package com.goldenchart.service;

import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.filter.Filter;
import ch.qos.logback.core.read.ListAppender;
import ch.qos.logback.core.spi.FilterReply;
import org.slf4j.LoggerFactory;
import org.ta4j.core.Rule;
import org.ta4j.core.TradingRecord;

/**
 * Ta4j Rule 평가 시 TRACE 로그를 메모리에 수집 (AI 검증용).
 */
final class Ta4jRuleTraceCapture implements AutoCloseable {

    private static final int MAX_LINES = 100;
    private static final int MAX_LINE_LEN = 600;

    private final ListAppender<ILoggingEvent> appender;
    private final Logger rulesLogger;
    private final Level previousLevel;

    private Ta4jRuleTraceCapture(ListAppender<ILoggingEvent> appender, Logger rulesLogger, Level previousLevel) {
        this.appender = appender;
        this.rulesLogger = rulesLogger;
        this.previousLevel = previousLevel;
    }

    static Ta4jRuleTraceCapture open() {
        LoggerContext ctx = (LoggerContext) LoggerFactory.getILoggerFactory();
        Logger rulesLogger = ctx.getLogger("org.ta4j.core.rules");
        Level prev = rulesLogger.getLevel();

        ListAppender<ILoggingEvent> appender = new ListAppender<>();
        appender.addFilter(new Filter<>() {
            @Override
            public FilterReply decide(ILoggingEvent event) {
                if (event == null || event.getLoggerName() == null) return FilterReply.DENY;
                return event.getLoggerName().startsWith("org.ta4j.core.rules")
                        ? FilterReply.ACCEPT
                        : FilterReply.DENY;
            }
        });
        appender.setContext(ctx);
        appender.start();

        rulesLogger.setLevel(Level.TRACE);
        rulesLogger.setAdditive(true);
        rulesLogger.addAppender(appender);

        return new Ta4jRuleTraceCapture(appender, rulesLogger, prev);
    }

    boolean evaluateWithTrace(Rule rule, int index, TradingRecord tradingRecord) {
        return rule.isSatisfiedWithTraceMode(index, tradingRecord, Rule.TraceMode.VERBOSE);
    }

    java.util.List<String> lines() {
        return appender.list.stream()
                .filter(e -> e.getLevel().isGreaterOrEqual(Level.TRACE))
                .map(ILoggingEvent::getFormattedMessage)
                .map(Ta4jRuleTraceCapture::truncate)
                .limit(MAX_LINES)
                .toList();
    }

    @Override
    public void close() {
        rulesLogger.detachAppender(appender);
        appender.stop();
        rulesLogger.setLevel(previousLevel);
    }

    private static String truncate(String s) {
        if (s == null) return "";
        if (s.length() <= MAX_LINE_LEN) return s;
        return s.substring(0, MAX_LINE_LEN) + "…";
    }
}