package com.vincent.rsf.server.ai.service.impl.chat;

import com.vincent.rsf.server.ai.dto.AiChatThinkingEventDto;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;

import java.time.Instant;
import java.util.Objects;

public class AiThinkingTraceEmitter {

    private final AiSseEventPublisher aiSseEventPublisher;
    private final SseEmitter emitter;
    private final String requestId;
    private final Long sessionId;
    private String currentPhase;
    private String currentStatus;

    public AiThinkingTraceEmitter(AiSseEventPublisher aiSseEventPublisher, SseEmitter emitter, String requestId, Long sessionId) {
        this.aiSseEventPublisher = aiSseEventPublisher;
        this.emitter = emitter;
        this.requestId = requestId;
        this.sessionId = sessionId;
    }

    public void startAnalyze() {
        if (currentPhase != null) {
            return;
        }
        currentPhase = "ANALYZE";
        currentStatus = "STARTED";
        emitThinkingEvent("ANALYZE", "STARTED", "正在分析问题",
                "已接收你的问题，正在理解意图并判断是否需要调用工具。", null);
    }

    public void onToolStart(String toolName, String toolCallId) {
        switchPhase("TOOL_CALL", "STARTED", "正在调用工具", "已判断需要调用工具，正在查询相关信息。", null);
        currentStatus = "UPDATED";
        emitThinkingEvent("TOOL_CALL", "UPDATED", "正在调用工具",
                "正在调用工具 " + safeLabel(toolName, "未知工具") + " 获取所需信息。", toolCallId);
    }

    public void onToolResult(String toolName, String toolCallId, boolean failed) {
        currentPhase = "TOOL_CALL";
        currentStatus = failed ? "FAILED" : "UPDATED";
        emitThinkingEvent("TOOL_CALL", failed ? "FAILED" : "UPDATED",
                failed ? "工具调用失败" : "工具调用完成",
                failed
                        ? "工具 " + safeLabel(toolName, "未知工具") + " 调用失败，正在评估失败影响并整理可用信息。"
                        : "工具 " + safeLabel(toolName, "未知工具") + " 已返回结果，正在继续分析并提炼关键信息。",
                toolCallId);
    }

    public void startAnswer() {
        switchPhase("ANSWER", "STARTED", "正在整理答案", "已完成分析，正在组织最终回复内容。", null);
    }

    public void completeCurrentPhase() {
        if (!StringUtils.hasText(currentPhase) || isTerminalStatus(currentStatus)) {
            return;
        }
        currentStatus = "COMPLETED";
        emitThinkingEvent(currentPhase, "COMPLETED", resolveCompleteTitle(currentPhase),
                resolveCompleteContent(currentPhase), null);
    }

    public void markTerminated(String terminalStatus) {
        if (!StringUtils.hasText(currentPhase) || isTerminalStatus(currentStatus)) {
            return;
        }
        currentStatus = terminalStatus;
        emitThinkingEvent(currentPhase, terminalStatus,
                "ABORTED".equals(terminalStatus) ? "思考已中止" : "思考失败",
                "ABORTED".equals(terminalStatus)
                        ? "本轮对话已被中止，思考过程提前结束。"
                        : "本轮对话在生成答案前失败，当前思考过程已停止。",
                null);
    }

    private void switchPhase(String nextPhase, String nextStatus, String title, String content, String toolCallId) {
        if (!Objects.equals(currentPhase, nextPhase)) {
            completeCurrentPhase();
        }
        currentPhase = nextPhase;
        currentStatus = nextStatus;
        emitThinkingEvent(nextPhase, nextStatus, title, content, toolCallId);
    }

    private void emitThinkingEvent(String phase, String status, String title, String content, String toolCallId) {
        aiSseEventPublisher.emitSafely(emitter, "thinking", AiChatThinkingEventDto.builder()
                .requestId(requestId)
                .sessionId(sessionId)
                .phase(phase)
                .status(status)
                .title(title)
                .content(content)
                .toolCallId(toolCallId)
                .timestamp(Instant.now().toEpochMilli())
                .build());
    }

    private boolean isTerminalStatus(String status) {
        return "COMPLETED".equals(status) || "FAILED".equals(status) || "ABORTED".equals(status);
    }

    private String resolveCompleteTitle(String phase) {
        if ("ANSWER".equals(phase)) {
            return "答案整理完成";
        }
        if ("TOOL_CALL".equals(phase)) {
            return "工具分析完成";
        }
        return "问题分析完成";
    }

    private String resolveCompleteContent(String phase) {
        if ("ANSWER".equals(phase)) {
            return "最终答复已生成完成。";
        }
        if ("TOOL_CALL".equals(phase)) {
            return "工具调用阶段已结束，相关信息已整理完毕。";
        }
        return "问题意图和处理方向已分析完成。";
    }

    private String safeLabel(String value, String fallback) {
        return StringUtils.hasText(value) ? value : fallback;
    }
}