package processor

import (
	"compress/gzip"
	"context"
	"encoding/json"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"time"

	"example.com/siem-greenfield/internal/clickhouse"
	"example.com/siem-greenfield/internal/config"
	"example.com/siem-greenfield/internal/contracts"
	"example.com/siem-greenfield/internal/normalize"
	"example.com/siem-greenfield/internal/queue"
)

func Run(ctx context.Context, cfg config.Config) error {
	ch := clickhouse.New(cfg)
	con := queue.NewConsumer(cfg.KafkaBrokers, cfg.KafkaTopic, cfg.KafkaGroup)
	defer con.Close()
	log.Printf("processor started topic=%s group=%s", cfg.KafkaTopic, cfg.KafkaGroup)
	for {
		m, e := con.Fetch(ctx)
		if e != nil {
			if ctx.Err() != nil {
				return nil
			}
			return e
		}
		var env contracts.IngestEnvelope
		if e = json.Unmarshal(m.Value, &env); e != nil {
			log.Printf("dropping malformed queue message offset=%d: %v", m.Offset, e)
			_ = con.Commit(ctx, m)
			continue
		}
		rawKey := ""
		if cfg.RawArchiveEnabled {
			rawKey = normalize.ArchiveKey(env.ReceivedAt, env.AgentID, env.BatchUID, m.Partition, m.Offset)
			if e = spool(cfg, rawKey, m.Value); e != nil {
				log.Printf("raw spool failed offset=%d (message will be retried): %v", m.Offset, e)
				time.Sleep(time.Second)
				continue
			}
		}
		events := make([]contracts.CanonicalEvent, 0, len(env.Events))
		for i, p := range env.Events {
			events = append(events, normalize.Event(env, p, rawKey, m.Partition, m.Offset, i))
		}
		cctx, cancel := context.WithTimeout(ctx, 30*time.Second)
		e = ch.InsertEvents(cctx, events)
		cancel()
		if e != nil {
			log.Printf("clickhouse insert failed offset=%d: %v", m.Offset, e)
			time.Sleep(time.Second)
			continue
		}
		if e = con.Commit(ctx, m); e != nil {
			return fmt.Errorf("commit queue offset: %w", e)
		}
	}
}
func spool(cfg config.Config, key string, payload []byte) error {
	path := filepath.Join(cfg.RawSpoolDir, filepath.FromSlash(key))
	if e := os.MkdirAll(filepath.Dir(path), 0750); e != nil {
		return e
	}
	tmp := path + ".tmp"
	f, e := os.Create(tmp)
	if e != nil {
		return e
	}
	gz := gzip.NewWriter(f)
	_, e = gz.Write(payload)
	if ce := gz.Close(); e == nil {
		e = ce
	}
	if ce := f.Close(); e == nil {
		e = ce
	}
	if e != nil {
		_ = os.Remove(tmp)
		return e
	}
	return os.Rename(tmp, path)
}