package builder

import (
	"context"
	"time"
)

// tickCompileProgress emits interpolated progress during long compile steps (garble can run 10+ minutes).
// Returns a stop function; call it when the compile finishes.
func (h *Handler) tickCompileProgress(ctx context.Context, token, stage string, startPct, capPct int, obfuscated bool) func() {
	if token == "" || capPct <= startPct {
		return func() {}
	}
	est := 3 * time.Minute
	if obfuscated {
		est = 12 * time.Minute
	}
	done := make(chan struct{})
	go func() {
		h.setProgress(token, stage, startPct)
		ticker := time.NewTicker(2 * time.Second)
		defer ticker.Stop()
		start := time.Now()
		for {
			select {
			case <-done:
				return
			case <-ctx.Done():
				return
			case <-ticker.C:
				elapsed := time.Since(start)
				ratio := float64(elapsed) / float64(est)
				if ratio > 0.92 {
					ratio = 0.92
				}
				pct := startPct + int(float64(capPct-startPct)*ratio)
				if pct >= capPct {
					pct = capPct - 1
				}
				h.setProgress(token, stage, pct)
			}
		}
	}()
	return func() { close(done) }
}