// Copyright (c) 2015 Egor Tensin <egor@tensin.name>
// This file is part of the "AES tools" project.
// For details, see https://github.com/egor-tensin/aes-tools.
// Distributed under the MIT License.

#pragma once

#include "cmd_parser.hpp"
#include "data_parsers.hpp"

#include <aesxx/all.hpp>

#include <boost/program_options.hpp>

#include <deque>
#include <iterator>
#include <optional>
#include <string>
#include <string_view>
#include <utility>
#include <vector>

class BlockSettings : public SettingsParser {
public:
    class Input {
    public:
        Input(
            std::string_view key,
            std::optional<aes::Block>&& iv,
            std::vector<aes::Block>&& blocks
        )
            : key{key}, iv{std::move(iv)}, blocks{std::move(blocks)} {}

        std::string get_key() const {
            return key;
        }

        std::optional<aes::Block> get_iv() const {
            return iv;
        }

        std::vector<aes::Block> get_blocks() const {
            return blocks;
        }

    private:
        std::string key;
        std::optional<aes::Block> iv;
        std::vector<aes::Block> blocks;
    };

    explicit BlockSettings(std::string_view argv0) : SettingsParser{argv0} {
        namespace po = boost::program_options;

        visible.add_options()("verbose,v", po::bool_switch(&verbose), "enable verbose output");
        visible.add_options()(
            "algorithm,a", po::value(&algorithm)->required()->value_name("NAME"), "set algorithm"
        );
        visible.add_options()(
            "mode,m", po::value(&mode)->required()->value_name("MODE"), "set mode of operation"
        );
    }

    const char* get_short_description() const override {
        return "[-h|--help] [-v|--verbose] [-a|--algorithm NAME] [-m|--mode MODE]"
               " [-- KEY [IV] [BLOCK]...]...";
    }

    void parse(int argc, char* argv[]) override {
        std::vector<std::string> args;
        hidden.add_options()("args", boost::program_options::value(&args), "shouldn't be visible");
        positional.add("args", -1);

        SettingsParser::parse(argc, argv);
        if (exit_with_usage())
            return;

        parse_inputs(
            std::deque<std::string>{
                std::make_move_iterator(args.begin()), std::make_move_iterator(args.end())
            }
        );
    }

    aes::Algorithm get_algorithm() const {
        return algorithm;
    }

    aes::Mode get_mode() const {
        return mode;
    }

    const std::vector<Input>& get_inputs() const {
        return inputs;
    }

    bool get_verbose() const {
        return verbose;
    }

private:
    void parse_inputs(std::deque<std::string>&& src) {
        while (!src.empty())
            inputs.emplace_back(parse_input(src));
    }

    Input parse_input(std::deque<std::string>& src) const {
        std::string key{std::move(src.front())};
        src.pop_front();

        std::optional<aes::Block> iv;

        if (aes_mode_requires_init_vector(mode)) {
            if (src.empty()) {
                throw boost::program_options::error{
                    "an initialization vector is required for the selected mode of operation"
                };
            }
            iv = aes::Block::parse(src.front());
            src.pop_front();
        }

        return {key, std::move(iv), parse_blocks(src)};
    }

    static std::vector<aes::Block> parse_blocks(std::deque<std::string>& src) {
        std::vector<aes::Block> blocks;

        while (!src.empty()) {
            std::string block{std::move(src.front())};
            src.pop_front();
            if (block == "--")
                break;
            blocks.emplace_back(aes::Block::parse(block));
        }

        return blocks;
    }

    aes::Algorithm algorithm;
    aes::Mode mode;
    std::vector<Input> inputs;
    bool verbose = false;
};