package handler

import (
	"encoding/json"
	"net/http"
	"time"

	"silk-server-go/internal/middleware"
	"silk-server-go/internal/model"

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

// RegisterConsultationRoutes 注册专家会诊路由
func RegisterConsultationRoutes(rg *gin.RouterGroup, db *gorm.DB) {
	read := middleware.RequirePermission(db, "consultation:read")
	write := middleware.RequirePermission(db, "consultation:write")
	rg.GET("/consultations", read, listConsultations(db))
	rg.GET("/consultations/:id", read, getConsultation(db))
	rg.POST("/consultations", write, createConsultation(db))
	rg.PATCH("/consultations/:id", write, updateConsultation(db))
	rg.POST("/consultations/:id/resolve", write, resolveConsultation(db))
	rg.POST("/consultations/:id/archive", write, archiveConsultation(db))
}

// listConsultations 会诊单列表（status 过滤）
func listConsultations(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		q := db.Model(&model.Consultation{})
		if status := c.Query("status"); status != "" {
			q = q.Where("status = ?", status)
		}
		var list []model.Consultation
		q.Order("created_at DESC").Find(&list)
		fillConsultationRoomNames(db, list)
		c.JSON(http.StatusOK, list)
	}
}

func fillConsultationRoomNames(db *gorm.DB, list []model.Consultation) {
	var rooms []model.Room
	db.Select("id", "name").Find(&rooms)
	names := make(map[string]string, len(rooms))
	for _, r := range rooms {
		names[r.ID] = r.Name
	}
	for i := range list {
		if list[i].RoomID != nil {
			if n, ok := names[*list[i].RoomID]; ok {
				list[i].RoomName = &n
			}
		}
	}
}

// getConsultation 会诊单详情
func getConsultation(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		var t model.Consultation
		if db.Where("id = ?", c.Param("id")).First(&t).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "consultation not found"})
			return
		}
		fillConsultationRoomNames(db, []model.Consultation{t})
		c.JSON(http.StatusOK, t)
	}
}

// createConsultation 新建会诊单（可关联 LAMP 任务，自动打包病例快照）
func createConsultation(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		var body struct {
			Title     string  `json:"title"`
			Summary   *string `json:"summary"`
			RoomID    *string `json:"roomId"`
			BatchID   *string `json:"batchId"`
			LampTestID *string `json:"lampTestId"`
		}
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		for _, id := range []*string{body.RoomID, body.BatchID, body.LampTestID} {
			if id != nil && *id != "" && !isUUID(*id) {
				c.JSON(http.StatusBadRequest, gin.H{"error": "关联 ID 不是合法的 UUID"})
				return
			}
		}

		rec := model.Consultation{
			RoomID:     body.RoomID,
			BatchID:    body.BatchID,
			LampTestID: body.LampTestID,
			Summary:    body.Summary,
			Status:     "pending",
		}
		if body.Title != "" {
			rec.Title = body.Title
		} else {
			rec.Title = "LAMP 交叉验证会诊"
			if body.Summary != nil {
				rec.Title = "专家会诊：" + *body.Summary
			}
		}

		// 病例快照
		var lamp *model.LampTest
		if body.LampTestID != nil && *body.LampTestID != "" {
			var lt model.LampTest
			if db.Where("id = ?", *body.LampTestID).First(&lt).Error == nil {
				lamp = &lt
				if rec.RoomID == nil {
					rec.RoomID = lt.RoomID
				}
				if rec.BatchID == nil {
					rec.BatchID = lt.BatchID
				}
			}
		}
		snapshot := buildConsultationSnapshot(db, rec.RoomID, rec.BatchID, lamp)
		raw, _ := json.Marshal(snapshot)
		rec.Snapshot = raw

		if err := db.Create(&rec).Error; err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "创建失败"})
			return
		}
		c.JSON(http.StatusCreated, rec)
	}
}

// buildConsultationSnapshot 打包病例快照（房间/巡检/LAMP/批次/天气）
func buildConsultationSnapshot(db *gorm.DB, roomID, batchID *string, lamp *model.LampTest) model.ConsultationSnapshot {
	s := model.ConsultationSnapshot{CreatedAt: time.Now()}
	if roomID != nil {
		var room model.Room
		if db.Where("id = ?", *roomID).First(&room).Error == nil {
			s.RoomName = room.Name
		}
		var insp model.InspectionRecord
		if db.Where("room_id = ?", *roomID).Order("created_at DESC").First(&insp).Error == nil {
			s.Inspection = &insp
		}
		var alerts []model.WeatherAlert
		db.Order("created_at DESC").Limit(3).Find(&alerts)
		s.WeatherAlerts = alerts
	}
	if lamp != nil {
		s.LampTest = lamp
	}
	if batchID != nil {
		var b model.Batch
		if db.Where("id = ?", *batchID).First(&b).Error == nil {
			s.Batch = &b
		}
	} else if lamp != nil && lamp.BatchID != nil {
		var b model.Batch
		if db.Where("id = ?", *lamp.BatchID).First(&b).Error == nil {
			s.Batch = &b
		}
	}
	return s
}

// updateConsultation 更新会诊单（标题/摘要/状态流转）
func updateConsultation(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id := c.Param("id")
		var t model.Consultation
		if db.Where("id = ?", id).First(&t).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "consultation not found"})
			return
		}
		updates, err := bindUpdates(c)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		if s, ok := updates["status"]; ok {
			to, _ := s.(string)
			if !model.ValidConsultationTransition(t.Status, to) {
				c.JSON(http.StatusBadRequest, gin.H{"error": "非法的会诊状态流转"})
				return
			}
		}
		if len(updates) > 0 {
			db.Model(&model.Consultation{}).Where("id = ?", id).Updates(updates)
		}
		db.Where("id = ?", id).First(&t)
		c.JSON(http.StatusOK, t)
	}
}

// resolveConsultation 专家出会诊意见与防控方案
func resolveConsultation(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id := c.Param("id")
		var t model.Consultation
		if db.Where("id = ?", id).First(&t).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "consultation not found"})
			return
		}
		if !model.ValidConsultationTransition(t.Status, "resolved") {
			c.JSON(http.StatusBadRequest, gin.H{"error": "当前状态不能出方案"})
			return
		}
		var body struct {
			Opinion string `json:"opinion"`
			Plan    string `json:"plan"`
		}
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		if body.Plan == "" {
			c.JSON(http.StatusBadRequest, gin.H{"error": "防控方案不能为空"})
			return
		}
		now := time.Now()
		updates := map[string]interface{}{
			"status":      "resolved",
			"expert_id":   currentUserID(c),
			"opinion":     body.Opinion,
			"plan":        body.Plan,
			"resolved_at": now,
		}
		db.Model(&model.Consultation{}).Where("id = ?", id).Updates(updates)
		db.Where("id = ?", id).First(&t)
		c.JSON(http.StatusOK, t)
	}
}

// archiveConsultation 归档
func archiveConsultation(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id := c.Param("id")
		var t model.Consultation
		if db.Where("id = ?", id).First(&t).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "consultation not found"})
			return
		}
		if !model.ValidConsultationTransition(t.Status, "archived") {
			c.JSON(http.StatusBadRequest, gin.H{"error": "仅已出方案的会诊可归档"})
			return
		}
		now := time.Now()
		db.Model(&model.Consultation{}).Where("id = ?", id).
			Updates(map[string]interface{}{"status": "archived", "archived_at": now})
		db.Where("id = ?", id).First(&t)
		c.JSON(http.StatusOK, t)
	}
}