/*
 * Copyright 2012 astamuse company,Ltd.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package com.astamuse.asta4d.snippet;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import com.astamuse.asta4d.Configuration;
import com.astamuse.asta4d.Context;
import com.astamuse.asta4d.interceptor.base.Executor;
import com.astamuse.asta4d.interceptor.base.InterceptorUtil;
import com.astamuse.asta4d.render.RenderUtil;
import com.astamuse.asta4d.render.Renderer;
import com.astamuse.asta4d.snippet.extract.SnippetExtractor;
import com.astamuse.asta4d.snippet.interceptor.ContextDataAutowireInterceptor;
import com.astamuse.asta4d.snippet.interceptor.SnippetInitializeInterceptor;
import com.astamuse.asta4d.snippet.interceptor.SnippetInterceptor;
import com.astamuse.asta4d.snippet.resolve.SnippetResolver;

public class DefaultSnippetInvoker implements SnippetInvoker {

    private List<SnippetInterceptor> snippetInterceptorList = getDefaultSnippetInterceptorList();

    protected static class InterceptorResult {
        Renderer renderer = null;
        SnippetInterceptor finalInterceptor = null;
    }

    @Override
    public Renderer invoke(String renderDeclaration) throws SnippetNotResovlableException, SnippetInvokeException {
        Configuration conf = Configuration.getConfiguration();

        SnippetExtractor extractor = conf.getSnippetExtractor();
        SnippetDeclarationInfo declaration = extractor.extract(renderDeclaration);

        SnippetResolver resolver = conf.getSnippetResolver();
        SnippetExcecutionInfo exeInfo = resolver.resloveSnippet(declaration);

        SnippetExecutionHolder execution = new SnippetExecutionHolder(declaration, exeInfo.getInstance(), exeInfo.getMethod(), null, null);

        Executor<SnippetExecutionHolder> executor = new Executor<SnippetExecutionHolder>() {
            @Override
            public void execute(SnippetExecutionHolder executionHolder) throws Exception {
                Object instance = executionHolder.getInstance();
                Method method = executionHolder.getMethod();
                Object[] params = executionHolder.getParams();

                if (params == null) {
                    executionHolder.setExecuteResult((Renderer) method.invoke(instance));
                } else {
                    executionHolder.setExecuteResult((Renderer) method.invoke(instance, params));
                }
            }
        };
        Context context = Context.getCurrentThreadContext();
        try {
            context.setData(RenderUtil.TRACE_VAR_SNIPPET, execution.getInstance());
            InterceptorUtil.executeWithInterceptors(execution, snippetInterceptorList, executor);
            return execution.getExecuteResult();
        } catch (SnippetInvokeException ex) {
            throw ex;
        } catch (Exception ex) {
            String rawMsg = ex instanceof InvocationTargetException ? ((InvocationTargetException) ex).getTargetException().getMessage()
                    : ex.getMessage();

            Object[] params = execution.getParams();
            String msg = "execute with params:" + (params == null ? null : Arrays.asList(params)) + ".";
            msg += " The raw exception message is:" + rawMsg;

            throw new SnippetInvokeException(declaration, msg, ex);
        } finally {
            context.setData(RenderUtil.TRACE_VAR_SNIPPET, null);
        }

    }

    protected List<SnippetInterceptor> getDefaultSnippetInterceptorList() {
        List<SnippetInterceptor> list = new ArrayList<>();
        list.add(new ContextDataAutowireInterceptor());
        list.add(new SnippetInitializeInterceptor());
        return list;
    }

    public List<SnippetInterceptor> getSnippetInterceptorList() {
        return snippetInterceptorList;
    }

    public void setSnippetInterceptorList(List<SnippetInterceptor> snippetInterceptorList) {
        this.snippetInterceptorList.clear();
        this.snippetInterceptorList.addAll(getDefaultSnippetInterceptorList());
        if (snippetInterceptorList != null) {
            this.snippetInterceptorList.addAll(snippetInterceptorList);
        }
    }

}