#include "templating.hpp"
#include <filesystem>
#include <fstream>
#include <regex>
#include <stdexcept>

Templating::Templating(const std::string& template_dir)
    : inja_env(std::filesystem::canonical(template_dir).string()),
      template_dir(std::filesystem::canonical(template_dir).string())
{
    inja_env.set_search_included_templates_in_files(true);
}

std::string Templating::preprocess_template(const std::string& template_name) {
    namespace fs = std::filesystem;

    fs::path abs_template_dir = fs::path(template_dir);
    fs::path abs_template_file = fs::canonical(abs_template_dir / template_name);

    std::ifstream file(abs_template_file);
    if (!file.is_open()) {
        throw std::runtime_error("Failed to open template file: " + abs_template_file.string());
    }

    std::string content((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());

    std::regex extends_regex(R"(\{\%\s*extends\s*(['"])(.+?)\1\s*\%\})");
    std::smatch match;

    if (std::regex_search(content, match, extends_regex)) {
        std::string quote = match[1].str();
        std::string original_path = match[2].str();

        if (original_path.find("/") == std::string::npos &&
            !original_path.empty() &&
            original_path.front() != '/') {

            fs::path abs_extended_template = fs::canonical(abs_template_dir / original_path);
            fs::path rel_path = fs::relative(abs_extended_template, abs_template_file.parent_path());

            std::string new_path = rel_path.generic_string();

            content = std::regex_replace(content, extends_regex,
                "{% extends " + quote + new_path + quote + " %}");
        }
    }

    return content;
}


crow::response Templating::render_template(const std::string& template_name, const inja::json& data) {
    try {
        std::string preprocessed = preprocess_template(template_name);
        inja::Template tpl = inja_env.parse(preprocessed);
        std::string rendered = inja_env.render(tpl, data);
        return crow::response(rendered);

    } catch (const std::exception& e) {
        return crow::response(500, e.what());
    }
}

crow::response Templating::render_template(const std::string& template_name) {
    return render_template(template_name, inja::json{});
}

std::string Templating::render_template_string(const std::string& template_name, const inja::json& data) {
    std::string preprocessed = preprocess_template(template_name);
    inja::Template tpl = inja_env.parse(preprocessed);
    return inja_env.render(tpl, data);
}

std::string Templating::render_template_string(const std::string& template_name) {
    return render_template_string(template_name, inja::json{});
}