import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

import jetbrick.template.JetAnnotations.Functions;
import jetbrick.template.JetContext;
import jetbrick.template.runtime.JetPageContext;
import jetbrick.template.web.JetWebContext;

import org.springframework.context.MessageSource;
import org.springframework.context.NoSuchMessageException;
import org.springframework.validation.BindingResult;
import org.springframework.validation.Errors;
import org.springframework.validation.FieldError;
import org.springframework.validation.ObjectError;
import org.springframework.web.servlet.support.RequestContextUtils;

@Functions
public class SpringFunctions {

	private static final List<String> EMPTY_STRING_LIST = Collections.unmodifiableList(new ArrayList<String>());
	
	public static List<String> errors(JetPageContext ctx, String filedName) {
		HttpServletRequest request = (HttpServletRequest) ctx.getContext().get(JetWebContext.REQUEST);
		
		Errors errors = findErrors(ctx);
		if (errors == null) {
			System.out.println("没有找到Errors");
			return EMPTY_STRING_LIST;
		}
		
		List<FieldError> fes =  errors.getFieldErrors(filedName);
		List<String> msgs = new ArrayList<String>(0);

		for(FieldError fe : fes) {
			String[] codes = fe.getCodes();
			String defaultMsg = fe.getDefaultMessage();
			Object[] args = fe.getArguments();
			Locale locale = findLocale(request);
			MessageSource ms = findMessageSource(request);
			
			if (codes == null || codes.length == 0 || ms == null) {
				msgs.add(defaultMsg);
			} else {
				String msg = null;
				for (int i = 0; i < codes.length; i ++) {
					try {
						msg = ms.getMessage(codes[i], args, locale);
					} catch (NoSuchMessageException e) {
						// 忽略
					}
					if (msg == null) {
						msg = defaultMsg;
					}
				}
				msgs.add(msg);
			}
		}
		
		return Collections.unmodifiableList(msgs);
	}

	public static List<String> errors(JetPageContext ctx) {
		HttpServletRequest request = (HttpServletRequest) ctx.getContext().get(JetWebContext.REQUEST);
		
		Errors errors = findErrors(ctx);
		if (errors == null) {
			return EMPTY_STRING_LIST;
		}
		
		List<ObjectError> oes = errors.getGlobalErrors();
		List<String> msgs = new ArrayList<String>(0);

		for (ObjectError oe : oes) {
			String[] codes = oe.getCodes();
			String defaultMsg = oe.getDefaultMessage();
			Object[] args = oe.getArguments();
			Locale locale = findLocale(request);
			MessageSource ms = findMessageSource(request);
			
			if (codes == null || codes.length == 0 || ms == null) {
				msgs.add(defaultMsg);
			} else {
				String msg = null;
				for (int i = 0; i < codes.length; i ++) {
					try {
						msg = ms.getMessage(codes[i], args, locale);
					} catch (NoSuchMessageException e) {
						// 忽略
					}
					if (msg == null) {
						msg = defaultMsg;
					}
				}
				msgs.add(msg);
			}
		}
		return Collections.unmodifiableList(msgs);
	}
	
	@SuppressWarnings("unchecked")
	private static Errors findErrors(JetPageContext ctx) {
		try {
			JetContext jetContext = ctx.getContext();
			Field[] fileds = JetContext.class.getDeclaredFields();
			
			Field f = null;
			for (Field field : fileds) {
				if (field.getName().equals("context")) {
					f = field;
					break;
				}
			}
			
			if (f == null) {
				return null;
			}
			
			f.setAccessible(true);
			Map<String, Object> context = (Map<String, Object>) f.get(jetContext);
			Set<String> keyset = context.keySet();
			String key = null;
			
			for (String k : keyset) {
				if (k.startsWith(BindingResult.MODEL_KEY_PREFIX)) {
					key = k;
					break;
				}
			}
			
			if (key == null) {
				return null;
			}
			
			return (Errors) jetContext.g