package controllers

import (
	"net/http"
	"time"

	"gitea.tbdevent.eu/TBD/reforger_crawler_main/metrics"
	"gitea.tbdevent.eu/TBD/reforger_crawler_main/models"
	"github.com/gin-gonic/gin"
)

const (
	maxTelemetryBody    = 1 << 20
	maxTelemetryMetrics = 1000
	maxTelemetryEvents  = 200
)

// SubmitTelemetry receives metrics, events and a heartbeat from a service
// (indexer, scraper, ...). See models.TelemetryBatch for the payload.
func SubmitTelemetry(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, maxTelemetryBody)

	var batch models.TelemetryBatch
	if err := c.ShouldBindJSON(&batch); err != nil {
		c.JSON(400, gin.H{"error": "Invalid JSON"})
		return
	}
	if !metrics.ValidName(batch.Service) || batch.Service == metrics.MainService {
		c.JSON(400, gin.H{"error": "service must match ^[a-z_][a-z0-9_]{0,63}$ and not be \"main\""})
		return
	}
	if batch.Instance == "" || len(batch.Instance) > 128 {
		c.JSON(400, gin.H{"error": "instance is required (max 128 characters)"})
		return
	}
	if len(batch.Metrics) > maxTelemetryMetrics || len(batch.Events) > maxTelemetryEvents {
		c.JSON(413, gin.H{"error": "too many metrics or events in one batch"})
		return
	}

	now := time.Now()
	if err := metrics.Heartbeat(&batch, c.ClientIP(), now); err != nil {
		c.JSON(500, gin.H{"error": "failed to store heartbeat"})
		return
	}
	result := metrics.Ingest(batch.Service, batch.Instance, batch.Metrics, now)
	if err := metrics.RecordEvents(batch.Service, batch.Instance, batch.Events, now); err != nil {
		c.JSON(500, gin.H{"error": "failed to store events"})
		return
	}

	c.JSON(200, result)
}