package torrent

import (
	"io"
	"os"

	cmap "github.com/orcaman/concurrent-map/v2"
)

// fixers are commands that will be run on the next refresh
// they are stored in a file so that they can be run on startup
// they follow the format of:
// key: <id_trigger> value: <command>
// id_trigger: this means a specific torrent id's completion
// commands: delete | repair

func (t *TorrentManager) fixerAddCommand(trigger, command string) {
	t.log.Debugf("Adding fixer command: %s %s", trigger, command)
	t.fixers.Set(trigger, command)
	t.writeFixersToFile()
}

func (t *TorrentManager) handleFixers() {
	var toDelete []string
	allTorrents, _ := t.DirectoryMap.Get(INT_ALL)
	infoCache, _ := t.DirectoryMap.Get(INT_INFO_CACHE)
	infoCache.IterCb(func(id string, torrent *Torrent) {
		if !t.fixers.Has(id) || torrent.AnyInProgress() {
			return
		}
		command, _ := t.fixers.Pop(id) // delete the fixer if it's done
		switch command {
		case "replaced": // id is old torrent id
			t.log.Debugf("Deleting old id=%s because it's redundant to fixed %s ", id, t.GetKey(torrent))
			toDelete = append(toDelete, id)
		case "download_failed": // id is failed fixer id
			t.log.Debugf("Deleting failed fixer id=%s of torrent %s", id, t.GetKey(torrent))
			toDelete = append(toDelete, id)
		case "repaired": // id is fixer id
			t.log.Debugf("Repairing torrent %s again now that fixer id=%s is done", t.GetKey(torrent), id)
			repairMe, _ := allTorrents.Get(t.GetKey(torrent))
			repairMe.DownloadedIDs.Remove(id)
			toDelete = append(toDelete, id)
			t.TriggerRepair(repairMe)
		}
	})
	for _, id := range toDelete {
		t.Api.DeleteTorrent(id)
		infoCache.Remove(id)
		t.deleteTorrentFile(id)
	}

	// remove expired fixers
	var expired []string
	t.fixers.IterCb(func(trigger string, command string) {
		if infoCache.Has(trigger) {
			return
		}
		expired = append(expired, trigger)
	})
	for _, trigger := range expired {
		t.log.Debugf("Removing expired fixer id=%s", trigger)
		t.fixers.Remove(trigger)
	}

	t.writeFixersToFile()

	t.log.Debugf("Finished handling fixers")
}

func (t *TorrentManager) writeFixersToFile() {
	filePath := "data/fixers.json"
	file, err := os.Create(filePath)
	if err != nil {
		t.log.Warnf("Cannot create fixer file %s: %v", filePath, err)
		return
	}
	defer file.Close()

	fileData, err := t.fixers.MarshalJSON()
	if err != nil {
		t.log.Warnf("Cannot marshal fixers: %v", err)
		return
	}

	_, err = file.Write(fileData)
	if err != nil {
		t.log.Warnf("Cannot write to fixer file %s: %v", filePath, err)
		return
	}
}

func (t *TorrentManager) readFixersFromFile() (ret cmap.ConcurrentMap[string, string]) {
	ret = cmap.New[string]()
	filePath := "data/fixers.json"
	file, err := os.Open(filePath)
	if err != nil {
		if os.IsNotExist(err) {
			return
		}
		t.log.Warnf("Cannot open fixer file %s: %v", filePath, err)
		return
	}
	defer file.Close()
	fileData, err := io.ReadAll(file)
	if err != nil {
		t.log.Warnf("Cannot read fixer file %s: %v", filePath, err)
		return
	}

	err = ret.UnmarshalJSON(fileData)
	if err != nil {
		t.log.Warnf("Cannot unmarshal fixer file %s: %v", filePath, err)
		return
	}

	return
}