package handler

import (
	"net/http"

	"silk-server-go/internal/model"

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

const defaultOrgCode = "default"

// currentUserRole 从 JWT context 中取当前角色。
func currentUserRole(c *gin.Context) string {
	user, ok := c.Get("user")
	if !ok {
		return ""
	}
	m, ok := user.(map[string]interface{})
	if !ok {
		return ""
	}
	role, _ := m["role"].(string)
	return role
}

// hasGlobalAccess admin 拥有跨组织全部对象访问权。
func hasGlobalAccess(c *gin.Context) bool {
	return currentUserRole(c) == model.RoleAdmin
}

// applyOrgScope 对组织归属列（如 rooms.org_id）追加当前用户可见组织过滤。
func applyOrgScope(q *gorm.DB, c *gin.Context, column string) *gorm.DB {
	if hasGlobalAccess(c) {
		return q
	}
	userID := currentUserID(c)
	if userID == nil {
		return q.Where("1 = 0")
	}
	return q.Where("CAST("+column+" AS text) IN (SELECT organization_id::text FROM organization_members WHERE user_id = ?)", *userID)
}

// applyRoomScope 对业务记录的房间列追加当前用户可见房间过滤。
func applyRoomScope(q *gorm.DB, c *gin.Context, column string) *gorm.DB {
	if hasGlobalAccess(c) {
		return q
	}
	userID := currentUserID(c)
	if userID == nil {
		return q.Where("1 = 0")
	}
	return q.Where("CAST("+column+" AS text) IN ("+
		"SELECT r.id::text FROM rooms r "+
		"JOIN organization_members om ON om.organization_id = r.org_id "+
		"WHERE om.user_id = ?)", *userID)
}

// canAccessOrganization 判断当前用户是否属于指定组织。
func canAccessOrganization(db *gorm.DB, c *gin.Context, orgID string) bool {
	if hasGlobalAccess(c) {
		return true
	}
	userID := currentUserID(c)
	if userID == nil {
		return false
	}
	var count int64
	db.Model(&model.OrganizationMember{}).
		Where("organization_id = ? AND user_id = ?", orgID, *userID).
		Count(&count)
	return count > 0
}

// canAccessRoom 判断当前用户是否能访问指定房间。
func canAccessRoom(db *gorm.DB, c *gin.Context, roomID *string) bool {
	if roomID == nil || *roomID == "" {
		return false
	}
	if hasGlobalAccess(c) {
		return true
	}
	userID := currentUserID(c)
	if userID == nil {
		return false
	}
	var count int64
	db.Model(&model.Room{}).
		Joins("JOIN organization_members om ON om.organization_id = rooms.org_id").
		Where("rooms.id = ? AND om.user_id = ?", *roomID, *userID).
		Count(&count)
	return count > 0
}

// canAccessDeviceKey 判断当前用户是否能访问指定 deviceKey 对应的设备。
func canAccessDeviceKey(db *gorm.DB, c *gin.Context, deviceKey string) bool {
	if hasGlobalAccess(c) {
		return true
	}
	if deviceKey == "" {
		return false
	}
	if currentUserID(c) == nil {
		return false
	}
	var device model.Device
	if db.Where("device_key = ?", deviceKey).First(&device).Error != nil {
		return false
	}
	return canAccessRoom(db, c, &device.RoomID)
}

// requireDeviceKeyAccess 统一校验 deviceKey 对象授权；无权返回 403。
func requireDeviceKeyAccess(c *gin.Context, db *gorm.DB, deviceKey string) bool {
	if canAccessDeviceKey(db, c, deviceKey) {
		return true
	}
	if deviceKey == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "deviceKey 不能为空"})
		return false
	}
	var count int64
	db.Model(&model.Device{}).Where("device_key = ?", deviceKey).Count(&count)
	if count == 0 {
		c.JSON(http.StatusNotFound, gin.H{"error": "device not found"})
		return false
	}
	c.JSON(http.StatusForbidden, gin.H{"error": "无权访问该设备"})
	return false
}

// requireObjectAccess 统一对象授权检查；无权返回 403。
func requireObjectAccess(c *gin.Context, db *gorm.DB, entityType, id string) bool {
	if hasGlobalAccess(c) {
		return true
	}
	roomID, ok := objectRoomID(db, entityType, id)
	if !ok {
		c.JSON(http.StatusNotFound, gin.H{"error": entityType + " not found"})
		return false
	}
	if !canAccessRoom(db, c, roomID) {
		c.JSON(http.StatusForbidden, gin.H{"error": "无权访问该对象"})
		return false
	}
	return true
}

// objectRoomID 返回实体归属房间；实体不存在时返回 false。
func objectRoomID(db *gorm.DB, entityType, id string) (*string, bool) {
	switch entityType {
	case "room":
		var room model.Room
		if db.Where("id = ?", id).First(&room).Error != nil {
			return nil, false
		}
		return &room.ID, true
	case "device":
		var device model.Device
		if db.Where("id = ?", id).First(&device).Error != nil {
			return nil, false
		}
		return &device.RoomID, true
	case "sensor":
		var sensor model.Sensor
		if db.Where("id = ?", id).First(&sensor).Error != nil {
			return nil, false
		}
		var device model.Device
		if db.Where("id = ?", sensor.DeviceID).First(&device).Error != nil {
			return nil, false
		}
		return &device.RoomID, true
	case "threshold":
		var threshold model.Threshold
		if db.Where("id = ?", id).First(&threshold).Error != nil {
			return nil, false
		}
		var sensor model.Sensor
		if db.Where("id = ?", threshold.SensorID).First(&sensor).Error != nil {
			return nil, false
		}
		var device model.Device
		if db.Where("id = ?", sensor.DeviceID).First(&device).Error != nil {
			return nil, false
		}
		return &device.RoomID, true
	case "alarm":
		var alarm model.Alarm
		if db.Where("id = ?", id).First(&alarm).Error != nil {
			return nil, false
		}
		if alarm.DeviceKey == nil || *alarm.DeviceKey == "" {
			return nil, false
		}
		var device model.Device
		if db.Where("device_key = ?", *alarm.DeviceKey).First(&device).Error != nil {
			return nil, false
		}
		return &device.RoomID, true
	case "device_maintenance_record":
		var rec model.DeviceMaintenanceRecord
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		var device model.Device
		if db.Where("id = ?", rec.DeviceID).First(&device).Error != nil {
			return nil, false
		}
		return &device.RoomID, true
	case "camera":
		var camera model.Camera
		if db.Where("id = ?", id).First(&camera).Error != nil {
			return nil, false
		}
		return camera.RoomID, true
	case "video_clip":
		var clip model.VideoClip
		if db.Where("id = ?", id).First(&clip).Error != nil {
			return nil, false
		}
		return clip.RoomID, true
	case "tray":
		var tray model.Tray
		if db.Where("id = ?", id).First(&tray).Error != nil {
			return nil, false
		}
		return &tray.RoomID, true
	case "batch":
		var batch model.Batch
		if db.Where("id = ?", id).First(&batch).Error != nil {
			return nil, false
		}
		return &batch.RoomID, true
	case "rearing_record":
		var rec model.RearingRecord
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return batchRoomID(db, &rec.BatchID)
	case "inspection":
		var rec model.InspectionRecord
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return rec.RoomID, true
	case "lamp_test":
		var rec model.LampTest
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return rec.RoomID, true
	case "detection_task":
		var rec model.DetectionTask
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return rec.RoomID, true
	case "consultation":
		var rec model.Consultation
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return rec.RoomID, true
	case "trace_record":
		var rec model.TraceRecord
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return rec.RoomID, true
	case "disease_event":
		var rec model.DiseaseEvent
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return rec.RoomID, true
	case "sample":
		var rec model.Sample
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return rec.RoomID, true
	case "seed_source":
		var rec model.SeedSource
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		return batchRoomID(db, rec.BatchID)
	case "disinfection_record":
		var rec model.DisinfectionRecord
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		if rec.RoomID != nil {
			return rec.RoomID, true
		}
		return batchRoomID(db, rec.BatchID)
	case "production_loss_record":
		var rec model.ProductionLossRecord
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		if rec.RoomID != nil {
			return rec.RoomID, true
		}
		return batchRoomID(db, rec.BatchID)
	case "laboratory_result":
		var rec model.LaboratoryResult
		if db.Where("id = ?", id).First(&rec).Error != nil {
			return nil, false
		}
		if rec.RoomID != nil {
			return rec.RoomID, true
		}
		if rec.BatchID != nil {
			return batchRoomID(db, rec.BatchID)
		}
		if rec.TraceRecordID != nil {
			var trace model.TraceRecord
			if db.Where("id = ?", *rec.TraceRecordID).First(&trace).Error == nil {
				return trace.RoomID, true
			}
		}
		return nil, true
	default:
		return nil, false
	}
}

func batchRoomID(db *gorm.DB, batchID *string) (*string, bool) {
	if batchID == nil {
		return nil, false
	}
	var batch model.Batch
	if db.Where("id = ?", *batchID).First(&batch).Error != nil {
		return nil, false
	}
	return &batch.RoomID, true
}

// defaultOrgID 返回当前用户第一个组织；管理员未指定时返回默认组织。
func defaultOrgID(db *gorm.DB, c *gin.Context) *string {
	if userID := currentUserID(c); userID != nil {
		var member model.OrganizationMember
		if db.Where("user_id = ?", *userID).Order("created_at ASC").First(&member).Error == nil {
			return &member.OrganizationID
		}
	}
	var org model.Organization
	if db.Where("code = ?", defaultOrgCode).First(&org).Error == nil {
		return &org.ID
	}
	return nil
}

// firstAccessibleRoomID 返回当前用户可见的第一个房间；用于无显式 roomId 的历史创建流程。
func firstAccessibleRoomID(db *gorm.DB, c *gin.Context) *string {
	var room model.Room
	q := db.Model(&model.Room{})
	if !hasGlobalAccess(c) {
		q = applyOrgScope(q, c, "org_id")
	}
	if q.Order("created_at ASC").First(&room).Error == nil {
		return &room.ID
	}
	return nil
}

// assignDefaultOrganization 注册新用户时补齐默认组织成员关系。
func assignDefaultOrganization(db *gorm.DB, userID string) {
	var org model.Organization
	if db.Where("code = ?", defaultOrgCode).First(&org).Error != nil {
		return
	}
	var count int64
	db.Model(&model.OrganizationMember{}).
		Where("organization_id = ? AND user_id = ?", org.ID, userID).
		Count(&count)
	if count == 0 {
		_ = db.Create(&model.OrganizationMember{OrganizationID: org.ID, UserID: userID, Role: "member"}).Error
	}
}