package service

import (
	"encoding/json"
	"errors"
	"fmt"
	"strconv"
	"time"

	"gorm.io/gorm"

	"laic-backend/cache"
	"laic-backend/common"
	"laic-backend/logger"
	"laic-backend/model"
	"laic-backend/mqtt"
	"laic-backend/tool"
	"laic-backend/vo"
)

type FirmwareService struct{}

var DefaultFirmwareService = &FirmwareService{}

const defaultFirmwareComponent = "dock-edge-agent"

// GetPage 固件分页列表（admin）
func (s *FirmwareService) GetPage(req *vo.FirmwarePageReq) (*common.PageResponse[model.Firmware], *common.BusiError) {
	db := common.DB.Model(&model.Firmware{})
	if req.Status != "" {
		db = db.Where("status = ?", req.Status)
	}
	if req.Component != "" {
		db = db.Where("component = ?", req.Component)
	}
	if req.Keyword != "" {
		kw := "%" + req.Keyword + "%"
		db = db.Where("version LIKE ? OR description LIKE ?", kw, kw)
	}

	var total int64
	if err := db.Count(&total).Error; err != nil {
		logger.ERROR("统计固件失败", err)
		return nil, common.ErrInternal
	}
	var list []model.Firmware
	if err := db.Scopes(req.Paginate).Order("created_at DESC, id DESC").Find(&list).Error; err != nil {
		logger.ERROR("查询固件列表失败", err)
		return nil, common.ErrInternal
	}
	return common.Page(req.Pagination, total, list), nil
}

// GetReleasedList 已发布固件列表（供普通用户选择升级）
func (s *FirmwareService) GetReleasedList() ([]model.Firmware, *common.BusiError) {
	var list []model.Firmware
	if err := common.DB.Where("status = ?", "released").Order("updated_at DESC, id DESC").Find(&list).Error; err != nil {
		logger.ERROR("查询已发布固件失败", err)
		return nil, common.ErrInternal
	}
	return list, nil
}

// GetDetail 固件详情（admin）
func (s *FirmwareService) GetDetail(id int64) (*model.Firmware, *common.BusiError) {
	var fw model.Firmware
	if err := common.DB.First(&fw, id).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrFirmwareNotFound
		}
		return nil, common.ErrInternal
	}
	return &fw, nil
}

// Create 新增固件版本（admin）
func (s *FirmwareService) Create(adminID int64, req *vo.FirmwareCreateReq) (*model.Firmware, *common.BusiError) {
	id, err := tool.NextID()
	if err != nil {
		return nil, common.ErrInternal
	}
	component := req.Component
	if component == "" {
		component = defaultFirmwareComponent
	}
	now := time.Now()
	fw := &model.Firmware{
		ID:          id,
		Component:   component,
		Version:     req.Version,
		Description: req.Description,
		FileURL:     req.FileURL,
		Sha256:      req.Sha256,
		Signature:   req.Signature,
		FileSize:    req.FileSize,
		Mandatory:   req.Mandatory,
		Status:      "draft",
		CreatedBy:   adminID,
		CreatedAt:   now,
		UpdatedAt:   now,
	}
	if err := common.DB.Create(fw).Error; err != nil {
		if code, _ := common.ParseError(err); code == 1062 {
			return nil, common.ErrFirmwareVersionExist
		}
		logger.ERROR("新增固件失败", err)
		return nil, common.ErrInternal
	}
	return fw, nil
}

// Update 编辑固件（admin）
func (s *FirmwareService) Update(id int64, req *vo.FirmwareUpdateReq) *common.BusiError {
	var fw model.Firmware
	if err := common.DB.First(&fw, id).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return common.ErrFirmwareNotFound
		}
		return common.ErrInternal
	}

	updates := map[string]any{"updated_at": time.Now()}
	if req.Description != "" {
		updates["description"] = req.Description
	}
	if req.FileURL != "" {
		updates["file_url"] = req.FileURL
	}
	if req.Sha256 != "" {
		updates["sha256"] = req.Sha256
	}
	if req.Signature != "" {
		updates["signature"] = req.Signature
	}
	if req.FileSize != 0 {
		updates["file_size"] = req.FileSize
	}
	if req.Mandatory != nil {
		updates["mandatory"] = *req.Mandatory
	}
	if req.Status != "" {
		updates["status"] = req.Status
	}

	if err := common.DB.Model(&fw).Updates(updates).Error; err != nil {
		logger.ERROR("编辑固件失败", err)
		return common.ErrInternal
	}
	return nil
}

// Delete 删除固件（admin）
func (s *FirmwareService) Delete(id int64) *common.BusiError {
	res := common.DB.Delete(&model.Firmware{}, id)
	if res.Error != nil {
		logger.ERROR("删除固件失败", res.Error)
		return common.ErrInternal
	}
	if res.RowsAffected == 0 {
		return common.ErrFirmwareNotFound
	}
	return nil
}

// Upgrade 下发 OTA 升级：校验机巢归属+在线 → 校验固件已发布 → MQTT ota/desired
func (s *FirmwareService) Upgrade(userID int64, isAdmin bool, dockID int64, firmwareID int64) (*vo.FirmwareUpgradeVO, *common.BusiError) {
	var dock model.Dock
	if err := common.DB.Scopes(withUserFilter(userID, isAdmin)).First(&dock, dockID).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrDockNotFound
		}
		return nil, common.ErrInternal
	}

	online, _ := common.SetMemberExists(cache.OnlineDockSetKey, dock.DockID)
	if !online {
		return nil, common.ErrDockOffline
	}

	var fw model.Firmware
	if err := common.DB.First(&fw, firmwareID).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrFirmwareNotFound
		}
		return nil, common.ErrInternal
	}
	if fw.Status != "released" {
		return nil, common.ErrFirmwareNotReleased
	}

	updateID, err := tool.NextID()
	if err != nil {
		return nil, common.ErrInternal
	}
	payload := map[string]any{
		"updateId":  strconv.FormatInt(updateID, 10),
		"component": fw.Component,
		"version":   fw.Version,
		"url":       fw.FileURL,
		"sha256":    fw.Sha256,
		"signature": fw.Signature,
		"mandatory": fw.Mandatory == 1,
		"issuedAt":  time.Now().UnixMilli(),
	}
	b, err := json.Marshal(payload)
	if err != nil {
		return nil, common.ErrInternal
	}
	topic := fmt.Sprintf("dock-edge/v1/dock/%s/ota/desired", dock.DockID)
	if err := mqtt.Publish(topic, 1, true, b); err != nil {
		logger.ERROR("下发 OTA 升级失败", err)
		return nil, common.ErrInternal
	}

	return &vo.FirmwareUpgradeVO{
		UpdateID: strconv.FormatInt(updateID, 10),
		DockID:   dock.DockID,
		Firmware: &fw,
	}, nil
}