package handlers

// presence.go — Heartbeat upsert and status query (v0.23.1)
//
// Clients POST /api/v1/presence/heartbeat every 30s while active.
// GET  /api/v1/presence?users=id1,id2 returns current status.
// Online = last_seen within 90s.

import (
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"git.gobha.me/xcaliber/chat-switchboard/database"
)

const presenceOnlineThreshold = 90 * time.Second

// PresenceHeartbeat upserts the calling user's last_seen timestamp.
func PresenceHeartbeat(c *gin.Context) {
	userID := getUserID(c)
	_, err := database.DB.ExecContext(c.Request.Context(), database.Q(`
		INSERT INTO user_presence (user_id, last_seen, status)
		VALUES ($1, NOW(), 'online')
		ON CONFLICT (user_id) DO UPDATE
		  SET last_seen = NOW(), status = 'online'
	`), userID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "presence update failed"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"ok": true})
}

// PresenceQuery returns online/offline status for a list of user IDs.
// Query param: ?users=uuid1,uuid2,...
func PresenceQuery(c *gin.Context) {
	raw := c.Query("users")
	if raw == "" {
		c.JSON(http.StatusOK, gin.H{"presence": map[string]string{}})
		return
	}
	ids := strings.Split(raw, ",")
	if len(ids) > 100 {
		ids = ids[:100]
	}

	threshold := time.Now().Add(-presenceOnlineThreshold)

	result := make(map[string]string, len(ids))
	for _, id := range ids {
		id = strings.TrimSpace(id)
		if id == "" {
			continue
		}
		var lastSeen time.Time
		err := database.DB.QueryRowContext(c.Request.Context(), database.Q(`
			SELECT last_seen FROM user_presence WHERE user_id = $1
		`), id).Scan(&lastSeen)
		if err != nil || lastSeen.Before(threshold) {
			result[id] = "offline"
		} else {
			result[id] = "online"
		}
	}
	c.JSON(http.StatusOK, gin.H{"presence": result})
}