AngelscriptLanguageServer/server/src/src/ASTypeDefParser/Parser.cpp

#include "Parser.hpp"
#include <iostream>
#include <regex>
#include <unordered_set>
#include "TypeDefResult.hpp"
#include "angelscript.h"

namespace ASTypeDefParser {
    std::string trim(const std::string& str) {
        size_t first = str.find_first_not_of(" \r\n\t");
        if (std::string::npos == first) {
            return str;
        }
        size_t last = str.find_last_not_of(" \r\n\t");
        return str.substr(first, (last - first + 1));
    }

    static std::string ReadUpTo(const std::string& data, size_t& index, const std::unordered_set<char>& chars,
                                char& lastChar) {
        std::stringstream s;
        while (index < data.size()) {
            lastChar = data.at(index);
            if (lastChar == ' ' || lastChar == '\t' || lastChar == '\n' || lastChar == '\r') {
                index++;
                continue;
            } else {
                break;
            }
        }
        while (index < data.size()) {
            lastChar = data.at(index);
            if (chars.contains(lastChar)) {
                break;
            }
            s << lastChar;
            index++;
        }
        return s.str();
    }

#define Assert(expression)                                                                                             \
    if (!(expression)) {                                                                                               \
        throw std::logic_error("Failed assertion: " #expression);                                                      \
    }

    std::regex templateTypeCleaner("class ");
    std::regex propertyCleaner(R"((.*?)\s*(\w+)\s*\{\s*(get)?\s*(const)?;*\s*(set)?\s*(const)?;*\s*\})");

    static void ParseType(const std::string& type, TypeDefResult& result, const std::string& data, size_t& index) {
        char end;
        auto def = trim(ReadUpTo(data, index, {'{', ';'}, end));

        long flags;
        if (type == "type"){
            flags = asOBJ_REF | asOBJ_NOCOUNT;
        }
        else if (type == "valuetype"){
            flags = asOBJ_VALUE;
        }

        std::string className = def;
        if (def.find('<') != std::string::npos) {
            flags |= asOBJ_TEMPLATE;
            className = std::regex_replace(className, templateTypeCleaner, "");
        }

        std::vector<std::string> definitions;
        std::vector<std::tuple<int, std::string>> behaviours;
        if (end == '{') {
            index++;
            while (index < data.size()) {
                if (std::string(" \r\n\t").find(data.at(index)) != std::string::npos){
                    index++;
                    continue;
                }
                if (data.at(index) == '}') {
                    break;
                }
                auto innerDef = trim(ReadUpTo(data, index, {';'}, end));

                index++;
                if (innerDef.empty()) {
                    continue;
                }
                if (innerDef == "}") {
                    break;
                }

                if (innerDef.find("behave") == 0){
                    char c;
                    size_t pos = 0;
                    ReadUpTo(innerDef, pos, {'b'}, c);
                    ReadUpTo(innerDef, pos, {' '}, c);
                    pos++;
                    auto behaviour = ReadUpTo(innerDef, pos, {' '}, c);
                    auto i = std::stoi(behaviour);
                    auto d = ReadUpTo(innerDef, pos, {';'}, c);
                    behaviours.emplace_back(i, d);
                }
                // Ugly hack for properties.
                else if (innerDef.find('{') != std::string::npos) {
                    index--;
                    innerDef += ReadUpTo(data, index, {'}'}, end) + end;
                    index++;
                    std::smatch m;
                    if (std::regex_search(innerDef, m, propertyCleaner)) {
                        auto ret = m[1].str();
                        auto name = m[2].str();
                        if (m.size() > 3) {
                            if (m[3].str() == "get") {
                                bool isConst = m.size() > 4 && m[4].str() == "const";
                                auto decl = ret + " get_" + name + "() ";
                                if (isConst) {
                                    decl += "const ";
                                }
                                decl += "property";
                                definitions.push_back(decl);
                            }
                        }
                        if (m.size() > 5) {
                            if (m[5].str() == "set") {
                                bool isConst = m.size() > 6 && m[6].str() == "const";
                                auto decl = "void set_" + name + "(" + ret + " value) ";
                                if (isConst) {
                                    decl += "const ";
                                }
                                decl += "property";
                                definitions.push_back(decl);
                            }
                        }
                    }
                } else {
                    definitions.push_back(innerDef);
                }
            }
        }
        index++;
        result.StoreType(type, def, className, flags, definitions, behaviours);
    }
    static void ParseEnum(TypeDefResult& result, const std::string& data, size_t& index) {
        char end;
        auto def = trim(ReadUpTo(data, index, {'{'}, end));
        index++;
        std::vector<std::tuple<std::string, int>> values;
        auto block = ReadUpTo(data, index, {'}'}, end);
        size_t innerIndex = 0;
        int enumValue = 0;
        while (true) {
            if (innerIndex >= block.size()) {
                break;
            }
            auto statement = trim(ReadUpTo(block, innerIndex, {',', '}'}, end));
            innerIndex++;
            if (statement.empty()) {
                continue;
            }
            size_t i = 0;
            char statementEnd;
            auto first = trim(ReadUpTo(statement, i, {'='}, statementEnd));
            if (statementEnd == '=') {
                i++;
                auto val = trim(ReadUpTo(statement, i, {}, statementEnd));
                auto num = std::stoi(val);
                enumValue = num;
                values.emplace_back(first, enumValue);
            } else {
                values.emplace_back(first, enumValue);
            }
            enumValue++;
            if (end == '}') {
                break;
            }
        }
        result.StoreEnum(def, values);
    }

    static void ParseFunc(TypeDefResult& result, const std::string& data, size_t& index) {
        char end;
        auto statement = ReadUpTo(data, index, {';'}, end);
        result.StoreFunc(statement);
    }

    TypeDefResult Parser::ParseAndRegister(TypeDefResult& result, const std::string& data) {
        size_t index = 0;
        while (true) {
            if (index >= data.size()) {
                break;
            }

            auto c = data[index];
            if (c >= 'a' && c <= 'z') {
                std::stringstream identifier;
                while (c >= 'a' && c <= 'z') {
                    identifier << c;

                    index++;
                    if (index >= data.size()) {
                        break;
                    }
                    c = data[index];
                }
                auto str = identifier.str();
                if (str == "type" || str == "valuetype") {
                    index++;
                    ParseType(str, result, data, index);
                } else if (str == "enum") {
                    index++;
                    ParseEnum(result, data, index);
                } else if (str == "func") {
                    index++;
                    ParseFunc(result, data, index);
                }
            }

            index++;
        }
        return result;
    }
}