package parking

import (
	"errors"
	"fmt"
	"net/url"
	"strings"

	"wails-app/internal/dao"
	"wails-app/internal/global"
	"wails-app/internal/model/parking/request"
)

// CameraStreamOption 是工作台使用的安全摄像头信息，不包含用户名和密码。
type CameraStreamOption struct {
	DeviceCode  string `json:"device_code"`
	DeviceName  string `json:"device_name"`
	ChannelID   uint   `json:"channel_id"`
	ChannelCode string `json:"channel_code"`
	ChannelName string `json:"channel_name"`
	Protocol    string `json:"protocol"`
	PlayURL     string `json:"play_url"`
	SnapshotURL string `json:"snapshot_url"`
	Status      string `json:"status"`
	Online      bool   `json:"online"`
}

// CreateCamera 创建摄像头配置，并校验它绑定的通道。
func (s *PassageService) CreateCamera(req request.CameraCreate) error {
	if err := validateCameraConfig(req); err != nil {
		return err
	}
	var existing dao.Camera
	if global.GVA_DB.Where("device_code = ?", req.DeviceCode).First(&existing).RowsAffected > 0 {
		return errors.New("摄像头编码已存在")
	}
	return global.GVA_DB.Create(&dao.Camera{
		DeviceCode: req.DeviceCode, DeviceName: req.DeviceName, ChannelID: req.ChannelID,
		IPAddress: req.IPAddress, Port: req.Port, Username: req.Username, Password: req.Password,
		Channel: req.Channel, IsActive: req.IsActive, StreamProtocol: req.StreamProtocol,
		SourceURL: req.SourceURL, StreamURL: req.StreamURL, SnapshotURL: req.SnapshotURL, Description: req.Description,
	}).Error
}

// UpdateCamera 更新摄像头配置；为了避免浏览器回显凭据，空密码不会覆盖数据库已有密码。
func (s *PassageService) UpdateCamera(req request.CameraUpdate) error {
	if err := validateCameraConfig(req.CameraCreate); err != nil {
		return err
	}
	var camera dao.Camera
	if err := global.GVA_DB.First(&camera, req.ID).Error; err != nil {
		return errors.New("摄像头不存在")
	}
	var existing dao.Camera
	if global.GVA_DB.Where("device_code = ? AND id != ?", req.DeviceCode, req.ID).First(&existing).RowsAffected > 0 {
		return errors.New("摄像头编码已被其他设备使用")
	}
	previousDeviceCode := camera.DeviceCode
	camera.DeviceCode, camera.DeviceName, camera.ChannelID = req.DeviceCode, req.DeviceName, req.ChannelID
	camera.IPAddress, camera.Port = req.IPAddress, req.Port
	if strings.TrimSpace(req.Username) != "" {
		camera.Username = req.Username
	}
	if strings.TrimSpace(req.Password) != "" {
		camera.Password = req.Password
	}
	camera.Channel, camera.IsActive, camera.StreamProtocol = req.Channel, req.IsActive, req.StreamProtocol
	// 前端编辑时密码会被掩码；此时保留数据库中的完整 RTSP 地址。
	if !strings.Contains(req.SourceURL, "***") {
		camera.SourceURL = req.SourceURL
	}
	camera.StreamURL, camera.SnapshotURL, camera.Description = req.StreamURL, req.SnapshotURL, req.Description
	if err := global.GVA_DB.Save(&camera).Error; err != nil {
		return err
	}
	cameraMJPEGHub.stop(previousDeviceCode)
	if camera.DeviceCode != previousDeviceCode {
		cameraMJPEGHub.stop(camera.DeviceCode)
	}
	return nil
}

func (s *PassageService) ListCameras(req request.CameraQuery) (int64, []dao.Camera, error) {
	var total int64
	var cameras []dao.Camera
	query := global.GVA_DB.Model(&dao.Camera{}).Preload("BoundChannel")
	if req.ParkingLotID != 0 {
		query = query.Joins("JOIN channel ON channel.id = camera.channel_id AND channel.deleted_at IS NULL").Where("channel.parking_lot_id = ?", req.ParkingLotID)
	}
	if err := query.Count(&total).Error; err != nil {
		return 0, nil, err
	}
	if err := query.Order("camera.device_name ASC").Offset((req.Page - 1) * req.PageSize).Limit(req.PageSize).Find(&cameras).Error; err != nil {
		return 0, nil, err
	}
	// 播放地址可能含凭据，配置列表不向浏览器返回它。
	for i := range cameras {
		cameras[i].Status = cameraDisplayStatus(cameras[i])
		cameras[i].Username = ""
		cameras[i].Password = ""
		cameras[i].SourceURL = redactCameraURL(cameras[i].SourceURL)
	}
	return total, cameras, nil
}

func (s *PassageService) DeleteCamera(id uint) error {
	var camera dao.Camera
	if err := global.GVA_DB.First(&camera, id).Error; err != nil {
		return errors.New("摄像头不存在")
	}
	result := global.GVA_DB.Delete(&camera)
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return errors.New("摄像头不存在")
	}
	cameraMJPEGHub.stop(camera.DeviceCode)
	return nil
}

func validateCameraConfig(req request.CameraCreate) error {
	if global.GVA_DB == nil {
		return errors.New("数据库未初始化")
	}
	if req.StreamProtocol == "system-mjpeg" && strings.TrimSpace(req.SourceURL) == "" {
		return errors.New("系统转换模式必须填写原始 RTSP/HTTP 地址")
	}
	if req.StreamProtocol != "system-mjpeg" && strings.TrimSpace(req.StreamURL) == "" {
		return errors.New("边缘播放模式必须填写浏览器播放地址")
	}
	var channel dao.Channel
	if err := global.GVA_DB.First(&channel, req.ChannelID).Error; err != nil {
		return errors.New("绑定通道不存在")
	}
	return nil
}

// ListCameraStreams 返回启用摄像头的浏览器播放配置，并按通道绑定到道闸设备。
func (s *PassageService) ListCameraStreams() ([]CameraStreamOption, error) {
	if global.GVA_DB == nil {
		return nil, errors.New("数据库未初始化")
	}
	var cameras []dao.Camera
	if err := global.GVA_DB.Preload("BoundChannel").Where("is_active = ?", true).
		Order("device_name ASC").Find(&cameras).Error; err != nil {
		return nil, err
	}

	options := make([]CameraStreamOption, 0, len(cameras))
	for _, camera := range cameras {
		protocol := camera.StreamProtocol
		if protocol == "" {
			protocol = "webrtc"
		}
		playURL := camera.StreamURL
		systemConversionEnabled := strings.ToLower(strings.TrimSpace(global.GVA_CONFIG.Camera.ConversionMode)) != "edge"
		if systemConversionEnabled && isSystemMJPEG(protocol) {
			token := issueCameraStreamToken(camera.DeviceCode)
			prefix := global.GVA_CONFIG.System.RouterPrefix
			if prefix == "" {
				prefix = "/api"
			}
			playURL = fmt.Sprintf("%s/parking/camera/stream/%s/%s", strings.TrimRight(prefix, "/"), url.PathEscape(camera.DeviceCode), token)
			protocol = "mjpeg"
		} else if isSystemMJPEG(protocol) {
			// 切到 edge 模式后，沿用数据库中的 StreamURL（由边缘或外部媒体网关提供）。
			protocol = "webrtc"
		}
		status := cameraDisplayStatus(camera)
		options = append(options, CameraStreamOption{
			DeviceCode:  camera.DeviceCode,
			DeviceName:  camera.DeviceName,
			ChannelID:   camera.ChannelID,
			ChannelCode: cameraChannelCode(camera.BoundChannel),
			ChannelName: cameraChannelName(camera.BoundChannel),
			Protocol:    protocol,
			PlayURL:     playURL,
			SnapshotURL: camera.SnapshotURL,
			Status:      status,
			Online:      status == "online" || status == "connected",
		})
	}
	return options, nil
}

// cameraDisplayStatus returns the observed stream state for system-side
// conversion. Camera.Status is not updated by FFmpeg, so using it there made
// an actively playing RTSP stream appear offline indefinitely.
func cameraDisplayStatus(camera dao.Camera) string {
	if isSystemMJPEG(camera.StreamProtocol) && strings.ToLower(strings.TrimSpace(global.GVA_CONFIG.Camera.ConversionMode)) != "edge" {
		if hasRecentCameraStreamFrame(camera.DeviceCode) {
			return "online"
		}
		return "offline"
	}
	if camera.Status == "" {
		return "offline"
	}
	return camera.Status
}

func cameraChannelCode(channel *dao.Channel) string {
	if channel == nil {
		return ""
	}
	return channel.ChannelCode
}

func cameraChannelName(channel *dao.Channel) string {
	if channel == nil {
		return ""
	}
	return channel.ChannelName
}