package api

import (
	"encoding/json"
	"net/http"
	"time"
)

const upstreamDownAfter = 10 * time.Second

// HandleStatus returns the current stream status as JSON.
// GET /api/status
func (a *App) HandleStatus(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	a.mu.RLock()
	status := a.Status
	a.mu.RUnlock()

	// Attach live stream health metrics when FFmpeg is running
	status.Health = a.FFmpeg.Health()

	// Auto-clear transitioning once FFmpeg is producing health data.
	// If no progress arrives for a while after a channel switch, flag upstream_down
	// so all watchers see an "Upstream down?" warning via polling.
	if status.Transitioning && status.Health != nil && status.Health.Speed != "" {
		a.mu.Lock()
		a.Status.Transitioning = false
		a.Status.UpstreamDown = false
		a.mu.Unlock()
		status.Transitioning = false
		status.UpstreamDown = false
	} else if status.Transitioning {
		a.mu.RLock()
		switchStartedAt := a.SwitchStartedAt
		a.mu.RUnlock()
		if !switchStartedAt.IsZero() && time.Since(switchStartedAt) >= upstreamDownAfter {
			a.mu.Lock()
			a.Status.UpstreamDown = true
			a.mu.Unlock()
			status.UpstreamDown = true
		}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(status)
}