package handler

import (
	"net/http"
	"strconv"
	"time"

	"tcm-agent/internal/agent"
	"tcm-agent/internal/model/entity"

	"github.com/gin-gonic/gin"
)

// ========================================================================
//  病历 HTTP 接口处理器
//  ========================================================================
//  职责链：
//   HTTP 请求 → 参数校验 → 调用 Agent → 持久化 → 响应封装
//  ========================================================================

// EMRHandler 病历接口处理器
type EMRHandler struct {
	agentRunner *agent.Runner
	emrAgent   *agent.EMRGenerator
}

// NewEMRHandler 创建病历处理器
//
// 参数：
//
//	runner - Agent 引擎
//	scene  - 场景名（对应 config.yaml 中 routes 的 key）
//	        为空则使用默认值 "emr-generator"
func NewEMRHandler(runner *agent.Runner, scene string) *EMRHandler {
	return &EMRHandler{
		agentRunner: runner,
		emrAgent:   agent.NewEMRGenerator(runner, scene),
	}
}

// GenerateRequest 生成病历请求体
type GenerateRequest struct {
	PatientID      string   `json:"patient_id"      binding:"required"`
	ChiefComplaint string   `json:"chief_complaint" binding:"required"`
	HistoryNotes   string   `json:"history_notes"`
	Allergies      []string `json:"allergies"`
	PastIllness    []string `json:"past_illness"`
}

// Generate 根据主诉+病史生成病历
//
// POST /api/v1/emr/generate
//
// 完整生命周期：
//  1. 参数校验
//  2. Agent 感知 → 规划 → 检索 → 工具 → 反思 → 输出
//  3. 规则引擎质控
//  4. 持久化到数据库
//  5. 返回结构化响应
func (h *EMRHandler) Generate(c *gin.Context) {
	// ===== ① 参数校验 =====
	var req GenerateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{
			"error":   "参数错误",
			"detail":  err.Error(),
			"example": `{"patient_id":"P001","chief_complaint":"反复头晕3个月","history_notes":"...","allergies":[],"past_illness":[]}`,
		})
		return
	}

	doctorID := c.GetString("user_id")

	// ===== ②~⑤ 调用 Agent =====
	agentReq := &agent.EMRRequest{
		PatientID:      req.PatientID,
		ChiefComplaint: req.ChiefComplaint,
		HistoryNotes:   req.HistoryNotes,
		Allergies:      req.Allergies,
		PastIllness:    req.PastIllness,
	}

	resp, err := h.emrAgent.Generate(c.Request.Context(), agentReq)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{
			"error":  "病历生成失败",
			"detail": err.Error(),
		})
		return
	}

	// ===== ⑥ 持久化 =====
	emr := &entity.EMR{
		PatientID:  req.PatientID,
		DoctorID:   doctorID,
		Draft:      resp.Draft,
		Structured: resp.Structured,
		Status:     resp.Status,
		SessionID:  resp.SessionID,
		CreatedAt:  time.Now(),
		UpdatedAt:  time.Now(),
	}
	// dao.EMR.Create(emr) // 实际项目取消注释

	// ===== ⑦ 返回响应 =====
	c.JSON(http.StatusOK, gin.H{
		"code":    200,
		"message": "病历生成成功",
		"data": gin.H{
			"session_id":  resp.SessionID,
			"draft":       resp.Draft,
			"structured":  resp.Structured,
			"issues":      resp.Issues,
			"status":      resp.Status,
			"emr_id":      emr.ID,
			"next_action": getNextAction(resp.Status),
		},
	})
}

// KnowledgeQA 病历书写规范问答
//
// POST /api/v1/emr/qa
func (h *EMRHandler) KnowledgeQA(c *gin.Context) {
	var req struct {
		Question string `json:"question" binding:"required"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(400, gin.H{"error": "问题不能为空"})
		return
	}

	answer, err := h.agentRunner.MaxKB().Chat(c.Request.Context(), req.Question)
	if err != nil {
		c.JSON(500, gin.H{"error": "知识库查询失败", "detail": err.Error()})
		return
	}

	c.JSON(200, gin.H{
		"code": 200,
		"data": gin.H{
			"question": req.Question,
			"answer":   answer,
			"source":   "MaxKB 知识库",
		},
	})
}

// GetByID 查询病历详情
//
// GET /api/v1/emr/:id
func (h *EMRHandler) GetByID(c *gin.Context) {
	idStr := c.Param("id")
	id, _ := strconv.ParseInt(idStr, 10, 64)

	c.JSON(200, gin.H{
		"code": 200,
		"data": gin.H{
			"id":   id,
			"note": "实际项目从数据库查询",
		},
	})
}

// Update 更新病历（医生人工修改后保存）
//
// PUT /api/v1/emr/:id
func (h *EMRHandler) Update(c *gin.Context) {
	idStr := c.Param("id")
	id, _ := strconv.ParseInt(idStr, 10, 64)

	var req struct {
		Draft   string `json:"draft"`
		IsFinal bool   `json:"is_final"`
	}
	c.ShouldBindJSON(&req)

	userID := c.GetString("user_id")
	logAudit("emr_update", userID, idStr, req.Draft)

	c.JSON(200, gin.H{
		"code":    200,
		"message": "病历已更新",
		"data": gin.H{
			"id":         id,
			"is_final":   req.IsFinal,
			"updated_by": userID,
		},
	})
}

// getNextAction 根据状态给出下一步建议
func getNextAction(status string) string {
	switch status {
	case "success":
		return "病历生成完成，请医生审核确认"
	case "need_revision":
		return "病历存在质控问题，请查看 issues 列表并修改"
	default:
		return "请检查输入信息是否完整"
	}
}

// logAudit 审计日志
func logAudit(action, userID, targetID, detail string) {
	// 实际项目：写入审计表
	_ = action
	_ = userID
	_ = targetID
	_ = detail
}