package com.baiyue.integration.provider;

import com.baiyue.integration.config.IntegrationProperties;
import com.baiyue.integration.dto.CarrierScheduleDtos.QueryRequest;
import jakarta.annotation.PostConstruct;
import jakarta.annotation.Resource;
import org.springframework.stereotype.Component;
import org.springframework.web.util.HtmlUtils;

import java.io.IOException;
import java.net.URLEncoder;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpTimeoutException;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

@Component
public class EvergreenTrackingClient {
    private static final Pattern INPUT = Pattern.compile("(?is)<input\\b[^>]*>");
    private static final Pattern ATTRIBUTE = Pattern.compile("(?i)\\b([a-z_:][-a-z0-9_:.]*)\\s*=\\s*([\"'])(.*?)\\2");
    private static final Pattern DISP_INFO = Pattern.compile("(?is)GetDispInfo[^0-9]{0,160}(\\d{12})");
    private static final Pattern BL_QUERY = Pattern.compile("(?i)(?:[?&]|&amp;)(?:BL|bl_no)=(\\d{12})");
    private final Object requestLock = new Object();
    @Resource private IntegrationProperties properties;
    private IntegrationProperties.CarrierSchedule.Evergreen config;
    private HttpClient httpClient;
    private long nextRequestAtMillis;

    @PostConstruct
    void initialize() {
        config = properties.carrierSchedule() == null ? null : properties.carrierSchedule().evergreen();
        httpClient = HttpClient.newBuilder()
            .connectTimeout(config == null ? Duration.ofSeconds(10) : config.effectiveConnectTimeout())
            .followRedirects(HttpClient.Redirect.NORMAL).build();
    }

    public boolean configured() { return config != null && config.configured(); }

    public TrackingResponse query(QueryRequest request) {
        if (!configured()) manual("EMC_NOT_CONFIGURED", "长荣公开货柜动态查询未启用");
        if (!"CONTAINER_NO".equalsIgnoreCase(request.trackingType())) {
            manual("EMC_CONTAINER_REQUIRED", "长荣首批自动节点仅支持柜号查询");
        }
        synchronized (requestLock) {
            waitForSlot();
            try {
                String container = normalize(request.trackingNo());
                String containerHtml = post("TYPE=CNTR&CNTR=" + encode(container), "CONTAINER");
                String bill = relatedBill(containerHtml);
                if (bill == null) manual("EMC_RELATED_BL_MISSING", "长荣柜号结果缺少关联提单，需人工复核");
                String billHtml = post("TYPE=BL&BL=" + encode(bill), "BILL");
                return new TrackingResponse(containerHtml, billHtml, bill.substring(bill.length() - 4),
                    containerHtml + billHtml);
            } finally {
                nextRequestAtMillis = System.currentTimeMillis() + config.effectiveMinRequestInterval().toMillis();
            }
        }
    }

    private String post(String form, String stage) {
        try {
            HttpResponse<String> response = httpClient.send(HttpRequest.newBuilder(config.queryUrl())
                    .timeout(config.effectiveRequestTimeout()).header("Accept", "text/html")
                    .header("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8")
                    .POST(HttpRequest.BodyPublishers.ofString(form, StandardCharsets.UTF_8)).build(),
                HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8));
            if (response.statusCode() == 429 || response.statusCode() >= 500) {
                throw retryable("EMC_" + stage + "_HTTP_" + response.statusCode(), "长荣公开查询暂时不可用", null);
            }
            if (response.statusCode() < 200 || response.statusCode() >= 300) {
                manual("EMC_" + stage + "_HTTP_" + response.statusCode(), "长荣公开查询拒绝请求");
            }
            if (!looksLikeHtml(response.body())) manual("EMC_" + stage + "_NON_HTML", "长荣返回非 HTML 内容");
            return response.body();
        } catch (EvergreenTrackingException exception) {
            throw exception;
        } catch (HttpTimeoutException exception) {
            throw retryable("EMC_" + stage + "_TIMEOUT", "长荣公开查询超时", exception);
        } catch (InterruptedException exception) {
            Thread.currentThread().interrupt();
            throw retryable("EMC_" + stage + "_INTERRUPTED", "长荣公开查询被中断", exception);
        } catch (IOException exception) {
            throw retryable("EMC_" + stage + "_IO_FAILED", "长荣公开查询网络失败", exception);
        }
    }

    static String relatedBill(String html) {
        Matcher inputs = INPUT.matcher(html == null ? "" : html);
        while (inputs.find()) {
            String name = attribute(inputs.group(), "name");
            String value = HtmlUtils.htmlUnescape(attribute(inputs.group(), "value"));
            if ("bl_no".equalsIgnoreCase(name) && value.matches("\\d{12}")) return value;
        }
        String decoded = HtmlUtils.htmlUnescape(html == null ? "" : html);
        Matcher action = DISP_INFO.matcher(decoded);
        if (action.find()) return action.group(1);
        Matcher query = BL_QUERY.matcher(decoded);
        return query.find() ? query.group(1) : null;
    }

    private static String attribute(String tag, String expected) {
        Matcher attributes = ATTRIBUTE.matcher(tag);
        while (attributes.find()) if (expected.equalsIgnoreCase(attributes.group(1))) return attributes.group(3).trim();
        return "";
    }
    private static boolean looksLikeHtml(String value) {
        String lower = value == null ? "" : value.toLowerCase(Locale.ROOT);
        return lower.contains("<html") || lower.contains("<table") || lower.contains("<input");
    }
    private void waitForSlot() {
        long wait = nextRequestAtMillis - System.currentTimeMillis();
        if (wait <= 0) return;
        try { Thread.sleep(wait); }
        catch (InterruptedException exception) {
            Thread.currentThread().interrupt();
            throw retryable("EMC_INTERRUPTED", "等待长荣查询限流窗口时被中断", exception);
        }
    }
    private static void manual(String code, String message) {
        throw new EvergreenTrackingException("MANUAL_REQUIRED", code, message);
    }
    private static EvergreenTrackingException retryable(String code, String message, Throwable cause) {
        return new EvergreenTrackingException("RETRYABLE_FAILURE", code, message, cause);
    }
    private static String normalize(String value) {
        return value == null ? "" : value.replaceAll("[^A-Za-z0-9]", "").toUpperCase(Locale.ROOT);
    }
    private static String encode(String value) { return URLEncoder.encode(value, StandardCharsets.UTF_8); }

    public record TrackingResponse(String containerHtml, String billHtml, String billSuffix, String rawBody) {
        @Override public String toString() {
            return "TrackingResponse[billSuffix=" + billSuffix + ",html=<redacted>]";
        }
    }
    public static final class EvergreenTrackingException extends RuntimeException {
        private final String outcome; private final String code;
        public EvergreenTrackingException(String outcome, String code, String message) {
            super(message); this.outcome = outcome; this.code = code;
        }
        public EvergreenTrackingException(String outcome, String code, String message, Throwable cause) {
            super(message, cause); this.outcome = outcome; this.code = code;
        }
        public String outcome() { return outcome; }
        public String code() { return code; }
    }
}