package ota

import (
	"net/http"
	"sync"
	"time"

	"github.com/Masterminds/semver/v3"
	"github.com/rs/zerolog"
)

var (
	availableComponents = []string{"app", "system"}
	defaultComponents   = map[string]string{
		"app":    "",
		"system": "",
	}
)

// UpdateMetadata represents the metadata of an update
type UpdateMetadata struct {
	AppVersion    string `json:"appVersion"`
	AppURL        string `json:"appUrl"`
	AppHash       string `json:"appHash"`
	SystemVersion string `json:"systemVersion"`
	SystemURL     string `json:"systemUrl"`
	SystemHash    string `json:"systemHash"`
}

// LocalMetadata represents the local metadata of the system
type LocalMetadata struct {
	AppVersion    string `json:"appVersion"`
	SystemVersion string `json:"systemVersion"`
}

// UpdateStatus represents the current update status
type UpdateStatus struct {
	Local                 *LocalMetadata  `json:"local"`
	Remote                *UpdateMetadata `json:"remote"`
	SystemUpdateAvailable bool            `json:"systemUpdateAvailable"`
	AppUpdateAvailable    bool            `json:"appUpdateAvailable"`

	// for backwards compatibility
	Error string `json:"error,omitempty"`
}

// PostRebootAction represents the action to be taken after a reboot
// It is used to redirect the user to a specific page after a reboot
type PostRebootAction struct {
	HealthCheck string `json:"healthCheck"` // The health check URL to call after the reboot
	RedirectTo  string `json:"redirectTo"`  // The URL to redirect to after the reboot
}

// componentUpdateStatus represents the status of a component update
type componentUpdateStatus struct {
	pending              bool
	available            bool
	availableReason      string // why the component is available or not available
	version              string
	localVersion         string
	url                  string
	hash                 string
	downloadProgress     float32
	downloadFinishedAt   time.Time
	verificationProgress float32
	verifiedAt           time.Time
	updateProgress       float32
	updatedAt            time.Time
	dependsOn            []string
}

func (c *componentUpdateStatus) getZerologLogger(l *zerolog.Logger) *zerolog.Logger {
	logger := l.With().
		Bool("pending", c.pending).
		Bool("available", c.available).
		Str("availableReason", c.availableReason).
		Str("version", c.version).
		Str("localVersion", c.localVersion).
		Str("url", c.url).
		Str("hash", c.hash).
		Float32("downloadProgress", c.downloadProgress).
		Time("downloadFinishedAt", c.downloadFinishedAt).
		Float32("verificationProgress", c.verificationProgress).
		Time("verifiedAt", c.verifiedAt).
		Float32("updateProgress", c.updateProgress).
		Time("updatedAt", c.updatedAt).
		Strs("dependsOn", c.dependsOn).
		Logger()
	return &logger
}

// HwRebootFunc is a function that reboots the hardware
type HwRebootFunc func(force bool, postRebootAction *PostRebootAction, delay time.Duration) error

// ResetConfigFunc is a function that resets the config
type ResetConfigFunc func() error

// GetHTTPClientFunc is a function that returns the HTTP client
type GetHTTPClientFunc func() *http.Client

// OnStateUpdateFunc is a function that updates the state of the OTA
type OnStateUpdateFunc func(state *RPCState)

// OnProgressUpdateFunc is a function that updates the progress of the OTA
type OnProgressUpdateFunc func(progress float32)

// GetLocalVersionFunc is a function that returns the local version of the system and app
type GetLocalVersionFunc func() (systemVersion *semver.Version, appVersion *semver.Version, err error)

// State represents the current OTA state for the UI
type State struct {
	releaseAPIEndpoint      string
	l                       *zerolog.Logger
	mu                      sync.Mutex
	updating                bool
	error                   string
	metadataFetchedAt       time.Time
	rebootNeeded            bool
	componentUpdateStatuses map[string]componentUpdateStatus
	client                  GetHTTPClientFunc
	reboot                  HwRebootFunc
	getLocalVersion         GetLocalVersionFunc
	onStateUpdate           OnStateUpdateFunc
	resetConfig             ResetConfigFunc
}

func toUpdateStatus(appUpdate *componentUpdateStatus, systemUpdate *componentUpdateStatus, error string) *UpdateStatus {
	return &UpdateStatus{
		Local: &LocalMetadata{
			AppVersion:    appUpdate.localVersion,
			SystemVersion: systemUpdate.localVersion,
		},
		Remote: &UpdateMetadata{
			AppVersion:    appUpdate.version,
			AppURL:        appUpdate.url,
			AppHash:       appUpdate.hash,
			SystemVersion: systemUpdate.version,
			SystemURL:     systemUpdate.url,
			SystemHash:    systemUpdate.hash,
		},
		SystemUpdateAvailable: systemUpdate.available,
		AppUpdateAvailable:    appUpdate.available,
		Error:                 error,
	}
}

// ToUpdateStatus converts the State to the UpdateStatus
func (s *State) ToUpdateStatus() *UpdateStatus {
	appUpdate, ok := s.componentUpdateStatuses["app"]
	if !ok {
		return nil
	}

	systemUpdate, ok := s.componentUpdateStatuses["system"]
	if !ok {
		return nil
	}

	return toUpdateStatus(&appUpdate, &systemUpdate, s.error)
}

// IsUpdatePending returns true if an update is pending
func (s *State) IsUpdatePending() bool {
	return s.updating
}

// Options represents the options for the OTA state
type Options struct {
	Logger             *zerolog.Logger
	GetHTTPClient      GetHTTPClientFunc
	GetLocalVersion    GetLocalVersionFunc
	OnStateUpdate      OnStateUpdateFunc
	OnProgressUpdate   OnProgressUpdateFunc
	HwReboot           HwRebootFunc
	ReleaseAPIEndpoint string
	ResetConfig        ResetConfigFunc
	SkipConfirmSystem  bool
}

// NewState creates a new OTA state
func NewState(opts Options) *State {
	components := make(map[string]componentUpdateStatus)
	for _, component := range availableComponents {
		components[component] = componentUpdateStatus{}
	}

	s := &State{
		l:                       opts.Logger,
		client:                  opts.GetHTTPClient,
		reboot:                  opts.HwReboot,
		onStateUpdate:           opts.OnStateUpdate,
		getLocalVersion:         opts.GetLocalVersion,
		componentUpdateStatuses: components,
		releaseAPIEndpoint:      opts.ReleaseAPIEndpoint,
		resetConfig:             opts.ResetConfig,
	}
	if !opts.SkipConfirmSystem {
		go s.confirmCurrentSystem()
	}
	return s
}

// appUpdateStatus.url = remoteMetadata.AppURL
// appUpdateStatus.hash = remoteMetadata.AppHash
// appUpdateStatus.version = remoteMetadata.AppVersion

// systemUpdateStatus.url = remoteMetadata.SystemURL
// systemUpdateStatus.hash = remoteMetadata.SystemHash
// systemUpdateStatus.version = remoteMetadata.SystemVersion

// // Get remote versions
// systemVersionRemote, err := semver.NewVersion(remoteMetadata.SystemVersion)
//
//	if err != nil {
//		err = fmt.Errorf("error parsing remote system version: %w", err)
//		return err
//	}
//
// systemUpdateStatus.available = systemVersionRemote.GreaterThan(systemVersionLocal)