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

#include <unistd.h>
#include <termios.h>
#include <cstring>
#include <fstream>
#include <iostream>
#include <sstream>
#include <filesystem>
#include <libassert/assert.hpp>

namespace dropshell {

int edit_handler(const CommandContext& ctx);

static std::vector<std::string> edit_name_list={"edit","create-config"};

// Static registration
struct EditCommandRegister {
    EditCommandRegister() {
        CommandRegistry::instance().register_command({
            edit_name_list,
            edit_handler,
            shared_commands::std_autocomplete,
            false, // hidden
            false, // requires_config
            false, // requires_install
            0,     // min_args (after command)
            2,     // max_args (after command)
            "edit [SERVER] [SERVICE] | edit override",
            "Edit dropshell, server, service, or override configuration",
            // heredoc
            R"(
            Edit dropshell, server or service configuration.
            edit                      edit the dropshell config.
            edit override             edit the overrides.env for a server location.
            edit <server>             edit the server config.
            edit <server> <service>   edit the service config.
            )"
        });
    }
} edit_command_register;
 
// ------------------------------------------------------------------------------------------------
// edit command implementation
// ------------------------------------------------------------------------------------------------



// ------------------------------------------------------------------------------------------------
// utility function to edit a file
// ------------------------------------------------------------------------------------------------
bool edit_file(const std::string &file_path, bool has_bb64)
{
    // make sure parent directory exists.
    std::string parent_dir = get_parent(file_path);
    std::filesystem::create_directories(parent_dir);

    std::string editor_cmd;
    const char* editor_env = std::getenv("EDITOR");

    if (editor_env && std::strlen(editor_env) > 0) {
        editor_cmd = std::string(editor_env) + " " + quote(file_path);
    } else if (isatty(STDIN_FILENO)) {
        // Check if stdin is connected to a terminal if EDITOR is not set
        editor_cmd = "nano -w " + quote(file_path);
    } else {
        error << "Standard input is not a terminal and EDITOR environment variable is not set." << std::endl;
        info << "Try setting the EDITOR environment variable (e.g., export EDITOR=nano) or run in an interactive terminal." << std::endl;
        info << "You can manually edit the file at: " << file_path << std::endl;
        return false;
    }

    info << "Editing file: " << file_path << std::endl;

    if (has_bb64) {
        return execute_local_command("", editor_cmd, {}, nullptr, cMode::Interactive);
    }
    else {
        // might not have bb64 at this early stage. Direct edit.
        int ret = system(editor_cmd.c_str());
        return EXITSTATUSCHECK(ret);
    }
}

int create_config()
{
    if (!gConfig().is_config_set())
    {
        bool ok = gConfig().save_config(); // save defaults.
        info << "Default dropshell.json created." << std::endl;
        return (ok ? 0 : 1);
    } 
    else
        info << "Existing dropshell.json unchanged." << std::endl;

    return 0;
}


// ------------------------------------------------------------------------------------------------
// edit config
// ------------------------------------------------------------------------------------------------
int edit_config()
{
    create_config();

    std::string config_file = localfile::dropshell_json();
    if (!edit_file(config_file, false) || !std::filesystem::exists(config_file))
        return return_die("Failed to edit config file.");

    gConfig().load_config();
    if (!gConfig().is_config_set())
        return return_die("Failed to load and parse edited config file!");

    // Don't save_config after loading - it would rewrite the file the user just edited!
    // The config is already saved by the editor, we just validated it by loading it.
    gConfig().create_aux_directories();

    info << "Successfully edited config file at " << config_file << std::endl;
    return 0;
}

// ------------------------------------------------------------------------------------------------
// edit server
// ------------------------------------------------------------------------------------------------
int edit_server(const std::string &server_name)
{
    if (localpath::server(server_name).empty()) {
        error << "Server not found: " << server_name << std::endl;
        return -1;
    }

    std::string config_file = localfile::server_json(server_name);

    if (!edit_file(config_file, true)) {
        error << "Failed to edit server config" << std::endl;
        info << "You can manually edit this file at: " << config_file << std::endl;
        return 1;
    }

    info << "If you have changed DROPSHELL_DIR, you should manually move the files to the new location NOW." << std::endl;
    info << "You can ssh in to the remote server with:  dropshell ssh "<<server_name<< std::endl;
    info << "Once moved, reinstall all services with:   dropshell install " << server_name << std::endl;
    return 0;
}

void list_directory(std::string dir, std::string msg)
{
    bool first=true;
    std::vector<std::string> directories;
    for (const auto &file : std::filesystem::directory_iterator(dir))
    {
        if (first)
        {
            if (!msg.empty())
                info << msg << std::endl;
            first=false;
        }
        if (std::filesystem::is_directory(file.path()))
            directories.push_back(file.path());
        else
            info << "  " << file.path() << std::endl;
    }

    for (const auto &dir : directories)
        list_directory(dir, "");
}

// ------------------------------------------------------------------------------------------------
// edit service config
// ------------------------------------------------------------------------------------------------
int edit_service_config(const std::string &server, const std::string &service)
{
    std::string config_file = localfile::service_env(server, service);
    if (!std::filesystem::exists(config_file))
    {
        error << "Service config file not found: " << config_file << std::endl;
        return 1;
    }

    // Validate service.env matches template BEFORE editing (adds any missing variables)
    {
        LocalServiceInfo service_info = get_service_info(server, service);
        if (!SIvalid(service_info))
        {
            error << "Failed to get service info for " << service << std::endl;
            return 1;
        }

        template_info tinfo = gTemplateManager().get_template_info(service_info.template_name);
        if (!tinfo.is_set())
        {
            error << "Template not found: " << service_info.template_name << std::endl;
            return 1;
        }

        std::filesystem::path template_service_env = tinfo.local_template_path() / "config" / "service.env";
        std::filesystem::path template_info_env = tinfo.local_template_path() / "config" / ".template_info.env";

        std::vector<std::string> missing_vars;
        std::vector<std::string> extra_vars;

        if (!validate_and_fix_service_env(template_service_env.string(), config_file, missing_vars, extra_vars, template_info_env.string()))
        {
            info << "Service environment file updated to match template:" << std::endl;

            if (!missing_vars.empty()) {
                info << "  Added missing variables: ";
                for (size_t i = 0; i < missing_vars.size(); ++i) {
                    info << missing_vars[i];
                    if (i < missing_vars.size() - 1) info << ", ";
                }
                info << std::endl;
            }

            if (!extra_vars.empty()) {
                info << "  Commented out extra variables: ";
                for (size_t i = 0; i < extra_vars.size(); ++i) {
                    info << extra_vars[i];
                    if (i < extra_vars.size() - 1) info << ", ";
                }
                info << std::endl;
            }
        }
    }

    if (edit_file(config_file, true) && std::filesystem::exists(config_file))
        info << "Successfully edited service config file at " << config_file << std::endl;

    std::string service_dir = localpath::service(server, service);
    list_directory(service_dir, "You may wish to edit the other files in " + service_dir);

    info << "Then to apply your changes, run:" << std::endl;
    info << "   dropshell uninstall " + server + " " + service << std::endl;
    info << "   dropshell install " + server + " " + service << std::endl;
    return 0;
}

// ------------------------------------------------------------------------------------------------
// edit override
// ------------------------------------------------------------------------------------------------
int edit_override()
{
    auto paths = gConfig().get_local_server_definition_paths();
    if (paths.empty()) {
        error << "No server definition paths configured." << std::endl;
        return 1;
    }

    std::string chosen_path;
    if (paths.size() == 1) {
        chosen_path = paths[0];
    } else {
        // Multiple paths - ask user to choose with single keypress
        info << "Multiple server locations found. Choose one:" << std::endl;
        for (size_t i = 0; i < paths.size() && i < 9; ++i)
            info << "  " << (i + 1) << ") " << paths[i] << std::endl;

        info << "Enter choice [1-" << std::min(paths.size(), (size_t)9) << "]: " << std::flush;

        // Read single keypress
        struct termios oldt, newt;
        tcgetattr(STDIN_FILENO, &oldt);
        newt = oldt;
        newt.c_lflag &= ~(ICANON | ECHO);
        tcsetattr(STDIN_FILENO, TCSANOW, &newt);
        int ch = getchar();
        tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
        info << (char)ch << std::endl;

        int idx = ch - '1';
        if (idx < 0 || idx >= (int)paths.size()) {
            error << "Invalid choice." << std::endl;
            return 1;
        }
        chosen_path = paths[idx];
    }

    std::string override_file = (std::filesystem::path(chosen_path) / filenames::overrides_env).string();

    // Create with comment header if it doesn't exist
    if (!std::filesystem::exists(override_file)) {
        std::ofstream f(override_file);
        f << "# Overrides for all services in this server location." << std::endl;
        f << "# Variables set here will be forced into every service.env" << std::endl;
        f << "# during create-service and install." << std::endl;
        f << "#" << std::endl;
        f << "# Format is the same as service.env:" << std::endl;
        f << "#   VARIABLE_NAME=\"value\"" << std::endl;
        f << std::endl;
        info << "Created new overrides file: " << override_file << std::endl;
    }

    return edit_file(override_file, true) ? 0 : 1;
}

// ------------------------------------------------------------------------------------------------
// edit command handler
// ------------------------------------------------------------------------------------------------
int edit_handler(const CommandContext& ctx) {
    // edit dropshell config
    if (ctx.args.size() < 1)
    {
        if (ctx.command=="create-config")
        {
            int rval = create_config();
            gConfig().create_aux_directories();
            return rval;
        }
        else
            return edit_config();
    }

    // edit override - check before server/service dispatch
    if (safearg(ctx.args, 0) == "override")
        return edit_override();

    // edit server config
    if (ctx.args.size() < 2) {
        edit_server(safearg(ctx.args,0));
        return 0;
    }

    // edit service config
    if (ctx.args.size() < 3) {
        edit_service_config(safearg(ctx.args,0), safearg(ctx.args,1));
        return 0;
    }

    info << "Edit handler called with " << ctx.args.size() << " args\n";
    return -1;
}




} // namespace dropshell