#include <iostream>
#include <fstream>
#include <sstream>
#include <cstdlib>
#include <chrono>
#include <iomanip>
#include <filesystem>
#include <unistd.h>
#include "utils/assert.hpp"

#include "config.hpp"
#include "service_runner.hpp"
#include "server_env_manager.hpp"
#include "templates.hpp"
#include "services.hpp"
#include "utils/directories.hpp"
#include "utils/utils.hpp"
#include "command_registry.hpp"
#include "shared_commands.hpp"

namespace fs = std::filesystem;

namespace dropshell {

static const std::string magic_string = "-_-";

service_runner::service_runner(const std::string& server_name, const std::string& service_name) : 
    mServerEnv(server_name), mServer(server_name), mService(service_name), mValid(false)
{
    if (server_name.empty() || service_name.empty())
        return; 

    // Initialize server environment
    if (!mServerEnv.is_valid()) 
        return;

    mServiceInfo = get_service_info(server_name, service_name);
    if (mServiceInfo.service_name.empty())
        return;

    mService = mServiceInfo.service_name;
    
    mValid = !mServiceInfo.local_template_path.empty();
}



bool service_runner::nuke(bool silent)
{
    maketitle("Nuking " + mService + " (" + mServiceInfo.template_name + ") on " + mServer);

    if (!mServerEnv.is_valid()) return false; // should never hit this.

    std::string remote_service_path = remotepath::service(mServer, mService);
    bool okay = mServerEnv.run_remote_template_command("dropshell-agent", "_nuke_other", {mService, remote_service_path}, silent, {});
    if (!okay)
    {
        std::cerr << "Warning: Nuke script failed" << std::endl;
        return false;
    }

    std::cout << "Service " << mService << " successfully nuked from " << mServer << std::endl;

    if (!silent) {
        std::cout << "There's nothing left on the remote server." << std::endl;
        std::cout << "You can remove the local files with:" << std::endl;
        std::cout << "   rm -rf " << localpath::service(mServer,mService) << std::endl;
    }
    return true;
}

bool service_runner::fullnuke()
{
    if (!nuke(true))
    {
        std::cerr << "Warning: Nuke script failed, aborting fullnuke!" << std::endl;
        return false;
    }

    std::string local_service_path = mServiceInfo.local_service_path;
    if (local_service_path.empty() || !fs::exists(local_service_path)) {
        std::cerr << "Error: Service directory not found: " << local_service_path << std::endl;
        return false;
    }  
    
    std::string rm_cmd = "rm -rf " + quote(local_service_path);
    if (!execute_local_command(rm_cmd, nullptr, cMode::Silent)) {
        std::cerr << "Failed to remove service directory" << std::endl;
        return false;
    }
    
    return true;
}


// ------------------------------------------------------------------------------------------------
// Run a command on the service.
// ------------------------------------------------------------------------------------------------
bool service_runner::run_command(const std::string& command, std::vector<std::string> additional_args, std::map<std::string, std::string> env_vars) {
    if (!mServerEnv.is_valid()) {
        std::cerr << "Error: Server service not initialized" << std::endl;
        return false;
    }
    template_info tinfo = gTemplateManager().get_template_info(mServiceInfo.template_name);
    if (!tinfo.is_set()) {
        std::cerr << "Error: Template '" << mServiceInfo.template_name << "' not found" << std::endl;
        return false;
    }

    if (command == "fullnuke") 
        return fullnuke();

    if (command == "nuke") 
    {
        std::cout << "Nuking " << mService << " (" << mServiceInfo.template_name << ") on " << mServer << std::endl;
        return nuke();
    }

    if (!gTemplateManager().template_command_exists(mServiceInfo.template_name, command)) {
        std::cout << "No command script for " << mServiceInfo.template_name << " : " << command << std::endl;
        return true; // nothing to run.
    }

    // install doesn't require anything on the server yet.
    if (command == "install") 
        return install_service(mServer, mService, false);

    std::string script_path = remotepath::service_template(mServer, mService) + "/" + command + ".sh";
    
    // Check if service directory exists
    if (!mServerEnv.check_remote_dir_exists(remotepath::service(mServer, mService))) {
        std::cerr << "Error: Service is not installed: " << mService << std::endl;
        return false;
    }
    
    // Check if command script exists
    if (!mServerEnv.check_remote_file_exists(script_path)) {
        std::cerr << "Error: Remote command script not found: " << script_path << std::endl;
        return false;
    }

    // Check if env file exists
    if (!mServerEnv.check_remote_file_exists(remotefile::service_env(mServer, mService))) {
        std::cerr << "Error: Service config file not found: " << remotefile::service_env(mServer, mService) << std::endl;
        return false;
    }

    // if (command == "uninstall") 
    //     return uninstall();

    if (command == "ssh") {
        interactive_ssh_service();
        return true;
    }
    if (command == "restore") {
        if (additional_args.size() < 1) {
            std::cerr << "Error: restore requires a backup file:" << std::endl;
            std::cerr << "dropshell restore <server> <service> <backup-file>" << std::endl;
            return false;
        }
        return restore(additional_args[0], false);
    }
    if (command == "backup") {
        return backup(false);
    }

    // Run the generic command
    std::vector<std::string> args; // not passed through yet.
    return mServerEnv.run_remote_template_command(mService, command, args, false, env_vars);
}


std::map<std::string, ServiceStatus> service_runner::get_all_services_status(std::string server_name)
{
    std::map<std::string, ServiceStatus> status;

    std::string command = "_allservicesstatus";
    std::string service_name = "dropshell-agent";

    if (!gTemplateManager().template_command_exists(service_name, "shared/"+command))
        {
            std::cerr << "Error: " << service_name << " does not contain the " << command << " script" << std::endl;
            return status;
        }

    server_env_manager env(server_name);
    if (!env.is_valid()) {
        std::cerr << "Error: Invalid server environment" << std::endl;
        return status;
    }

    std::string output;
    if (!env.run_remote_template_command_and_capture_output(service_name, "shared/"+command, {}, output, true, {}))
        return status;

    std::stringstream ss(output);
    std::string line;
    while (std::getline(ss, line)) {
        std::string key, value;
        std::size_t pos = line.find("=");
        if (pos != std::string::npos) {
            key = dequote(trim(line.substr(0, pos)));
            value = dequote(trim(line.substr(pos + 1)));

            // decode key, it's of format SERVICENAME_[HEALTH|PORTS]
            std::string service_name = key.substr(0, key.find_last_of("_"));
            std::string status_type = key.substr(key.find_last_of("_") + 1);

            if (status_type == "HEALTH") { // healthy|unhealthy|unknown
                if (value == "healthy")
                    status[service_name].health = HealthStatus::HEALTHY;
                else if (value == "unhealthy")
                    status[service_name].health = HealthStatus::UNHEALTHY;
                else if (value == "unknown")
                    status[service_name].health = HealthStatus::UNKNOWN;
                else
                    status[service_name].health = HealthStatus::ERROR;
            } else if (status_type == "PORTS") { // port1,port2,port3
                std::vector<std::string> ports = string2multi(value);
                for (const auto& port : ports) {
                    if (port!="unknown")
                        status[service_name].ports.push_back(str2int(port));
                }
            }
        }
    }
    return status;
}


bool service_runner::interactive_ssh(const std::string & server_name, const std::string & command) {
    std::string serverpath = localpath::server(server_name);
    if (serverpath.empty()) {
        std::cerr << "Error: Server not found: " << server_name << std::endl;
        return false;
    }
    
    server_env_manager env(server_name);
    if (!env.is_valid()) {
        std::cerr << "Error: Invalid server environment file: " << server_name << std::endl;
        return false;
    }
    sCommand scommand("", "bash",{});
    return execute_ssh_command(env.get_SSH_INFO(), scommand, cMode::Interactive);
}



bool service_runner::interactive_ssh_service()
{
    std::set<std::string> used_commands = get_used_commands(mServer, mService);
    if (used_commands.find("ssh") == used_commands.end()) {
        std::cerr << "Error: "<< mService <<" does not support ssh" << std::endl;
        return false;
    }

    std::vector<std::string> args; // not passed through yet.
    return mServerEnv.run_remote_template_command(mService, "ssh", args, false, {});
}

bool service_runner::scp_file_to_remote(const std::string &local_path, const std::string &remote_path, bool silent)
{
    std::string scp_cmd = "scp -P " + mServerEnv.get_SSH_PORT() + " " + quote(local_path) + " " + mServerEnv.get_SSH_USER() + "@" + mServerEnv.get_SSH_HOST() + ":" + quote(remote_path) + (silent ? " > /dev/null 2>&1" : "");
    return execute_local_command(scp_cmd, nullptr, (silent ? cMode::Silent : cMode::Defaults));
}

bool service_runner::scp_file_from_remote(const std::string &remote_path, const std::string &local_path, bool silent)
{
    std::string scp_cmd = "scp -P " + mServerEnv.get_SSH_PORT() + " " + mServerEnv.get_SSH_USER() + "@" + mServerEnv.get_SSH_HOST() + ":" + quote(remote_path) + " " + quote(local_path) + (silent ? " > /dev/null 2>&1" : "");
    return execute_local_command(scp_cmd, nullptr, (silent ? cMode::Silent : cMode::Defaults));
}

bool service_runner::restore(std::string backup_file, bool silent)
{
    if (backup_file.empty()) {
        std::cerr << "Error: not enough arguments.  dropshell restore <server> <service> <backup-file>" << std::endl;
        return false;
    }

    std::string local_backups_dir = gConfig().get_local_backup_path();

    if (backup_file == "latest") {
        // get the latest backup file from the server
        backup_file = get_latest_backup_file(mServer, mService);
    }

    std::string local_backup_file_path = (std::filesystem::path(local_backups_dir) / backup_file).string();

    if (! std::filesystem::exists(local_backup_file_path)) {
        std::cerr << "Error: Backup file not found at " << local_backup_file_path << std::endl;
        return false;
    }

    // split the backup filename into parts based on the magic string
    std::vector<std::string> parts = dropshell::split(backup_file, magic_string);
    if (parts.size() != 4) {
        std::cerr << "Error: Backup file format is incompatible, - in one of the names?" << std::endl;
        return false;
    }

    std::string backup_server_name = parts[0];
    std::string backup_template_name = parts[1];
    std::string backup_service_name = parts[2];
    std::string backup_datetime = parts[3];

    if (backup_template_name != mServiceInfo.template_name) {
        std::cerr << "Error: Backup template does not match service template. Can't restore." << std::endl;
        return false;
    }

    std::string nicedate = std::string(backup_datetime).substr(0, 10);

    std::cout << "Restoring " << nicedate << " backup of " << backup_template_name << " taken from "<<backup_server_name<<", onto "<<mServer<<"/"<<mService<<std::endl;
    std::cout << std::endl;
    std::cout << "*** ALL DATA FOR "<<mServer<<"/"<<mService<<" WILL BE OVERWRITTEN! ***"<<std::endl;

    // run the restore script
    std::cout << "OK, here goes..." << std::endl;

    { // backup existing service
        maketitle("1) Backing up old service... ");
        if (!backup(true)) // silent=true
        {
            std::cerr << std::endl;
            std::cerr << "Error: Backup failed, restore aborted." << std::endl;
            std::cerr << "You can try using   dropshell install "<<mServer<<" "<<mService<<"   to install the service afresh." << std::endl;
            std::cerr << "Otherwise, stop the service, create and initialise a new one, then restore to that." << std::endl;
            return false;
        }
        std::cout << "Backup complete." << std::endl;
    }

    { // uninstall service, then nuke it.
        maketitle("2) Uninstalling old service...");
        // if (!uninstall(true))
        //     return false;

        maketitle("3) Nuking old service...");
        // if (!nuke(true))
        //     return false;
    }


    { // restore service from backup
        maketitle("4) Restoring service data from backup...");
        std::string remote_backups_dir = remotepath::backups(mServer);
        std::string remote_backup_file_path = remote_backups_dir + "/" + backup_file;

        // Copy backup file from local to server
        if (!scp_file_to_remote(local_backup_file_path, remote_backup_file_path, silent)) {
            std::cerr << "Failed to copy backup file from local to server" << std::endl;
            return false;
        }

        cRemoteTempFolder remote_temp_folder(mServerEnv);
        mServerEnv.run_remote_template_command(mService, "restore", {}, silent, {{"BACKUP_FILE", remote_backup_file_path}, {"TEMP_DIR", remote_temp_folder.path()}});
    } // dtor of remote_temp_folder will clean up the temp folder on the server


    { // installing fresh service
        maketitle("5) Non-destructive install of fresh service...");
        if (!install_service(mServer, mService, true))
            return false;
    }

    bool healthy = false;
    {// healthcheck the service
        maketitle("6) Healthchecking service...");
        std::string green_tick = "\033[32m✓\033[0m";
        std::string red_cross = "\033[31m✗\033[0m";    
        healthy= (mServerEnv.run_remote_template_command(mService, "status", {}, silent, {}));
        if (!silent)
            std::cout << (healthy ? green_tick : red_cross) << " Service is " << (healthy ? "healthy" : "NOT healthy") << std::endl;
    }

    return healthy;
}


bool name_breaks_backups(std::string name)
{
    // if name contains -_-, return true
    return name.find("-_-") != std::string::npos;
}

// backup the service over ssh, using the credentials from server.env (via server_env.hpp)
// 1. run backup.sh on the server
// 2. create a backup file with format server-service-datetime.tgz
// 3. store it in the server's DROPSHELL_DIR/backups folder
// 4. copy it to the local user_dir/backups folder

// ------------------------------------------------------------------------------------------------
// Backup the service.
// ------------------------------------------------------------------------------------------------
bool service_runner::backup(bool silent) {
    auto service_info = get_service_info(mServer, mService);
    if (service_info.local_service_path.empty()) {
        std::cerr << "Error: Service not found" << std::endl;
        return 1;
    }

    const std::string command = "backup";

    if (!gTemplateManager().template_command_exists(service_info.template_name, command)) {
        std::cout << "No backup script for " << service_info.template_name << std::endl;
        return true; // nothing to back up.
    }
    
    // Check if basic installed stuff is in place.
    std::string remote_service_template_path = remotepath::service_template(mServer, mService);
    std::string remote_command_script_file = remote_service_template_path + "/" + command + ".sh";
    std::string remote_service_config_path = remotepath::service_config(mServer, mService);
    if (!mServerEnv.check_remote_items_exist({
        remotepath::service(mServer, mService),
        remote_command_script_file,
        remotefile::service_env(mServer, mService)})
    )
    {
        std::cerr << "Error: Required service directories not found on remote server" << std::endl;
        std::cerr << "Is the service installed?" << std::endl;
        return false;
    }

    // Create backups directory on server if it doesn't exist
    std::string remote_backups_dir = remotepath::backups(mServer);
    if (!silent) std::cout << "Remote backups directory on "<< mServer <<": " << remote_backups_dir << std::endl;
    std::string mkdir_cmd = "mkdir -p " + quote(remote_backups_dir);
    if (!execute_ssh_command(mServerEnv.get_SSH_INFO(), sCommand("",mkdir_cmd, {}), cMode::Silent)) {
        std::cerr << "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 = gConfig().get_local_backup_path();
    if (local_backups_dir.empty()) {
        std::cerr << "Error: Local backups directory not found" << std::endl;
        std::cerr << "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
    auto now = std::chrono::system_clock::now();
    auto time = std::chrono::system_clock::to_time_t(now);
    std::stringstream datetime;
    datetime << std::put_time(std::localtime(&time), "%Y-%m-%d_%H-%M-%S");
    
    if (name_breaks_backups(mServer)) {std::cerr << "Error: Server name contains invalid character sequence ( -_- ) that would break backup naming scheme" << std::endl; return 1;}
    if (name_breaks_backups(mService)) {std::cerr << "Error: Service name contains invalid character sequence ( -_- ) that would break backup naming scheme" << std::endl; return 1;}
    if (name_breaks_backups(service_info.template_name)) {std::cerr << "Error: Service template name contains invalid character sequence ( -_- ) that would break backup naming scheme" << std::endl; return 1;}

    // Construct backup filename
    std::string backup_filename = mServer + magic_string + service_info.template_name + magic_string + mService + magic_string + datetime.str() + ".tgz";
    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
        cRemoteTempFolder remote_temp_folder(mServerEnv);
        if (!mServerEnv.run_remote_template_command(mService, command, {}, silent, {{"BACKUP_FILE", remote_backup_file_path}, {"TEMP_DIR", remote_temp_folder.path()}})) {
            std::cerr << "Backup script failed on remote server: " << remote_backup_file_path << std::endl;
            return false;
        }

        // Copy backup file from server to local
        if (!scp_file_from_remote(remote_backup_file_path, local_backup_file_path, silent)) {
            std::cerr << "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

    if (!silent) {
        std::cout << "Backup created successfully. Restore with:"<<std::endl;
        std::cout << "   dropshell restore " << mServer << " " << mService << " " << backup_filename << std::endl;
    }
    return true;
}

cRemoteTempFolder::cRemoteTempFolder(const server_env_manager &server_env) : mServerEnv(server_env)
{
    std::string p = remotepath::temp_files(server_env.get_server_name()) + "/" + random_alphanumeric_string(10);
    std::string mkdir_cmd = "mkdir -p " + quote(p);
    if (!execute_ssh_command(server_env.get_SSH_INFO(), sCommand("", mkdir_cmd, {}), cMode::Silent)) 
        std::cerr << "Failed to create temp directory on server" << std::endl;
    else 
        mPath = p;
}

cRemoteTempFolder::~cRemoteTempFolder()
{
    std::string rm_cmd = "rm -rf " + quote(mPath);
    execute_ssh_command(mServerEnv.get_SSH_INFO(), sCommand("", rm_cmd, {}), cMode::Silent);
}

std::string cRemoteTempFolder::path() const
{
    return mPath;
}

// Helper function to get the latest backup file for a given server and service
std::string service_runner::get_latest_backup_file(const std::string& server, const std::string& service) {
    std::string local_backups_dir = gConfig().get_local_backup_path();
    if (local_backups_dir.empty() || !std::filesystem::exists(local_backups_dir)) {
        std::cerr << "Error: Local backups directory not found: " << local_backups_dir << std::endl;
        return "";
    }

    // Get the template name for this service
    LocalServiceInfo info = get_service_info(server, service);
    if (info.template_name.empty()) {
        std::cerr << "Error: Could not determine template name for service: " << service << std::endl;
        return "";
    }

    // Build the expected prefix for backup files
    std::string prefix = server + magic_string + info.template_name + magic_string + service + magic_string;
    std::string latest_file;
    std::string latest_datetime;

    std::cout << "Looking for backup files in " << local_backups_dir << std::endl;

    for (const auto& entry : std::filesystem::directory_iterator(local_backups_dir)) {
        if (!entry.is_regular_file()) continue;
        std::string filename = entry.path().filename().string();
        if (filename.rfind(prefix, 0) == 0) { // starts with prefix
            // Extract the datetime part
            size_t dt_start = prefix.size();
            size_t dt_end = filename.find(".tgz", dt_start);
            if (dt_end == std::string::npos) continue;
            std::string datetime = filename.substr(dt_start, dt_end - dt_start);
            std::cout << "Found backup file: " << filename << " with datetime: " << datetime << std::endl;
            if (datetime > latest_datetime) {
                latest_datetime = datetime;
                latest_file = filename;
            }
        }
    }

    if (latest_file.empty()) {
        std::cerr << "Error: No backup files found for " << server << ", " << service << std::endl;
    }

    std::cout << "Latest backup file: " << latest_file << std::endl;
    return latest_file;
}

} // namespace dropshell