sub-cli/internal/sync/utils.go
2025-04-23 19:22:41 +08:00

136 lines
3.8 KiB
Go

package sync
import (
"sub-cli/internal/model"
)
// scaleTimeline scales a timeline to match a different number of entries
func scaleTimeline(timeline []model.Timestamp, targetCount int) []model.Timestamp {
if targetCount <= 0 || len(timeline) == 0 {
return []model.Timestamp{}
}
result := make([]model.Timestamp, targetCount)
if targetCount == 1 {
result[0] = timeline[0]
return result
}
sourceLength := len(timeline)
// Handle simple case: same length
if targetCount == sourceLength {
copy(result, timeline)
return result
}
// Handle case where target is longer than source
// We need to interpolate timestamps between source entries
for i := 0; i < targetCount; i++ {
if sourceLength == 1 {
// If source has only one entry, use it for all target entries
result[i] = timeline[0]
continue
}
// Calculate a floating-point position in the source timeline
floatIndex := float64(i) * float64(sourceLength-1) / float64(targetCount-1)
lowerIndex := int(floatIndex)
upperIndex := lowerIndex + 1
// Handle boundary case
if upperIndex >= sourceLength {
upperIndex = sourceLength - 1
lowerIndex = upperIndex - 1
}
// If indices are the same, just use the source timestamp
if lowerIndex == upperIndex || lowerIndex < 0 {
result[i] = timeline[upperIndex]
} else {
// Calculate the fraction between the lower and upper indices
fraction := floatIndex - float64(lowerIndex)
// Convert timestamps to milliseconds for interpolation
lowerMS := timeline[lowerIndex].Hours*3600000 + timeline[lowerIndex].Minutes*60000 +
timeline[lowerIndex].Seconds*1000 + timeline[lowerIndex].Milliseconds
upperMS := timeline[upperIndex].Hours*3600000 + timeline[upperIndex].Minutes*60000 +
timeline[upperIndex].Seconds*1000 + timeline[upperIndex].Milliseconds
// Interpolate
resultMS := int(float64(lowerMS) + fraction*float64(upperMS-lowerMS))
// Convert back to timestamp
hours := resultMS / 3600000
resultMS %= 3600000
minutes := resultMS / 60000
resultMS %= 60000
seconds := resultMS / 1000
milliseconds := resultMS % 1000
result[i] = model.Timestamp{
Hours: hours,
Minutes: minutes,
Seconds: seconds,
Milliseconds: milliseconds,
}
}
}
return result
}
// calculateDuration calculates the time difference between two timestamps
func calculateDuration(start, end model.Timestamp) model.Timestamp {
startMillis := start.Hours*3600000 + start.Minutes*60000 + start.Seconds*1000 + start.Milliseconds
endMillis := end.Hours*3600000 + end.Minutes*60000 + end.Seconds*1000 + end.Milliseconds
durationMillis := endMillis - startMillis
if durationMillis < 0 {
// Return zero duration if end is before start
return model.Timestamp{
Hours: 0,
Minutes: 0,
Seconds: 0,
Milliseconds: 0,
}
}
hours := durationMillis / 3600000
durationMillis %= 3600000
minutes := durationMillis / 60000
durationMillis %= 60000
seconds := durationMillis / 1000
milliseconds := durationMillis % 1000
return model.Timestamp{
Hours: hours,
Minutes: minutes,
Seconds: seconds,
Milliseconds: milliseconds,
}
}
// addDuration adds a duration to a timestamp
func addDuration(start, duration model.Timestamp) model.Timestamp {
startMillis := start.Hours*3600000 + start.Minutes*60000 + start.Seconds*1000 + start.Milliseconds
durationMillis := duration.Hours*3600000 + duration.Minutes*60000 + duration.Seconds*1000 + duration.Milliseconds
totalMillis := startMillis + durationMillis
hours := totalMillis / 3600000
totalMillis %= 3600000
minutes := totalMillis / 60000
totalMillis %= 60000
seconds := totalMillis / 1000
milliseconds := totalMillis % 1000
return model.Timestamp{
Hours: hours,
Minutes: minutes,
Seconds: seconds,
Milliseconds: milliseconds,
}
}