package de.zonlykroks.advancedscripts.lexer;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public class ScriptSyntaxPacketParser {

    private ScriptSyntaxPacketParser() {
        throw new IllegalStateException("Utility class");
    }

    private static final TokenType[] TOKEN_TYPES = TokenType.values();

    private static void reset() {
        Operators.OPERATORS.clear();
        Headers.HEADERS.clear();
        VariablePrefixes.RPEFIXES.clear();
        VariableSuffixes.SUFFIXES.clear();
        Commands.COMMANDS.clear();
    }

    public static synchronized void parse(String scriptSyntax) {
        reset();

        JsonObject jsonObject = JsonParser.parseString(scriptSyntax).getAsJsonObject();
        for (String key : jsonObject.keySet()) {
            JsonArray jsonElements = jsonObject.get(key).getAsJsonArray();
            if (key.startsWith("@")) {
                parseSpecial(key, jsonElements);
            } else {
                parseCommand(key, jsonElements);
            }
        }
    }

    private static void parseCommand(String key, JsonArray value) {
        boolean repeating = value.get(0).getAsBoolean();
        List<List<TokenType>> validArgumentTypes = new ArrayList<>();
        for (int i = 1; i < value.size(); i++) {
            JsonArray parameters = value.get(i).getAsJsonArray();
            List<TokenType> parameterTypes = new ArrayList<>();
            for (JsonElement parameter : parameters) {
                parameterTypes.add(TOKEN_TYPES[parameter.getAsInt()]);
            }
            validArgumentTypes.add(parameterTypes);
        }
        Commands.COMMANDS.put(key, new Command(repeating, validArgumentTypes));
    }

    private static void parseSpecial(String key, JsonArray value) {
        Set<String> set;
        switch (key) {
            case "@operators":
                set = Operators.OPERATORS;
                break;
            case "@headers":
                set = Headers.HEADERS;
                break;
            case "@prefixes":
                set = VariablePrefixes.RPEFIXES;
                break;
            case "@suffixes":
                set = VariableSuffixes.SUFFIXES;
                break;
            default:
                return;
        }
        for (JsonElement element : value) {
            set.add(element.getAsString());
        }
    }
}