package jobs

import (
	"os"
	"path/filepath"
	"regexp"
	"time"

	"ddc/internal/files"
)

var jobIDPattern = regexp.MustCompile(`^[0-9a-f]{32}$`)

func (manager *Manager) RestoreExisting() error {
	entries, err := os.ReadDir(manager.settings.DownloadDir)
	if err != nil {
		return err
	}

	for _, entry := range entries {
		if !entry.IsDir() || !jobIDPattern.MatchString(entry.Name()) {
			continue
		}
		directory := filepath.Join(manager.settings.DownloadDir, entry.Name())
		os.Remove(filepath.Join(directory, files.PartFileName))

		createdAt := time.Now()
		if info, err := entry.Info(); err == nil {
			createdAt = info.ModTime()
		}

		job := manager.newJob(entry.Name(), directory, createdAt)
		job.status = StatusReady
		job.fileName = firstEntryName(directory, entry.Name())
		manager.store(job)
	}
	return nil
}

func firstEntryName(directory, fallback string) string {
	entries, err := os.ReadDir(directory)
	if err != nil {
		return fallback
	}
	for _, entry := range entries {
		if entry.Name() != files.PartFileName {
			return entry.Name()
		}
	}
	return fallback
}