package io.trygvis.persistence.generators;

import io.trygvis.container.compiler.model.FieldRef;
import io.trygvis.container.compiler.model.MethodRef;
import io.trygvis.container.compiler.model.Parameters;
import io.trygvis.container.compiler.model.TypeRef;

import java.io.CharArrayWriter;
import java.io.PrintWriter;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.List;

import static java.lang.reflect.Modifier.*;
import static org.apache.commons.lang.StringUtils.join;

public class GeneratorUtils {
    public static FieldRef staticVersion(TypeRef interfaceType, String interfaceMethod, MethodRef methodRef, TypeRef klass) {
        if (!Modifier.isStatic(methodRef.modifiers)) {
            throw new RuntimeException("This only works on static methods.");
        }

        List<String> params = new ArrayList<>();
        List<String> args = new ArrayList<>();
        for (Parameters.ParameterRef parameter : methodRef.parameters) {
            params.add(parameter.klass.plainName + " " + parameter.name);
            args.add(parameter.name);
        }

        List<String> exceptions = new ArrayList<>();
        for (TypeRef exception : methodRef.exceptions) {
            exceptions.add(exception.plainName);
        }

        String e = exceptions.isEmpty() ? "" : "throws " + join(exceptions, ", ") + " ";

        CharArrayWriter buffer = new CharArrayWriter();
        PrintWriter w = new PrintWriter(buffer);
        w.println("new " + interfaceType.plainName + "() {");
        w.println("    public " + methodRef.returnType.plainName + " " + interfaceMethod + "(" + join(params, ", ") + ") " + e + "{");
        w.println("        return " + klass.plainName + "." + methodRef.name + "(" + join(args, ", ") + ");");
        w.println("    }");
        w.println("}");
        return new FieldRef(PUBLIC | STATIC | FINAL, interfaceType, methodRef.name).value(buffer.toString());
    }
}