#ifndef RUBY_PARSER_DRIVER_HH
#define RUBY_PARSER_DRIVER_HH

#include <memory>

#include "diagnostic.hh"
#include "lexer.hh"
#include "node.hh"

namespace ruby_parser {

struct builder;

using ForeignPtr = const void *;
using SelfPtr = const void *;

struct node_list {
    node_list() = default;
    node_list(ForeignPtr node) {
        nodes.emplace_back(node);
    }

    node_list &operator=(const ForeignPtr &other) = delete;
    node_list &operator=(ForeignPtr &&other) = delete;

    inline size_t size() const {
        return nodes.size();
    }

    inline void emplace_back(const ForeignPtr &ptr) {
        nodes.emplace_back(ptr);
    }

    inline void push_front(const ForeignPtr &ptr) {
        nodes.insert(nodes.begin(), ptr);
    }

    inline ForeignPtr &at(size_t n) {
        return nodes.at(n);
    }

    inline void concat(node_list *other) {
        nodes.insert(nodes.end(), std::make_move_iterator(other->nodes.begin()),
                     std::make_move_iterator(other->nodes.end()));
    }

protected:
    std::vector<ForeignPtr> nodes;
};

struct delimited_node_list {
    delimited_node_list() = default;
    delimited_node_list(const token_t &begin, node_list *inner, const token_t &end)
        : begin(begin), inner(inner), end(end) {}

    token_t begin = nullptr;
    node_list *inner = nullptr;
    token_t end = nullptr;
};

struct delimited_block {
    delimited_block() = default;
    delimited_block(const token_t &begin, ForeignPtr args, ForeignPtr body, const token_t &end)
        : begin(begin), args(args), body(body), end(end) {}

    token_t begin = nullptr;
    ForeignPtr args = nullptr;
    ForeignPtr body = nullptr;
    token_t end = nullptr;
};

struct node_with_token {
    node_with_token() = default;
    node_with_token(const token_t &token_, ForeignPtr node_) : tok(token_), nod(node_) {}

    token_t tok = nullptr;
    ForeignPtr nod = nullptr;
};

struct case_body {
    case_body() = default;
    case_body(node_with_token *else_) : els(else_) {}
    node_list whens;
    node_with_token *els = nullptr;
};

class mempool {
    pool<ruby_parser::node_list, 16> _node_list;
    pool<ruby_parser::delimited_node_list, 32> _delimited_node_list;
    pool<ruby_parser::delimited_block, 32> _delimited_block;
    pool<ruby_parser::node_with_token, 32> _node_with_token;
    pool<ruby_parser::case_body, 32> _case_body;
    pool<ruby_parser::state_stack, 8> _stacks;
    friend class base_driver;

public:
    mempool() = default;

    template <typename... Args> ruby_parser::node_list *node_list(Args &&... args) {
        return _node_list.alloc(std::forward<Args>(args)...);
    }

    template <typename... Args> ruby_parser::delimited_node_list *delimited_node_list(Args &&... args) {
        return _delimited_node_list.alloc(std::forward<Args>(args)...);
    }

    template <typename... Args> ruby_parser::delimited_block *delimited_block(Args &&... args) {
        return _delimited_block.alloc(std::forward<Args>(args)...);
    }

    template <typename... Args> ruby_parser::node_with_token *node_with_token(Args &&... args) {
        return _node_with_token.alloc(std::forward<Args>(args)...);
    }

    template <typename... Args> ruby_parser::case_body *case_body(Args &&... args) {
        return _case_body.alloc(std::forward<Args>(args)...);
    }
};

class base_driver {
public:
    diagnostics_t diagnostics;
    const builder &build;
    lexer lex;
    mempool alloc;

    bool pending_error;
    size_t def_level;
    ForeignPtr ast;
    token_t last_token;

    base_driver(ruby_version version, const std::string &source, const struct builder &builder);
    virtual ~base_driver() {}
    virtual ForeignPtr parse(SelfPtr self) = 0;

    bool valid_kwarg_name(const token *name) {
        char c = name->string().at(0);
        return !(c >= 'A' && c <= 'Z');
    }

    ruby_parser::state_stack *copy_stack() {
        return alloc._stacks.alloc(lex.cmdarg);
    }

    void replace_stack(ruby_parser::state_stack *stack) {
        lex.cmdarg = *stack;
    }

    void external_diagnostic(dlevel lvl, dclass cls, size_t begin, size_t end, const std::string &msg) {
        diagnostics.emplace_back(lvl, cls, diagnostic::range(begin, end), msg);
        if (lvl == dlevel::ERROR) {
            pending_error = true;
        }
    }
};

class typedruby25 : public base_driver {
public:
    typedruby25(const std::string &source, const struct builder &builder);
    virtual ForeignPtr parse(SelfPtr self);
    ~typedruby25() {}
};

} // namespace ruby_parser

#endif