#include "comdelparser.h"

#include "poly.h"
#include "tokenstype.h"

#include <utility>
#include <algorithm>
#include <fstream>
#include <sstream>

ComdelParser::ComdelParser(std::vector<Token> tokens)
    : tokens(std::move(tokens))
    , position(0)
{}

// Tries to consume a token, returns an error otherwise.
// Unlike the regular consume() call this should be used
// when a missing token means a syntax error.
#define RETURN_IF_NOT_TOKEN(tokenType) \
    do { \
        if (!consume(tokenType)) { \
            return unexpected(); \
        } \
    } while (0)


// Checks if the current token matches the argument.
// Otherwise, adds the token to the list of expected tokens (used in
// error message).
bool ComdelParser::check(TokenType tokenType)
{
    if(current().type == tokenType)
        return true;

    expectedTokens.insert(tokenType);
    return false;
}

Token &ComdelParser::current() {
    return tokens[position];
}

// attempts to consume a token and returns whether it's successful
bool ComdelParser::consume(TokenType tokenType) {
    bool exists = check(tokenType);
    if (exists) {
        bump();
    }
    return exists;
}

#define ATLAS_ASSERT_FAIL(x) \
    do{}while(0)

void ComdelParser::bump() {
    if (tokens[position].type == TokenType::END_OF_FILE) {
        ATLAS_ASSERT_FAIL("Internal parser error, called bump after EOF");
    } else {
        tokens[++position];
    }

    expectedTokens.clear();
}

// Generates an "unexpected token" error that also
// includes a list of valid alternatives based on the contents
// of the expectedTokens vector
//
// e.g. "expected one of: ',', ')', found 'c'"
// when parsing "func(a, b  c);"
PError ComdelParser::unexpected() {
    std::stringstream ss;
    ss << "Found: `" << current().text << "`. ";

    ss << "Expected";
    if (expectedTokens.size() > 1) {
        ss << " one of: ";
    } else {
        ss << ": ";
    }
    uint token_counter = 0;
    for (auto& type : expectedTokens) {
        if (type == TokenType::IDENTIFIER ||
            type == TokenType::NUMBER ||
            type == TokenType::STRING ||
            type == TokenType::COLOR) {
            ss << tokenTypeToString(type);
        } else {
            ss << "`" << tokenTypeToString(type) << "`";
        }
        ++token_counter;
        if (token_counter < expectedTokens.size())
            ss << ", ";
        else
            ss <<".";
    }
    return PError({current().span, ss.str()});
}

// Parses a list of 'nodes' separated by 'separator'. Parsed nodes
// are returned in a vector. A list can be empty which will give
// an empty vector.
//
// The list is enclosed in 'openDelim' and 'closeDelim'.
//
// 'openDelim' and 'separator' are optional (could be nullopt).
//
// 'closeDelim' is mandatory, and it will be consumed.
//
// Function 'parse_f' should only parse a single node of type T.
//
// Parameter allowTrailing==true means that the list should end with
// 'separator' and otherwise the list should end with 'node'. This
// parameter is false in every call-site!
template<typename T> PResult<std::vector<T>>
ComdelParser::parseList(std::optional<TokenType> openDelim,
                        TokenType closeDelim,
                        std::optional<TokenType> separator,
                        bool allowTrailing,
                        const std::function<PResult<T>()>& parse_f)
{
    std::vector<T> vec;

    if(openDelim) {
        RETURN_IF_NOT_TOKEN(*openDelim);
    }

    bool first = true;
    while (true) {
        if (consume(closeDelim)) {
            break;
        }
        if (!first && separator) {
            RETURN_IF_NOT_TOKEN(*separator);
            if (allowTrailing && consume(closeDelim)) {
                break;
            }
        }
        first = false;
        auto item = parse_f();
        RETURN_IF_ERR(item);
        vec.push_back(*item);
    }

    return vec;
}

const std::vector<SourceError> &ComdelParser::getErrors()
{
    return errors;
}

Span &ComdelParser::getPreviousSpan() {
    static Span span;
    if(position == 0) {
        return span;
    } else {
        return tokens[position].span;
    }
}

// See comment for Spanner
Spanner ComdelParser::getSpanner()
{
    return Spanner(current().span, getPreviousSpan());
}

// utility for reading strings
#define ASSIGN_OR_SET_ERR(var, presult) \
    do { \
        auto&& assign_or_return_if_err_temp_ = (presult); \
        if (!assign_or_return_if_err_temp_) { \
            err = PError(assign_or_return_if_err_temp_.error()); \
        } else { \
            var = *assign_or_return_if_err_temp_; \
        } \
    } while (0)

// utility for reading strings
#define APPEND_OR_SET_ERR(var, presult) \
    do { \
        auto&& assign_or_return_if_err_temp_ = (presult); \
        if (!assign_or_return_if_err_temp_) { \
            err = PError(assign_or_return_if_err_temp_.error()); \
        } else { \
            var.push_back(*assign_or_return_if_err_temp_); \
        } \
    } while (0)

// utility for reading strings
#define APPEND_OR_RETURN_IF_ERR(var, presult) \
    do { \
        auto&& assign_or_return_if_err_temp_ = (presult); \
        if (!assign_or_return_if_err_temp_) { \
            return PError(assign_or_return_if_err_temp_.error()); \
        } else { \
            var.push_back(*assign_or_return_if_err_temp_); \
        } \
    } while (0)


/****************************************************************************
*
*  F U N C T I O N S   O F   R E C U R S I V E   D E S C E N T   P A R S E R
*
****************************************************************************/

std::optional<LibraryNode> ComdelParser::parse()
{

    auto spanner = getSpanner();
    LibraryNode library{};

    while ( ! check(TokenType::END_OF_FILE) ) {
        PResult<poly<AstNode>> err;
        if(check(TokenType::KW_NAME)){
            bump();
            ASSIGN_OR_SET_ERR(library.name, parseString());
        } else if(check(TokenType::KW_HEADER)) {
            bump();
            ASSIGN_OR_SET_ERR(library.header, parseString());
        } else if(check(TokenType::KW_DIRECTORY)) {
            bump();
            ASSIGN_OR_SET_ERR(library.componentDirectory, parseString());
        } else if(check(TokenType::KW_INFO)) {
            bump();
            ASSIGN_OR_SET_ERR(library.libraryInfo, parseString());
        } else if(check(TokenType::KW_ADDRESS)) {
            APPEND_OR_SET_ERR(library.addressSpaces, parseAddress());
        } else if(check(TokenType::KW_COMPONENT)) {
            APPEND_OR_SET_ERR(library.components, parseComponent());
        } else if(check(TokenType::KW_BUS)) {
            APPEND_OR_SET_ERR(library.buses, parseBus());
        } else if(check(TokenType::KW_CONNECTION)) {
            APPEND_OR_SET_ERR(library.connections, parseConnection());
        } else if(check(TokenType::KW_MESSAGES)) {
            bump();
            ASSIGN_OR_SET_ERR(library.messages, parseList<PropertyNode>(std::optional<TokenType>(TokenType::LBRACE),
                                                          TokenType::RBRACE,
                                                          std::nullopt,
                                                          false,
                                                          [this]{return parseProperty(std::optional<TokenType>(TokenType::STRING));}
                                                          ));
        } else {
            err = unexpected();
        }
        if(!err.has_value()) {
            errors.push_back(err.error());
            break;
        }
    }

    if (errors.size())
        return std::nullopt;

    return spanner(library);
}

/****************************************************************************
*
*    StringNode :=  "\"" + CONTENT + "\""
*
****************************************************************************/
PResult<StringNode> ComdelParser::parseString()
{
    auto spanner = getSpanner();
    if (check(TokenType::STRING)) {
        StringNode node;
        node.value = current().text;
        node.span = current().span;
        bump();
        return spanner(node);
    }
    return unexpected();
}


/****************************************************************************
*
*    IdentifierNode :=  IDENTIFIER
*
****************************************************************************/
PResult<IdentifierNode> ComdelParser::parseIdentifier()
{
    auto spanner = getSpanner();
    if (check(TokenType::IDENTIFIER)) {
        IdentifierNode node;
        node.value = current().text;
        node.span = current().span;
        bump();
        return spanner(node);
    }
    return unexpected();
}

/****************************************************************************
*
*    NumberNode := ('0x' | '0b'){0,1}[0-9]*
*
****************************************************************************/
PResult<NumberNode> ComdelParser::parseNumber()
{
    auto spanner = getSpanner();
    if (check(TokenType::NUMBER)) {
        NumberNode node{current().text};
        node.span = current().span;
        bump();
        return spanner(node);
    }
    return unexpected();
}


/****************************************************************************
*
*    CountNode := "@size (" + NumberNode + "," + NumberNode + ")"
*
****************************************************************************/
PResult<CountNode> ComdelParser::parseCount()
{
    auto spanner = getSpanner();
    RETURN_IF_NOT_TOKEN(TokenType::KW_COUNT);

    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
    auto first = parseNumber();
    if(!first.has_value()) {
        return PError(first.error());
    }
    RETURN_IF_NOT_TOKEN(TokenType::COMMA);
    auto second = parseNumber();
    if(!second.has_value()) {
        return PError(second.error());
    }
    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    return spanner(CountNode{first.value(), second.value()});
}

/****************************************************************************
*
*    PropertyNode := key: value;
*
****************************************************************************/
PResult<PropertyNode> ComdelParser::parseProperty(std::optional<TokenType> valueType = std::nullopt)
{
    auto spanner = getSpanner();
    IdentifierNode key;
    ASSIGN_OR_RETURN_IF_ERR(key, parseIdentifier());

    RETURN_IF_NOT_TOKEN(TokenType::COLON);

    if(valueType.has_value()) {
        if(valueType == TokenType::BOOL_TYPE) {
            if(!(check(TokenType::TRUE) || check(TokenType::FALSE))) {
                return unexpected();
            }
        } else if(!check(*valueType)) {
            return unexpected();
        }
    }
    ValueNode value;
    ASSIGN_OR_RETURN_IF_ERR(value, parseValue());

    RETURN_IF_NOT_TOKEN(TokenType::SEMICOLON);

    PropertyNode node;
    node.key = key;
    node.value = value;

    return spanner(node);
}

/****************************************************************************
*
*    AddressSpaceNode :=  "@address" + IDENTIFIER "(" + NUMBER + "," + NUMBER + ")"
*
****************************************************************************/
PResult<AddressSpaceNode> ComdelParser::parseAddress()
{
    auto spanner = getSpanner();

    AddressSpaceNode addressSpace{};

    RETURN_IF_NOT_TOKEN(TokenType::KW_ADDRESS);

    ASSIGN_OR_RETURN_IF_ERR(addressSpace.name, parseIdentifier());
    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
    ASSIGN_OR_RETURN_IF_ERR(addressSpace.start, parseNumber());
    RETURN_IF_NOT_TOKEN(TokenType::COMMA);
    ASSIGN_OR_RETURN_IF_ERR(addressSpace.end, parseNumber());
    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    return spanner(addressSpace);
}


/****************************************************************************
*
*    ComponentNode :=  "@component" + IDENTIFIER + ("processor" | "memory") { COMPONENT_BLOCK }
*
****************************************************************************/
PResult<ComponentNode> ComdelParser::parseComponent()
{
    auto spanner = getSpanner();

    ComponentNode component{};

    RETURN_IF_NOT_TOKEN(TokenType::KW_COMPONENT);

    ASSIGN_OR_RETURN_IF_ERR(component.name, parseIdentifier());

    auto type = parseComponentType();

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        PResult<poly<AstNode>> err;
        if(check(TokenType::KW_INSTANCE_NAME)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(component.instanceName, parseString());
        } else if(check(TokenType::KW_TOOLTIP)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(component.tooltip, parseString());
        } else if(check(TokenType::KW_SOURCE)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(component.source, parseString());
        } else if(check(TokenType::KW_COUNT)) {
            ASSIGN_OR_RETURN_IF_ERR(component.count, parseCount());
        } else if(check(TokenType::KW_DISPLAY)) {
            ASSIGN_OR_RETURN_IF_ERR(component.display, parseDisplay());
        } else if(check(TokenType::KW_PIN)) {
            APPEND_OR_RETURN_IF_ERR(component.pins, parsePin());
        } else if(check(TokenType::KW_ATTRIBUTE)) {
            APPEND_OR_RETURN_IF_ERR(component.attributes, parseAttribute());
        } else if(check(TokenType::KW_RULE)) {
            APPEND_OR_RETURN_IF_ERR(component.rules, parseRule());
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(component);
}

PResult<EnumNode<ComponentNode::ComponentType>> ComdelParser::parseComponentType() {
    EnumNode<ComponentNode::ComponentType> type;

    auto spanner = getSpanner();

    if(check(TokenType::CT_PROCESSOR)) {
        bump();
        type = EnumNode(ComponentNode::PROCESSOR);
    } else if(check(TokenType::CT_MEMORY)) {
        bump();
        type = EnumNode(ComponentNode::MEMORY);
    } else {
        type = EnumNode(ComponentNode::OTHER);
    }
    return spanner(type);
}


/****************************************************************************
*
*    DisplayNode :=  "@display {" + (DISPLAY_ITEM)* +  "}"
*
****************************************************************************/
PResult<DisplayNode> ComdelParser::parseDisplay() {
    auto spanner = getSpanner();

    RETURN_IF_NOT_TOKEN(TokenType::KW_DISPLAY);
    DisplayNode display;
    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);
    while(!check(TokenType::RBRACE)) {
        PResult<DisplayItemNode> item;
        item = parseDisplayItem();
        RETURN_IF_ERR(item);
        display.items.push_back(*item);
    }
    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);
    return spanner(display);
}

/****************************************************************************
*
*    DisplayItemNode :=  "TYPE {(KEY + ":" + VALUE + ";")*}
*
****************************************************************************/
PResult<DisplayItemNode> ComdelParser::parseDisplayItem() {
    auto spanner = getSpanner();
    DisplayItemNode displayItem;
    ASSIGN_OR_RETURN_IF_ERR(displayItem.type, parseIdentifier());

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        PResult<PropertyNode> item{parseProperty()};
        RETURN_IF_ERR(item);
        displayItem.values.push_back(*item);
    }
    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);
    return spanner(displayItem);
}


/****************************************************************************
*
*    BusNode :=  "@bus " + NAME + TYPE + "{" + POPUP + "}"
*
****************************************************************************/
PResult<BusNode> ComdelParser::parseBus() {
    auto spanner = getSpanner();
    BusNode bus;

    RETURN_IF_NOT_TOKEN(TokenType::KW_BUS);

    ASSIGN_OR_RETURN_IF_ERR(bus.name, parseIdentifier());

    auto type = parseBusType();
    RETURN_IF_ERR(type);

    bus.type = *type;

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        if(check(TokenType::KW_TOOLTIP)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(bus.tooltip, parseString());
        } else if(check(TokenType::KW_COUNT)) {
            ASSIGN_OR_RETURN_IF_ERR(bus.count, parseCount());
        } else if(check(TokenType::KW_DISPLAY)) {
            ASSIGN_OR_RETURN_IF_ERR(bus.display, parseDisplay());
        } else if(check(TokenType::KW_WIRES)) {
            bump();
            RETURN_IF_NOT_TOKEN(TokenType::LBRACE);
            while(check(TokenType::IDENTIFIER)) {
                APPEND_OR_RETURN_IF_ERR(bus.wires, parseWire());

                if(check(TokenType::COMMA)) {
                    RETURN_IF_NOT_TOKEN(TokenType::COMMA);
                }
            }
            RETURN_IF_NOT_TOKEN(TokenType::RBRACE);
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(bus);
}

PResult<EnumNode<BusNode::BusType>> ComdelParser::parseBusType() {
    PResult<EnumNode<BusNode::BusType>> type;

    if(check(TokenType::IDENTIFIER)) {
        auto tokenType = parseIdentifier();
        if(tokenType.value().value == "automatic") {
            type = EnumNode(BusNode::AUTOMATIC);
        } else if(tokenType.value().value == "regular") {
            type = EnumNode(BusNode::REGULAR);
        } else {
            type = PError(SourceError{current().span, "expected 'automatic' or 'regular'"});
        }
    } else {
        type = PError(SourceError{current().span, "expected 'automatic' or 'regular'"});
    }
    return type;
}


/****************************************************************************
*
*    WireNode := NAME(<SIZE>){0,1} TYPE [hidden | terminated_with (#number | null)])*
*
****************************************************************************/
PResult<WireNode> ComdelParser::parseWire() {
    auto spanner = getSpanner();
    WireNode wire;

    ASSIGN_OR_RETURN_IF_ERR(wire.name, parseIdentifier());

    if(check(TokenType::LT)) {
        RETURN_IF_NOT_TOKEN(TokenType::LT);
        ASSIGN_OR_RETURN_IF_ERR(wire.size, parseNumber());
        RETURN_IF_NOT_TOKEN(TokenType::GT);
    } else {
        wire.size.value = 1;
    }

    // default
    wire.type = EnumNode(WireNode::WIRE);

    if(check(TokenType::WIRE_DEFAULT)) {
        bump();
        wire.type = EnumNode(WireNode::WIRE);
    } else if(check(TokenType::WIRE_AND)) {
        bump();
        wire.type = EnumNode(WireNode::WIRED_AND);
    } else if(check(TokenType::WIRE_OR)) {
        bump();
        wire.type = EnumNode(WireNode::WIRED_OR);
    } else if(check(TokenType::R_WIRE)) {
        bump();
        wire.type = EnumNode(WireNode::R_WIRE);
    }

    while(true) {
        if(check(TokenType::HIDDEN)) {
            bump();
            wire.hidden = true;
        } else if(check(TokenType::TERMINATE_WITH)) {
            bump();
            wire.hasTerminateWith = true;
            if(check(TokenType::NIL)) {
                bump();
                wire.terminateWith = ValueNode::ofNull();
            } else if(check(TokenType::NUMBER)) {
                auto number = parseNumber();
                wire.terminateWith = ValueNode::ofInt(number->value);
            } else {
                auto token = current();
                return PError(SourceError{token.span, "unexpected token"});
            }
        } else {
            break;
        }
    }

    return spanner(wire);
}


/****************************************************************************
*
*    PinNode :=  "@pin" NAME TYPE "{"
        "@tooltip" MESSAGE
        "@connection" TYPE "(" MESSAGE ")"
        DisplayNode
    }
*
****************************************************************************/
PResult<PinNode> ComdelParser::parsePin() {
    auto spanner = getSpanner();

    RETURN_IF_NOT_TOKEN(TokenType::KW_PIN);
    PinNode pin{};

    ASSIGN_OR_RETURN_IF_ERR(pin.name, parseIdentifier());

    if(check(TokenType::PIN_IN)) {
        bump();
        pin.type = EnumNode(PinNode::IN);
    } else if(check(TokenType::PIN_OUT)) {
        bump();
        pin.type = EnumNode(PinNode::OUT);
    } else if(check(TokenType::PIN_IN_OUT)) {
        bump();
        pin.type = EnumNode(PinNode::IN_OUT);
    } else {
        return unexpected();
    }

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        if (check(TokenType::KW_TOOLTIP)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(pin.tooltip, parseString());
        } else if (check(TokenType::KW_DISPLAY)) {
            ASSIGN_OR_RETURN_IF_ERR(pin.display, parseDisplay());
        } else if (check(TokenType::KW_CONNECTION)) {
            ASSIGN_OR_RETURN_IF_ERR(pin.connection, parsePinConnection());
        } else if (check(TokenType::KW_WIRES)){
            bump();
            auto wires = parseList<ValueNode>(std::optional<TokenType>(TokenType::LBRACE), TokenType::RBRACE, std::optional<TokenType>(TokenType::COMMA), false,
                                              [this] { return parseConnectionWire(); });
            RETURN_IF_ERR(wires);
            pin.wires = *wires;
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(pin);
}


/****************************************************************************
*
*    PinConnectionNode :=  "@connection " + ("check_only" | "automatically") + "(" + MESSAGE + ")"
*
****************************************************************************/
PResult<PinConnectionNode> ComdelParser::parsePinConnection() {
    auto spanner = getSpanner();
    PinConnectionNode connection{};

    RETURN_IF_NOT_TOKEN(TokenType::KW_CONNECTION);

    ASSIGN_OR_RETURN_IF_ERR(connection.type, parseConnectionType());

    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
    ASSIGN_OR_RETURN_IF_ERR(connection.message, parseString());
    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    return spanner(connection);
}

PResult<EnumNode<PinConnectionNode::ConnectionType>> ComdelParser::parseConnectionType() {
    auto spanner = getSpanner();

    EnumNode<PinConnectionNode::ConnectionType> type;

    if(check(TokenType::IDENTIFIER)) {
        auto identifier = parseIdentifier();
        if(identifier.value().value == "check_only") {
            type = EnumNode(PinConnectionNode::CHECK_ONLY);
        } else if(identifier.value().value == "automatically") {
            type = EnumNode(PinConnectionNode::AUTOMATICALLY);
        } else {
            return PError(SourceError{current().span, "expected identifiers 'check_only' or 'automatically'"});
        }
    } else {
        return PError(SourceError{current().span, "expected identifiers 'check_only' or 'automatically'"});
    }

    return spanner(type);
}

/****************************************************************************
*
*    AttributeNode :=  "@attribute " + NAME + TYPE ("default" + VALUE){0,1} ("{" POPUP "}"){0,1}
*
****************************************************************************/
PResult<AttributeNode> ComdelParser::parseAttribute() {
    auto spanner = getSpanner();
    AttributeNode attribute;

    RETURN_IF_NOT_TOKEN(TokenType::KW_ATTRIBUTE);

    if(check(TokenType::IDENTIFIER)) {
        ASSIGN_OR_RETURN_IF_ERR(attribute.name, parseIdentifier());
    } else {
        return unexpected();
    }

    if(check(TokenType::INT_TYPE)) {
        attribute.type = ValueNode::INT;
    } else if(check(TokenType::STRING_TYPE)) {
        attribute.type = ValueNode::STRING;
    } else if(check(TokenType::BOOL_TYPE)) {
        attribute.type = ValueNode::BOOL;
    } else if(check(TokenType::WIRE_TYPE)) {
        attribute.type = ValueNode::WIRE;
    } else {
        return unexpected();
    }
    bump();

    RETURN_IF_NOT_TOKEN(TokenType::DEFAULT);

    if(attribute.type == ValueNode::BOOL) {
        if(check(TokenType::TRUE)) {
            bump();
            attribute.defaultValue = ValueNode::ofBool(true);
        } else if(check(TokenType::FALSE)) {
            bump();
            attribute.defaultValue = ValueNode::ofBool(false);
        } else {
            return unexpected();
        }
    } else if(attribute.type == ValueNode::INT) {
        if(check(TokenType::NUMBER)) {
            auto number = parseNumber();
            attribute.defaultValue = ValueNode::ofInt(number->value);
        }  else {
            return unexpected();
        }
    } else if(attribute.type == ValueNode::STRING) {
        if(check(TokenType::STRING)) {
            auto string = parseString();
            attribute.defaultValue = ValueNode::ofString(string->asString());
        }  else {
            return unexpected();
        }
    } else if(attribute.type == ValueNode::IDENTIFIER) {
        if(check(TokenType::IDENTIFIER)) {
            auto identifier = parseIdentifier();
            attribute.defaultValue = ValueNode::ofIdentifier(identifier->value);
        }  else {
            return unexpected();
        }
    } else if(attribute.type == ValueNode::WIRE) {
        if(check(TokenType::IDENTIFIER)) {
            auto identifier = parseIdentifier();
            attribute.defaultValue = ValueNode::ofWire(identifier->value);
        } else if(check(TokenType::NIL)) {
            bump();
            attribute.defaultValue = ValueNode::ofNull();
        } else {
            return unexpected();
        }
    }

    if(check(TokenType::LBRACE)) {
        RETURN_IF_NOT_TOKEN(TokenType::LBRACE);
        PopupNode popup;

        if(!check(TokenType::KW_POPUP)) {
            return unexpected();
        }

        ASSIGN_OR_RETURN_IF_ERR(popup, parsePopup());
        attribute.popup = std::optional<PopupNode>(popup);
        RETURN_IF_NOT_TOKEN(TokenType::RBRACE);
    }

    return spanner(attribute);
}

/****************************************************************************
*
*    Enumeration
*
****************************************************************************/
PResult<EnumerationNode> ComdelParser::parseEnumeration() {
    auto spanner = getSpanner();
    StringNode key;

    ASSIGN_OR_RETURN_IF_ERR(key, parseString());
    RETURN_IF_NOT_TOKEN(TokenType::EQUALS);

    ValueNode value;
    ASSIGN_OR_RETURN_IF_ERR(value, parseValue());

    EnumerationNode node;
    node.key = key;
    node.value = value;

    return spanner(node);
}

/****************************************************************************
*
*    PopupNode :=  "@popup " + ("automatic" | "on_demand") { POPUP BODY }
*
****************************************************************************/
PResult<PopupNode> ComdelParser::parsePopup() {
    auto spanner = getSpanner();
    PopupNode popup;

    RETURN_IF_NOT_TOKEN(TokenType::KW_POPUP);

    if(check(TokenType::IDENTIFIER)) {
        auto identifier = parseIdentifier();
        if(identifier.value().value == "automatic") {
            popup.type = EnumNode(PopupNode::AUTOMATIC);
        } else if(identifier.value().value == "on_demand") {
            popup.type = EnumNode(PopupNode::ON_DEMAND);
        } else {
            return PError(SourceError{current().span, "expected type 'automatic', 'on_demand'"});
        }
    } else {
        popup.type = EnumNode(PopupNode::ON_DEMAND);
    }

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        if(check(TokenType::KW_TITLE)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(popup.title, parseString());
        } else if(check(TokenType::KW_TEXT)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(popup.text, parseString());
        } else if(check(TokenType::KW_RULE)) {
            APPEND_OR_RETURN_IF_ERR(popup.rules, parseRule());
        } else if(check(TokenType::KW_ENUMERATED)) {
            bump();
            popup.enumerated = true;
            ASSIGN_OR_RETURN_IF_ERR(popup.enumeration,
                                    parseList<EnumerationNode>(
                                      std::optional<TokenType>(TokenType::LBRACE),
                                      TokenType::RBRACE,
                                      std::optional<TokenType>(TokenType::COMMA),
                                      true,
                                      [this]{ return parseEnumeration();}
                                      )
            );
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(popup);
}

/****************************************************************************
*
*    ConnectionNode :=  "@connection (" + COMPONENT + "." + PIN + "," + BUS) {" + CONNECTION + "}"
*
****************************************************************************/
PResult<ConnectionNode> ComdelParser::parseConnection() {
    auto spanner = getSpanner();
    ConnectionNode connection;

    RETURN_IF_NOT_TOKEN(TokenType::KW_CONNECTION);

    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
    ASSIGN_OR_RETURN_IF_ERR(connection.first.component, parseIdentifier());
    RETURN_IF_NOT_TOKEN(TokenType::DOT);
    ASSIGN_OR_RETURN_IF_ERR(connection.first.pin, parseIdentifier());
    RETURN_IF_NOT_TOKEN(TokenType::COMMA);
    ASSIGN_OR_RETURN_IF_ERR(connection.bus, parseIdentifier());

    if(check(TokenType::COMMA)) {
        auto conn = ConnectionComponentNode{};
        RETURN_IF_NOT_TOKEN(TokenType::COMMA);
        RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
        ASSIGN_OR_RETURN_IF_ERR(conn.component, parseIdentifier());
        RETURN_IF_NOT_TOKEN(TokenType::DOT);
        ASSIGN_OR_RETURN_IF_ERR(conn.pin, parseIdentifier());
        connection.second = conn;
    }

    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    int wireCount = 0;

    while(!check(TokenType::RBRACE)) {
        if (check(TokenType::KW_ATTRIBUTE)) {
            APPEND_OR_RETURN_IF_ERR(connection.attributes, parseAttribute());
        } else if(check(TokenType::KW_WIRES)) {
            bump();
            auto wires = parseList<ValueNode>(TokenType::LBRACE, TokenType::RBRACE, TokenType::COMMA, false,
                      [this] { return parseConnectionWire(); });
            RETURN_IF_ERR(wires);
            if(wireCount == 0) {
                connection.firstWires = *wires;
            } else if(wireCount == 1 && connection.second.has_value()) {
                connection.secondWires = *wires;
            } else {
                return unexpected();
            }
            wireCount++;
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(connection);
}


/****************************************************************************
*
*    RuleNode :=  "@rule {" + if-else statements +  "}"
*
****************************************************************************/
PResult<RuleNode> ComdelParser::parseRule() {
    auto spanner = getSpanner();
    RuleNode rule;

    RETURN_IF_NOT_TOKEN(TokenType::KW_RULE);

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        APPEND_OR_RETURN_IF_ERR(rule.statements, parseIfStatement());
        if(check(TokenType::RBRACE)) {
            break;
        }
        RETURN_IF_NOT_TOKEN(TokenType::ELSE);
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(rule);
}


/****************************************************************************
*
*    IfStatement := "if(!function(params...)) { error(MESSAGE) | warning(MESSAGE) }
*
****************************************************************************/
PResult<IfStatementNode> ComdelParser::parseIfStatement() {
    auto spanner = getSpanner();
    IfStatementNode ifStatement;

    RETURN_IF_NOT_TOKEN(TokenType::IF);

    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);

    if(check(TokenType::NOT)) {
        ifStatement.condition.negated = true;
        bump();
    } else {
        ifStatement.condition.negated = false;
    }

    ASSIGN_OR_RETURN_IF_ERR(ifStatement.condition.functionName, parseIdentifier());

    ASSIGN_OR_RETURN_IF_ERR(ifStatement.condition.params, parseList<ValueNode>(std::optional<TokenType>(TokenType::LPAREN),
                                                                           TokenType::RPAREN,
                                                                           TokenType::COMMA,
                                                                           false,
                                                                           [this]{return parseValue();}
                                                                           ));

    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    if(check(TokenType::ERROR)) {
        ifStatement.action.type = EnumNode(ActionNode::ERROR);
    } else if(check(TokenType::WARNING)) {
        ifStatement.action.type = EnumNode(ActionNode::WARNING);
    } else {
        return unexpected();
    }
    bump();

    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
    ASSIGN_OR_RETURN_IF_ERR(ifStatement.action.message, parseString());
    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);


    return spanner(ifStatement);
}

PResult<ValueNode> ComdelParser::parseValue() {
    auto spanner = getSpanner();
    ValueNode value;

    if(check(TokenType::IDENTIFIER)) {
        value = ValueNode::ofIdentifier(parseIdentifier()->value);
    } else if(check(TokenType::STRING)) {
        value = ValueNode::ofString(parseString()->asString());
    } else if(check(TokenType::NUMBER)) {
        value = ValueNode::ofInt(parseNumber()->value);
    } else if(check(TokenType::TRUE)) {
        bump();
        value = ValueNode::ofBool(true);
    } else if(check(TokenType::FALSE)) {
        bump();
        value = ValueNode::ofBool(false);
    } else if(check(TokenType::NIL)) {
        bump();
        value = ValueNode::ofNull();
    } else {
        return unexpected();
    }

    return spanner(value);
}

std::optional<SchemaNode> ComdelParser::parseSchema() {
    auto spanner = getSpanner();
    SchemaNode schema{};

    if(check(TokenType::KW_SOURCE)) {
        bump();
        if(check(TokenType::STRING)) {
            auto source = parseString();
            schema.source = *source;
        } else {
            errors.emplace_back(current().span, "expected `@source`");
            return std::nullopt;
        }
    } else {
        errors.emplace_back(current().span, "expected `@source`");
        return std::nullopt;
    }

    if(!check(TokenType::KW_SCHEMA)) {
        errors.emplace_back(current().span, "expected `@schema`");
        return std::nullopt;
    }
    bump();
    if(!check(TokenType::LBRACE)) {
        errors.emplace_back(current().span, "expected `{`");
        return std::nullopt;
    }
    bump();

    while ( ! check(TokenType::RBRACE) ) {
        PResult<poly<AstNode>> err;
        if(check(TokenType::KW_INSTANCE)){
            APPEND_OR_SET_ERR(schema.instances, parseInstance());
        } else if(check(TokenType::KW_WIRE)) {
            APPEND_OR_SET_ERR(schema.wires, parseWireInstance());
        } else if(check(TokenType::KW_CONNECTION)) {
            APPEND_OR_SET_ERR(schema.connections, parseConnectionInstance());
        } else {
            err = unexpected();
        }
        if(!err.has_value()) {
            errors.push_back(err.error());
            break;
        }
    }
    if(!check(TokenType::RBRACE)) {
        errors.emplace_back(current().span, "expected `}`");
        return std::nullopt;
    } else {
        bump();
    }

    if(!check(TokenType::END_OF_FILE)) {
        errors.emplace_back(current().span, "expected `EOF`");
    }

    if (errors.size())
        return std::nullopt;

    return spanner(schema);
}
PResult<WireInstanceNode> ComdelParser::parseWireInstance() {
    auto spanner = getSpanner();
    WireInstanceNode wireInstance;

    RETURN_IF_NOT_TOKEN(TokenType::KW_WIRE);
    ASSIGN_OR_RETURN_IF_ERR(wireInstance.name, parseIdentifier());
    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        if(check(TokenType::KW_POSITION)) {
            ASSIGN_OR_RETURN_IF_ERR(wireInstance.position, parsePosition());
        } else if(check(TokenType::KW_DISPLAY)) {
            ASSIGN_OR_RETURN_IF_ERR(wireInstance.display, parseDisplay());
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(wireInstance);

}


/****************************************************************************
*
*    CountNode := "@position (" + NumberNode + "," + NumberNode + ")"
*
****************************************************************************/
PResult<CountNode> ComdelParser::parsePosition()
{
    auto spanner = getSpanner();
    RETURN_IF_NOT_TOKEN(TokenType::KW_POSITION);

    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
    auto first = parseNumber();
    if(!first.has_value()) {
        return PError(first.error());
    }
    RETURN_IF_NOT_TOKEN(TokenType::COMMA);
    auto second = parseNumber();
    if(!second.has_value()) {
        return PError(second.error());
    }
    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    return spanner(CountNode{first.value(), second.value()});
}

PResult<InstanceNode> ComdelParser::parseInstance() {
    auto spanner = getSpanner();
    RETURN_IF_NOT_TOKEN(TokenType::KW_INSTANCE);

    InstanceNode instance;

    ASSIGN_OR_RETURN_IF_ERR(instance.name, parseIdentifier());
    ASSIGN_OR_RETURN_IF_ERR(instance.component, parseIdentifier());

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        if(check(TokenType::KW_POSITION)) {
            ASSIGN_OR_RETURN_IF_ERR(instance.position, parsePosition());
        } else if(check(TokenType::KW_ATTRIBUTE)) {
            APPEND_OR_RETURN_IF_ERR(instance.attributes, parseInstanceAttribute());
        } else if(check(TokenType::KW_SIZE)) {
            bump();
            auto number = parseNumber();
            RETURN_IF_ERR(number);
            instance.size = *number;
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(instance);
}
PResult<InstanceAttributeNode> ComdelParser::parseInstanceAttribute() {
    auto spanner = getSpanner();
    RETURN_IF_NOT_TOKEN(TokenType::KW_ATTRIBUTE);
    InstanceAttributeNode attribute;

    ASSIGN_OR_RETURN_IF_ERR(attribute.name, parseIdentifier());
    ASSIGN_OR_RETURN_IF_ERR(attribute.value, parseValue());

    return spanner(attribute);
}
PResult<ConnectionInstanceNode> ComdelParser::parseConnectionInstance() {
    auto spanner = getSpanner();
    RETURN_IF_NOT_TOKEN(TokenType::KW_CONNECTION);

    ConnectionInstanceNode connection;

    RETURN_IF_NOT_TOKEN(TokenType::LPAREN);
    ASSIGN_OR_RETURN_IF_ERR(connection.first.instance, parseIdentifier());
    RETURN_IF_NOT_TOKEN(TokenType::DOT);
    ASSIGN_OR_RETURN_IF_ERR(connection.first.pin, parseIdentifier());
    RETURN_IF_NOT_TOKEN(TokenType::COMMA);
    ASSIGN_OR_RETURN_IF_ERR(connection.bus, parseIdentifier());

    if(check(TokenType::COMMA)) {
        bump();
        ConnectionComponentInstance second;
        ASSIGN_OR_RETURN_IF_ERR(second.instance, parseIdentifier());
        RETURN_IF_NOT_TOKEN(TokenType::DOT);
        ASSIGN_OR_RETURN_IF_ERR(second.pin, parseIdentifier());
        connection.second = second;
    }

    RETURN_IF_NOT_TOKEN(TokenType::RPAREN);

    RETURN_IF_NOT_TOKEN(TokenType::LBRACE);

    while(!check(TokenType::RBRACE)) {
        if(check(TokenType::KW_WIRE)) {
            bump();
            ASSIGN_OR_RETURN_IF_ERR(connection.wire, parseIdentifier());
        } else if(check(TokenType::KW_ATTRIBUTE)) {
            APPEND_OR_RETURN_IF_ERR(connection.attributes, parseInstanceAttribute());
        } else {
            return unexpected();
        }
    }

    RETURN_IF_NOT_TOKEN(TokenType::RBRACE);

    return spanner(connection);
}

PResult<ValueNode> ComdelParser::parseConnectionWire() {
    if(check(TokenType::NUMBER)) {
        return ValueNode::ofInt(parseNumber()->value);
    } else if(check(TokenType::NIL)) {
        bump();
        return ValueNode::ofNull();
    } else if(check(TokenType::IDENTIFIER)) {
        return ValueNode::ofIdentifier(parseIdentifier()->value);
    } else {
        return unexpected();
    }
}