// backend\tray_stats.go

package main

import (
	"fmt"
	"strconv"
	"strings"
	"time"

	godisk "github.com/shirou/gopsutil/v3/disk"
)

type TrayStats struct {
	ActiveDownloads      int
	DownloadLimitEnabled bool
	DownloadLimitMax     int
	DownloadLimitReached bool

	PostworkWaiting int
	PostworkRunning int

	EnrichWaiting int
	EnrichRunning int

	AutostartPaused       bool
	AutostartPausedByUser bool
	AutostartPausedByDisk bool

	DiskFreeBytes uint64
	HasDiskInfo   bool
	DiskEmergency bool

	Uptime time.Duration
}

func buildTrayStats() TrayStats {
	active := activeRecordingJobsCount()

	limitEnabled, limitMax, _, limitReached := concurrentDownloadsLimitState()
	if limitMax < 1 {
		limitMax = 1
	}

	pwWaiting, pwRunning, _ := postWorkQ.Stats()
	enWaiting, enRunning, _ := enrichQ.Stats()

	auto := getAutostartStatePayload()

	diskFree, hasDisk := getTrayDiskFreeBytes()

	return TrayStats{
		ActiveDownloads:      active,
		DownloadLimitEnabled: limitEnabled,
		DownloadLimitMax:     limitMax,
		DownloadLimitReached: limitReached,

		PostworkWaiting: pwWaiting,
		PostworkRunning: pwRunning,

		EnrichWaiting: enWaiting,
		EnrichRunning: enRunning,

		AutostartPaused:       auto.Paused,
		AutostartPausedByUser: auto.PausedByUser,
		AutostartPausedByDisk: auto.PausedByDisk,

		DiskFreeBytes: diskFree,
		HasDiskInfo:   hasDisk,
		DiskEmergency: diskEmergencyActive(),

		Uptime: time.Since(serverStartedAt).Round(time.Second),
	}
}

func getTrayDiskFreeBytes() (uint64, bool) {
	s := getSettings()

	recordDir, err := resolvePathRelativeToApp(s.RecordDir)
	if err != nil || strings.TrimSpace(recordDir) == "" {
		recordDir = strings.TrimSpace(s.RecordDir)
	}
	if strings.TrimSpace(recordDir) == "" {
		return 0, false
	}

	u, err := godisk.Usage(recordDir)
	if err != nil || u == nil {
		return 0, false
	}

	return u.Free, true
}

func diskEmergencyActive() bool {
	return isAutostartPaused() && getAutostartStatePayload().PausedByDisk
}

func (s TrayStats) MenuTitle() string {
	return fmt.Sprintf(
		"Aktiv: %d • PW: %d/%d • Enrich: %d/%d",
		s.ActiveDownloads,
		s.PostworkRunning,
		s.PostworkWaiting,
		s.EnrichRunning,
		s.EnrichWaiting,
	)
}

func (s TrayStats) Tooltip() string {
	return fmt.Sprintf(
		"Recorder | Downloads %s | PW %d/%d | Enrich %d/%d",
		s.downloadLimitText(),
		s.PostworkRunning,
		s.PostworkWaiting,
		s.EnrichRunning,
		s.EnrichWaiting,
	)
}

func (s TrayStats) AutostartLine() string {
	switch {
	case s.AutostartPausedByDisk:
		return "Autostart: Pausiert (Disk-Notbremse)"
	case s.AutostartPausedByUser:
		return "Autostart: Pausiert"
	default:
		return "Autostart: Aktiv"
	}
}

func (s TrayStats) DownloadsLine() string {
	if s.DownloadLimitEnabled {
		if s.DownloadLimitReached {
			return fmt.Sprintf(
				"Downloads: %d/%d aktiv (Limit erreicht)",
				s.ActiveDownloads,
				s.DownloadLimitMax,
			)
		}
		return fmt.Sprintf(
			"Downloads: %d/%d aktiv",
			s.ActiveDownloads,
			s.DownloadLimitMax,
		)
	}

	return fmt.Sprintf("Downloads: %d aktiv (kein Limit)", s.ActiveDownloads)
}

func (s TrayStats) PostworkLine() string {
	return fmt.Sprintf(
		"Postwork: %d läuft • %d wartend",
		s.PostworkRunning,
		s.PostworkWaiting,
	)
}

func (s TrayStats) EnrichLine() string {
	return fmt.Sprintf(
		"Enrich: %d läuft • %d wartend",
		s.EnrichRunning,
		s.EnrichWaiting,
	)
}

func (s TrayStats) DiskLine() string {
	if !s.HasDiskInfo {
		return "Freier Speicher: unbekannt"
	}

	if s.DiskEmergency {
		return fmt.Sprintf(
			"Freier Speicher: %s (kritisch)",
			formatTrayBytes(s.DiskFreeBytes),
		)
	}

	return fmt.Sprintf(
		"Freier Speicher: %s",
		formatTrayBytes(s.DiskFreeBytes),
	)
}

func (s TrayStats) UptimeLine() string {
	return "Uptime: " + formatTrayDuration(s.Uptime)
}

func (s TrayStats) ToggleAutostartTitle() string {
	if s.AutostartPausedByDisk {
		return "Autostart fortsetzen (gesperrt: Disk)"
	}
	if s.AutostartPaused {
		return "Autostart fortsetzen"
	}
	return "Autostart pausieren"
}

func (s TrayStats) downloadLimitText() string {
	if s.DownloadLimitEnabled {
		return fmt.Sprintf("%d/%d", s.ActiveDownloads, s.DownloadLimitMax)
	}
	return strconv.Itoa(s.ActiveDownloads)
}

func formatTrayDuration(d time.Duration) string {
	if d < 0 {
		d = 0
	}

	total := int(d.Seconds())
	h := total / 3600
	m := (total % 3600) / 60
	s := total % 60

	return fmt.Sprintf("%02d:%02d:%02d", h, m, s)
}

func formatTrayBytes(b uint64) string {
	const unit = 1000
	if b < unit {
		return fmt.Sprintf("%d B", b)
	}

	div, exp := uint64(unit), 0
	for n := b / unit; n >= unit; n /= unit {
		div *= unit
		exp++
	}

	return fmt.Sprintf("%.1f %cB", float64(b)/float64(div), "kMGTPE"[exp])
}