#include "env_validator.hpp"
#include "envmanager.hpp"
#include "ordered_env.hpp"
#include "utils.hpp"
#include "output.hpp"

#include <fstream>
#include <sstream>
#include <set>
#include <algorithm>
#include <filesystem>

namespace dropshell {

bool validate_and_fix_service_env(
    const std::string& template_service_env_path,
    const std::string& service_env_path,
    std::vector<std::string>& missing_vars,
    std::vector<std::string>& extra_vars,
    const std::string& template_info_env_path
) {
    missing_vars.clear();
    extra_vars.clear();

    // Load template service.env
    envmanager template_env(template_service_env_path);
    if (!template_env.load()) {
        error << "Failed to load template service.env from: " << template_service_env_path << std::endl;
        return false;
    }

    ordered_env_vars template_vars;
    template_env.get_all_variables(template_vars);

    // Create a set of template variable names for quick lookup
    std::set<std::string> template_var_names;
    for (const auto& [key, value] : template_vars) {
        template_var_names.insert(key);
    }

    // Also load template_info.env if provided - these variables are allowed in service.env
    std::set<std::string> template_info_var_names;
    if (!template_info_env_path.empty() && std::filesystem::exists(template_info_env_path)) {
        envmanager template_info_env(template_info_env_path);
        if (template_info_env.load()) {
            ordered_env_vars template_info_vars;
            template_info_env.get_all_variables(template_info_vars);
            for (const auto& [key, value] : template_info_vars) {
                template_info_var_names.insert(key);
            }
        }
    }

    // Load service service.env
    envmanager service_env(service_env_path);
    if (!service_env.load()) {
        error << "Failed to load service service.env from: " << service_env_path << std::endl;
        return false;
    }

    ordered_env_vars service_vars;
    service_env.get_all_variables(service_vars);

    // Create a set of service variable names for quick lookup
    std::set<std::string> service_var_names;
    for (const auto& [key, value] : service_vars) {
        service_var_names.insert(key);
    }

    // Find missing variables (in template but not in service)
    for (const auto& template_var_name : template_var_names) {
        if (service_var_names.find(template_var_name) == service_var_names.end()) {
            missing_vars.push_back(template_var_name);
        }
    }

    // Find extra variables (in service but not in template or template_info)
    for (const auto& service_var_name : service_var_names) {
        if (template_var_names.find(service_var_name) == template_var_names.end() &&
            template_info_var_names.find(service_var_name) == template_info_var_names.end()) {
            extra_vars.push_back(service_var_name);
        }
    }

    // If there are no differences, validation passes
    if (missing_vars.empty() && extra_vars.empty()) {
        return true;
    }

    // There are differences - need to fix the service.env file
    debug << "Fixing service.env file: " << service_env_path << std::endl;

    // Read the original file line by line
    std::ifstream infile(service_env_path);
    if (!infile.is_open()) {
        error << "Failed to open service.env for reading: " << service_env_path << std::endl;
        return false;
    }

    std::vector<std::string> lines;
    std::string line;
    while (std::getline(infile, line)) {
        lines.push_back(line);
    }
    infile.close();

    // Process lines and comment out extra variables
    std::set<std::string> extra_vars_set(extra_vars.begin(), extra_vars.end());
    for (auto& line : lines) {
        std::string trimmed = trim(line);

        // Skip empty lines and comments
        if (trimmed.empty() || trimmed[0] == '#') {
            continue;
        }

        // Check if this line defines a variable
        size_t pos = trimmed.find('=');
        if (pos != std::string::npos) {
            std::string key = trim(trimmed.substr(0, pos));
            key = dequote(key);

            // If this is an extra variable, comment it out
            if (extra_vars_set.find(key) != extra_vars_set.end()) {
                // Only comment out if not already commented
                if (line[0] != '#') {
                    line = "# " + line;
                }
            }
        }
    }

    // Add missing variables at the end
    if (!missing_vars.empty()) {
        lines.push_back("");
        lines.push_back("# Variables added from template update:");
        for (const auto& var_name : missing_vars) {
            // Get the value from the template
            std::string value = get_var(template_vars, var_name);
            lines.push_back(var_name + "=" + quote(value));
        }
    }

    // Write the modified file back
    std::ofstream outfile(service_env_path);
    if (!outfile.is_open()) {
        error << "Failed to open service.env for writing: " << service_env_path << std::endl;
        return false;
    }

    for (const auto& l : lines) {
        outfile << l << std::endl;
    }
    outfile.close();

    // Validation failed because we had to make changes
    return false;
}

} // namespace dropshell