package com.github.dtschust.zork.parser;

import com.github.dtschust.zork.ZorkGame;
import com.github.dtschust.zork.objects.*;

import java.util.Map;

import static com.github.dtschust.zork.objects.ZorkObjectTypes.*;

public abstract class ZorkParser {
    private final Map<ZorkObjectTypes, PropertyParseStrategy<? extends ZorkObject>> strategies;

    public ZorkParser(final PropertyParseStrategy<ZorkCreature> creatureStrategy,
                      final PropertyParseStrategy<ZorkContainer> containerStrategy,
                      final PropertyParseStrategy<ZorkItem> itemStrategy,
                      final PropertyParseStrategy<ZorkRoom> roomStrategy) {
        this.strategies = Map.ofEntries(
                Map.entry(CREATURE, creatureStrategy),
                Map.entry(CONTAINER, containerStrategy),
                Map.entry(ITEM, itemStrategy),
                Map.entry(ROOM, roomStrategy)
        );
    }

    protected abstract Property getRootProperty(final String filename);

    public ZorkGame parse(final String filename) {
        ZorkGame data = new ZorkGame();

        final Property rootElement = getRootProperty(filename);

        // Every single first generation child is a room, container, creature, or item. So load them in
        for (final Property element : rootElement.subProperties()) {
            final String name = element.name();
            final ZorkObjectTypes t = ZorkObjectTypes.fromPropertyName(name)
                    .orElseThrow(() -> new IllegalStateException("Unexpected value: " + name));
            final ZorkObject built = strategies.get(t).parse(element);
            data.addObjectThroughLookup(t, built);
        }

        return data;
    }
}