package core

import (
	"context"
	"errors"
	"fmt"
	"log"
	"path/filepath"

	"github.com/syonad/clonepack/internal/clone/rpm"
	"github.com/syonad/clonepack/internal/store"
)

var ErrCloneAlreadyRunning = errors.New("a clone job is already running for this repo")

type CloneService struct {
	repoStore store.RepoStore
	jobStore  store.CloneJobStore
	dataDir   string
}

func NewCloneService(repoStore store.RepoStore, jobStore store.CloneJobStore, dataDir string) *CloneService {
	return &CloneService{repoStore: repoStore, jobStore: jobStore, dataDir: dataDir}
}

func (s *CloneService) StartClone(ctx context.Context, repoID int64) (int64, error) {
	repo, err := s.repoStore.GetRepo(ctx, repoID)
	if err != nil {
		return 0, err
	}
	if repo.Type != "rpm" {
		return 0, fmt.Errorf("clone is only supported for rpm repositories")
	}

	running, err := s.jobStore.HasRunningCloneJob(ctx, repoID)
	if err != nil {
		return 0, err
	}
	if running {
		return 0, ErrCloneAlreadyRunning
	}

	jobID, err := s.jobStore.CreateCloneJob(ctx, repoID)
	if err != nil {
		return 0, err
	}

	go s.runClone(repoID, jobID, repo.SourceURL, repo.Type)
	return jobID, nil
}

func (s *CloneService) GetLatestCloneJob(ctx context.Context, repoID int64) (*store.CloneJob, error) {
	return s.jobStore.GetLatestCloneJob(ctx, repoID)
}

func (s *CloneService) runClone(repoID, jobID int64, sourceURL, repoType string) {
	ctx := context.Background()

	if err := s.jobStore.MarkCloneJobStarted(ctx, jobID); err != nil {
		log.Printf("clone job %d: failed to mark started: %v", jobID, err)
		return
	}

	destDir := filepath.Join(s.dataDir, "repos", fmt.Sprintf("%d", repoID), repoType)
	cloner := rpm.New(sourceURL, destDir)
	cloner.OnProgress = func(p rpm.Progress) {
		log.Printf("clone job %d: %s (%d bytes)", jobID, p.File, p.BytesDone)
	}

	if err := cloner.Clone(ctx); err != nil {
		errMsg := err.Error()
		_ = s.jobStore.MarkCloneJobFinished(ctx, jobID, store.CloneJobFailed, &errMsg)
		log.Printf("clone job %d: failed: %v", jobID, err)
		return
	}

	if err := rpm.RegenerateMetadata(destDir); err != nil {
		log.Printf("clone job %d: metadata regeneration failed: %v", jobID, err)
	}

	_ = s.jobStore.MarkCloneJobFinished(ctx, jobID, store.CloneJobCompleted, nil)
	log.Printf("clone job %d: completed", jobID)
}