"os"
	"path/filepath"

	Night     bool
	Day       bool
	Lat       float64
	Lng       float64
	Timezone  string

	FileIdx       int
	SegmentIdx    int
	Dirty         bool
	Player        *utils.AudioPlayer
	PlaybackSpeed float64 // Current playback speed (1.0 = normal, 0.5 = half speed)

	FileIdx           int
	SegmentIdx        int
	Dirty             bool
	Player            *utils.AudioPlayer
	PlaybackSpeed     float64 // Current playback speed (1.0 = normal, 0.5 = half speed)
	TimeFilteredCount int     // files skipped by --night or --day filter

	var timeFiltered int

		// Day/night filter: runs after segment filter to avoid IsNight on irrelevant files.
		if config.Night || config.Day {
			wavPath := filepath.Clean(strings.TrimSuffix(df.FilePath, ".data"))
			result, err := IsNight(IsNightInput{
				FilePath: wavPath,
				Lat:      config.Lat,
				Lng:      config.Lng,
				Timezone: config.Timezone,
			})
			if err != nil {
				fmt.Fprintf(os.Stderr, "warning: skipping %s (isnight error: %v)\n", wavPath, err)
				timeFiltered++
				continue
			}
			if config.Night && !result.SolarNight {
				timeFiltered++
				continue
			}
			if config.Day && result.SolarNight {
				timeFiltered++
				continue
			}
		}

		Config:       config,
		DataFiles:    kept,
		filteredSegs: cachedSegs,
		totalSegs:    total,

		Config:            config,
		DataFiles:         kept,
		filteredSegs:      cachedSegs,
		totalSegs:         total,
		TimeFilteredCount: timeFiltered,

	fmt.Fprintf(os.Stderr, "  --night               Only review solar-night recordings (requires --lat and --lng)\n")
	fmt.Fprintf(os.Stderr, "  --day                 Only review solar-day recordings (requires --lat and --lng)\n")
	fmt.Fprintf(os.Stderr, "  --lat <float>         Latitude in decimal degrees (required with --night or --day)\n")
	fmt.Fprintf(os.Stderr, "  --lng <float>         Longitude in decimal degrees (required with --night or --day)\n")
	fmt.Fprintf(os.Stderr, "  --timezone <zone>     IANA timezone ID (e.g. Pacific/Auckland). Required for non-AudioMoth\n")
	fmt.Fprintf(os.Stderr, "                        recorders whose filenames embed local time (e.g. DOC AR4).\n")

	var folder, file, filter, species, gotoFile string

	var folder, file, filter, species, gotoFile, timezone string

	var night, day bool
	var lat, lng float64
	var latSet, lngSet bool

			i += 2
		case "--night":
			night = true
			i++
		case "--day":
			day = true
			i++
		case "--lat":
			if i+1 >= len(args) {
				fmt.Fprintf(os.Stderr, "Error: --lat requires a value\n")
				os.Exit(1)
			}
			v, err := strconv.ParseFloat(args[i+1], 64)
			if err != nil {
				fmt.Fprintf(os.Stderr, "Error: --lat must be a number\n")
				os.Exit(1)
			}
			lat = v
			latSet = true
			i += 2
		case "--lng":
			if i+1 >= len(args) {
				fmt.Fprintf(os.Stderr, "Error: --lng requires a value\n")
				os.Exit(1)
			}
			v, err := strconv.ParseFloat(args[i+1], 64)
			if err != nil {
				fmt.Fprintf(os.Stderr, "Error: --lng must be a number\n")
				os.Exit(1)
			}
			lng = v
			lngSet = true
			i += 2
		case "--timezone":
			if i+1 >= len(args) {
				fmt.Fprintf(os.Stderr, "Error: --timezone requires a value\n")
				os.Exit(1)
			}
			timezone = args[i+1]

	if night && day {
		fmt.Fprintf(os.Stderr, "Error: --night and --day are mutually exclusive\n\n")
		printClassifyUsage()
		os.Exit(1)
	}
	if (night || day) && (!latSet || !lngSet) {
		fmt.Fprintf(os.Stderr, "Error: --night/--day requires both --lat and --lng\n\n")
		printClassifyUsage()
		os.Exit(1)
	}

		Night:     night,
		Day:       day,
		Lat:       lat,
		Lng:       lng,
		Timezone:  timezone,

	if state.TimeFilteredCount > 0 {
		label := "daytime"
		if config.Day {
			label = "nighttime"
		}
		fmt.Fprintf(os.Stderr, "Skipped %d %s files\n", state.TimeFilteredCount, label)
	}

## [2026-04-18] `calls classify --night` / `--day`: filter TUI to solar-night or solar-day recordings

Adds `--night`, `--day`, `--lat`, `--lng`, and `--timezone` flags to `skraak calls classify`.
Filtering happens at load time (before the TUI launches) inside `LoadDataFiles`, after the
existing segment filter — so `IsNight` is only called for files that have matching segments.
Skipped file count is reported to stderr before the TUI starts.
Same `--timezone` caveat as `calls clip`: required for non-AudioMoth recorders (e.g. DOC AR4)
that embed local time in filenames. AudioMoth files don't need it.
```bash
skraak calls classify --folder F09/2026-04-06/ --species "Don't Know" \
  --night --lat -45.50603 --lng 167.47371
```
**Files changed:**
- `tools/calls_classify.go` — `ClassifyConfig` (Night/Day/Lat/Lng/Timezone fields),
  `ClassifyState` (TimeFilteredCount), `LoadDataFiles` (day/night filter block).
- `cmd/calls_classify.go` — flag parsing, mutual-exclusivity + lat/lng validation,
  config construction, skipped-count summary line, updated usage text.