#ifndef COMDEL_PARSER_H
#define COMDEL_PARSER_H

#include "sourceerror.h"
#include "presult.h"
#include "token.h"
#include "astnode.h"

#include <optional>
#include <set>
#include <vector>

/// Records the current span and can later be called on
/// an ast node to apply the entire span to that node
///
/// Spanner's call operator MOVES from the node so it should
/// be always used last.
class Spanner {
    const Span lo; // the low end of the span, beginning of the node

    // REFERENCE to the parser's prevSpan. After parsing a node this will
    // "point" to the span of the last token contained in the node.
    const Span& prevSpan;

public:
    Spanner(Span lo, Span& prevSpan) : lo(lo), prevSpan(prevSpan) {}

    template <typename T, typename = std::enable_if<std::is_base_of<AstNode, T>::value>>
    typename std::remove_reference_t<T> operator()(T&& astNode) const {
        astNode.span = lo.to(prevSpan);
        return std::move(astNode);
    }
};

class ComdelParser
{
private:
    std::vector<Token> tokens;
    std::set<TokenType> expectedTokens;

    unsigned int position;
    std::vector<SourceError> errors;

    Span &getPreviousSpan();

    void bump();

    bool consume(TokenType tokenType);
    bool check(TokenType tokenType);

    Token &current();

    [[nodiscard]] PError unexpected();

    template<typename T>
    PResult<std::vector<T>> parseList(std::optional<TokenType> openDelim,
                                       TokenType closeDelim,
                                       std::optional<TokenType> separator,
                                       bool allowTrailing,
                                       const std::function<PResult<T> ()> &parse_f);

    Spanner getSpanner();


    PResult<StringNode> parseString();
    PResult<IdentifierNode> parseIdentifier();
    PResult<NumberNode> parseNumber();
    PResult<CountNode> parseCount();
    PResult<PropertyNode> parseProperty(std::optional<TokenType> valueType);
    PResult<EnumerationNode> parseEnumeration();

    PResult<ComponentNode> parseComponent();
    PResult<AddressSpaceNode> parseAddress();
    PResult<PinNode> parsePin();
    PResult<DisplayNode> parseDisplay();
    PResult<PinConnectionNode> parsePinConnection();
    PResult<AttributeNode> parseAttribute();
    PResult<PopupNode> parsePopup();
    PResult<RuleNode> parseRule();
    PResult<BusNode> parseBus();
    PResult<WireNode> parseWire();
    PResult<ConnectionNode> parseConnection();
    PResult<DisplayItemNode> parseDisplayItem();
    PResult<IfStatementNode> parseIfStatement();
    PResult<ValueNode> parseValue();

    PResult<WireInstanceNode> parseWireInstance();
    PResult<CountNode> parsePosition();
    PResult<InstanceNode> parseInstance();
    PResult<InstanceAttributeNode> parseInstanceAttribute();
    PResult<ConnectionInstanceNode> parseConnectionInstance();

public:
    ComdelParser(std::vector<Token> tokens);
    std::optional<SchemaNode> parseSchema();
    std::optional<LibraryNode> parse();
    const std::vector<SourceError>& getErrors();
};

#endif // COMDEL_PARSER_H