#include <unistd.h>
#include <cstring>
#include <iostream>
#include <sstream>
#include <filesystem>

#include "utils/output.hpp"
#include "utils/assert.hpp"
#include "utils/utils.hpp"
#include "command_registry.hpp"
#include "config.hpp"
#include "services.hpp"
#include "servers.hpp"
#include "server_env_manager.hpp"
#include "templates.hpp"
#include "utils/directories.hpp"
#include "shared_commands.hpp"

namespace dropshell
{

    int backupdata_handler(const CommandContext &ctx);

    static std::vector<std::string> backupdata_name_list = {"backupdata", "bd", "backup", "bup"};

    // Static registration
    struct BackupDataCommandRegister
    {
        BackupDataCommandRegister()
        {
            CommandRegistry::instance().register_command({backupdata_name_list,
                                                          backupdata_handler,
                                                          shared_commands::std_autocomplete_allowall,
                                                          false, // hidden
                                                          true,  // requires_config
                                                          true,  // requires_install
                                                          2,     // min_args (after command)
                                                          2,     // max_args (after command)
                                                          "backupdata SERVER SERVICE",
                                                          "Backup data for a service on a server.",
                                                          // heredoc
                                                          R"(
                backupdata SERVER SERVICE     Backup data for a service on a server.
                backupdata SERVER all         Backup data for all services on a server.

                Note: This command will not create any data or configuration.
                It will simply backup the data on the remote server, saving it to a local file.
                Restore the data with restore.
            )"});
        }
    } backupdata_command_register;

    namespace shared_commands
    {

        bool backupdata_service(const std::string &server, const std::string &service)
        {
            server_env_manager server_env(server);
            if (!server_env.is_valid())
            {
                error << "Server " << server << " is not valid" << std::endl;
                return false;
            }

            LocalServiceInfo sinfo = get_service_info(server, service);
            if (!SIvalid(sinfo))
            {
                error << "Service " << service << " is not valid" << std::endl;
                return false;
            }

            const std::string command = "backup";

            if (!gTemplateManager().template_command_exists(sinfo.template_name, command))
            {
                info << service << " has no data to backup" << std::endl;
                debug << "(no backup script for " << sinfo.template_name << ")" << std::endl;
                return true; // nothing to back up.
            }

            std::string user = server_env.get_user_for_service(server, service);

            // Check if basic installed stuff is in place.
            std::string remote_service_template_path = remotepath(server, user).service_template(service);
            std::string remote_command_script_file = remote_service_template_path + "/" + command + ".sh";
            std::string remote_service_config_path = remotepath(server, user).service_config(service);
            if (!server_env.check_remote_items_exist({remotepath(server, user).service(service),
                                                      remote_command_script_file,
                                                      remotefile(server, user).service_env(service)}, user))
            {
                error << "Error: Required service directories not found on remote server" << std::endl;
                info << "Is the service installed?" << std::endl;
                return false;
            }

            // Create backups directory on server if it doesn't exist
            std::string remote_backups_dir = remotepath(server, user).backups();
            debug << "Remote backups directory on " << server << ": " << remote_backups_dir << std::endl;
            std::string mkdir_cmd = "mkdir -p " + quote(remote_backups_dir);
            if (!execute_ssh_command(server_env.get_SSH_INFO(user), sCommand("", mkdir_cmd, {}), cMode::Defaults))
            {
                error << "Failed to create backups directory on server" << std::endl;
                return false;
            }

            // Create backups directory locally if it doesn't exist
            std::string local_backups_dir = localpath::backups();
            if (local_backups_dir.empty())
            {
                error << "Error: Local backups directory not found" << std::endl;
                info << "Run 'dropshell edit' to configure DropShell" << std::endl;
                return false;
            }
            if (!std::filesystem::exists(local_backups_dir))
                std::filesystem::create_directories(local_backups_dir);

            // Get current datetime for backup filename
            shared_commands::cBackupFileName backup_filename_construction(server, service, sinfo.template_name);
            if (!backup_filename_construction.is_valid())
            {
                error << "Invalid backup filename" << std::endl;
                return false;
            }

            // Construct backup filename
            std::string backup_filename = backup_filename_construction.get_filename();
            std::string remote_backup_file_path = remote_backups_dir + "/" + backup_filename;
            std::string local_backup_file_path = (std::filesystem::path(local_backups_dir) / backup_filename).string();

            // assert that the backup filename is valid - -_- appears exactly 3 times in local_backup_file_path.
            ASSERT(3 == count_substring(magic_string(), local_backup_file_path), "Invalid backup filename");

            { // Run backup script
                shared_commands::cRemoteTempFolder remote_temp_folder(server_env, user);
                if (!server_env.run_remote_template_command(service, command, {}, false, {{"BACKUP_FILE", remote_backup_file_path}, {"TEMP_DIR", remote_temp_folder.path()}}))
                {
                    error << "Backup script failed on remote server: " << remote_backup_file_path << std::endl;
                    return false;
                }

                // Copy backup file from server to local
                if (!shared_commands::scp_file_from_remote(server_env, remote_backup_file_path, local_backup_file_path, false))
                {
                    error << "Failed to copy backup file from server" << std::endl;
                    return false;
                }
            } // dtor of remote_temp_folder will clean up the temp folder on the server

            info << "Backup created successfully. Restore with:" << std::endl;
            info << "   dropshell restore " << server << " " << service << " " << backup_filename << std::endl;
            return true;
        }
    } // namespace shared_commands

    int backupdata_handler(const CommandContext &ctx)
    {
        ASSERT(ctx.args.size() == 2, "Invalid number of arguments");

        std::string server = safearg(ctx.args, 0);
        std::string service = safearg(ctx.args, 1);

        if (service == "all")
        {
            // backup all services on the server
            maketitle("Backing up data for all services on " + server);
            bool okay = true;
            std::vector<LocalServiceInfo> services = get_server_services_info(server);
            for (const LocalServiceInfo &si : services)
                okay &= shared_commands::backupdata_service(server, si.service_name);
            return okay ? 0 : 1;
        }

        return shared_commands::backupdata_service(server, service) ? 0 : 1;
    }

} // namespace dropshell