// main.go
package main

import (
	"context"
	"encoding/json"
	"log"
	"os"
	"os/signal"
	"strings"
	"syscall"

	"github.com/rabbitmq/amqp091-go"
)

type S3Event struct {
	Key     string `json:"Key"`
	Records []struct {
		EventName string `json:"eventName"`
		S3        struct {
			Bucket struct {
				Name string `json:"name"`
			} `json:"bucket"`
			Object struct {
				Key string `json:"key"`
			} `json:"object"`
		} `json:"s3"`
	} `json:"Records"`
}

func main() {
	cfg := LoadConfig()

	rabbitConn, rabbitChannel, err := ConnectRabbitMQ(cfg)
	if err != nil {
		log.Fatalf("🚨 Failed to connect RabbitMQ: %v", err)
	}
	defer rabbitConn.Close()
	defer rabbitChannel.Close()

	minioClient, err := ConnectMinIO(cfg)
	if err != nil {
		log.Fatalf("🚨 Failed to connect MinIO: %v", err)
	}

	msgs, err := rabbitChannel.Consume(
		cfg.QueueName,
		"",
		false, // manual ack
		false,
		false,
		false,
		nil,
	)
	if err != nil {
		log.Fatalf("🚨 Failed to consume RabbitMQ: %v", err)
	}

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// Graceful shutdown
	go func() {
		c := make(chan os.Signal, 1)
		signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
		<-c
		log.Println("👋 Shutting down...")
		cancel()
		rabbitConn.Close()
		os.Exit(0)
	}()

	for msg := range msgs {
		go func(msg amqp091.Delivery) {
			if ctx.Err() != nil {
				return
			}

			var event S3Event
			err := json.Unmarshal(msg.Body, &event)
			if err != nil || len(event.Records) == 0 {
				log.Printf("❌ Invalid message: %v", err)
				msg.Nack(false, false)
				return
			}

			record := event.Records[0]
			if record.EventName != "s3:ObjectCreated:Put" {
				log.Printf("⏭️ Skipping event: %s", record.EventName)
				msg.Ack(false)
				return
			}

			bucket := record.S3.Bucket.Name
			key := strings.TrimPrefix(event.Key, bucket+"/")
			log.Printf("📥 Processing image: %s/%s", bucket, key)
			err = ProcessImage(ctx, minioClient, bucket, key)
			if err != nil {
				log.Printf("❌ Error processing image: %v", err)
				log.Println("🔁 Retrying once")
				SleepWithCountdown(5)
				msg.Nack(false, true)
				return
			}

			msg.Ack(false)
		}(msg)
	}
}