package io.dico.dicore.command.parameter.type;

import io.dico.dicore.Reflection;
import io.dico.dicore.command.CommandException;
import io.dico.dicore.command.ExecutionContext;
import io.dico.dicore.command.annotation.Range;
import io.dico.dicore.command.parameter.ArgumentBuffer;
import io.dico.dicore.command.parameter.Parameter;
import org.bukkit.Location;
import org.bukkit.command.CommandSender;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Objects;

/**
 * A parameter type.
 * Takes care of parsing, default values as well as completions.
 *
 * @param <TReturn>    type of the parameter
 * @param <TParamInfo> the info object type for the parameter (Example: {@link Range.Memory}
 */
public abstract class ParameterType<TReturn, TParamInfo> {
    private final Class<TReturn> returnType;
    private final ParameterConfig<?, TParamInfo> parameterConfig;
    protected final ParameterType<TReturn, TParamInfo> otherType; // flag or non-flag, depending on current

    public ParameterType(Class<TReturn> returnType) {
        this(returnType, null);
    }

    public ParameterType(Class<TReturn> returnType, ParameterConfig<?, TParamInfo> paramConfig) {
        this.returnType = Objects.requireNonNull(returnType);
        this.parameterConfig = paramConfig;

        ParameterType<TReturn, TParamInfo> otherType = flagTypeParameter();
        this.otherType = otherType == null ? this : otherType;
    }

    protected ParameterType(Class<TReturn> returnType, ParameterConfig<?, TParamInfo> parameterConfig, ParameterType<TReturn, TParamInfo> otherType) {
        this.returnType = returnType;
        this.parameterConfig = parameterConfig;
        this.otherType = otherType;
    }

    public int getExpectedAmountOfConsumedArguments() {
        return 1;
    }

    public boolean canBeFlag() {
        return this == otherType;
    }

    public boolean isFlagExplicitly() {
        return this instanceof FlagParameterType;
    }

    /**
     * @return The return type
     */
    public final Class<TReturn> getReturnType() {
        return returnType;
    }

    public final Class<?> getAnnotationClass() {
        return parameterConfig == null ? null : parameterConfig.getAnnotationClass();
    }

    public final ParameterConfig<?, TParamInfo> getParameterConfig() {
        return parameterConfig;
    }

    public ParameterKey getTypeKey() {
        return new ParameterKey(returnType, parameterConfig != null ? parameterConfig.getAnnotationClass() : null);
    }

    public ParameterKey getInfolessTypeKey() {
        return new ParameterKey(returnType, null);
    }

    protected FlagParameterType<TReturn, TParamInfo> flagTypeParameter() {
        return null;
    }

    public ParameterType<TReturn, TParamInfo> asFlagParameter() {
        return canBeFlag() ? this : otherType;
    }

    public ParameterType<TReturn, TParamInfo> asNormalParameter() {
        return isFlagExplicitly() ? otherType : this;
    }

    public abstract TReturn parse(Parameter<TReturn, TParamInfo> parameter, CommandSender sender, ArgumentBuffer buffer) throws CommandException;

    public TReturn parseForContext(Parameter<TReturn, TParamInfo> parameter, ExecutionContext context, ArgumentBuffer buffer) throws CommandException {
        return parse(parameter, context.getSender(), buffer);
    }

    public TReturn getDefaultValue(Parameter<TReturn, TParamInfo> parameter, CommandSender sender, ArgumentBuffer buffer) throws CommandException {
        return null;
    }

    public TReturn getDefaultValueForContext(Parameter<TReturn, TParamInfo> parameter, ExecutionContext context, ArgumentBuffer buffer) throws CommandException {
        return getDefaultValue(parameter, context.getSender(), buffer);
    }

    public List<String> complete(Parameter<TReturn, TParamInfo> parameter, CommandSender sender, Location location, ArgumentBuffer buffer) {
        return Collections.emptyList();
    }

    public List<String> completeForContext(Parameter<TReturn, TParamInfo> parameter, ExecutionContext context, Location location, ArgumentBuffer buffer) {
        return complete(parameter, context.getSender(), location, buffer);
    }

    protected static abstract class FlagParameterType<TResult, TParamInfo> extends ParameterType<TResult, TParamInfo> {

        protected FlagParameterType(ParameterType<TResult, TParamInfo> otherType) {
            super(otherType.returnType, otherType.parameterConfig, otherType);
        }

        @Override
        public int getExpectedAmountOfConsumedArguments() {
            return otherType.getExpectedAmountOfConsumedArguments();
        }

        @Override
        public boolean canBeFlag() {
            return true;
        }

        @Override
        protected final FlagParameterType<TResult, TParamInfo> flagTypeParameter() {
            return this;
        }

        @Override
        public ParameterType<TResult, TParamInfo> asFlagParameter() {
            return this;
        }

        @Override
        public ParameterType<TResult, TParamInfo> asNormalParameter() {
            return otherType;
        }

    }

}