vector<std::string> tokens;
        boost::split(tokens, package_ids[i], boost::is_any_of(";"));

        sqlite3_bind_text(stmt, 1, tokens[0].c_str(), -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(stmt, 2, tokens[1].c_str(), -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(stmt, 3, tokens[2].c_str(), -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(stmt, 4, tokens[3].c_str(), -1, SQLITE_TRANSIENT);
        if (sqlite3_step(stmt) == SQLITE_ROW)
        {
            auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3].c_str());
            if (repo != std::end(repos))
            {
                (*repo)->download(job_data, directory, tokens[0].c_str());
                auto path = std::filesystem::path(directory)
                    / reinterpret_cast<const char *>(sqlite3_column_text(stmt, 1));
                std::vector<std::string> to_strv{ path };
                job_data->files(to_strv);
            }
        }
        sqlite3_clear_bindings(stmt);
        sqlite3_reset(stmt);
    }

out:
    sqlite3_finalize(stmt);
}

void pk_backend_install_packages(JobData *job_data, const std::vector<std::string> package_ids)
{
    unsigned i;
    double percent_step;
    std::list<std::string> install_list;
    sqlite3_stmt *pkglist_stmt = nullptr, *collection_stmt = nullptr;

    if ((sqlite3_prepare_v2(job_data->db,
                            "SELECT summary, cat FROM pkglist NATURAL JOIN repos "
                            "WHERE name LIKE @name AND ver LIKE @ver AND arch LIKE @arch AND repo LIKE @repo",
                            -1,
                            &pkglist_stmt,
                            nullptr) != SQLITE_OK) ||
        (sqlite3_prepare_v2(job_data->db,
                           "SELECT (c.collection_pkg || ';' || p.ver || ';' || p.arch || ';' || r.repo), p.summary, "
                           "p.full_name, p.ext FROM collections AS c "
                           "JOIN pkglist AS p ON c.collection_pkg = p.name "
                           "JOIN repos AS r ON p.repo_order = r.repo_order "
                           "WHERE c.name LIKE @name AND r.repo LIKE @repo",
                           -1,
                           &collection_stmt,
                           nullptr) != SQLITE_OK))
    {
        std::cerr << sqlite3_errmsg(job_data->db) << std::endl;
        goto out;
    }

    for (const std::string& package_id : package_ids)
    {
        std::vector<std::string> tokens;
        boost::split(tokens, package_id, boost::is_any_of(";"));

        sqlite3_bind_text(pkglist_stmt, 1, tokens[0].c_str(), -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(pkglist_stmt, 2, tokens[1].c_str(), -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(pkglist_stmt, 3, tokens[2].c_str(), -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(pkglist_stmt, 4, tokens[3].c_str(), -1, SQLITE_TRANSIENT);

        if (sqlite3_step(pkglist_stmt) == SQLITE_ROW)
        {
            /* If it isn't a collection */
            if (strcmp(reinterpret_cast<const char *>(sqlite3_column_text(pkglist_stmt, 1)), "collections"))
            {
                install_list.push_back(package_id);
            }
            else
            {
                sqlite3_bind_text(collection_stmt, 1, tokens[0].c_str(), -1, SQLITE_TRANSIENT);
                sqlite3_bind_text(collection_stmt, 2, tokens[3].c_str(), -1, SQLITE_TRANSIENT);

                while (sqlite3_step(collection_stmt) == SQLITE_ROW)
                {
                    katja::Info ret = is_installed((char*) sqlite3_column_text(collection_stmt, 2));
                    if ((ret == Info::installing) || (ret == Info::updating))
                    {
                        install_list.push_back(
                                reinterpret_cast<const char *>(sqlite3_column_text(collection_stmt, 0)));
                    }
                }
                sqlite3_clear_bindings(collection_stmt);
                sqlite3_reset(collection_stmt);
            }
        }

        sqlite3_clear_bindings(pkglist_stmt);
        sqlite3_reset(pkglist_stmt);
    }

    if (!install_list.empty())
    {
        /* / 2 means total percentage for installing and for downloading */
        percent_step = 100.0 / install_list.size() / 2;

        /* Download the packages */
        auto dest_dir_name = std::filesystem::path(LOCALSTATEDIR) / "cache" / "katja" / "downloads";
        for (const auto& l : install_list)
        {
            job_data->set_percentage(percent_step * i);
            std::vector<std::string> tokens;
            boost::split(tokens, l, boost::is_any_of(";"));

            auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3].c_str());

            if (repo != std::end(repos))
            {
                (*repo)->download(job_data, dest_dir_name.native().c_str(), tokens[0].c_str());
            }
        }

        /* Install the packages */
        for (const auto& l : install_list)
        {
            job_data->set_percentage(percent_step * i);
            std::vector<std::string> tokens;
            boost::split(tokens, l, boost::is_any_of(";"));

            auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3].c_str());

            if (repo != std::end(repos))
            {
                (*repo)->install(job_data, tokens[0].c_str());
            }
        }
    }

out:
    sqlite3_finalize(pkglist_stmt);
    sqlite3_finalize(collection_stmt);
}

void pk_backend_remove_packages(JobData* job_data, const std::vector<std::string>& package_ids)
{
    unsigned i;
    double percent_step;
 
    /* Add percent_step percents per removed package */
    percent_step = 100.0 / package_ids.size();
    for (i = 0; i < package_ids[i].size(); i++)
    {
        job_data->set_percentage(percent_step * i);
        std::vector<std::string> tokens;
        boost::split(tokens, package_ids[i], boost::is_any_of(";"));

        std::string cmd_line = "/sbin/removepkg " + tokens[0];

        /* Pkgtools return always 0 */
        system(cmd_line.c_str());

        job_data->set_percentage(100);
    }
}

void pk_backend_get_updates(JobData *job_data)
{
    std::filesystem::path pkg_metadata_filename;
    std::filesystem::path pkg_metadata_dir;
    sqlite3_stmt *stmt;

    if ((sqlite3_prepare_v2(job_data->db,
                            "SELECT p1.full_name, p1.name, p1.ver, p1.arch, r.repo, p1.summary, p1.ext "
                            "FROM pkglist AS p1 NATURAL JOIN repos AS r "
                            "WHERE p1.name LIKE @name AND p1.repo_order = "
                            "(SELECT MIN(p2.repo_order) FROM pkglist AS p2 WHERE p2.name = p1.name GROUP BY p2.name)",
                            -1,
                            &stmt,
                            nullptr) != SQLITE_OK))
    {
        std::cerr << sqlite3_errmsg(job_data->db) << std::endl;
        goto out;
    }

    /* Read the package metadata directory and comprare all installed packages with ones in the cache */
    pkg_metadata_dir = std::filesystem::path("/var/log/packages");
    for (const auto& pkg_metadata_file_info : std::filesystem::directory_iterator{ pkg_metadata_dir })
    {
        pkg_metadata_filename = pkg_metadata_file_info.path();
        std::vector<std::string> tokens = split_package_name(pkg_metadata_filename).value();

        /* Select the package from the database */
        sqlite3_bind_text(stmt, 1, tokens[0].c_str(), -1, SQLITE_TRANSIENT);

        /* If there are more packages with the same name, remember the one from the
         * repository with the lowest order. */
        if ((sqlite3_step(stmt) == SQLITE_ROW)
         || cmp_repo(std::begin(repos), std::end(repos), (const char *) sqlite3_column_text(stmt, 4)) != std::end(repos))
        {
            std::string full_name{ reinterpret_cast<const char *>(sqlite3_column_text(stmt, 0)) };

            if (full_name != pkg_metadata_filename)
            { /* Update available */
                std::array<std::string, 4> id_parts{
                    reinterpret_cast<const char *>(sqlite3_column_text(stmt, 1)),
                    reinterpret_cast<const char *>(sqlite3_column_text(stmt, 2)),
                    reinterpret_cast<const char *>(sqlite3_column_text(stmt, 3)),
                    reinterpret_cast<const char *>(sqlite3_column_text(stmt, 4))
                };
                std::string pkg_id = boost::algorithm::join(id_parts, ";");
                std::string desc{ reinterpret_cast<const char *>(sqlite3_column_text(stmt, 5)) };

                job_data->package(katja::Info::updating, pkg_id.c_str(), desc.c_str());
            }
        }

        sqlite3_clear_bindings(stmt);
        sqlite3_reset(stmt);
    }

out:
    sqlite3_finalize(stmt);
}

void pk_backend_update_packages(JobData *job_data, char **package_ids)
{
    char *cmd_line;
    unsigned i;

    /* Download the packages */
    auto dest_dir_name = std::filesystem::path(LOCALSTATEDIR) / "cache" / "katja" / "downloads";
    for (i = 0; package_ids[i]; i++)
    {
        std::vector<std::string> tokens;
        boost::split(tokens, package_ids[i], boost::is_any_of(";"));
        auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3].c_str());

        if (repo != std::end(repos))
        {
            (*repo)->download(job_data, dest_dir_name.c_str(), tokens[0].c_str());
        }
    }

    /* Install the packages */
    for (i = 0; package_ids[i]; i++)
    {
        std::vector<std::string> tokens;
        boost::split(tokens, package_ids[i], boost::is_any_of(";"));
        auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3].c_str());

        if (repo != std::end(repos))
        {
            (*repo)->install(job_data, tokens[0].c_str());
        }
    }
}

void pk_backend_refresh_cache(JobData *job_data, bool force)
{
    char *db_err;
    int ret;
    std::forward_list<katja::cache_entry> file_list;
    sqlite3_stmt *stmt = nullptr;

    /* Create temporary directory */
    std::filesystem::path tmp_dir_name =
        std::filesystem::temp_directory_path() / boost::filesystem::unique_path("katja.%%%%%%").native();
    std::filesystem::create_directories(tmp_dir_name);

    /* Force the complete cache refresh if the read configuration file is newer than the metadata cache */
    if (!force)
    {
        auto path = std::filesystem::path(LOCALSTATEDIR) / "cache" / "katja" / "metadata.db";
        std::chrono::time_point<std::chrono::file_clock> file_info = std::filesystem::last_write_time(path);
        auto microseconds = std::chrono::duration_cast<std::chrono::microseconds>(file_info.time_since_epoch());
        ret = sqlite3_prepare_v2(job_data->db,
                                 "SELECT value FROM cache_info WHERE key LIKE 'last_modification'",
                                 -1,
                                 &stmt,
                                 nullptr);
        if ((ret != SQLITE_OK) || ((ret = sqlite3_step(stmt)) != SQLITE_ROW))
        {
            std::cerr << path << ": " << sqlite3_errstr(ret) << std::endl;
            goto out;
        }
        if ((std::uint32_t) sqlite3_column_int(stmt, 0) > microseconds.count())
        {
            force = true;
        }
    }
    if (force) /* It should empty all tables */
    {
        if (sqlite3_exec(job_data->db, "DELETE FROM repos", nullptr, 0, &db_err) != SQLITE_OK)
        {
            std::cerr << db_err << std::endl;
            sqlite3_free(db_err);
            goto out;
        }
    }

    // Get list of files that should be downloaded.
    for (auto& l : repos)
    {
        file_list.prepend_range(l->collect_cache_info(tmp_dir_name));
    }

    /* Download repository */
    for (auto& l : file_list)
    {
        get_file(&job_data->curl, l.first.c_str(), l.second);
    }

    /* Refresh cache */
    for (auto& l : repos)
    {
        l->generate_cache(job_data, tmp_dir_name);
    }

out:
    sqlite3_finalize(stmt);
    std::filesystem::remove_all(tmp_dir_name);
}
}