package com.company.agentfoundation.integration.wecom;

import com.company.agentfoundation.config.FoundationProperties;
import com.company.agentfoundation.domain.ChatRequest;
import com.company.agentfoundation.domain.ChatResponse;
import com.company.agentfoundation.security.AgentContext;
import com.company.agentfoundation.service.ChatService;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.*;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.HexFormat;
import java.util.List;

@RestController
@RequestMapping("/v1/integrations/wecom")
public class WecomCallbackController {
  private final FoundationProperties properties;
  private final ChatService chatService;
  private final WecomClient wecomClient;
  private final XmlMapper xmlMapper = new XmlMapper();

  public WecomCallbackController(FoundationProperties properties, ChatService chatService, WecomClient wecomClient) {
    this.properties = properties;
    this.chatService = chatService;
    this.wecomClient = wecomClient;
  }

  @GetMapping("/callback")
  public String verify(@RequestParam("msg_signature") String signature,
                       @RequestParam("timestamp") String timestamp,
                       @RequestParam("nonce") String nonce,
                       @RequestParam("echostr") String echostr) {
    if (!validSignature(signature, timestamp, nonce)) {
      throw new IllegalArgumentException("Invalid WeCom signature");
    }
    return echostr;
  }

  @PostMapping(value = "/callback", consumes = {MediaType.TEXT_XML_VALUE, MediaType.APPLICATION_XML_VALUE})
  public String receive(@RequestParam("msg_signature") String signature,
                        @RequestParam("timestamp") String timestamp,
                        @RequestParam("nonce") String nonce,
                        @RequestBody String body) throws Exception {
    if (!validSignature(signature, timestamp, nonce)) {
      throw new IllegalArgumentException("Invalid WeCom signature");
    }

    WecomIncomingMessage msg = xmlMapper.readValue(body, WecomIncomingMessage.class);
    if (msg == null || msg.getMsgType() == null || !"text".equalsIgnoreCase(msg.getMsgType())) {
      return "success";
    }

    String userText = msg.getContent() == null ? "" : msg.getContent().trim();
    if (userText.isBlank()) {
      return "success";
    }

    ChatRequest req = new ChatRequest(
        null,
        List.of(
            new ChatRequest.Message("system", "你是企业CRM智能助手。请给出简洁、可执行的客户跟进建议。"),
            new ChatRequest.Message("user", userText)
        ),
        0.3
    );

    ChatResponse chat = chatService.chat(new AgentContext(properties.getWecom().getCrmAgentId()), req);
    String reply = (chat.content() == null || chat.content().isBlank()) ? "我已收到你的请求，但暂时无法生成建议。" : chat.content();
    wecomClient.sendText(msg.getFromUserName(), reply);

    return "success";
  }

  private boolean validSignature(String signature, String timestamp, String nonce) {
    String token = properties.getWecom().getToken();
    if (token == null || token.isBlank()) {
      return false;
    }

    String[] arr = new String[]{token, timestamp, nonce};
    Arrays.sort(arr);
    String raw = String.join("", arr);

    try {
      MessageDigest digest = MessageDigest.getInstance("SHA-1");
      byte[] sha1 = digest.digest(raw.getBytes(StandardCharsets.UTF_8));
      String localSignature = HexFormat.of().formatHex(sha1);
      return signature.equalsIgnoreCase(localSignature);
    } catch (Exception e) {
      return false;
    }
  }
}