package main

import (
	"fmt"
	"io"
	"time"
)

func secs_to_srt_time(secs float64) string {
	dur := time.Duration(secs) * time.Second

	hh := int64(dur.Hours())
	mm := int64(dur.Minutes()) - (hh * 60)
	ss := int64(dur.Seconds()) - (hh * 3600) - (mm * 60)
	ms := int64(dur.Milliseconds()) - (hh * 3600000) - (mm * 60000) - (ss * 1000)

	return fmt.Sprintf("%02d:%02d:%02d,%03d", hh, mm, ss, ms)
}

func (ltc *loadTupContent) WriteSRT(w io.Writer, totalVideoDurationSecs float64) error {
	/*

		SRT file format (example from Wikipedia):

		1
		00:02:17,440 --> 00:02:20,375
		Senator, we're making
		our final approach into Coruscant.

		2
		00:02:20,476 --> 00:02:22,501
		Very good, Lieutenant.
	*/

	ctr := 1
	for i := 0; i < len(ltc.Caps); i += 1 {
		if ltc.Caps[i] == "" {
			// Don't show anything
			continue
		}

		start := secs_to_srt_time(ltc.Secs[i])
		var end string
		if i < len(ltc.Caps)-1 {
			end = secs_to_srt_time(ltc.Secs[i+1])
		} else {
			// The final subtitle. Loadtup displays these for the entire
			// remaining video duration
			end = secs_to_srt_time(totalVideoDurationSecs)
		}

		fmt.Fprintf(w, "%d\n%s --> %s\n%s\n\n",
			ctr, start, end, ltc.Caps[i])
		// We emitted a message, increase the counter
		ctr += 1
	}

	return nil
}